JP4829463B2 - Thick film resistor, adjusting device therefor, and resistance value adjusting method - Google Patents

Description

【０１４０】
表１中の記号は、各ノズルの吐出安定性を示しており、×：目詰まり等での不吐出あり、△：連続吐出にて吐出不安定、○：安定吐出である。
【０１４１】
表１から、微粒子径としてはφ３０ｎｍ以下が好ましいことが分かった。特に微粒子径φ１０ｎｍ以下になるとインク中の微粒子１個の帯電量はインク吐出における電荷としての影響がほぼ無視できるとともに、電荷による移動速度も非常に遅くなり微粒子のメニスカス中心への集中も発生しない。また、ノズル径がφ３μｍ以下では、メニスカスの電界集中により極端に最大電界強度が高くなり、微粒子１個毎の静電力も大きくなるためφ１０ｎｍ以下の微粒子を含んだインクを用いることが好ましい。但し、微粒子径がφ１ｎｍ以下になると、微粒子の凝集及び濃度の不均一の発生が大きくなるため、微粒子径は、φ１ｎｍからφ１０ｎｍの範囲が好ましい。しかし、ノズル径がφ１μｍ以上では、平均粒子径φ５０ｎｍでも、使用可能な吐出状態であった。
【０１４２】
サブミクロンヘッドを説明している本実施の形態においては、平均粒径がφ３ｎｍからφ７ｎｍの間の銀の微粒子を含んだペーストを使用しており、該微粒子には凝集防止のコーティングを施している。
【０１４３】
ここで、ノズル２４のノズル径と電界強度との関係について、図１０（ａ）（ｂ）〜図１５（ａ）（ｂ）を参照しながら以下に説明する。図１０（ａ）（ｂ）から図１５（ａ）（ｂ）に対応して、ノズル径をφ０．２、０．４、１、８、２０μｍ及び参考として従来にて使用されているノズル径φ５０μｍの場合の電界強度分布を示す。
【０１４４】
ここで、各図において、ノズル中心位置とは、ノズル２４のインク吐出孔２４ｂのインク吐出面の中心位置を示す。また、各々の図の（ａ）は、ノズルと対向電極との距離が２０００μｍに設定したときの電界強度分布を示し、（ｂ）は、ノズルと対向電極との距離が１００μｍに設定されたときの電界強度分布を示す。なお、印加電圧は、各条件とも２００Ｖと一定にした。図中の分布線は、電界強度が１×１０⁶Ｖ／ｍから１×１０⁷Ｖ／ｍまでの範囲を示している。
【０１４５】
以下の表２に、各条件下での最大電界強度を示す。
【０１４６】
【表２】

【０１４７】
図１０（ａ）（ｂ）〜図１５（ａ）（ｂ）から、ノズル径がφ２０μｍ（図１４（ａ）（ｂ））以上だと電界強度分布は広い面積に広がっていることが分かった。また、表２から、ノズルと対向電極の距離が電界強度に影響していることも分かった。
【０１４８】
これらのことから、ノズル径がφ８μｍ（図１３（ａ）（ｂ））以下であると電界強度は集中するとともに、対向電極の距離の変動が電界強度分布にほとんど影響することがなくなる。したがって、ノズル径がφ８μｍ以下であれば、対向電極の位置精度及び被記録媒体の材料特性のバラツキや厚さバラツキの影響を受けずに安定した吐出が可能となる。
【０１４９】
次に、上記ノズル２４のノズル径とメニスカス３４の最大電界強度と強電界領域の関係を図１６に示す。
【０１５０】
図１６に示すグラフから、ノズル径がφ４μｍ以下になると、電界集中が極端に大きくなり最大電界強度を高くすることができるのが分かった。これによって、インクの初期吐出速度を大きくすることができるので、インク（液滴）の飛翔安定性が増すとともに、メニスカスでの電荷の移動速度が増すため吐出応答性が向上する。
【０１５１】
続いて、吐出したインク２２の液滴２３における帯電可能な最大電荷量について、以下に説明する。液滴２３に帯電可能な電荷量は、液滴２３のレイリー分裂を考慮した以下の（１）式で示される。
【０１５２】
ｑ＝８×π×(ε0×γ×ｒ³)² …（２）
ここで、ｑはレイリー限界を与える電荷量、ε0は真空の誘電率、γはインクの表面張力、ｒはインク液滴の半径である。
【０１５３】
上記（１）式で求められる電荷量ｑがレイリー限界値に近い程、同じ電界強度でも静電力が強く、吐出の安定性が向上するが、レイリー限界値に近すぎると、逆にノズル２４のインク吐出孔２４ｂでインク２２の霧散が発生してしまい、吐出安定性に欠けてしまう。
【０１５４】
ここで、ノズルのノズル径とメニスカスで吐出する液滴が飛翔を開始する吐出開始電圧、該初期吐出液滴のレイリー限界での電圧値及び吐出開始電圧とレイリー限界電圧値の比との関係を示すグラフを図１７に示す。
【０１５５】
図１７に示すグラフから、ノズル径がφ０．２μｍからφ４μｍの範囲において、吐出開始電圧とレイリー限界電圧値の比が０．６を超え、液滴の帯電効率が良い結果となっており、該範囲において安定した吐出が行えることが分かった。
【０１５６】
例えば、図１８に示すノズル径とメニスカスの強電界（１×１０⁶Ｖ／ｍ以上）の領域の関係で表されるグラフでは、ノズル径がφ０．２以下になると電界集中の領域が極端に狭くなることが示されている。このことから、吐出する液滴は、加速するためのエネルギを十分に受ける事ができず飛翔安定性が悪くなることを示す。よって、ノズル径はφ０．２μｍより大きく設定する必要がある。
【０１５７】
次に、上記構成のインクジェット装置を実際に駆動する場合の印加電圧、すなわち液滴の吐出開始電圧以上の電圧で最適な電圧値を変動した場合の最大電界強度から誘導されるメニスカスの初期吐出液滴を一定とした場合の該液滴の電荷量と、液滴の表面張力からくるレイリー限界値との関係を図１９のグラフに示す。
【０１５８】
図１９に示すグラフにおいて、Ａ点は上記液滴の電荷量と液滴の表面張力からくるレイリー限界値との交点であり、インクへの印加電圧が、Ａ点より高い電圧であれば、初期吐出液滴にはほぼレイリー限界に近い最大電荷量が形成されており、Ａ点より低い電圧であればレイリー限界以下でかつ吐出に必要な電荷量が形成されていることを示している。
【０１５９】
ここで、吐出液滴の運動方程式にのみ着目すると、強電界かつ最大電荷量の吐出エネルギとして最適な条件での飛翔が行われるため、印加電圧としてはＡ点より高い電圧が好ましい。
【０１６０】
ところで、図２０に、環境湿度を５０％とした場合のインク（ここでは純水）の初期吐出液滴径と乾燥時間（液滴の溶剤が全て蒸発してしまう時間）との関係を示すグラフを示す。このグラフから、初期吐出液滴径が小さい場合には、蒸発によるインクの液滴径の変化が非常に早く、飛翔中の短い時間においても乾燥が進んでしまうことが分かる。
【０１６１】
このため、初期吐出時に最大電荷量が液滴に形成されていると乾燥による液滴径の減少すなわち電荷が形成されている液滴の表面積が減少することにより、インクの飛翔中にレイリー分裂が発生し、過分の電荷を放出する際に電荷は液滴の一部を引き連れて放出されるため、蒸発以上の飛翔液滴の減少が発生することなる。
【０１６２】
従って、着弾時の液滴径のバラツキ及び着弾精度が悪化するとともに、ノズルと被記録媒体中に分裂したミストが浮遊することになり、被記録媒体を汚染することになる。このため、安定した吐出ドットの形成を考慮すると、初期吐出液滴に誘導される電荷量をレイリー限界に相当する電荷量よりもある程度小さくする必要がある。この場合、該電荷量をレイリー限界値に相当する電荷量の９５％程度では、着弾ドット径のバラツキの精度が向上できず、結果的として９０％以下にすることが好ましい。
【０１６３】
具体的な数値としては、ノズル孔径を針電極の先端形状と見なした場合のメニスカスの最大電界強度による初期吐出液滴径のレイリー限界を算出し、該算出値以下の範囲とすることにより着弾時の液滴のバラツキを抑えることができた。これは、吐出液滴が分離する直前の表面積が吐出直後の液滴に比べ小さく、かつ電荷の移動時間のタイムラグにより、実際の初期吐出液滴に誘導される電荷量は、上記計算により求められる電荷量より小さくなっているためと考えられる。
【０１６４】
このような条件であれば、飛翔時のレイリー分裂を防げると共にメニスカスでの吐出液滴の分離時に電荷量が多いことによるミスト化等の安定吐出を軽減する事ができる。
【０１６５】
なお、帯電した液滴は、蒸気圧が減少して蒸発しにくくなる。これは、以下の（２）式から分かる。
【０１６６】
ＲＴρ／Ｍ×log（Ｐ／Ｐ０）＝２γ／ｒ？ｑ²／（８πｒ⁴） …（３）
ここで、Ｒは気体定数、Ｍは分子量、Ｔは温度、ρは液体の体積密度、Ｐは液滴での蒸気圧、Ｐ０は液面が平面のときの蒸気圧、γはインクの表面張力、ｒはインク液滴の半径である。
【０１６７】
上記の（２）式に示されるように、帯電した液滴は、該液滴の帯電量により蒸気圧が減少するもので、帯電量が少なすぎると蒸発の緩和に影響が少ないため、レイリー限界に相当する電界強度及び電圧値の６０％以上が好ましい結果となった。この結果は、上記と同様にノズル孔径を針電極の先端形状と見なした場合のメニスカスの最大電界強度による初期吐出液滴径のレイリー限界を算出し、該算出値の０．８倍以上の範囲を示すことと同じである。
【０１６８】
特に、図２０に示すように、初期吐出液滴径がφ５μｍ以下になると乾燥時間は極端に短くなり蒸発の影響を受けやすくなるため、初期吐出液滴の電荷量を低く抑えることは蒸発を抑える観点からより効果があることが分かる。なお、図２０に示す乾燥時間と初期吐出液滴径との関係を求める場合の周囲湿度は５０％とした。
【０１６９】
また、吐出液滴の乾燥を考慮すると、被記録媒体までの液体の吐出時間を短くする必要がある。
【０１７０】
ここで、吐出液滴がメニスカスより分離してノズルより被記録媒体に着弾するまでの平均飛翔速度を５ｍ／ｓ、１０ｍ／ｓ、２０ｍ／ｓ、３０ｍ／ｓ、４０ｍ／ｓ、５０ｍ／ｓとして、吐出の安定性と着弾ドットの位置精度を比較し、以下の表３に示す。
【０１７１】
【表３】

【０１７２】
表３中の吐出安定性の記号において、×：ほとんど吐出せず、△：連続吐出にて不吐出あり、○：不吐出なしを示しており、着弾精度の記号においては、×：着弾ズレ＞着弾ドット径、△：着弾ズレ＞着弾ドット径×０．５、○：着弾ズレ＜着弾ドット径×０．５、◎：着弾ズレ＜着弾ドット径×０．２を示している。
【０１７３】
上記の表３から分かるように、平均飛翔速度５ｍ／ｓでは、着弾精度が悪く、吐出安定性も悪くなる。特に、ノズル径がφ１μｍ以下では、吐出速度が遅いと液滴にかかる空気抵抗の要因が大きくかつ蒸発によるドット径の更なる微少化により、着弾できない場合があった。逆に、平均飛翔速度５０ｍ／ｓでは、印加電圧を高くする必要があるため、メニスカスでの電界強度が非常に強くなり、吐出液滴のミスト化が頻繁に発生してしまい、安定した吐出が難しいことが分かった。
【０１７４】
以上のことから、吐出液滴がメニスカスより分離して被記録媒体に着弾するまでの平均飛翔速度は１０ｍ／ｓから４０ｍ／ｓの間が好ましいことが分かった。
【０１７５】
ところで、図２０では、周囲湿度として５０％とした場合の、初期吐出液滴径と乾燥時間との関係を示したが、図２１では、初期吐出液滴径がφ０．５μｍでノズルと被記録媒体の距離を０．２ｍｍとした場合の周囲湿度と乾燥時間の関係を示す。
【０１７６】
図２１に示すグラフから、周囲湿度が６０％以下では該乾燥速度の数値は大きく変動しないことが分かった。しかしながら、周囲湿度が７０％を超えるとインクの蒸発を極端に抑える事が可能であり、周囲湿度を７０％以上とする場合には、上記条件等の影響は低いものとなり、特に周囲湿度を９５％以上に設定すると乾燥の影響をほぼ無視する事ができ、本発明のインクジェット記録装置の設計条件の自由度を広くかつ適用範囲を広げる事が可能であることが分かった。
【０１７７】
ここで、ノズル径をφ１及びφ３μｍとして、初期吐出液滴径を変動した場合の吐出安定性及び吐出ドット径バラツキ（着弾バラツキ）を以下の表４に示す。なお、ノズルによる初期吐出径は、印加電圧値を変動することにより制御可能であり、又印加する電圧パルスのパルス幅を調整する事によっても制御可能であり、ここでは、同一ノズル径での電界強度の影響を排除するため、前記パルス幅を変動させて初期吐出径を調整している。
【０１７８】
【表４】

