JP4801855B2 - Conductive paste and conductive pattern forming method using the same - Google Patents

Description

酢酸ブチルカルビトール １００なおエチルセルロースとしては、ダウケミカル社製の商品名エトセル（エトキシル基の含有割合：４５〜５３％、重量平均分子量Ｍｗ：４０，０００〜１００，０００）を用いた。またアクリル系樹脂としては、共栄社化学(株)製の商品名オリコックス（重量平均分子量Ｍｗ：５０，０００〜２００，０００）を用いた。銀粉末としては、平均粒径５μｍの鱗片状のものを用いた。さらにガラスフリットとしては平均粒径５μｍのものを用いた。
【００４０】
〔導電性パターンの形成〕
上記の導電性ペーストを、下記の凹版、および転写体としてのシリコーンブランケットを使用した凹版オフセット印刷法によって、被印刷物としてのガラス基板の表面に印刷した。印刷速度は、凹版からシリコーンブランケットへの転写速度を５０ｍｍ／秒、シリコーンブランケットからガラス基板への転写速度を１００ｍｍ／秒に設定した。
【００４１】
（凹版）
ソーダライムガラス製の、平板状の基板の表面に、幅５０μｍ、深さ１０μｍの直線を、２００μｍのピッチで多数、ストライプ状に形成したもの。
（シリコーンブランケット）
最表面に、スプリング式硬さ（ＪＩＳ Ａ硬さ）が４０°の、付加型ＲＴＶシリコーンゴムの層（十点平均粗さ０．３μｍ）を形成したもの。
【００４２】
次に、クリーンオーブンを用いて、１００℃で１時間、加熱乾燥させることで、上記凹版のパターンに対応したストライプ状の印刷パターンを形成した。
そしてこの印刷パターンを形成したガラス基板を、オーブンを用いて、さらに５５０℃で１時間、焼成して樹脂を完全に分解、除去して導電性パターンを形成した。
実施例２〜６、比較例１、２
エチルセルロースおよびアクリル系樹脂を、表１に示した配合量（重量部）で配合したこと以外は実施例１と同様にして導電性ペーストを作製し、導電性パターンを形成した。両樹脂の合計の配合量はいずれも１００重量部とした。
【００４３】
上記各実施例、比較例の、導電性パターンの形成工程のうち凹版オフセット印刷工程において、印刷パターンの、凹版からシリコーンブランケットへの転写性、およびシリコーンブランケットからガラス基板への転写性を、それぞれ目視にて検査して、下記の基準で評価した。なお検査は、凹版オフセット印刷を２０回、連続して繰り返し行い、その全ての回について検査した結果から評価した。
○：全ての回で、導電性パターンの転写が完全に行われた。転写性良好。
【００４４】
△：導電性パターンの一部が転写されない回があった。転写性やや良好。
×：導電性パターンが殆ど転写されない回があった。転写性不良。
以上の結果を表１に示す。
【００４５】
【表１】

【００４６】
表より、結着樹脂としてエチルセルロースのみを使用した比較例１では、シリコーンブランケットからガラス基板への転写性が悪化し、逆に結着樹脂としてアクリル系樹脂のみを使用した比較例２では、凹版からシリコーンブランケットへの転写性が悪化した。
これに対し、結着樹脂としてエチルセルロースとアクリル系樹脂とを重量比で１／９〜９／１の割合で併用した実施例１〜６はいずれも、シリコーンブランケットからガラス基板への転写性が良好ないしやや良好で、かつ凹版からシリコーンブランケットへの転写性が良好であった。
【００４７】
また各実施例を比較すると、エチルセルロースとアクリル系樹脂とを重量比で１５／８５〜９０／１０の割合で併用した実施例１〜５はいずれも、シリコーンブランケットからガラス基板への転写性、および凹版からシリコーンブランケットへの転写性がともに良好であって、より好ましいことが確認された。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel conductive paste particularly suitable for printing a fine pattern by an intaglio offset printing method, and a method for forming a fine conductive pattern using the conductive paste.
[0002]
[Prior art]
With the recent development of electronic devices, the importance of technology for accurately and efficiently forming fine conductive patterns used in electric circuits and the like tends to increase.
Even when the line width is extremely thin and fine, the conductive pattern is required to have a flat surface and a sharp edge, and not to cause defects such as disconnection.
[0003]
As a typical method for forming such a highly accurate conductive pattern, a photolithographic method can be mentioned. However, the photolithographic method requires extremely high precision and cleanliness for the equipment to be used, the manufacturing process is complicated, and a large amount of harmful waste liquid is generated, so that the burden on the environment and waste liquid treatment is also large. There is. For this reason, the manufacturing cost is extremely high.