【０１７９】
表４中の吐出安定性の記号において、×：ほとんど吐出せず、△：１０分間連続吐出にて不吐出あり、○：１０分間連続吐出にて不吐出なし、◎：３０分間連続吐出にて不吐出なしを示しており、バラツキの記号においては、△：着弾ドットのバラツキ＞着弾ドット径×０．２、○：着弾ドットのバラツキ≦着弾ドット径×０．２、◎：着弾ドットのバラツキ≦着弾ドット径×０．１を示している。
【０１８０】
表４から、ノズル径に対し１．５倍〜３倍程度において吐出の安定性が良く、特に１．５倍〜２倍において着弾ドット径のバラツキが極端に抑えられることが分かった。これは、メニスカスから引き出されるインク形状を液柱と見なした場合、該液柱の表面積が該液柱の体積分の球の表面積より大きくなる条件での液滴分離が最も安定するためと考えられる。
【０１８１】
上記の構成によれば、インクの吐出直後の液滴量が１ｐｌ以下の微少なインク液滴を吐出する静電吸引型インクジェット記録装置において、ノズル２４のインク吐出孔２４ｂの直径を、インクの吐出直後の液滴直径と同等以下（より好ましくは、液滴直径よりも小さく）とすることによりノズル２４のメニスカス３４に吐出のための電界を集中させることができるので、インクを吐出するのに必要な印加電圧を大幅に下げることができ、個々に分離、吐出する液滴の径のバラツキを小さく安定した吐出を実現可能とした。
【０１８２】
また、従来必要とされていたバイアス電圧の印加が不要となり、駆動電圧を正負交互に印加する事が可能となり、被記録媒体の表面電位の増加による着弾精度への影響を軽減する事ができた。
【０１８３】
また、ノズルの孔の直径をφ８μｍ以下の範囲とすることによりノズルのメニスカスに電界を集中させることができると共に、対向電極の位置精度及び被記録媒体の材料特性のバラツキや厚さバラツキの影響を受けずに安定した吐出が可能となった。
【０１８４】
特に、ノズル２４のインク吐出孔２４ｂの直径をφ０．４μｍ以上φ４μｍ以下の範囲とすることにより、電界集中が極端に大きくなる。このように、最大電界強度を高くすることが、インクの初期吐出速度を大きくすることになるので、飛翔安定性が増すとともに、メニスカスでの電荷の移動速度が増すため吐出応答性が向上すると共に、レイリー分裂の影響による着弾ドット径のバラツキを抑える事ができる。
【０１８５】
更に、ノズル２４からのインクの吐出直後の液滴直径を、ノズル２４のインク吐出孔２４ｂの直径の１．５倍から３倍以下の範囲とすることにより、吐出の安定性が向上でき、特にインクの吐出直後の液滴直径を該ノズル径の１．５倍から２倍以下の範囲とすることにより吐出ドット径のバラツキを極端に抑えることができる。
【０１８６】
本実施の形態では、上述のように、インク室２１内のインクに負圧が印加された例について説明したが、インクに正圧が印加された場合でも構わない。インク室２１内のインクに正圧を印加するには、例えば、図２２に示すように、インク供給路の図示しないインクタンク側にポンプ３２を設け、該ポンプ３２を用いてインク室２１内のインクに正圧を印加することが考えられる。この場合、インク室２１からのインク吐出のタイミングに合わせて駆動させるようにプロセス制御部３３を用いて上記ポンプ３２を駆動制御すればよい。このように、インク室２１内のインクに正圧を印加するようにすれば、メニスカスの凸形状を静電力で形成する手間が省け、印加電圧の低減及び応答速度の向上が図ることができる。
【０１８７】
なお、本実施の形態では、説明の簡単化のため単一ノズルを備えたインクジェット装置について説明を行ったが、これに限定されるものではなく、隣接ノズルでの電界強度の影響を考慮した設計を行えば、複数のノズルを有するマルチヘッドを備えたインクジェット装置にも適用可能である。
【０１８８】
更に、本実施の形態では、図８および図２２に示すように、対向電極２７を常に設けたインクジェット装置について説明したが、表２から分かるように、対向電極２７とノズル２４のインク吐出孔２４ｂとの間の距離（ギャップ）は、被記録媒体とノズル間の電界強度にほとんど影響せず、該被記録媒体とノズル間の距離が近く、被記録媒体の表面電位が安定しているならば対向電極は不要となる。
【０１８９】
本願発明者等は、図２３に示すように、従来方法において、静電吸引の過程において形成されるノズル部４１のテーラーコーン形状の流体のメニスカス４２の液滴吐出直前の先端部曲率４４とほぼ同等サイズのノズル径になるように、流体吐出孔側が絞り込まれたノズル４３を使用することにより、広範囲に必要であった電場の形成を狭くでき、かつメニスカスでの電荷の移動量を少なくできることを見出した。
【０１９０】
本願発明者等は、上記の原理を利用して、さらに、ノズル先端部の流体吐出孔の直径を、吐出直後の流体の液滴径と同等以下に設定することで、電荷の集中領域とメニスカス領域とをほぼ同じにできることを見出した。
【０１９１】
次にこのサブミクロンヘッドの生産工程における特徴を説明する。
【０１９２】
第１に、静電界印加用電極２９と対向電極２７との間に生じた電界により、帯電した液滴２３に力を与えている。このため、液滴２３は、微小液滴であるために飛翔中の空気抵抗の影響が大きくなっても、大きく減速することはなく、着弾精度（被記録媒体２８上での着弾位置制度）が向上する。
【０１９３】
第２に、高粘度のインクであっても液滴２３として吐出が可能である。実際に７０ｃＰのインクの吐出が実現している。高粘度のインクを吐出できるため、インクの濃度を高くできる。
【０１９４】
一般にインク粘度は、メニスカス３４の成長率に反比例し、高粘度ではメニスカス３４が十分成長できず、液滴の吐出ができない。しかしながら、本インクジェット装置では、メニスカス３４の成長率がインクの粘度に依存せず、表面張力と帯電量に依存する。したがって、インクの溶媒に対して、その最大溶解度まで溶質材料を溶解させても、インクの吐出可能である。
【０１９５】
第３に、液滴２３の着弾後、瞬時にインクの溶媒分が乾燥することである。液滴２３の溶媒分の体積は、液滴径の３乗に比例する。したがって、溶媒分を蒸発させるために必要なエネルギも、液滴径の３乗に比例する。また、（体積）／（表面積）の値が小さいほど、液滴２３は蒸発しやすくなると考えられる。このため、液滴が小さいほど早く蒸発させることには有利である。
【０１９６】
従来のインクジェット装置では、吐出する液滴サイズが大きく、溶媒分が蒸発するのに時間がかかった。また、液滴を微小にしただけでは、十分な飛翔速度が得られず、運動エネルギが熱エネルギに変化した分だけでは、液滴の溶媒分の気化熱に達せず、着弾後瞬時に乾燥という現象が得られなかった。しかしサブミクロンヘッドでは、液滴体積を小さくしながらも、十分な飛翔速度が得られるので、着弾後瞬時に乾燥という現象が得られる。
【０１９７】
以上の点を確認するために下記の試験を行った。その結果について説明する。表１〜表３は、従来のインクジェット方式であるピエゾ型、サーマル型および液滴径の大きい静電吸引型のインクジェット装置を用いた場合と、本発明の実施に使用するインクジェット装置、即ち吐出する液滴径が小さい静電吸引型のインクジェット装置を用いた場合との特性を比較したものである。
【０１９８】
【表５】

【０１９９】
表５の結果は、液滴２３の着弾精度、吐出しやすさ、乾燥速度および着弾回数に対する液滴体積の影響を示したものである。なお、着弾回数とは、所望する面積と厚さを形成するために必要な吐出回数のことであり、生産効率の観点から、少ない方がよいものと評価される。
【０２００】
本インクジェット装置を使用した場合には、液滴体積が０．１ｐｌおよび１ｐｌの場合にも、着弾精度および吐出しやすさにおいて、使用可能あるいは良好であったのに対し、従来のインクジェット装置では何れの項目においても不可能であった。また、本インクジェット装置では、乾燥速度において、液滴体積が０．１ｐｌおよび１ｐｌの場合に良好である。着弾回数において、０．１ｐｌの場合に不向き（生産効率が悪い）、１ｐｌの場合に適している（生産効率がよい）と言える。
【０２０１】
【表６】

【０２０２】
表６の結果は、本インクジェット装置と従来のインクジェット装置とについて、インクの各粘度に対する適性を示したものである。本インクジェット装置では高粘度のインクの吐出が可能であった。
【０２０３】
【表７】

【０２０４】
表７の結果は、本インクジェット装置と従来のインクジェット装置とについて、各濃度に対する適正、即ち吐出しやすさと、本インクジェット装置について各濃度に対する乾燥速度と着弾回数の評価結果を示したものである。
【０２０５】
表３の結果から、インクの吐出しやすさにおいて、従来のインクジェット装置では、中および高濃度のインクについて吐出不可能であったのに対して、本インクジェット装置では、低濃度から高濃度のインクについて良好であった。また、本インクジェット装置では、乾燥速度において、インクが中濃度である場合に可能、高濃度である場合に良好となった。また、生産効率の観点から、高濃度ほど着弾回数が少なくて済み、適していると言える。
【０２０６】
上記の結果から分かるように、本インクジェット装置を使用した場合には、乾燥時間が大幅に短縮されることから、先に吐出した液滴が基板上で乾燥し終わるまでの待ち時間を設ける必要がなく、同１箇所に対しての吐出間隔時間を短縮でき、生産効率を向上させることができる。
【０２０７】
また、高濃度のインクの吐出が可能であることから、１弾の液滴に含まれる溶質材料の割合を大きくできるので、吐出回数を少なくすることが可能となる。
【０２０８】
また、インクの濃度が高くなると粘度が高くなるものの、本インクジェット装置では、高粘度の液滴を吐出可能であるので、高濃度のインクを吐出することができる。この場合、濃度が高くなると、上述のように、吐出回数を少なくすることが可能となる。
【０２０９】
ここで、上記説明したサブミクロンヘッドを用いたトリミング装置６０について説明する。
【０２１０】
トリミング装置６０の構成は、図２４に示すように、実施の形態１で説明されたトリミング装置５０と比べて、インクジェットヘッド５１の代わりに、上記サブミクロンヘッド１５が搭載されていること以外は、同じ構成である。また、抵抗値調整工程についても実施の形態１と同様にすればよい。
【０２１１】
本実施の形態では、サブミクロンヘッド１５を用いることにより、導電性材料を含む液体からなる液滴を噴射する部分（短絡部３）が、液滴の基板着弾後から溶媒乾燥までに、移動することを回避することができる。このため、より高精度な抵抗値の調整が可能となる。また、サブミクロンヘッド１５では、インクの液滴が基板に着弾後、瞬時に乾燥するため、導電性材料からなる短絡部３を連続的に形成できる。また、高濃度のインクを吐出できるので、短絡部３を少ない液滴数で形成できる。このため、インク液滴の微小化による生産性の悪化が回避される。
【０２１２】
なお、本発明にかかる厚膜抵抗体調整装置は、回路を形成する端子間に厚膜抵抗体が形成された回路基板に対して、その厚膜抵抗体の所望する箇所に導電性材料を噴射せしめるインクジェットノズルを備えた厚膜抵抗体調整装置において、前記厚膜抵抗体が、１箇所以上の箇所で短絡できる形状に形成され、その箇所のうち１つ以上の箇所で、短絡させた場合の端子間の抵抗値が、回路設計上の選択したい抵抗値になるように、前記形状が決定され、導電性材料を塗布することにより、厚膜抵抗体の上記箇所の一部を短絡させて、端子間を所望する抵抗値にする構成であってもよい。
【０２１３】
【発明の効果】
本発明の厚膜抵抗体は、以上のように、インクジェットノズルの吐出孔から液滴として噴射される、導電性材料を含む液体によって短絡される厚膜抵抗体であって、
前記厚膜抵抗体が、一箇所以上の箇所で短絡できる近接部分を有し、
その箇所のうち１つ以上の箇所で、短絡させた場合の、厚膜抵抗体を持つ端子間の抵抗値が、回路設計上の選択したい抵抗値になるように、上記厚膜抵抗体の形状が決定される構成である。
【０２１４】
それゆえ、従来と比べて、厚膜抵抗体の抵抗値を広い範囲で設定することができるとともに、該抵抗値の微調整を可能とするという効果を奏する。
【０２１５】
本発明の厚膜抵抗体は、上記近接部分は、上記インクジェットノズルから噴射される１滴の液滴の着弾時の直径よりも小さい間隔である構成がより好ましい。
【０２１６】
本発明の厚膜抵抗体は、互上記抵抗部が、互いに平行に配置されることにより、近接部分を形成している構成がより好ましい。それゆえ、幅広い近接部分を有しているので、従来と比べて、より広い範囲での抵抗値の設定が可能である。
【０２１７】
本発明の厚膜抵抗体は、略コの字形状の抵抗部が、互いに噛み合うように配置されることにより近接部分を形成している構成がより好ましい。それゆえ、近接部分が広く形成されることとなるので、従来と比べて、より広い範囲での抵抗値の設定が可能である。
【０２１８】
本発明の厚膜抵抗体は、パルス形状である近接部分を有している構成がより好ましい。それゆえ、従来と比べて、より広い範囲での抵抗値の設定が可能である。
【０２１９】
本発明の厚膜抵抗体は、互いに抵抗値の異なる抵抗部にて、近接部分が形成されている構成がより好ましい。それゆえ、より広い範囲で抵抗値の設定が可能となる。
【０２２０】
本発明の厚膜抵抗体調整装置は、以上のように、導電性材料を含む液体をインクジェットノズルの吐出孔から液滴として吐出するインクジェット装置を備えている構成である。
【０２２１】
それゆえ、所望の抵抗値に設定された厚膜抵抗体を好適に製造することができるという効果を奏する。
【０２２２】
本発明の厚膜抵抗体調整装置は、上記インクジェット装置は、静電吸引型インクジェット装置であり、上記静電吸引型インクジェット装置は、吐出孔の径が前記液滴の径よりも小さくなっているとともに、このインクジェット装置のノズルから１滴の量が１ｐｌ以下の液滴を吐出するようになっている構成がより好ましい。これにより、微量の液滴を厚膜抵抗体の近接部分に吐出することができるので、小さい厚膜抵抗体を製造する場合にも好適に用いることができる。
【０２２３】
本発明の厚膜抵抗体調整装置は、上記液体に含まれる導電性材料の平均粒子径がφ５０ｎｍ以下である構成がより好ましい。それゆえ、厚膜抵抗体の抵抗値の微調整を容易に行なうことができる。
【０２２４】
本発明の厚膜抵抗体調整装置は、上記導電性材料を含む液体の粘度が２０ｃＰ以上である構成がより好ましい。これにより、小さい厚膜抵抗体を好適に製造することができる。
【０２２５】
本発明の厚膜抵抗体調整装置は、上記インクジェット装置は、厚膜抵抗体の抵抗部と接続されている配線部の形成に使用される装置と同一である構成がより好ましい。それゆえ、インクヘッドの位置調整等の手間を省略することができるので、作業効率を向上させることができる。
【０２２６】
本発明にかかる抵抗値調整方法は、以上のように、前記厚膜抵抗体が、一箇所以上の箇所で短絡できる近接部分を有し、その箇所のうち１つ以上の箇所で、短絡させた場合の、厚膜抵抗体を持つ端子間の抵抗値が、回路設計上の選択したい抵抗値になるように、上記厚膜抵抗体の形状が決定される構成である。
【０２２７】
本発明の抵抗値調整方法は、上記厚膜抵抗体は、上記インクジェットノズルから噴射される１滴の液滴の直径よりも小さい間隔に、該抵抗部が複数存在する近接部分を少なくとも１箇所以上有するとともに、上記近接部分の少なくとも１箇所に上記液体を噴射することにより、該近接部分を短絡させることがより好ましい。
【０２２８】
それゆえ、従来と比べて、広い範囲での抵抗値の設定を可能するとともに、抵抗値の微調整を可能にするという効果を奏する。
【図面の簡単な説明】
【図１】本発明の実施の一形態に係る厚膜抵抗体の配線部の構成を示す平面図である。
【図２】上記厚膜抵抗体を製造する製造装置の構成を示す正面図である。
【図３】実施の形態１における厚膜抵抗体の抵抗部における抵抗値の変化を説明したグラフである。
【図４】実施の形態２における厚膜抵抗体の抵抗部の構成を示す平面図である。
【図５】実施の形態３における厚膜抵抗体の抵抗部の構成を示す平面図である。
【図６】実施の形態４における厚膜抵抗体の抵抗部の構成を示す平面図である。
【図７】実施の形態５における厚膜抵抗体の抵抗部の構成を示す平面図である。
【図８】本実施の他の形態におけるサブミクロンインクジェット装置の要部の構成を示す断面図である。
【図９】図９（ａ）〜図９（ｃ）は、上記サブミクロンインクジェット装置におけるインクのメニスカスの挙動を説明する断面図である。
【図１０】図１０（ａ）は、ノズルと対向電極との距離が１００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフであり、図１０（ｂ）は、ノズルと対向電極との距離が２０００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフである。
【図１１】図１１（ａ）は、ノズルと対向電極との距離が１００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフであり、図１１（ｂ）は、ノズルと対向電極との距離が２０００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフである。
【図１２】図１２（ａ）は、ノズルと対向電極との距離が１００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフであり、図１２（ｂ）は、ノズルと対向電極との距離が２０００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフである。
【図１３】図１３（ａ）は、ノズルと対向電極との距離が１００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフであり、図１３（ｂ）は、ノズルと対向電極との距離が２０００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフである。
【図１４】図１４（ａ）は、ノズルと対向電極との距離が１００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフであり、図１４（ｂ）は、ノズルと対向電極との距離が２０００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフである。
【図１５】図１５（ａ）は、ノズルと対向電極との距離が２０００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフであり、図１５（ｂ）は、ノズルと対向電極との距離が１００μｍのときのノズル中心からの距離と対向電極からの距離との関係を示すグラフである。
【図１６】ノズル径と最大電界強度との関係を示すグラフである。
【図１７】ノズル径と各種電圧との関係示すグラフである。
【図１８】ノズル径と強電界領域との関係を示すグラフである。
【図１９】印加電圧と帯電電荷量との関係を示すグラフである。
【図２０】初期吐出液滴径と乾燥時間との関係を示すグラフである。
【図２１】周囲湿度と乾燥時間との関係を示すグラフである。
【図２２】本発明の他の実施の形態にかかるサブミクロンインクジェット装置の概略の構成を示す断面図である。
【図２３】本発明の実施の他の形態にかかる、サブミクロンインクジェット装置の原理を説明する断面図である。
【図２４】本実施の形態の他の形態に係るサブミクロンヘッドを用いた厚膜抵抗体調整装置の概略の構成を示す正面図である。
【符号の説明】
１、１１、１２、１３、１４ 抵抗体（抵抗部）
２ａ、２ｂ 端子
３ 短絡部
４ チップ
５ レーザカット部
６ 配線部（抵抗部）
１５ サブミクロンヘッド
２１ インク室
２２ インク
２３ 液滴
２４ ノズル
２４ａ 先端部
２４ｂ 内径
２５ パッキン
２７ 対向電極
２８ 記録媒体
２９ 静電界印加用電極
３０ プロセス制御部
３２ バルブ
３３ 圧力調整器
５０、６０ トリミング装置（厚膜抵抗体調整装置）
５１ インクジェットヘッド
５２ 回路基板
５３ Ｘ−Ｙステージ
５４ ＣＣＤ
５５ インクジェット制御装置
５６ モニタ
５７ レーザ[0001]
BACKGROUND OF THE INVENTION
The present invention provides a thick film resistor whose resistance value is adjusted by spraying a conductive material, an apparatus for manufacturing the same, and a resistance value adjusting method.
[0002]
[Prior art]
Conventionally, for example, as a method of disposing a resistor between terminals on a substrate on which an IC chip or the like is mounted, for example, there is a method of forming a thick film resistor between terminals.
[0003]
As a method of forming a thick film resistor, for example, Patent Document 1 discloses a method of applying a resistance paste on a substrate by an ink jet method.
[0004]
In addition, as a method of forming a resistor whose resistance value is adjusted with high accuracy, for example, a thick film resistor is formed by an offset printing method or the like, and then the resistor is cut using a cutting means or the like. Thus, a method for adjusting the resistance value of the resistor has been proposed. Further, for example, in Patent Document 2, when a thick film resistor is laser-cut and the length and width of the thick film resistor are adjusted, the thick film resistor is prevented from being destroyed by the laser. A method of providing an opening in a laser cutting path of a thick film resistor is disclosed.
[0005]
Further, Patent Document 3 proposes a configuration in which the resistance value of the thick film resistor is adjusted by applying a conductive material while cutting with a laser.
[0006]
[Patent Document 1]
JP 59-215763 A (publication date: December 5, 1984)
[0007]
[Patent Document 2]
JP 58-105503 A (publication date; June 23, 1983)
[0008]
[Patent Document 3]
Japanese Utility Model Publication No.59-182903 (Publication date: December 6, 1984)
[0009]
[Problems to be solved by the invention]
However, the conventional method has the problems described below.
[0010]
First, when the resistance paste is applied by an ink jet method, the resistance paste spreads on the substrate when the droplet lands. Depending on the spreading direction, the resistance value may increase or decrease. In addition, the cross-sectional shape of the solute (thick film resistor) after solvent drying tends to be uneven in the thickness direction, and the shape after drying is not uniform and varies. Have difficulty. That is, in the configuration of Patent Document 1, the resistance value is adjusted according to the thickness of the resistance paste. However, since the thickness of the resistance paste can vary greatly, it is difficult to adjust the resistance value. It is.
[0011]
In addition, in the method of adjusting the resistance value of the resistor by cutting a thick film resistor formed in advance by an offset printing method with a laser, the resistance can be cut while checking the change in resistance in real time. Since the amount can be controlled, the resistance value can be adjusted with high accuracy. However, laser cutting can only increase the resistance value. That is, since the resistor can only be cut, the resistance value of the resistor can only be increased. For this reason, in order to be able to select a resistance value in a wide range so as to cope with a change in circuit design, it is necessary to reduce the initial resistance value, shorten the total length of the thick film resistor, In addition, the resistance value per unit length must be increased. However, shortening the total length of the thick film resistor decreases the cuttable range, and as a result, it becomes difficult to select a wide range of resistance values. Also, since the resistance value per unit length in the full length direction is large, the resistance value deviation amount with respect to the cut deviation amount (laser position accuracy limit) is large, and the resistance value is set in a wide range. This makes it difficult to adjust the resistance value with high accuracy. In this way, trimming with high accuracy so as to obtain a constant resistance value is contrary to selecting a wide range of resistance values with one thick film resistor.
[0012]
Further, in the method of applying a conductive material while cutting with a laser disclosed in Patent Document 3, the application of the conductive material is limited to correcting overcutting by a laser, and a wide range of resistance values. Cannot be selected. In other words, in Patent Document 3, a conductive material is applied to a thick film resistor having a certain length, and the resistance value of the thick film resistor is adjusted by laser-cutting an excess portion. Yes. However, in the above method, as in the method of adjusting the resistance value of the thick film resistor using the offset printing described above, when setting the resistance value in a wide range, the deviation at the time of laser cutting is set. The amount of deviation of the resistance value with respect to the amount increases, and it becomes difficult to adjust the resistance value with high accuracy.
[0013]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a thickness capable of setting a resistance value in a wider range and performing fine adjustment of the resistance value as compared with the conventional technique. An object of the present invention is to provide a film resistor, a manufacturing apparatus thereof, and a resistance value adjusting method.
[0014]
[Means for Solving the Problems]
In order to solve the above-described problem, the thick film resistor of the present invention is a thick film resistor that is short-circuited by a liquid containing a conductive material that is ejected as droplets from an ejection hole of an inkjet nozzle, The thick film resistor has a proximity portion that can be short-circuited at one or more locations, and the resistance value between the terminals having the thick film resistor when one or more locations are short-circuited, It is characterized in that the shape of the thick film resistor is determined so that a resistance value desired to be selected in circuit design is obtained.
[0015]
According to the above configuration, the thick film resistor has the resistance portion, and the resistance value is set by ejecting the conductive material from the inkjet nozzle to the resistance portion. And the said thick film resistor has the proximity | contact part which can be short-circuited in one or more places, The resistance between terminals with a thick film resistor at the time of making it short-circuit in one or more places among the places The shape of the thick film resistor is determined so that the value becomes a resistance value desired to be selected in circuit design. Therefore, even when a circuit or the like whose resistance value is significantly changed is formed, it can be easily handled.
[0016]
In the thick film resistor according to the present invention, it is more preferable that the proximity portion has an interval smaller than a diameter when one droplet ejected from the inkjet nozzle is landed.
[0017]
According to said structure, a thick film resistor is a shape which has the proximity | contact part in which several resistance parts exist in the space | interval smaller than the diameter of the droplet of 1 drop ejected from the said inkjet nozzle. . That is, the thick film resistor has a shape in which the proximity portion of the resistance portion is short-circuited by the ejection of the conductive material from the inkjet nozzle. And it can set to a desired resistance value by short-circuiting a proximity | contact part. Also, by changing the location to be short-circuited, it is possible to set the resistance value in a wider range than in the past. Furthermore, since the proximity portion is smaller than the diameter of one drop of the conductive material ejected from the inkjet nozzle, it can be short-circuited more easily.
[0018]
Therefore, the resistance value of the thick film resistor can be set in a wide range as compared with the conventional case, and the resistance value can be finely adjusted. The diameter may be a diameter when the droplet spreads by being ejected to the resistance portion.
[0019]
The thick film resistor of the present invention has a configuration in which the resistance portion has at least a straight portion, and the resistance portion forms a proximity portion by arranging the straight portions in parallel with each other. Is more preferable.
[0020]
According to said structure, the proximity | contact part is comprised from the resistance part formed mutually in parallel. That is, the interval between the resistance portions arranged in parallel to each other is smaller than the diameter of the liquid ejected from the inkjet nozzle. Since this has a wide proximity portion, it is possible to set the resistance value in a wider range than in the prior art.
[0021]
The thick film resistor of the present invention preferably has a configuration in which the substantially U-shaped resistor portions are arranged so as to mesh with each other to form a proximity portion.
[0022]
According to said structure, the proximity | contact part is comprised by arrange | positioning so that a substantially U-shaped resistance part may mutually mesh | engage. As a result, the proximity portion is formed widely, so that the resistance value can be set in a wider range than in the conventional case.
[0023]
The thick film resistor of the present invention is more preferably configured to have a proximity portion that has a pulse shape.
[0024]
According to said structure, since it has the proximity | contact part of a pulse shape, the setting of a resistance value in a wider range is possible compared with the past.
[0025]
The thick film resistor of the present invention preferably has a configuration in which adjacent portions are formed in resistance portions having different resistance values.
[0026]
According to said structure, since the proximity | contact part is formed in the resistance part from which resistance value mutually differs, it becomes possible to set resistance value in a wider range.
[0027]
In order to solve the above problems, a thick film resistor adjusting device according to the present invention is a thick film resistor adjusting device that manufactures the above thick film resistor, and discharges a liquid containing a conductive material from an inkjet nozzle. It is characterized by including an ink jet device that discharges liquid droplets from the holes.
[0028]
According to said structure, since the inkjet apparatus which discharges the liquid containing an electroconductive material as a droplet is provided, the thick film resistor set to the desired resistance value can be manufactured suitably.
[0029]
In the thick film resistor adjusting device of the present invention, the ink jet device is an electrostatic suction type ink jet device, and the electrostatic suction type ink jet device has a discharge hole diameter smaller than the droplet diameter. In addition, it is more preferable that a droplet with a droplet amount of 1 pl or less be ejected from the nozzle of the inkjet apparatus.
[0030]
According to the above configuration, the inkjet apparatus has a discharge hole diameter smaller than the droplet diameter, and discharges a droplet having a droplet amount of 1 pl or less from the nozzle of the inkjet apparatus. It has become. As a result, a small amount of liquid droplets can be discharged to the adjacent portion of the thick film resistor, and therefore, it can be suitably used even when a small thick film resistor is manufactured.
[0031]
The thick film resistor adjusting device of the present invention is more preferably configured such that the average particle diameter of the conductive material contained in the liquid is φ50 nm or less.
[0032]
When the average particle diameter of the conductive material is 50 nm or less, the adjacent portion can be short-circuited at a finer interval, so that the resistance value of the thick film resistor can be easily finely adjusted.
[0033]
The thick film resistor adjusting device of the present invention preferably has a configuration in which the viscosity of the liquid containing the conductive material is 20 cP or more.
[0034]
According to said structure, since the viscosity of the said liquid is 20 cP or more, it can prevent that the droplet discharged to the adjacent part spreads. Thereby, a small thick film resistance can be manufactured suitably.
[0035]
In the thick film resistor adjusting device of the present invention, it is more preferable that the ink jet device is the same as the device used for forming the wiring portion connected to the resistor portion of the thick film resistor.
[0036]
According to the above configuration, since the formation of the wiring portion connected to the resistance portion of the thick film resistor and the adjustment of the resistance value of the resistor can be performed at the same time, the trouble of adjusting the position of the ink head is reduced. Since it can be omitted, work efficiency can be improved.
[0037]
The resistance value adjusting method according to the present invention adjusts the resistance value of the thick film resistor by ejecting a liquid containing a conductive material as a droplet from the ejection hole of the ink jet nozzle onto the thick film resistor to cause a short circuit. A method of adjusting a resistance value, wherein the thick film resistor has a proximity portion that can be short-circuited at one or more locations, and the thick-film resistor is short-circuited at one or more locations. The shape of the thick film resistor is determined so that the resistance value between the terminals having the above becomes a resistance value desired to be selected in circuit design.
[0038]
In the resistance value adjusting method of the present invention, the thick film resistor has at least one or more adjacent portions where a plurality of the resistance portions exist at intervals smaller than the diameter of one droplet ejected from the inkjet nozzle. It is more preferable to short-circuit the proximity portion by spraying the liquid onto at least one location of the proximity portion.
[0039]
According to said structure, since the resistance value is set by injecting the liquid containing an electroconductive material to the said adjacent part, and short-circuiting the adjacent part of a resistance part, compared with the past, it is in a wide range. The resistance value can be set and the resistance value can be finely adjusted.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS.
[0041]
FIG. 1 is a top view of a circuit board for explaining trimming of the thick film resistor according to the first embodiment, and FIG. 2 is a front view showing an outline of the trimming apparatus.
[0042]
In general, a thick film resistor and a thin film resistor may be referred to as a resistor printed on a substrate or the like, but in the present invention, a thick film resistor is referred to regardless of the thickness of the resistor. And
[0043]
The thick film resistor according to the present embodiment is a thick film resistor that is short-circuited by a liquid containing a conductive material that is ejected as droplets from an ejection hole of an inkjet nozzle, and the thick film resistor is There is a proximity part that can be short-circuited at one or more locations, and the resistance value between the thick film resistors when short-circuited at one or more locations is the resistance value that you want to select in circuit design It is the structure designed in the shape which becomes.
[0044]
Specifically, the thick film resistor according to the present embodiment has a resistance portion whose resistance value is determined by ejecting a liquid containing a conductive material as a droplet from a discharge hole of an inkjet nozzle and causing a short circuit. A thick film resistor having at least one adjacent portion in which a plurality of the resistance portions exist at intervals smaller than the diameter of one droplet ejected from the inkjet nozzle. Shape.
[0045]
In the present embodiment, an example in which a thick film resistor is formed on a circuit board will be described, but the portion where the thick film resistor is formed is not particularly limited.
[0046]
First, a thick film resistor adjusting device (hereinafter referred to as a trimming device) that manufactures the above low thick film resistance will be described.
[0047]
The trimming apparatus 50 according to this embodiment includes a stage 53, an inkjet head 51, a CCD, a monitor 56, an inkjet control apparatus 55, and a laser 57.
[0048]
The stage 53 fixes the circuit board 52 having a thick film resistor and allows the circuit board 52 to move in the XY direction (mounting surface direction).
[0049]
The inkjet head 51 is for ejecting a liquid (hereinafter referred to as ink) containing a conductive material.
[0050]
The CCD 54 is for observing the surface of the circuit board 52, and the monitor 56 displays an image from the CCD 54. At this time, the CCD 54 is installed so that the landing position of the ink ejected from the inkjet head 51 (inkjet nozzle) on the circuit board 52 is approximately the center of the screen of the monitor 56.
[0051]
The ink jet control device 55 controls the amount of ink ejected from the ink jet head 51.
[0052]
The laser 57 cuts the thick film resistor. The laser 57 is not essential and may be attached as necessary.
[0053]
The trimming device 50 according to the present embodiment is provided with a resistance value measuring device 7. This is for measuring the resistance value of the thick film resistor attached to the circuit board 52.
[0054]
Next, the circuit board 52 will be described.
[0055]
As shown in FIG. 1, the circuit board 52 is formed by forming a plurality of conductive wiring patterns including wiring parts (resistance parts) 6 on a board.
[0056]
Specifically, the wiring part (substrate wiring) 6 is formed on the circuit board 52 by using, for example, an offset printing method. On the circuit board 52, terminals 2 are formed of a conductive material in order to connect chips 4a and 4b such as ICs and capacitors.
[0057]
Furthermore, the resistor 1 (resistor portion) is formed on the circuit board 52 by using, for example, an offset printing method.
[0058]
As the above substrate, a quartz substrate, an inorganic material substrate such as a glass substrate, and a resin substrate such as a polyethylene terephthalate substrate, a polyether sulfone substrate, and a polyimide substrate can be used, but the present invention is limited to these. is not.
[0059]
The wiring pattern is formed by depositing a conductive material such as Ag on the substrate by vacuum vapor deposition or sputtering, and patterning the deposited layer of the conductive material using a photolithography technique. Has been. The conductive material is not limited to Ag, but may be Au or Cu. Further, the formation of the wiring pattern is not limited to the photolithography method, and may be a transfer method or an ink jet method.
[0060]
In the present invention, the method for forming the wiring portion 6 and the resistor 1 is not limited to offset printing, and a photolithography method, an inkjet method, or the like may be used.
[0061]
In the present embodiment, the wiring portion 6 and the resistor 1 are combined to form a resistance portion. And the thick film resistor is comprised from the said resistance part. That is, in this embodiment, for convenience, the resistance portion is described using different names for the wiring portion 6 and the resistor 1, but the wiring portion 6 is also a part of the resistance portion. The wiring portion 6 and the resistor 1 are resistance portions having different resistance values, and a wiring portion (thick film resistor) is configured by both. In the present invention, what is formed between the terminals 2a and 2b is referred to as a thick film resistor.
[0062]
In the present embodiment, both ends of the resistor 1 are connected to the terminals 2a and 2b, respectively. The wiring portion 6 is connected to the terminal 2 a and is formed in parallel with the resistor 1. The wiring portion 6 is not connected to the terminal 2b. At this time, the distance between the wiring portion 6 and the resistor 1 is more preferably set smaller than the diameter when the ink ejected from the inkjet head 51 has landed on the circuit board 52. Thereby, for example, even when the amount of ink discharged is very small, that is, when the adjacent portion is short-circuited using a very small amount of ink, the wiring portion 6 and the resistor 1 are reliably connected (the adjacent portion). Can be connected (short-circuited). In the present embodiment, it is 8 μm.
[0063]
In the present embodiment, a portion where a plurality of resistance portions exist at intervals smaller than the diameter is referred to as a proximity portion. That is, in the present embodiment, a proximity portion is formed at a portion where the wiring portion 6 and the resistor 1 are arranged in parallel.
[0064]
That is, in this embodiment, the resistance portion has a shape that can be short-circuited at one or more locations, that is, a formation having a proximity portion. And a resistance value can be set in a wide range by short-circuiting the said proximity | contact part.
[0065]
The reason why the resistance value can be set in this wide range will be specifically described.
[0066]
As shown in FIG. 1, the resistor 1 and the wiring part 6 are arranged in parallel to each other and have a proximity part. The resistor 1 is connected to the terminals 2a and 2b, while the wiring portion is connected only to one terminal 2a. In this state, the resistance value between the terminals 2a and 2b corresponds to the resistance value of the entire length L1 of the wiring portion 6. Here, for example, as shown in FIG. 1, by ejecting ink from the inkjet head 51 at an arbitrary position of the proximity portion, the proximity portion, that is, the wiring portion 6 and the resistor 1 are electrically connected. Do (short circuit). As a result, when the resistance value between the wiring portion 6 and the resistor 1 is smaller in the wiring portion 6, the current flowing between the portion electrically connected to the terminal 2a (hereinafter, short-circuit portion) is Due to the difference in resistance value, it flows on the wiring part 6 side. That is, between the terminals 2a and 2b, the current flowing through the resistor 1 is between the terminal 2b and the short-circuited portion (L2). At this time, when the resistance value of the wiring portion 6 is substantially 0, the resistance value between the terminals 2a and 2b corresponds to the distance L2 of the resistor 1 described above. The resistance value can be changed in a wide range by changing the position to be short-circuited.
[0067]
Here, a method for adjusting the resistance value of the thick film resistor will be described.
[0068]
In the resistance value adjusting method according to the present embodiment, the resistance value is adjusted by short-circuiting the resistance portion by ejecting a liquid containing a conductive material as a droplet from the ejection hole of the inkjet nozzle to the thick film resistor. A method of adjusting a resistance value of a thick film resistor, comprising at least one adjacent portion having a plurality of resistance portions at intervals smaller than the diameter of one droplet ejected from the inkjet nozzle. This is a method of short-circuiting the adjacent portion by spraying the liquid onto the thick film resistor.
[0069]
Specifically, first, the circuit board 52 on which the thick film resistor whose resistance value is not adjusted is formed is fixed to the XY stage 53 of the trimming apparatus 50. Then, the XY stage 53 is moved so that the thick film resistor is located almost directly below the ejection port of the inkjet head 51.
[0070]
At this time, the thick film resistor enters the field of view of the CCD 54, and the XY stage 53 is moved so that the thick film resistor and its periphery are projected on the monitor 56. Then, while confirming the surface of the circuit board 52 with the monitor 56, the ink jet control device 55 ejects ink from the ink jet nozzles. At this time, the ink ejected from the nozzles of the inkjet head 51 is ejected so as to connect (short-circuit) the wiring portion 6 and the resistor 1. As a result, the resistance value is adjusted.
[0071]
The method for adjusting the resistance value will be specifically described.
[0072]
First, the resistance value of the thick film resistor is measured using a resistance value measuring instrument 7. This may be achieved by measuring the resistance value between the terminals 2a and 2b. The resistance value at this time is R1. When the target resistance value is R0, ink is ejected (applied) to the adjacent portion of the thick film resistor to cause a short circuit, that is, the wiring portion 6 and the resistor 1 are electrically connected to each other. Resistance value R0. Here, a method of determining the ejection (application) position of the ink containing the conductive material will be described. For example, as shown in FIG. 1, when the distance from the position where the ink is ejected to the terminal 2b is set to L2 in order to obtain a desired resistance value R0, and when the ink is ejected to the above position, L2 is a thick film resistor. For the total length L1 of
L2 = L1 × R0 / R1 (1)
It is calculated from. And the short circuit part 3a is formed by ejecting the said ink in the position.
[0073]
Next, after forming the short-circuit portion 3a, the resistance value between the terminals 2a and 2b is measured again.
[0074]
If the measured resistance value is larger than the desired value, the short circuit portion 3b is further formed on the side closer to the terminal 2b. On the other hand, when the measured resistance value becomes smaller than a desired value, the laser 57 is laser-cut by the laser 57 to form the laser cut portion 5. In this way, the resistance value between the terminals 2a and 2b is set to a desired value.
[0075]
A change in the resistance value between the terminals 2a and 2b in the resistance value adjusting method will be described with reference to the graph of FIG. FIG. 3 is a graph illustrating a change in resistance value between the terminals 2a and 2b for each process.
[0076]
First, the resistance value of the thick film resistor in the state before adjusting the resistance value is the largest, which is R1. The resistance value of the thick film resistor is adjusted to a desired resistance value R0. The shape of the thick film resistor may be any shape that satisfies R1> R0. For this reason, it is desirable that the shape of the resistance value R1 be large so as to cope with a change in resistance value due to a circuit design change. It is more preferable to increase the line width or thickness of the thick film resistor in advance to reduce the resistance value per unit length. Thereby, the shift amount of the resistance value with respect to the shift amount of the position where the short-circuit portions 3a and 3b are formed is reduced, and the accuracy is further improved.
[0077]
When the short-circuit portion 3a is formed, the resistance value decreases to R2, but this resistance value is still larger than the target value R0. Therefore, the short circuit part 3b is further formed. At this time, the resistance value drops to R3, which is smaller than the desired resistance value R0. Therefore, in order to increase the resistance value of the thick film resistor, a part of the short-circuit portion 3b is laser-cut by the laser 57, thereby matching the resistance value with the desired value R0. In this way, the resistance value between the terminals 2a and 2b is adjusted.
[0078]
As described above, the thick film resistor according to the present embodiment has a plurality of resistance portions having different resistance values, and has an interval smaller than the diameter of one droplet ejected from the inkjet nozzle. Are arranged parallel to each other so as to have a plurality of adjacent portions, and one resistance portion A is electrically connected to the outside at the other end while the other resistance portion B is connected to the outside. Has a shape in which only one end is electrically connected to the outside.
[0079]
That is, the thick film resistor according to the present embodiment is a thick film whose resistance value is determined by ejecting a liquid containing a conductive material as droplets from a discharge hole of an ink jet nozzle and short-circuiting the resistance portion. A resistor, wherein the resistor portion has a configuration having a proximity portion in which a plurality of the resistor portions are present at intervals smaller than the diameter of one droplet ejected from the inkjet nozzle. .
[0080]
According to the above configuration, the thick film resistor has the resistance portion, and the resistance value is set by ejecting the conductive material from the inkjet nozzle to the resistance portion. The thick film resistor has a shape having a proximity portion in which a plurality of resistance portions are present at intervals smaller than the diameter of one droplet ejected from the inkjet nozzle. That is, the thick film resistor has a shape in which the proximity portion of the resistance portion is short-circuited by the ejection of the conductive material from the inkjet nozzle. Then, by short-circuiting the proximity portion, it is possible to set the resistance value to be set in a wider range than in the past. Moreover, it can set to a desired resistance value by changing the location which short-circuits. Furthermore, since the proximity portion is smaller than the diameter of one drop of the conductive material ejected from the inkjet nozzle, it can be short-circuited more easily.
[0081]
For example, when the setting of the circuit board 52 is changed, it is necessary to set the resistance value of the thick film resistor disposed between the terminals to be greatly different from the preset resistance value. In the present embodiment, the resistance value can be changed in a wide range by changing the short-circuited portion in the proximity portion.
[0082]
Further, since the path through which the current flows can be lengthened as compared with the configuration in which the terminals are formed of a single resistor, the resistance value can be finely adjusted more easily.
[0083]
Therefore, the resistance value of the thick film resistor can be set in a wide range as compared with the conventional case, and the resistance value can be finely adjusted. The diameter may be the diameter when the droplet spreads by being ejected onto the resistance portion, and is more preferably the diameter of the droplet state.
[0084]
Ink jet application (jetting) of a thick film resistor material by ink jet is difficult to control the landing shape. On the other hand, when a liquid containing a conductive material is applied by inkjet, the resistance value in the short-circuit portions 3a and 3b is extremely small compared to the resistance value in the thick film resistor. Even if fine control is difficult, the resistance value between terminals is not affected. For this reason, workability | operativity improves.
[0085]
In addition, since the resistance value can be changed, the versatility of the wiring board is improved and the cost performance can be realized.
[0086]
The purpose of this embodiment is to set a resistance value between the terminals in a wide range by short-circuiting a part of the thick film resistor, and the shape of the thick film resistor achieves the above object. If it is the shape which can do, it will not specifically limit.
[0087]
In order to make the ejection position more accurate and not affect other resistances when ejecting (coating) ink containing a conductive material, for example, other than the region where the ink of the thick film resistor is ejected A cover may be applied so that the ink containing the conductive material is not fogged except in a place where the ink is short-circuited.
[0088]
Alternatively, the thick film resistor may be formed prior to the wiring, and the trimming device 50 may perform the formation of the wiring portion 6 by inkjet, and the resistance value may be adjusted while the circuit board 52 is fixed to the inkjet device. By doing in this way, a wiring part formation process and a trimming process can be performed continuously, the effort of head position adjustment etc. can be saved and work efficiency can be improved.
[0089]
In the above description, when the resistance value of the thick film resistor is decreased by ejecting ink, the resistance value is adjusted by cutting the short-circuit portion 3b with the laser 57. For example, if the desired resistance value can be set by shortening the interval at which ink is ejected, the laser 57 can be dispensed with.
[0090]
In the present embodiment, the configuration in which the resistance portion is conducted in advance has been described. However, the resistor portion may simply have a proximity portion in which the two resistance portions are arranged in parallel. That is, the two resistance units may not be electrically connected in advance. In this case, the short circuit portion 3 is formed at an arbitrary position in the proximity portion, and the resistance value of the thick film resistor may be adjusted based on the resistance value at this time.
[0091]
Moreover, the proximity | contact part may be comprised from the some resistance part, and may be comprised by one resistance part. Therefore, the presence of a plurality of the resistance portions may be formed, for example, by bending one resistance portion.
[0092]
[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIG. The thick film resistor according to the present embodiment is a thick film resistor in which a resistance value is determined by ejecting a liquid containing a conductive material as a droplet from a discharge hole of an ink jet nozzle and short-circuiting the resistance portion. The resistance portion has a shape having a proximity portion in which a plurality of the resistance portions exist at intervals smaller than the diameter of one droplet ejected from the ink jet nozzle. This is a configuration in which the substantially U-shaped resistance portions have adjacent portions arranged so as to mesh with each other. For convenience of explanation, members having the same functions as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0093]
As shown in FIG. 4, the resistance portion of the thick film resistor according to the present embodiment is formed of two resistance portions having different resistance values. Here, for the sake of convenience, of the two resistors, the resistance portion having a very low resistance value will be described as the wiring portion 6, and the resistance portion having a high resistance value will be described as the resistor 11.
[0094]
Specifically, as shown in FIG. 4, the resistor 11 is formed in a substantially U shape, and one end is connected to the terminal 2a. In addition, the wiring portion 6 has a substantially U-shaped portion, and one end is connected to the terminal 2b. The other end of the resistor 11, that is, the end not connected to the terminal 2 a is electrically connected to the bottom of the U-shaped open portion of the wiring portion 6. In other words, the other end of the resistor is sandwiched by the opening of the U-shaped portion of the wiring portion 6 and is electrically connected at the sandwiched portion. That is, the resistors 11 and the wiring portions 6 are alternately arranged and have portions that are parallel to each other. The portions parallel to each other are spaced smaller than the diameter of one droplet ejected from the inkjet nozzle. In other words, the wiring portions 6 and the resistors 11 arranged alternately form a proximity portion. The resistance value of the thick film resistor is adjusted by short-circuiting the adjacent portion.
[0095]
Next, a method for adjusting the resistance value of the thick film resistor having the above shape will be described.
[0096]
The trimming process for the thick film resistor will be described below.
[0097]
First, the resistance value measuring device 7 measures the resistance values of the terminals 2a and 2b. Then, the short-circuit portion 3 is formed by ejecting (applying) ink between the resistor 11 and the wiring portion 6, that is, in a proximity portion. When the desired resistance value is small, the position where the ink is ejected (applied) forms the short-circuit portion 3c on the closer side 11a of the resistor 11, while when the desired resistance value is large, the resistor 11 What is necessary is just to form the short circuit part 3d in the far side 11b.
[0098]
And what is necessary is just to form the new short circuit part 3 based on a measured value by measuring the resistance value when the short circuit part 3c (3d) is formed with the resistance value measuring instrument 7. Further, the short-circuit portion 3 is formed while moving the ink ejection position so that the resistance value approaches the desired value, and when the desired resistance value is reached, the ink ejection is terminated. Moreover, when the short circuit part 3 is formed and the resistance value when the short circuit part 3 is formed is larger than the desired resistance value, the short circuit part 3 may be cut with a laser. In addition, what is necessary is just to complete | finish adjustment of a resistance value, when the resistance value when forming the short circuit part 3c (3d) is a desired resistance value.
[0099]
As described above, the thick film resistor according to the present embodiment has two resistance portions that are substantially U-shaped, and each resistance portion is connected to a different external terminal. In addition, it has a configuration in which the plurality of resistance portions are in mesh with each other so as to have a plurality of adjacent portions at intervals smaller than the diameter of one droplet ejected from the inkjet nozzle. Thus, by making the resistance portion substantially U-shaped, the area of the proximity portion can be increased as compared with the first embodiment. Thereby, the resistance value can be adjusted in a wider range, and the resistance value can be finely adjusted more easily. In addition, by making the resistance portion substantially U-shaped, the total length of the thick film resistor can be increased even if the distance between the terminals 2a and 2b is small, and as a result, the range of selectable resistance values is It is possible to deal with a wide range of circuit design changes and to adjust the resistance value with high accuracy.
[0100]
Further, it is more preferable that the two resistance portions are electrically connected in advance. By being connected in advance, when adjusting the resistance value, the resistance value can be measured first, so that the short-circuit portion can be formed relatively easily.
[0101]
In addition, as a shape of the resistance part concerning this Embodiment, when a substantially U-shaped resistor is the mutually same magnitude | size, each resistor should just be arrange | positioned alternately. In addition, when the size of the substantially U-shaped resistor is different, the resistor may be covered with the other resistor.
[0102]
[Embodiment 3]
The following will describe another embodiment of the present invention with reference to FIG. The thick film resistor according to the present embodiment is a thick film resistor in which a resistance value is determined by ejecting a liquid containing a conductive material as a droplet from a discharge hole of an ink jet nozzle and short-circuiting the resistance portion. The resistance portion has a shape having a proximity portion in which a plurality of the resistance portions exist at intervals smaller than the diameter of one droplet ejected from the ink jet nozzle. It is the structure which has the proximity | contact part which consists of a resistance part formed in parallel with each other. For convenience of explanation, members having the same functions as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0103]
As shown in FIG. 5, the resistor portion of the thick film resistor according to the present embodiment is formed of four resistors 12a, 12b, 12c, and 12d. In the following description, the resistor 12 will be described unless otherwise specified. These four resistors 12 are arranged so as to be parallel to each other, and are not connected to the terminals 2a and 2b. At this time, a proximity portion is formed between each resistor 12 and the terminal 2a or 2b. In the present embodiment, at least one of the four resistors 12 is electrically connected to the terminals 2a and 2b via the short-circuit portion 3, so that the resistance between the terminals 2a and 2b is reduced. The value is set. That is, the four resistors have different resistance values, and can be set to desired resistance values by combining the resistors 12 connected to the terminals 2a and 2b. In addition, as a method of making the resistance values of the four resistors 12 different, for example, the material of each resistor 12 may be made different, or may be changed by changing the width and the thickness. Furthermore, although the four resistors 12 have been described in the above description, the number of the resistors is not particularly limited.
[0104]
Next, a method of setting the resistance value of the thick film resistor using the resistor 12 having the above shape will be described.
[0105]
First, according to the design of the circuit, any of the resistors 12 a to 12 d and the terminals 2 a and 2 b are connected via the short-circuit portion 3. Specifically, the short-circuit portion 3 may be formed by ejecting ink from the inkjet head 51 between the resistor 12 to be connected and the terminals 2a and 2b. At this time, the number of resistors 12 to be connected is not limited to one and may be a plurality.
[0106]
As described above, in the thick film resistor according to the present embodiment, the resistor portion is formed from a plurality of resistors arranged in parallel to each other, and the proximity is provided between the external terminal and the resistor. It is the structure in which the part is formed. For this reason, the resistance value between the terminals can be selected in a wide range in accordance with the circuit design change. Further, since the resistance value can be changed step by step, the setting of the resistance value can be made easier.
[0107]
[Embodiment 4]
The following will describe another embodiment of the present invention with reference to FIG. The thick film resistor according to the present embodiment is a thick film resistor in which a resistance value is determined by ejecting a liquid containing a conductive material as a droplet from a discharge hole of an ink jet nozzle and short-circuiting the resistance portion. The resistance portion has a shape having a proximity portion in which a plurality of the resistance portions exist at intervals smaller than the diameter of one droplet ejected from the ink jet nozzle. It is the structure which has the proximity | contact part which consists of a resistance part formed in parallel with each other. For convenience of explanation, members having the same functions as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0108]
The resistance portion of the thick film resistor according to the present embodiment is formed of two resistors 13a and 13b as shown in FIG. In the following description, the resistor 13 will be described unless otherwise distinguished. The two resistors 13a and 13b are arranged in parallel to each other and have different resistance values. Specifically, the specific resistance of the resistor 13a is set larger than that of the resistor 13b. That is, as for the resistance value between the terminals 2a and 2b, the resistance value of the resistor 13a is larger than the resistance value of the resistor 13b. The resistor 13a is connected to the terminal 2a and the terminal 2b. On the other hand, the resistor 13b is connected only to the terminal 2a. A proximity portion is formed between the resistors 13a and 13b formed in parallel to each other.
[0109]
Next, a method for setting the resistance value of the thick film resistor using the resistor 13 having the above shape will be described.
[0110]
First, the resistance value measuring device 7 measures the resistance value between the terminals 2a and 2b. Then, ink is ejected to the adjacent portion to form the short-circuit portion 3, thereby setting the desired resistance value.
[0111]
In the present embodiment, the range of the resistance value that can be adjusted is between the resistance value of the resistor 13a and the resistance value of the resistor 13b. Since the entire portion between the resistor 13a and the resistor 13b is a proximity portion, the change amount of the resistance value with respect to the change amount (deviation amount) of the position where the short-circuit portion 3 is formed is reduced, and trimming with higher accuracy is performed. Is possible.
[0112]
[Embodiment 5]
The following will describe another embodiment of the present invention with reference to FIG. The thick film resistor according to the present embodiment is a thick film resistor in which a resistance value is determined by ejecting a liquid containing a conductive material as a droplet from a discharge hole of an ink jet nozzle and short-circuiting the resistance portion. The resistance portion has a shape having a proximity portion in which a plurality of the resistance portions exist at intervals smaller than the diameter of a single droplet ejected from the inkjet nozzle, and further includes a pulse It is the structure which has the adjacent part which is a shape. For convenience of explanation, members having the same functions as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0113]
The resistance portion of the thick film resistor according to the present embodiment is formed of one resistor 14 as shown in FIG. The resistor 14 has a pulse shape (meandering shape), and one pulse interval forms a proximity portion between one pulse and the next pulse. The resistor 14 has both ends connected to the terminal 2a and the terminal 2b, respectively.
[0114]
Next, a method for setting the resistance value of the thick film resistor using the resistor 13 having the above shape will be described.
[0115]
First, the resistance value measuring device 7 measures the resistance value between the terminals 2a and 2b. Then, ink is ejected to the adjacent portion to form the short-circuit portion 3, thereby setting the desired resistance value.
[0116]
Specifically, first, the short circuit portion 3 is formed by ejecting ink so as to connect both ends (adjacent bent portions) of one pulse of the resistor 14 to each other in the longitudinal direction from the terminal 2a. When the target resistance value is approached, this time, by forming the short-circuit portion 3 by ejecting ink so as to connect the resistors 14 facing each other on the terminal 2b side, that is, the inside of the pulse. Finely adjust the resistance value. Here, the said longitudinal direction is the direction which tied the terminal 2a and the terminal 2b, and let the direction orthogonal to the said longitudinal direction be a horizontal direction.
[0117]
The thick film resistor according to the present embodiment can be selected because the resistance portion has a pulse shape (meandering shape), and the total length of the resistance portion becomes longer even if the distance between the terminals 2a and 2b is small. Since the range of the resistance value is widened, it is possible to cope with a circuit design change in a wider range, and fine adjustment of the resistance value can be performed with high accuracy.
[0118]
[Embodiment 6]
The following will describe another embodiment of the present invention with reference to FIGS.
[0119]
The thick film resistor adjusting device according to the present embodiment is configured to include a submicron head as an ink jet device. Specifically, in the thick film resistor adjusting device according to the present embodiment, the diameter of the discharge hole is smaller than the diameter of the droplet, and the amount of one droplet from the nozzle of the inkjet device is 1 pl or less. It is the structure provided with the electrostatic attraction type inkjet device which discharges the droplet. For convenience of explanation, members having the same functions as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
[0120]
First, the configuration of the sub-micron head used in this embodiment will be described with reference to FIG.
[0121]
FIG. 8 is a view showing the structure of an ink jet apparatus according to an embodiment of the present invention. The ink jet apparatus includes a nozzle 24 for discharging the ink 22 stored in the ink chamber 21. The nozzle 24 is connected to the ink chamber 21 via a packing 25. Thus, the ink 22 in the ink chamber 21 is sealed so as not to leak outside from the connecting portion between the nozzle 24 and the ink chamber 21.
[0122]
Further, the nozzle 24 has a shape that is narrowed so that the inner diameter becomes smaller toward the tip portion 24 a that is opposite to the connection portion with the ink chamber 21, that is, the discharge side of the ink 22. The inner diameter (diameter) of the ink discharge hole 24b of the tip 24a of the nozzle 24 is set in relation to the particle size of the ink 22 immediately after discharge. In order to distinguish between the ink 22 ejected from the nozzle 24 and the ink 22 stored in the ink chamber 21, the ink 22 ejected from the nozzle 24 will be hereinafter referred to as a droplet 23. Details of the relationship between the diameter of the ink discharge hole 24b and the droplet diameter of the droplet 23 immediately after discharge will be described later.
[0123]
Further, an electrostatic field applying electrode 29 for applying an electrostatic field to the ink 22 is provided inside the nozzle 24. The electrostatic field applying electrode 29 is connected to a process control unit 30, and the process control unit 30 controls the electric field strength by an applied voltage from a drive circuit (not shown). By controlling the electric field strength, the droplet diameter of the droplet 23 discharged from the nozzle 24 is adjusted.
[0124]
On the opposite surface side of the ink discharge hole 24b of the nozzle 24, a counter electrode 27 is disposed at a position separated by a predetermined distance. The counter electrode 27 causes the surface of the recording medium 28 conveyed between the nozzle 24 and the counter electrode 27 to have a reverse polarity potential to the charging potential of the droplet 23 discharged from the ink discharge hole 24 b of the nozzle 24. It is to be charged. Thereby, the droplets 23 ejected from the ink ejection holes 24b of the nozzles 24 are stably landed on the surface of the recording medium 28 (resistive portion).
[0125]
As described above, since the droplet 23 needs to be charged, it is desirable that at least the ink discharge surface of the tip 24a of the nozzle 24 is formed of an insulating member, and a fine nozzle diameter (ink discharge hole 24b). In this embodiment, a glass capillary tube is used as the nozzle 24.
[0126]
In addition to the nozzle 24, the ink chamber 21 is connected to an ink supply path for supplying ink 22 from an ink tank (not shown). Here, since the ink 22 is filled in the ink chamber 21 and the nozzle 24, negative pressure is applied to the ink 22.
[0127]
Here, the behavior of the meniscus (meniscus region) 34 formed in the vicinity of the ink discharge hole 24b when the ink 22 is discharged as the droplet 23 from the nozzle 24 will be described below. FIGS. 9A to 9C are model diagrams showing the behavior of the meniscus 34 in the vicinity of the ink discharge hole 24b.
[0128]
First, in the state before the ink 22 is discharged, as shown in FIG. 9A, since negative pressure is applied to the ink, the meniscus 34 has a concave shape inside the tip 24 a of the nozzle 24. 34a is formed.
[0129]
Next, in order to discharge the ink 22, the voltage applied to the electrostatic field applying electrode 29 is controlled by the process control unit 30, and when a predetermined voltage is applied to the electrostatic field applying electrode 29, the nozzle 24. Electric charges are induced on the surface of the ink 22, and as shown in FIG. 9B, the ink 22 forms a meniscus 34 on the surface of the ink discharge hole 24 b of the tip 24 a of the nozzle 24, that is, on the counter electrode side (not shown). ) Is formed. At this time, since the diameter of the nozzle 24 is very small, the meniscus 34b is pulled outward while forming the shape of a tailor cone from the beginning.
[0130]
Subsequently, as shown in FIG. 9C, the meniscus 34b pulled outward becomes a meniscus 34c having a shape further discharged to the counter electrode side (not shown) as the meniscus 34, and the surface of the induced meniscus 34c. When the electric charge and the force of the electric field (electric field strength) formed on the nozzle 24 are superior to the surface tension of the ink 22, a discharge droplet is formed.
[0131]
Here, the inner diameter (hereinafter referred to as the nozzle diameter) of the ink discharge hole 24b of the nozzle 24 used in the present embodiment is set to φ5 μm. Thus, when the nozzle diameter of the nozzle 24 is very small, the radius of curvature of the meniscus tip can be regarded as almost constant without gradually changing due to the concentration of surface charge as in the prior art.
[0132]
Therefore, if the physical property value of the ink is constant, the surface tension at the time of droplet separation is almost constant in the discharge state by applying a voltage, and the amount of surface charge that can be concentrated exceeds the surface tension of the ink, that is, The maximum amount is uniquely defined because it is below the Rayleigh split value.
[0133]
In addition, since the nozzle diameter is very small, the electric field strength is very strong only in the vicinity of the meniscus, and the discharge breakdown strength at a high electric field in the minimum region is very high, so there is no problem. .
[0134]
As the ink used in the ink jet apparatus according to this embodiment, a dye-based ink containing pure water and an ink containing fine particles can be used. Here, as the ink containing the fine particles, since the nozzle portion is much smaller than the conventional one, it is necessary to reduce the particle diameter of the fine particles contained. Generally, if it is about 1/20 to 1/100 of the nozzle Clogging is less likely to occur.
[0135]
For this reason, if the nozzle diameter of the nozzle 24 used in the present embodiment is φ5 μm as described above, the fine particle diameter of the ink corresponding to the nozzle diameter is 50 nm or less. At this time, as in the principle of ejecting ink containing fine particles as disclosed in Japanese Patent Application Laid-Open No. 2000-127410, the meniscus charge is concentrated by the movement of the fine particles by charging, and discharged by the electrostatic repulsion between the concentrated fine particles. In this method, the moving speed of the charged fine particles in the ink is lowered because it is smaller than the conventionally used minimum fine particle diameter φ100 nm, and the discharge response speed and the recording speed are slowed down.
[0136]
On the other hand, in the present invention, the electrostatic repulsion between the charged fine particles is not used, but the discharge is performed by the charge on the meniscus surface as in the case of the ink not containing the fine particles. In this case, in order to eliminate ejection instability caused by the influence of the charge of the fine particles in the ink on the charge on the meniscus surface, the charge amount of the fine particles in the ink is much smaller than the charge on the meniscus surface. Shape is desirable.
[0137]
This is because if the charge amount per unit mass of the fine particles in the ink is 10 μC / g or less, the electrostatic repulsion force and response speed between the fine particles are reduced, and the mass of the ink fine particles is reduced. By reducing the diameter of the fine particles, the total charge amount of the fine particles in the ink can be reduced.
[0138]
Table 1 below shows ejection stability when the average fine particle diameter in the ink is from 3 nm to 50 nm.
[0139]
[Table 1]