Therefore, in recent years, attempts have been made to form a conductive pattern using a printing method.
[0004]
The printing method uses a conductive paste containing a conductive powder and a binder resin to form a printed pattern on a substrate, and then baked as necessary to decompose and remove the resin. It is a method of forming, and the manufacturing process is simple and the mass productivity is excellent.
Although there are various printing methods, the intaglio offset printing method is considered to be suitable for forming a fine conductive pattern because a fine pattern can be formed with high dimensional accuracy.
[0005]
In the intaglio offset printing method, first, a printed pattern is formed by filling a conductive paste in a recess corresponding to a pattern formed on the surface of the intaglio. Next, a printing body such as a blanket is brought into pressure contact with the intaglio to transfer the printing pattern onto the transcription body. Then, when the transfer body is brought into pressure contact with the printed material, the printed pattern is transferred again onto the printed material, dried, and then fired as necessary, whereby a conductive pattern can be formed.
[0006]
In particular, when a conductive paste containing glass frit that functions as a binder instead of a resin after firing is used, and the resin is completely decomposed and removed by the firing, the conductive pattern can have any desired resistance. It is easy to reduce the resistance to a value range.
As the transfer body, in order to improve the transferability of the print pattern to the printing material, the surface is formed of a silicone rubber having a low surface energy, and therefore excellent in the releasability of the print pattern at the time of transfer. .
In addition, as the conductive paste from which the conductive pattern is based, a paste using an acrylic resin having a relatively low decomposition temperature as a binder resin is suitably employed.
[0007]
[Problems to be solved by the invention]
However, when a transfer body whose surface is formed of silicone rubber as described above and a conductive paste using an acrylic resin as a binder resin are combined, the affinity of the acrylic resin to silicone rubber in the first place However, the transferability of the print pattern from the transfer body to the printing material is good, but the transferability of the print pattern from the intaglio to the transfer body, which is the previous stage, is remarkably deteriorated. For this reason, the above combination has a problem that it is difficult to form a good conductive pattern.
[0008]
The first object of the present invention is excellent in both the transferability of the printing pattern from the intaglio to the transfer body and the transferability from the transfer body to the printing material. An object is to provide a conductive paste capable of forming a conductive pattern.
A second object of the present invention is to provide a method for forming a conductive pattern for forming a good conductive pattern on a substrate using the conductive paste.
[0009]
[Means for Solving the Problems and Effects of the Invention]
In order to solve the above-mentioned problems, the inventor has examined the binder resin contained in the conductive paste. As a result, it has been found that an acrylic resin having a specific molecular weight and ethyl cellulose having a specific molecular weight and an ethoxyl group content within a predetermined range may be used in combination as the binder resin.
Cellulose resins such as ethyl cellulose have a very good affinity for silicone rubber, and it is known that the printing pattern transfer property from the intaglio to the transfer body is good, contrary to the acrylic resin. Yes. However, the cellulose resin has a problem that the transferability of the printing pattern from the transfer body to the printing material is extremely poor because of its good affinity.
[0010]
However, the inventors have recently studied that, among the cellulose resins, ethyl cellulose having a specific molecular weight and having an ethoxyl group content within a predetermined range is used in combination with an acrylic resin having a specific molecular weight. The good point of both resins can act synergistically to obtain a good conductive paste with excellent transferability from the intaglio to the transfer body and transferability from the transfer body to the substrate. It turns out.
Therefore this inventions is a conductive paste containing a conductive powder and a binder resin and glass frit, as the binder resin,
Ethyl cellulose C having an ethoxyl group content of 40 to 60% and a weight average molecular weight Mw of 10,000 to 500,000,
An acrylic resin A having a weight average molecular weight Mw of 10,000 to 500,000 is used at a weight ratio of C / A = 1/9 to 9/1 , and further includes glass frit .
[0011]
In addition, the conductive pattern forming method of the present invention uses a transfer body having a surface made of silicone rubber, and after forming a printed pattern made of the above conductive paste on a substrate by intaglio offset printing. The printed pattern is baked at 500 ° C. or higher and 650 ° C. or lower to form a conductive pattern.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below.
[Conductive paste]
The conductive paste of the present invention includes the conductive powder, the binder resin, and the glass frit as described above, and as the binder resin,
Ethyl cellulose C having an ethoxyl group content of 40 to 60% and a weight average molecular weight Mw of 10,000 to 500,000,
An acrylic resin A having a weight average molecular weight Mw of 10,000 to 500,000 is used at a weight ratio C / A = 1/9 to 9/1.