[0140]
The symbols in Table 1 indicate the discharge stability of each nozzle. X: No discharge due to clogging or the like, Δ: Unstable discharge by continuous discharge, ○: Stable discharge.
[0141]
From Table 1, it was found that the particle diameter is preferably 30 nm or less. In particular, when the particle diameter is 10 nm or less, the charge amount of one fine particle in the ink can be almost ignored as the charge in discharging the ink, the moving speed due to the charge is very slow, and the fine particles do not concentrate at the meniscus center. In addition, when the nozzle diameter is 3 μm or less, the maximum electric field strength becomes extremely high due to the electric field concentration of the meniscus, and the electrostatic force for each fine particle also increases. Therefore, it is preferable to use ink containing fine particles of 10 nm or less. However, when the particle diameter becomes φ1 nm or less, the aggregation of the particles and the occurrence of non-uniformity of the concentration increase, so the particle diameter is preferably in the range of φ1 nm to φ10 nm. However, when the nozzle diameter was φ1 μm or more, even in the case of an average particle diameter of φ50 nm, the discharge state was usable.
[0142]
In this embodiment for explaining the submicron head, a paste containing fine silver particles having an average particle diameter of φ3 to φ7 nm is used, and the fine particles are coated with an anti-aggregation coating. .
[0143]
Here, the relationship between the nozzle diameter of the nozzle 24 and the electric field strength will be described below with reference to FIGS. 10 (a) (b) to 15 (a) (b). Corresponding to FIGS. 10 (a) (b) to 15 (a) (b), the nozzle diameter is φ0.2, 0.4, 1, 8, 20 μm and the nozzle diameter conventionally used as a reference. The electric field strength distribution in the case of φ50 μm is shown.
[0144]
Here, in each figure, the nozzle center position indicates the center position of the ink discharge surface of the ink discharge hole 24 b of the nozzle 24. Also, (a) in each figure shows the electric field intensity distribution when the distance between the nozzle and the counter electrode is set to 2000 μm, and (b) shows when the distance between the nozzle and the counter electrode is set to 100 μm. Shows the electric field intensity distribution. The applied voltage was fixed at 200 V for each condition. The distribution line in the figure has an electric field strength of 1 × 10. ⁶ V / m to 1 × 10 ⁷ The range up to V / m is shown.
[0145]
Table 2 below shows the maximum electric field strength under each condition.
[0146]
[Table 2]

[0147]
10 (a) (b) to 15 (a) (b), it was found that the electric field intensity distribution spreads over a wide area when the nozzle diameter is 20 μm or more (FIGS. 14 (a) (b)). . Table 2 also shows that the distance between the nozzle and the counter electrode affects the electric field strength.
[0148]
For these reasons, when the nozzle diameter is equal to or smaller than φ8 μm (FIGS. 13A and 13B), the electric field strength is concentrated and the variation in the distance of the counter electrode hardly affects the electric field strength distribution. Therefore, when the nozzle diameter is φ8 μm or less, stable ejection is possible without being affected by the positional accuracy of the counter electrode and the variations in the material characteristics and the thickness of the recording medium.
[0149]
Next, FIG. 16 shows the relationship between the nozzle diameter of the nozzle 24, the maximum electric field strength of the meniscus 34, and the strong electric field region.
[0150]
From the graph shown in FIG. 16, it was found that when the nozzle diameter is 4 μm or less, the electric field concentration becomes extremely large and the maximum electric field strength can be increased. As a result, the initial ejection speed of the ink can be increased, so that the flight stability of the ink (droplet) is increased and the charge moving speed at the meniscus is increased, thereby improving the ejection response.
[0151]
Next, the maximum charge amount that can be charged in the droplet 23 of the discharged ink 22 will be described below. The amount of charge that can be charged in the droplet 23 is expressed by the following equation (1) in consideration of Rayleigh splitting of the droplet 23.
[0152]
q = 8 × π × (ε0 × γ × r ^Three ) ² ... (2)
Here, q is the amount of charge that gives the Rayleigh limit, ε 0 is the dielectric constant of the vacuum, γ is the surface tension of the ink, and r is the radius of the ink droplet.
[0153]
As the charge amount q obtained by the above equation (1) is closer to the Rayleigh limit value, the electrostatic force is stronger even at the same electric field strength, and the discharge stability is improved. Dispersion of the ink 22 occurs in the ink discharge holes 24b, resulting in lack of discharge stability.
[0154]
Here, the relationship between the nozzle diameter of the nozzle and the discharge start voltage at which the droplet discharged by the meniscus starts to fly, the voltage value at the Rayleigh limit of the initial discharge droplet, and the ratio between the discharge start voltage and the Rayleigh limit voltage value is shown. The graph shown is shown in FIG.
[0155]
From the graph shown in FIG. 17, when the nozzle diameter is in the range of φ0.2 μm to φ4 μm, the ratio of the discharge start voltage to the Rayleigh limit voltage value exceeds 0.6, and the charging efficiency of the droplets is good. It was found that stable discharge can be performed in the range.
[0156]
For example, the nozzle diameter and the meniscus strong electric field (1 × 10 5 shown in FIG. ⁶ The graph expressed by the relationship of the region of V / m or more shows that the region of electric field concentration becomes extremely narrow when the nozzle diameter becomes φ0.2 or less. This indicates that the ejected droplets cannot receive sufficient energy for acceleration and the flight stability is deteriorated. Therefore, the nozzle diameter needs to be set larger than φ0.2 μm.
[0157]
Next, the initial discharge liquid of the meniscus derived from the maximum electric field strength when the optimum voltage value is fluctuated by the applied voltage when actually driving the ink jet apparatus having the above configuration, that is, a voltage equal to or higher than the discharge start voltage of the liquid droplet The graph of FIG. 19 shows the relationship between the charge amount of the droplet when the droplet is constant and the Rayleigh limit value derived from the surface tension of the droplet.
[0158]
In the graph shown in FIG. 19, point A is the intersection of the charge amount of the droplet and the Rayleigh limit value derived from the surface tension of the droplet. If the voltage applied to the ink is higher than point A, the initial point A maximum charge amount that is almost close to the Rayleigh limit is formed on the ejected liquid droplets. If the voltage is lower than the point A, it indicates that the charge amount that is below the Rayleigh limit and that is necessary for ejection is formed.
[0159]
Here, paying attention only to the equation of motion of the ejected droplets, flight is performed under the optimum conditions as the ejection energy of the strong electric field and the maximum charge amount. Therefore, the applied voltage is preferably higher than the point A.
[0160]
FIG. 20 is a graph showing the relationship between the initial discharge droplet diameter of ink (here, pure water) and the drying time (the time during which all of the solvent of the droplets evaporates) when the environmental humidity is 50%. Indicates. From this graph, it can be seen that when the initial droplet diameter is small, the change in the ink droplet diameter due to evaporation is very fast, and drying proceeds even in a short time during flight.
[0161]
For this reason, if the maximum charge amount is formed in the droplet at the time of initial ejection, the droplet diameter decreases due to drying, that is, the surface area of the droplet in which the charge is formed decreases, thereby causing Rayleigh splitting during the flight of the ink. When the excess charge is generated and released, the charge is released with a part of the droplet, so that the number of flying droplets more than evaporation occurs.
[0162]
Accordingly, the variation in droplet diameter at the time of landing and the landing accuracy are deteriorated, and the divided mist floats in the nozzle and the recording medium, thereby contaminating the recording medium. For this reason, in consideration of the formation of stable ejection dots, the amount of charge induced in the initial ejection droplets must be made somewhat smaller than the amount of charge corresponding to the Rayleigh limit. In this case, if the charge amount is about 95% of the charge amount corresponding to the Rayleigh limit value, the accuracy of variation in the landing dot diameter cannot be improved, and as a result, it is preferable to set it to 90% or less.
[0163]
As a specific numerical value, the Rayleigh limit of the initial discharge droplet diameter based on the maximum electric field strength of the meniscus when the nozzle hole diameter is regarded as the tip shape of the needle electrode is calculated, and the landing is achieved by setting it within the calculated value. It was possible to suppress variations in droplets at the time. This is because the surface area immediately before separation of the ejected droplets is smaller than that of the droplets immediately after ejection, and the amount of charge induced in the actual initial ejected droplets due to the time lag of the charge transfer time is obtained by the above calculation. This is considered to be because it is smaller than the charge amount.
[0164]
Under such conditions, Rayleigh splitting at the time of flight can be prevented, and stable discharge such as mist formation due to a large amount of charge when separating discharged droplets at the meniscus can be reduced.
[0165]
The charged droplets are less likely to evaporate due to a decrease in vapor pressure. This can be seen from the following equation (2).
[0166]
RTρ / M × log (P / P0) = 2γ / r? q ² / (8πr ^Four (3)
Where R is the gas constant, M is the molecular weight, T is the temperature, ρ is the volume density of the liquid, P is the vapor pressure in the droplet, P0 is the vapor pressure when the liquid level is flat, and γ is the surface tension of the ink. R is the radius of the ink droplet.
[0167]
As shown in the above equation (2), the charged droplet has a vapor pressure that is reduced by the charge amount of the droplet, and if the charge amount is too small, the effect on the evaporation is less affected. 60% or more of the electric field strength and voltage value corresponding to the preferred results. As a result, as described above, the Rayleigh limit of the initial discharge droplet diameter by the maximum electric field strength of the meniscus when the nozzle hole diameter is regarded as the tip shape of the needle electrode is calculated, and 0.8 times or more of the calculated value is calculated. It is the same as showing the range.
[0168]
In particular, as shown in FIG. 20, when the diameter of the initial ejection droplet is φ5 μm or less, the drying time becomes extremely short and is easily affected by evaporation. It turns out that it is more effective from the viewpoint. Note that the ambient humidity when determining the relationship between the drying time and the initial droplet diameter shown in FIG. 20 was 50%.
[0169]
In consideration of drying of the ejected droplets, it is necessary to shorten the liquid ejection time to the recording medium.
[0170]
Here, the average flight speed until the ejected droplets are separated from the meniscus and land on the recording medium from the nozzle is 5 m / s, 10 m / s, 20 m / s, 30 m / s, 40 m / s, and 50 m / s. Table 3 below compares the ejection stability and the positional accuracy of the landing dots.
[0171]
[Table 3]