[0013]
The weight ratio C / A between ethyl cellulose C and acrylic resin A is limited to the above range, as described above, transferability from intaglio to transfer body, and transferability from transfer body to substrate. This is to obtain a conductive paste excellent in both.
That conductive paste weight ratio C / A is outside the small side of ethylcellulose C than 1/9 is due to the ethyl cellulose, the printed pattern, not to obtain the effect of improving the transferability of the transfer member from the intaglio. On the other hand, the conductive paste with a weight ratio C / A that is less than 9/1 on the side of the acrylic resin A reduces the transfer property of the printing pattern from the transfer body to the substrate by the acrylic resin. The improvement effect cannot be obtained. Therefore, in either case, a good conductive pattern cannot be formed.
[0014]
In order to form a better conductive pattern in consideration of these characteristics, the weight ratio C / A is preferably 15/85 to 90/10 even within the above range.
Ethylcellulose, among a cellulose resin, particularly excellent in affinity for the silicone rubber mentioned above, the printing pattern, the effect of improving the transferability of the transfer member from the intaglio it is particularly good.
[0015]
The ethyl cellulose, which is an ethyl etherified derivative of cellulose, has an ethoxyl group content ratio expressed by the ratio of the ethoxyl group produced by the etherification of the hydroxyl group to the total number of hydroxyl groups and ethoxyl groups. Any of various ethyl celluloses can be used.
The ethyl cellulose has an ethoxyl group content of 40 to 60% and a weight average molecular weight Mw of 10,000 to 500,000 . Such ethyl cellulose is excellent in solubility in the solvent used for the conductive paste and also has good compatibility with the acrylic resin.
[0016]
Ethyl cellulose is preferably one that can be completely decomposed when gasified at a high temperature of 500 ° C. or higher and gasified to be removed from the pattern.
Suitable ethyl cellulose satisfying these conditions is not limited to this, but, for example, trade name etosel manufactured by Dow Chemical Co. (content of ethoxyl group: 45 to 53%, weight average molecular weight Mw: 40,000 to 100,000) ) And the like.
[0017]
As the acrylic resin, it has an acrylic main chain mainly composed of acrylic acid, methacrylic acid or esters thereof such as thermoplastic acrylic resin, thermosetting acrylic resin, ultraviolet curable acrylic resin, etc. Any of various acrylic resins can be used.
The acrylic resin is limited to a weight average molecular weight Mw of 10,000 to 500,000 . Such an acrylic resin has excellent solubility in the solvent used for the conductive paste and also has good compatibility with the cellulose resin .
[0018]
Furthermore, the acrylic resin is preferably one that can be completely decomposed and gasified and removed from the pattern when baked at a high temperature of 500 ° C. or higher.
As the binder resin, another resin having compatibility with both resins may be added as long as the effect of the present invention by using ethyl cellulose and an acrylic resin in combination is not hindered. Examples of the other resin include polyester-melamine resin, melamine resin, epoxy-melamine resin, epoxy resin, phenol resin, amino resin, polyimide, polyurethane, polyvinyl butyral, polyester, thermoplastic acrylic resin, and the like.
[0019]
Examples of the conductive powder constituting the conductive paste together with the binder resin include metal powder, conductive metal compound powder, carbon powder such as carbon black and graphite powder, and the like. used.
Examples of the metal powder include silver, copper, iron, nickel, aluminum, and gold powder. Each metal powder can be used alone or in combination of two or more. Moreover, it is good also as a powder of a plating composite (for example, silver plating copper) or an alloy body.
[0020]
Among these metal powders, silver, nickel, or copper powders are preferably used in consideration of conductivity, cost, and oxidation resistance, that is, characteristics that make it difficult to form highly insulating oxides.
The viewpoint that the metal powder in the conductive paste improves the dimensional accuracy of the conductive pattern by increasing the dimensional stability when forming the conductive pattern by baking the printed pattern and removing the binder resin Therefore, the higher the packing density, the better.
[0021]
Further, the conductivity of the formed conductive pattern is not only determined by the volume resistivity of the metal powder itself to be used, but also greatly depends on the contact resistance between the metal powders in the pattern. For example, even if the metal particles are filled in the pattern at a high density, if the contact resistance between the metal powders is large, the overall conductivity of the conductive pattern is low.