[0172]
In the symbols of ejection stability in Table 3, ×: hardly ejected, Δ: non-ejection in continuous ejection, ○: no ejection, and in the symbol of landing accuracy, x: landing deviation> Landing dot diameter, Δ: Landing shift> Landing dot diameter × 0.5, ○: Landing shift <landing dot diameter × 0.5, ◎: Landing shift <landing dot diameter × 0.2
[0173]
As can be seen from Table 3 above, at an average flight speed of 5 m / s, landing accuracy is poor and ejection stability is also poor. In particular, when the nozzle diameter is φ1 μm or less, if the discharge speed is low, the cause of air resistance applied to the droplets is large, and the dot diameter may not be landed due to further miniaturization of the dot diameter due to evaporation. On the other hand, at an average flying speed of 50 m / s, it is necessary to increase the applied voltage, so the electric field strength at the meniscus becomes very strong, and mist formation of discharged droplets frequently occurs, resulting in stable discharge. I found it difficult.
[0174]
From the above, it has been found that the average flight speed until the ejected droplets are separated from the meniscus and land on the recording medium is preferably between 10 m / s and 40 m / s.
[0175]
Incidentally, FIG. 20 shows the relationship between the initial discharge droplet diameter and the drying time when the ambient humidity is 50%. In FIG. 21, the initial discharge droplet diameter is φ0.5 μm and the nozzle and the recording target. The relationship between ambient humidity and drying time when the distance of the medium is 0.2 mm is shown.
[0176]
From the graph shown in FIG. 21, it was found that the numerical value of the drying rate did not vary greatly when the ambient humidity was 60% or less. However, if the ambient humidity exceeds 70%, it is possible to extremely suppress the evaporation of the ink. When the ambient humidity is set to 70% or more, the influence of the above conditions is low, and particularly the ambient humidity is 95%. It has been found that if the ratio is set to more than%, the influence of drying can be almost ignored, and the degree of freedom in the design conditions of the ink jet recording apparatus of the present invention can be widened and the application range can be expanded.
[0177]
Here, Table 4 shows the ejection stability and the ejection dot diameter variation (landing variation) when the nozzle diameter is φ1 and φ3 μm and the initial ejection droplet diameter is changed. The initial discharge diameter by the nozzle can be controlled by changing the applied voltage value, and can also be controlled by adjusting the pulse width of the applied voltage pulse. Here, the electric field with the same nozzle diameter is controlled. In order to eliminate the influence of intensity, the initial ejection diameter is adjusted by varying the pulse width.
[0178]
[Table 4]