Therefore, as the metal powder, in consideration of increasing the contact surface between the metal powders, a scaly shape or a spherical shape with a small particle size is preferably used. It does not exclude things.
[0022]
The amount of conductive powder such as metal powder added to the conductive paste is preferably 300 to 3,000 parts by weight, preferably about 700 to 2,000 parts by weight with respect to 100 parts by weight of the total amount of the binder resin. More preferably. When using 2 or more types of electroconductive powder together, the total amount is prescribed | regulated in this range.
If the amount of the conductive powder added is less than the above range, the amount of dimensional change when the printed pattern is baked to form the conductive pattern becomes large, and it is easy to form a good conductive pattern with high dimensional accuracy. Not. In addition, the packing density of the conductive powder may decrease, and the conductivity of the conductive pattern may decrease.
[0023]
On the other hand, when the addition amount of the conductive powder exceeds this range, the binding force of the binder resin as a binder for bonding the conductive powders is weakened, so that the conductivity of the conductive pattern may also decrease. There is.
A glass frit is added to the conductive paste so as to function as a binder instead of the binder resin in the conductive pattern after firing . The addition amount is not particularly limited, but is preferably 5 to 20 parts by weight with respect to 100 parts by weight of the binder resin.
[0024]
The solvent dissolves the binder resin and disperses the conductive powder and glass frit to form a conductive paste having a viscosity suitable for intaglio offset printing. For example, those having a boiling point of 150 ° C. or higher are preferably used. This is because when the boiling point of the solvent is less than 150 ° C., it becomes easy to dry at the time of printing, and the conductive paste easily changes with time.
Specific examples of such solvents include alcohols (hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, bentadecanol, stearyl alcohol, seryl alcohol, cyclohexanol, terpineol, etc.) and alkyl ethers. [Ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol monophenyl ether, diethylene glycol, diethylene glycol monobutyl ether (butyl carbitol), cellosolve acetate, butyl cellosolve acetate, strong lupitol acetate, butyl carbitol acetate, etc. 1 type or 2 types or more are appropriately selected in consideration of printability and workability.
[0025]
When higher alcohol is used as the solvent, the drying and fluidity of the conductive paste may be reduced, so butyl carbitol, butyl cellosolve, ethyl carbitol, butyl cellosolve acetate, Tall acetate or the like may be used in combination.
The addition amount of the solvent is preferably adjusted so that the viscosity of the conductive paste is about 50 to 2000 poise (P), particularly about 200 to 1000 P.
[0026]
This is because if the viscosity of the conductive paste falls below or exceeds this range, the printability of the conductive paste may be reduced and a fine pattern may not be formed. . The conductive paste is prepared by blending each of the above components, sufficiently stirring and mixing, and then kneading.
[Method of forming conductive pattern]
The conductive pattern forming method of the present invention uses a transfer body whose surface is formed of silicone rubber, and after forming a printing pattern made of the above conductive paste on a substrate by intaglio offset printing, In this method, the printed pattern is baked at 500 ° C. or higher and 650 ° C. or lower to form a conductive pattern.
[0027]
(intaglio)
As an intaglio used for the intaglio offset printing method, a flat plate having a predetermined concave portion corresponding to a printing pattern on the surface of a flat plate, a flat plate wound in a cylindrical shape, from the beginning Examples include a cylindrical shape or a columnar shape.
The smoothness of the surface of the substrate is important. When the smoothness is poor, when the conductive paste is filled into the concave portion of the intaglio, for example, by a doctor blade, the conductive paste remains on the surface of the intaglio plate other than the concave portion, and the non-image area becomes dirty ( Soiling) occurs.
[0028]
The degree of smoothness is not particularly limited, but is preferably about 1 μm or less, more preferably about 0.5 μm or less in terms of ten-point average roughness.
As the substrate, for example, glass substrate such as soda lime glass, non-alkali glass, quartz glass, low alkali glass, low expansion glass, fluorine resin, polycarbonate (PC), polyethersulfone (PES), polyester Resin plates such as polymethacrylic resin, metal substrates such as stainless steel, copper, nickel, and low expansion alloy amber can be used. Among these, it is preferable to use a glass product that can produce an intaglio with good surface smoothness at the lowest cost and that can form the edge shape of the pattern very sharply.
[0029]
However, since non-alkaline glass used for a photolithographic printing original plate in the field of LSI or the like is very expensive, soda lime glass is sufficient if it has an accuracy of intaglio for intaglio offset printing.
The concave portion of the intaglio is formed by a photolinograph method, an etching method, an electroforming method, or the like.