[0179]
In the symbols of ejection stability in Table 4, ×: hardly ejected, Δ: no ejection after 10 minutes of continuous ejection, ○: no ejection after 10 minutes of continuous ejection, ◎: 30 minutes of continuous ejection No discharge is indicated, and in the symbol of variation, △: variation in impact dot> impact dot diameter × 0.2, ○: variation in impact dot ≦ impact dot diameter × 0.2, ◎: variation in impact dot ≦ landing dot diameter × 0.1.
[0180]
From Table 4, it was found that the ejection stability is good at about 1.5 to 3 times the nozzle diameter, and that the variation in the landing dot diameter is extremely suppressed particularly at 1.5 to 2 times. This is because, when the ink shape drawn from the meniscus is regarded as a liquid column, droplet separation is most stable under the condition that the surface area of the liquid column is larger than the surface area of the sphere corresponding to the volume of the liquid column. It is done.
[0181]
According to the above configuration, in the electrostatic suction type inkjet recording apparatus that discharges a minute ink droplet having a droplet amount of 1 pl or less immediately after the ink is discharged, the diameter of the ink discharge hole 24b of the nozzle 24 is set to the ink discharge. Since the electric field for ejection can be concentrated on the meniscus 34 of the nozzle 24 by setting it to be equal to or less than the diameter of the droplet just after (more preferably smaller than the droplet diameter), it is necessary for ejecting ink. The applied voltage can be greatly reduced, and the dispersion of the diameters of the droplets that are individually separated and discharged can be reduced and stable discharge can be realized.
[0182]
In addition, it is no longer necessary to apply the bias voltage, which was required in the past, and the drive voltage can be applied alternately between positive and negative, and the effect on the landing accuracy due to the increase in the surface potential of the recording medium could be reduced. .
[0183]
In addition, by setting the nozzle hole diameter to be in the range of φ8 μm or less, the electric field can be concentrated on the meniscus of the nozzle, and the influence of the positional accuracy of the counter electrode and the variations in the material properties and thickness of the recording medium are affected. Stable discharge was possible without receiving it.
[0184]
In particular, when the diameter of the ink discharge hole 24b of the nozzle 24 is in the range of φ0.4 μm to φ4 μm, the electric field concentration becomes extremely large. As described above, increasing the maximum electric field strength increases the initial ejection speed of the ink, so that the flight stability increases and the charge transfer speed at the meniscus increases, thereby improving the ejection response. , Variation in the dot diameter due to Rayleigh splitting can be suppressed.
[0185]
Furthermore, by setting the droplet diameter immediately after the ink is discharged from the nozzle 24 to be in the range of 1.5 to 3 times the diameter of the ink discharge hole 24b of the nozzle 24, the discharge stability can be improved. By setting the droplet diameter immediately after ink ejection to a range of 1.5 to 2 times the nozzle diameter, variations in ejection dot diameter can be extremely suppressed.
[0186]
In the present embodiment, as described above, the example in which the negative pressure is applied to the ink in the ink chamber 21 has been described. However, the case where a positive pressure is applied to the ink may be used. In order to apply positive pressure to the ink in the ink chamber 21, for example, as shown in FIG. 22, a pump 32 is provided on the ink tank side (not shown) of the ink supply path, and the pump 32 is used to It is conceivable to apply a positive pressure to the ink. In this case, the pump 32 may be driven and controlled using the process control unit 33 so as to be driven in accordance with the timing of ink discharge from the ink chamber 21. In this way, if a positive pressure is applied to the ink in the ink chamber 21, it is possible to save the trouble of forming the convex shape of the meniscus with the electrostatic force, and to reduce the applied voltage and improve the response speed.
[0187]
In the present embodiment, an inkjet apparatus provided with a single nozzle has been described for the sake of simplicity. However, the present invention is not limited to this, and the design takes into account the influence of electric field strength at adjacent nozzles. In this case, the present invention can also be applied to an ink jet apparatus including a multi-head having a plurality of nozzles.
[0188]
Further, in the present embodiment, as shown in FIGS. 8 and 22, the ink jet apparatus in which the counter electrode 27 is always provided has been described. However, as can be seen from Table 2, the ink discharge hole 24b of the counter electrode 27 and the nozzle 24 is used. The distance between the recording medium and the nozzle has little effect on the electric field strength between the recording medium and the nozzle, the distance between the recording medium and the nozzle is close, and the surface potential of the recording medium is stable. A counter electrode is not necessary.
[0189]
As shown in FIG. 23, the inventors of the present application, in the conventional method, have a tip portion curvature 44 of the nozzle portion 41 formed in the process of electrostatic attraction in a tail cone-shaped fluid meniscus 42 just before the droplet discharge and substantially the same as the tip portion curvature 44. By using the nozzle 43 in which the fluid discharge hole side is narrowed down so that the nozzle diameter is the same size, the formation of the electric field required over a wide range can be narrowed, and the amount of electric charge movement at the meniscus can be reduced. I found it.
[0190]
The inventors of the present application, using the above principle, further set the diameter of the fluid discharge hole at the tip of the nozzle to be equal to or less than the droplet diameter of the fluid immediately after discharge, thereby reducing the charge concentration region and the meniscus. It was found that the area can be made almost the same.
[0191]
Next, characteristics of the submicron head in the production process will be described.
[0192]
First, a force is applied to the charged droplet 23 by the electric field generated between the electrostatic field applying electrode 29 and the counter electrode 27. For this reason, since the droplet 23 is a minute droplet, even if the influence of air resistance during flight increases, the droplet 23 is not greatly decelerated, and the landing accuracy (landing position system on the recording medium 28) is improved. improves.
[0193]
Second, even high-viscosity ink can be ejected as droplets 23. Actually, 70 cP of ink is discharged. Since high viscosity ink can be ejected, the ink concentration can be increased.
[0194]
In general, the ink viscosity is inversely proportional to the growth rate of the meniscus 34, and if the viscosity is high, the meniscus 34 cannot sufficiently grow and droplets cannot be ejected. However, in this ink jet apparatus, the growth rate of the meniscus 34 does not depend on the viscosity of the ink but depends on the surface tension and the charge amount. Therefore, even if the solute material is dissolved up to the maximum solubility in the ink solvent, the ink can be ejected.
[0195]
Third, the solvent content of the ink dries instantaneously after the droplet 23 has landed. The volume of the solvent component of the droplet 23 is proportional to the cube of the droplet diameter. Therefore, the energy required to evaporate the solvent component is also proportional to the cube of the droplet diameter. Further, it is considered that the smaller the value of (volume) / (surface area), the easier the droplet 23 evaporates. For this reason, the smaller the droplet, the more advantageous is the earlier evaporation.
[0196]
In the conventional inkjet device, the size of the ejected droplet is large, and it takes time for the solvent to evaporate. Also, if the droplets are made very small, a sufficient flying speed cannot be obtained, and if the kinetic energy is changed to thermal energy, the heat of vaporization of the solvent of the droplets will not be reached, and it will be dried immediately after landing. The phenomenon was not obtained. However, with a submicron head, a sufficient flying speed can be obtained while the droplet volume is reduced, so that a phenomenon of drying immediately after landing can be obtained.
[0197]
In order to confirm the above points, the following tests were conducted. The result will be described. Tables 1 to 3 show the cases where the conventional inkjet type piezo type, thermal type, and electrostatic attraction type inkjet device having a large droplet diameter are used, and the inkjet device used in the practice of the present invention, that is, discharge. This is a comparison of characteristics with a case where an electrostatic suction type ink jet apparatus having a small droplet diameter is used.
[0198]
[Table 5]

[0199]
The results in Table 5 show the influence of the droplet volume on the landing accuracy, the ease of ejection, the drying speed, and the number of landings of the droplet 23. The number of landings is the number of ejections required to form a desired area and thickness, and it is evaluated that a smaller number is better from the viewpoint of production efficiency.
[0200]
When this ink jet device was used, even when the droplet volume was 0.1 pl and 1 pl, the landing accuracy and the ease of ejection were usable or good. It was impossible even in the item. In addition, this inkjet apparatus is good when the droplet volume is 0.1 pl and 1 pl at the drying speed. In terms of the number of landings, it is unsuitable for 0.1 pl (low production efficiency) and suitable for 1 pl (good production efficiency).
[0201]
[Table 6]

[0202]
The results in Table 6 show the suitability of the ink jet apparatus and the conventional ink jet apparatus for each viscosity of the ink. With this ink jet apparatus, it was possible to discharge high viscosity ink.
[0203]
[Table 7]