The depth of the recess may be set as appropriate according to the thickness of the target print pattern, but the remainder of the conductive paste in the recess (usually about half of the depth of the conductive paste is present. In view of the reduction in the thickness after printing due to evaporation of the solvent or the like, it is preferably about 1 to 50 μm, particularly about 3 to 20 μm.
[0030]
(Transcript)
The transfer body is not particularly limited as long as the surface is formed of silicone rubber, but the surface energy value as an index indicating the releasability of the conductive paste is 15 to 30 dyn / cm, particularly 18 to 25 dyn /. What is cm is preferable.
Such a transfer body is excellent in the releasability of the conductive paste, and can transfer almost 100% of the printing pattern transferred from the intaglio onto the substrate.
[0031]
Silicone rubber includes various silicone rubbers such as heat curable type (HTV) and room temperature curable type (RTV). In particular, room temperature curable addition type silicone rubber generates no by-products at the time of curing. It has excellent dimensional accuracy.
The surface hardness of the transfer body is 20 to 20 in terms of spring hardness (JIS A hardness) defined in Japanese Industrial Standard JIS _K6301-1975 “Vulcanized Rubber Physical Test Method” in consideration of printing accuracy and the like. It is preferably 70 °, particularly 30 to 60 °.
[0032]
A hard transfer body with a surface hardness exceeding this range is not sufficiently pressed into the recess when pressed against the intaglio in intaglio offset printing, so the conductive paste in the recess is sufficient on the surface of the transfer body. There is a possibility that printing is not performed accurately. In addition, a soft transfer body having a surface hardness less than this range has a large deformation when pressed against an intaglio or a substrate in intaglio offset printing, and therefore there is a possibility that printing with high accuracy cannot be performed.
[0033]
The surface of the transfer body is also smooth in consideration of printing accuracy and the like, and it is preferable that the unevenness of the surface does not affect the printing. Specifically, it is represented by a 10-point average roughness of 1.0 μm or less. In particular, it is preferably 0.5 μm or less.
The shape of the transfer body is blanket-like (sheet-like) (used by wrapping around a cylindrical drum), roller-like, or curved surface used for pad printing etc. It may be an elastic body.
[0034]
(Intaglio offset printing)
In the intaglio offset printing, first, the concave portion corresponding to the printing pattern of the intaglio is filled with the conductive paste of the present invention using a doctor blade or the like as in the prior art to form a printing pattern.
Next, the transfer body is pressed against the intaglio to transfer the print pattern to the transfer body, and then the transfer body is pressed against the substrate to be printed, and the print pattern is transferred again onto the substrate.
[0035]
When the printing pattern is dried, the intaglio offset printing is completed.
(Baking)
Next, when this printed pattern is baked at a high temperature of 500 ° C. or higher, the acrylic resin and the cellulose resin in the printed pattern are completely decomposed, gasified, and removed from the pattern. At the same time, the conductive powder is sintered to form a conductive pattern whose resistance is reduced to a desired range of resistance values.
[0036]
In addition, when an inorganic binder such as glass frit is added as described above, the binder melts and penetrates between the conductive powders to function as a binder instead of the binder resin. Therefore, the strength of the conductive pattern can be increased.
If the firing temperature is too high, enormous energy consumption may occur, for example, it takes a long time to raise and lower the temperature. Therefore, the firing temperature is limited to 650 ° C. or less in consideration of the heat-resistant temperature of the substrate . In particular, it is preferably 600 ° C. or lower.
[0037]
As an object for forming a conductive pattern by the above-described forming method, in addition to an electric circuit of a wiring board, an electromagnetic wave placed on the front and back electrodes of a plasma display panel (PDP) or the front surface of a display element such as a PDP An electromagnetic shielding member for shielding The formation method of the present invention is particularly effective when forming a conductive pattern on a substrate having a relatively large area.
[0038]
【Example】
Hereinafter, the present invention will be described with reference to examples and comparative examples.
Example 1
[Preparation of conductive paste]
The following components were sufficiently stirred and mixed, and then kneaded with three rolls to prepare a conductive paste.
[0039]

Butyl carbitol acetate 100 As ethyl cellulose, trade name Etcel (Ethoxyl group content: 45 to 53%, weight average molecular weight Mw: 40,000 to 100,000) manufactured by Dow Chemical Co., Ltd. was used. As the acrylic resin, trade name Oricox (weight average molecular weight Mw: 50,000 to 200,000) manufactured by Kyoeisha Chemical Co., Ltd. was used. As the silver powder, a scaly powder having an average particle diameter of 5 μm was used. Further, glass frit having an average particle diameter of 5 μm was used.
[0040]
[Formation of conductive pattern]
The above conductive paste was printed on the surface of a glass substrate as a printing object by the intaglio offset printing method using the following intaglio and a silicone blanket as a transfer body. As for the printing speed, the transfer speed from the intaglio to the silicone blanket was set to 50 mm / second, and the transfer speed from the silicone blanket to the glass substrate was set to 100 mm / second.
[0041]
(intaglio)
A soda lime glass surface formed by forming a large number of straight lines with a width of 50 μm and a depth of 10 μm at a pitch of 200 μm on a flat substrate surface.
(Silicone blanket)
On the outermost surface, an additional RTV silicone rubber layer (10-point average roughness 0.3 μm) having a spring hardness (JIS A hardness) of 40 ° is formed.
[0042]
Next, by using a clean oven and heating and drying at 100 ° C. for 1 hour, a stripe-shaped print pattern corresponding to the intaglio pattern was formed.
The glass substrate on which this printed pattern was formed was baked at 550 ° C. for 1 hour using an oven to completely decompose and remove the resin to form a conductive pattern.
Examples 2 to 6, Comparative Examples 1 and 2
A conductive paste was produced in the same manner as in Example 1 except that ethyl cellulose and acrylic resin were blended in the blending amounts (parts by weight) shown in Table 1, and a conductive pattern was formed. The total amount of both resins was 100 parts by weight.
[0043]
In the intaglio offset printing step in the conductive pattern forming step of each of the above examples and comparative examples, the transferability of the printing pattern from the intaglio to the silicone blanket and the transferability from the silicone blanket to the glass substrate were visually observed. And evaluated according to the following criteria. In the inspection, intaglio offset printing was repeated 20 times in succession, and evaluation was performed based on the inspection results for all the times.
○: The conductive pattern was completely transferred at all times. Good transferability.
[0044]
Δ: There were times when a part of the conductive pattern was not transferred. Transferability is slightly good.
X: There were times when the conductive pattern was hardly transferred. Transferability is poor.
The results are shown in Table 1.
[0045]
[Table 1]

[0046]
From the table, in Comparative Example 1 using only ethylcellulose as the binder resin, the transferability from the silicone blanket to the glass substrate was deteriorated. Conversely, in Comparative Example 2 using only the acrylic resin as the binder resin, from the intaglio plate Transferability to silicone blanket deteriorated.
On the other hand, all of Examples 1 to 6 in which ethyl cellulose and an acrylic resin are used in combination at a ratio of 1/9 to 9/1 as a binder resin have good transferability from a silicone blanket to a glass substrate. The transfer from the intaglio to the silicone blanket was good.
[0047]
Moreover, when each Example is compared, Examples 1-5 which used ethyl cellulose and acrylic resin together in the ratio of 15 / 85-90 / 10 by weight ratio are all transferability from a silicone blanket to a glass substrate, and It was confirmed that the transferability from the intaglio to the silicone blanket was good and more preferable.

Claims (6)

A conductive paste containing conductive powder, a binder resin and glass frit, and as the binder resin,
Ethyl cellulose C having an ethoxyl group content of 40 to 60% and a weight average molecular weight Mw of 10,000 to 500,000,
A conductive paste characterized in that an acrylic resin A having a weight average molecular weight Mw of 10,000 to 500,000 is used at a weight ratio C / A = 1/9 to 9/1. The electrically conductive paste of Claim 1 which used the ethyl cellulose C and the acrylic resin A in the ratio of weight ratio C / A = 15 / 85-90 / 10. The conductive paste according to claim 1 or 2, wherein the conductive powder is used at a ratio of 300 to 3,000 parts by weight per 100 parts by weight of the binder resin. The conductive paste according to any one of claims 1 to 3, wherein the glass frit is used at a ratio of 5 to 20 parts by weight per 100 parts by weight of the binder resin. After forming the printing pattern which consists of the electrically conductive paste of any one of Claims 1 thru | or 4 on a to-be-printed material by the intaglio offset printing method using the transfer body which the surface formed with the silicone rubber, A method for forming a conductive pattern, wherein the printed pattern is baked at 500 ° C. or higher and 650 ° C. or lower to form a conductive pattern. The method for forming a conductive pattern according to claim 5, wherein a conductive pattern for an electric circuit of a wiring board, front and back electrodes of a plasma display panel, or an electromagnetic wave shielding member is formed.