[0204]
The results in Table 7 show the evaluation results of the appropriateness for each density, that is, the ease of ejection, and the drying speed and the number of landings for each density of the inkjet apparatus for the inkjet apparatus and the conventional inkjet apparatus.
[0205]
From the results shown in Table 3, in terms of the ease of ink ejection, the conventional ink jet device was unable to eject medium and high density inks, whereas in this ink jet device, low to high density inks were not possible. Was good about. Further, in the present ink jet apparatus, the drying speed is possible when the ink is at a medium concentration, and is good when the ink is at a high concentration. From the viewpoint of production efficiency, it can be said that the higher the concentration, the less the number of landings, and the more suitable.
[0206]
As can be seen from the above results, when this ink jet apparatus is used, the drying time is greatly shortened. Therefore, it is necessary to provide a waiting time until the previously ejected droplets finish drying on the substrate. In addition, the discharge interval time for the same location can be shortened, and the production efficiency can be improved.
[0207]
In addition, since high-density ink can be ejected, the ratio of the solute material contained in one droplet can be increased, so that the number of ejections can be reduced.
[0208]
In addition, although the viscosity increases as the ink concentration increases, the ink jet apparatus can discharge high-viscosity liquid droplets, so that high-density ink can be discharged. In this case, when the density is increased, the number of ejections can be reduced as described above.
[0209]
Here, the trimming apparatus 60 using the submicron head described above will be described.
[0210]
As shown in FIG. 24, the trimming device 60 has a configuration except that the submicron head 15 is mounted instead of the inkjet head 51 as compared with the trimming device 50 described in the first embodiment. It is the same configuration. The resistance value adjusting process may be the same as in the first embodiment.
[0211]
In the present embodiment, by using the submicron head 15, a portion (short-circuit portion 3) that ejects a droplet made of a liquid containing a conductive material moves after the droplet has landed on the substrate until the solvent is dried. You can avoid that. For this reason, it is possible to adjust the resistance value with higher accuracy. Further, in the submicron head 15, since the ink droplets are instantly dried after landing on the substrate, the short-circuit portion 3 made of a conductive material can be continuously formed. In addition, since high-density ink can be ejected, the short-circuit portion 3 can be formed with a small number of droplets. For this reason, deterioration of productivity due to miniaturization of ink droplets is avoided.
[0212]
The thick film resistor adjusting device according to the present invention injects a conductive material to a desired portion of the thick film resistor on the circuit board in which the thick film resistor is formed between the terminals forming the circuit. In the thick film resistor adjusting device provided with the inkjet nozzle to be squeezed, the thick film resistor is formed in a shape that can be short-circuited at one or more locations, and is short-circuited at one or more locations among the locations. The shape is determined so that the resistance value between the terminals becomes a resistance value to be selected in circuit design, and by applying a conductive material, a part of the thick film resistor is short-circuited, A configuration in which a desired resistance value between the terminals may be employed.
[0213]
【The invention's effect】
The thick film resistor of the present invention, as described above, is a thick film resistor that is short-circuited by a liquid containing a conductive material that is ejected as droplets from the ejection holes of the inkjet nozzle.
The thick film resistor has a proximity portion that can be short-circuited at one or more locations,
The shape of the thick film resistor so that the resistance value between the terminals having the thick film resistor when short-circuited at one or more of the locations becomes the resistance value desired to be selected in circuit design. Is determined.
[0214]
Therefore, the resistance value of the thick film resistor can be set in a wide range and the resistance value can be finely adjusted as compared with the conventional case.
[0215]
In the thick film resistor according to the present invention, it is more preferable that the proximity portion has an interval smaller than a diameter when one droplet ejected from the inkjet nozzle is landed.
[0216]
The thick film resistor of the present invention preferably has a configuration in which the resistance portions are arranged in parallel to each other to form a proximity portion. Therefore, since it has a wide proximity portion, it is possible to set the resistance value in a wider range than in the past.
[0217]
The thick film resistor of the present invention preferably has a configuration in which the substantially U-shaped resistor portions are arranged so as to mesh with each other to form a proximity portion. Therefore, since the proximity portion is formed widely, the resistance value can be set in a wider range as compared with the conventional case.
[0218]
The thick film resistor of the present invention is more preferably configured to have a proximity portion that has a pulse shape. Therefore, the resistance value can be set in a wider range as compared with the conventional case.
[0219]
The thick film resistor of the present invention preferably has a configuration in which adjacent portions are formed in resistance portions having different resistance values. Therefore, the resistance value can be set in a wider range.
[0220]
As described above, the thick film resistor adjusting device of the present invention is configured to include the ink jet device that ejects the liquid containing the conductive material as droplets from the ejection holes of the ink jet nozzle.
[0221]
Therefore, there is an effect that a thick film resistor set to a desired resistance value can be suitably manufactured.
[0222]
In the thick film resistor adjusting device of the present invention, the ink jet device is an electrostatic suction type ink jet device, and the electrostatic suction type ink jet device has a discharge hole diameter smaller than the droplet diameter. In addition, it is more preferable that a droplet with a droplet amount of 1 pl or less be ejected from the nozzle of the inkjet apparatus. As a result, a small amount of liquid droplets can be discharged to the adjacent portion of the thick film resistor, and therefore, it can be suitably used even when a small thick film resistor is manufactured.
[0223]
The thick film resistor adjusting device of the present invention is more preferably configured such that the average particle diameter of the conductive material contained in the liquid is φ50 nm or less. Therefore, the fine adjustment of the resistance value of the thick film resistor can be easily performed.
[0224]
The thick film resistor adjusting device of the present invention preferably has a configuration in which the viscosity of the liquid containing the conductive material is 20 cP or more. Thereby, a small thick film resistor can be manufactured suitably.
[0225]
In the thick film resistor adjusting device of the present invention, it is more preferable that the ink jet device is the same as the device used for forming the wiring portion connected to the resistor portion of the thick film resistor. Therefore, the labor for adjusting the position of the ink head and the like can be omitted, and the working efficiency can be improved.
[0226]
In the resistance value adjusting method according to the present invention, as described above, the thick film resistor has a proximity portion that can be short-circuited at one or more locations, and is short-circuited at one or more locations. In this case, the shape of the thick film resistor is determined so that the resistance value between the terminals having the thick film resistor becomes a resistance value desired to be selected in circuit design.
[0227]
In the resistance value adjusting method of the present invention, the thick film resistor has at least one or more adjacent portions where a plurality of the resistance portions exist at intervals smaller than the diameter of one droplet ejected from the inkjet nozzle. It is more preferable to short-circuit the proximity portion by spraying the liquid onto at least one location of the proximity portion.
[0228]
Therefore, compared to the conventional case, the resistance value can be set in a wide range and the resistance value can be finely adjusted.
[Brief description of the drawings]
FIG. 1 is a plan view showing a configuration of a wiring portion of a thick film resistor according to an embodiment of the present invention.
FIG. 2 is a front view showing a configuration of a manufacturing apparatus for manufacturing the thick film resistor.
FIG. 3 is a graph illustrating a change in resistance value in a resistance portion of the thick film resistor in the first embodiment.
4 is a plan view showing a configuration of a resistance portion of a thick film resistor according to Embodiment 2. FIG.
5 is a plan view showing a configuration of a resistance portion of a thick film resistor according to Embodiment 3. FIG.
6 is a plan view showing a configuration of a resistance portion of a thick film resistor according to a fourth embodiment. FIG.
7 is a plan view showing a configuration of a resistance portion of a thick film resistor in a fifth embodiment. FIG.
FIG. 8 is a cross-sectional view illustrating a configuration of a main part of a submicron inkjet device according to another embodiment.
FIGS. 9A to 9C are cross-sectional views illustrating the behavior of the ink meniscus in the submicron inkjet device. FIG.
FIG. 10A is a graph showing the relationship between the distance from the center of the nozzle and the distance from the counter electrode when the distance between the nozzle and the counter electrode is 100 μm, and FIG. It is a graph which shows the relationship between the distance from a nozzle center, and the distance from a counter electrode when the distance of a nozzle and a counter electrode is 2000 micrometers.
FIG. 11A is a graph showing the relationship between the distance from the center of the nozzle and the distance from the counter electrode when the distance between the nozzle and the counter electrode is 100 μm, and FIG. It is a graph which shows the relationship between the distance from a nozzle center, and the distance from a counter electrode when the distance of a nozzle and a counter electrode is 2000 micrometers.
FIG. 12 (a) is a graph showing the relationship between the distance from the nozzle center and the distance from the counter electrode when the distance between the nozzle and the counter electrode is 100 μm, and FIG. It is a graph which shows the relationship between the distance from a nozzle center, and the distance from a counter electrode when the distance of a nozzle and a counter electrode is 2000 micrometers.
FIG. 13 (a) is a graph showing the relationship between the distance from the nozzle center and the distance from the counter electrode when the distance between the nozzle and the counter electrode is 100 μm, and FIG. It is a graph which shows the relationship between the distance from a nozzle center, and the distance from a counter electrode when the distance of a nozzle and a counter electrode is 2000 micrometers.
FIG. 14A is a graph showing the relationship between the distance from the center of the nozzle and the distance from the counter electrode when the distance between the nozzle and the counter electrode is 100 μm, and FIG. It is a graph which shows the relationship between the distance from a nozzle center, and the distance from a counter electrode when the distance of a nozzle and a counter electrode is 2000 micrometers.
FIG. 15A is a graph showing the relationship between the distance from the center of the nozzle and the distance from the counter electrode when the distance between the nozzle and the counter electrode is 2000 μm, and FIG. It is a graph which shows the relationship between the distance from a nozzle center, and the distance from a counter electrode when the distance of a nozzle and a counter electrode is 100 micrometers.
FIG. 16 is a graph showing the relationship between the nozzle diameter and the maximum electric field strength.
FIG. 17 is a graph showing the relationship between the nozzle diameter and various voltages.
FIG. 18 is a graph showing a relationship between a nozzle diameter and a strong electric field region.
FIG. 19 is a graph showing the relationship between applied voltage and charged charge amount.
FIG. 20 is a graph showing the relationship between the initial discharge droplet diameter and the drying time.
FIG. 21 is a graph showing the relationship between ambient humidity and drying time.
FIG. 22 is a cross-sectional view showing a schematic configuration of a submicron inkjet device according to another embodiment of the present invention.
FIG. 23 is a cross-sectional view illustrating the principle of a submicron inkjet device according to another embodiment of the present invention.
FIG. 24 is a front view showing a schematic configuration of a thick film resistor adjusting device using a submicron head according to another embodiment of the present invention.
[Explanation of symbols]
1, 11, 12, 13, 14 Resistor (resistor)
2a, 2b terminals
3 Short circuit
4 chips
5 Laser cut part
6 Wiring part (resistance part)
15 Submicron head
21 Ink chamber
22 Ink
23 droplets
24 nozzles
24a Tip
24b Inner diameter
25 Packing
27 Counter electrode
28 Recording media
29 Electrostatic field application electrode
30 Process control unit
32 valves
33 Pressure regulator
50, 60 Trimming device (thick film resistor adjusting device)
51 Inkjet head
52 Circuit board
53 XY stage
54 CCD
55 Inkjet control device
56 monitors
57 laser

Claims (14)

A thick-film resistor that is short-circuited by a liquid containing a conductive material that is ejected as droplets from an ejection hole of an inkjet nozzle, wherein the thick-film resistor has a proximity portion that can be short-circuited at one or more locations. And the thick film resistor so that the resistance value between the terminals having the thick film resistor when short-circuited at one or more of the points becomes a resistance value desired to be selected in circuit design. A thick film resistor adjusting device for manufacturing a thick film resistor whose shape is determined,
The proximity portion is an interval smaller than the diameter at the time of landing of one droplet ejected from the inkjet nozzle,
An electrostatic suction type ink jet device is provided as an ink jet device for discharging a liquid containing a conductive material as droplets from a discharge hole of an ink jet nozzle.
In the electrostatic suction ink jet apparatus, the diameter of the discharge hole is in the range of 0.2 μm to 4 μm and smaller than the diameter of the droplet, and the amount of one drop from the nozzle of the ink jet apparatus is small. A thick film resistor adjusting device, wherein droplets of 1 pl or less are discharged.   2. The thick film according to claim 1, wherein an initial discharge droplet diameter of the droplet discharged from the discharge hole is 1.5 to 3 times larger than a diameter of the discharge hole. Resistor adjustment device.   The average flight speed of the droplets discharged from the discharge holes until they land on the recording medium from the ink jet nozzles is between 10 m / s and 40 m / s. The thick film resistor adjusting device as described.   The thick film resistor adjusting device according to any one of claims 1 to 3, wherein an average particle diameter of the conductive material contained in the liquid is 50 nm or less.   The thick film resistor adjusting device according to any one of claims 1 to 4, wherein a viscosity of the liquid containing the conductive material is 20 cP or more.   The thickness according to any one of claims 1 to 5, wherein the ink jet device is the same as a device used for forming a wiring portion connected to a resistance portion of a thick film resistor. Membrane resistor adjustment device. A thick film manufactured by being short-circuited by a liquid containing a conductive material, which is ejected as droplets from the ejection holes of the inkjet nozzle of the thick film resistor adjusting device according to any one of claims 1 to 6. A resistor,
The thick film resistor has a proximity portion that can be short-circuited at one or more locations, and has a proximity portion that is smaller than the diameter at the time of landing of one droplet ejected from the inkjet nozzle ,
The shape of the thick film resistor so that the resistance value between the terminals having the thick film resistor when short-circuited at one or more of the locations becomes the resistance value desired to be selected in circuit design. A thick film resistor characterized in that is determined.   The thick film resistor according to claim 7, wherein the adjacent portion has an interval smaller than a diameter when one droplet ejected from the inkjet nozzle is landed. The resistance portion of the thick film resistor has at least a straight portion, and
9. The thick film resistor according to claim 7, wherein the resistance portion forms a proximity portion by arranging the straight portions in parallel with each other.   The thick film resistor according to any one of claims 7 to 9, wherein the substantially U-shaped resistor portions are arranged so as to mesh with each other to form a proximity portion.   The thick film resistor according to any one of claims 7 to 10, wherein the thick film resistor has a proximity portion in a pulse shape.   The thick film resistor according to any one of claims 7 to 11, wherein a proximity portion is formed by resistance portions having different resistance values. A liquid containing a conductive material is ejected as a droplet from the discharge hole of the inkjet nozzle of the thick film resistor adjusting device according to any one of claims 1 to 6 to cause a short circuit. According to the resistance value adjustment method for adjusting the resistance value of the thick film resistor,
The thick film resistor has a proximity portion that can be short-circuited at one or more locations, and has a proximity portion that is smaller than the diameter at the time of landing of one droplet ejected from the inkjet nozzle ,
The shape of the thick film resistor so that the resistance value between the terminals having the thick film resistor when short-circuited at one or more of the locations becomes the resistance value desired to be selected in circuit design. A method for adjusting a resistance value of a thick film resistor, wherein: The thick film resistor has at least one adjacent portion where a plurality of the resistance portions exist at intervals smaller than the diameter of one droplet ejected from the inkjet nozzle,
14. The resistance value adjusting method according to claim 13, wherein the proximity portion is short-circuited by spraying the liquid onto at least one location of the proximity portion.

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