JP4093465B2 - Cover tape and package - Google Patents

Description

【００５５】
なお、実施例１〜４、比較例１，２で得られたカバーテープの評価は、以下の評価方法に基づいて行った。
評価方法：
ａ．透明性の測定（全光線透過率、ヘーズ）；村上色彩技術研究所製 HR-100を用いて測定した。
ｂ．表面抵抗：ダイヤインスツルメント社製、ハイレスタ UPを用いて測定した（測定電圧100V）。
ｃ．金属イオン濃度：試料に超音波発振をかけて抽出後、原子吸光法にて測定した。
ｄ．高温保存外観： 60℃で240H 保存後、目視にて外観の変化を確認した。
【００５６】
【発明の効果】
本発明のカバーテープは、基材シート上に設けられたシール層がシール材中にπ電子共役系導電性高分子を均質に溶解混合してなるため、透明性が高く、キャリアテープに内包された電子部品を良く確認することができる。さらに、シール層のいかなる部位で剥離されても、電荷減衰性が良く、静電気の発生を抑えることができ、電子部品に障害を与えることはない。
また、シール層が均質であり、有機化合物であるπ電子共役系導電性高分子を含むものであるから、接着強度ひいては剥離強度が安定し、キャリアテープから電子部品をスムースに取り出すことが可能な包装体を供給することができる。
【図面の簡単な説明】
【図１】 カバーテープの断面図である。
【図２】 中間層を含むカバーテープの断面図である。
【符号の説明】
１……基材シート、
２……シール層、
３……中間層。[0001]
BACKGROUND OF THE INVENTION
In the present invention, various small electronic components such as IC chips, transistors, capacitors, and diodes are housed in a continuous cavity of a carrier tape to protect the electronic components from external contamination and the environment. In particular, the present invention relates to a cover tape and a package used for sealing a carrier tape.
[0002]
[Prior art]
Electronic components housed in carrier tapes, particularly active components such as IC chips, may be damaged by static electricity generated by vibration friction during transportation or static electricity generated by peeling the cover tape from the carrier.
There has been proposed a cover tape that has an effect of preventing these obstacles and has transparency that allows the stored electronic components to be confirmed through the cover tape.
[0003]
For example, Patent Documents 1 and 2 provide an antistatic property and transparency by providing a π-electron conjugated conductive polymer layer or metal vapor deposition film having a thickness of 0.1 μm or less on the surface of a sealing layer on a substrate sheet. Cover tapes are mentioned.
In Patent Documents 3 and 4, a layer containing a cationic, anionic or nonionic surfactant or a metal fine powder, a metal oxide fine powder, carbon black or the like is provided between the base sheet and the seal layer. Proposed cover tapes have been proposed.
[0004]
In Patent Documents 5 and 6, organic cation imparted antistatic agents such as amino group-provided silicon dioxide having a particle size of 1 μm or more, carbon black, metal oxide, metal sulfide, etc. having a particle size of 0.01 to 10 μm are sealed. What is blended in the layer is described.
Patent Document 7 describes that a conductive compound such as spherical silicon, a polymer-type antistatic agent, and an organic conductive polymer agent can be added to the seal layer.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-301819
[Patent Document 2]
JP 2000-309761 A
[Patent Document 3]
Japanese Patent Laid-Open No. 11-286079
[Patent Document 4]
Japanese Patent Laid-Open No. 11-115088
[Patent Document 5]
JP 2002-226806 JP
[Patent Document 6]
JP 9-267450 A
[Patent Document 7]
Japanese Patent Laid-Open No. 2001-106994
[0006]
[Problems to be solved by the invention]
However, the cover tapes of Patent Documents 1 and 2 are provided with a conductive polymer layer or a metal vapor-deposited layer on the surface of the seal layer. I can't. In practice, adhesion is achieved by breaking through these surface layers and seeping out the sealing layer.
For this reason, the adhesive strength varies depending on the sealing conditions, and also appears at the same time when peeling.Therefore, when peeling continuously, the carrier tape vibrates and the contained electronic parts pop out, There was a problem that the cover tape was cut.
[0007]
In the cover tapes of Patent Documents 3 and 4, when the base sheet and the sealing layer are provided with an antistatic function, static electricity generated by vibration friction of electronic parts during transportation and when the cover tape is peeled off from the carrier tape The generated static electricity is removed through the insulating seal layer, but the charge decay time is long, and the countermeasures against static electricity are not sufficient.
[0008]
Next, in the cover tape described in Patent Documents 5 and 6, conductive fine particles such as amino group-added silicon dioxide, carbon black, metal oxide, and metal sulfide are blended in the seal layer. Due to poor nature and high haze, it is difficult to confirm the contents through the cover tape. Furthermore, the use of a transparent metal oxide is expensive and not economical. Furthermore, when sealing, hard conductive fine particle agglomerates sometimes cause scratches on the cover tape to trigger tearing, causing a problem of sudden cutting during peeling.
[0009]
Furthermore, in the cover tape described in Patent Document 7, a compound in which a polymer type antistatic agent is blended in the seal layer is not sufficient because the antistatic performance is affected by humidity, and the organic conductive polymer agent Although there is a description of adding, the details are not described and are unknown. In general, organic conductive polymers are insoluble and infusible polymers, and when added to the seal layer, they become aggregates or particles that change from what is added with a conductive filler such as carbon black. There is no.
[0010]
As described above, the antistatic function provided separately from the seal layer has poor adhesion and peeling stability. In addition, since the antistatic layer is provided in a separate process, there is a problem in productivity. Moreover, what mix | blended electroconductive fine particles with the sealing layer had a problem in transparency and haze.
More strictly speaking, the conductive fine particles are not added so as to occupy most of the volume in the seal layer, and in the seal layer, there are portions of the insulating sealing material in which no conductive fine particles exist, In this minimal part, the generated static electricity is stored, so that rapid charge decay is not performed. This minimal portion cannot be detected by a measuring instrument or the like because the measurement range is too wide, and thus an antistatic obstacle that is difficult to recognize has occurred.
Furthermore, in the formation process of the seal layer, there is a problem that the conductive fine particles are likely to settle, the concentration of the conductive fine particles in the seal layer is uneven, and the antistatic function is not stable.
[0011]
The present invention has stable and sufficient adhesion to the carrier tape, has excellent transparency and excellent sealing properties, can quickly eliminate static electricity generated with a short charge decay time, and can be cut during peeling. The aim is to provide no cover tape and packaging.
[0012]
[Means for Solving the Problems]
The present invention has been made in view of the above disadvantages and disadvantages, and the cover tape of the present invention is a cover tape comprising a base sheet and a seal layer provided thereon, and a π electron conjugate to the seal layer. It is characterized by substantially dissolving and mixing a conductive polymer.
Note that the seal layer is preferably an acrylic copolymer containing a π-electron conjugated conductive polymer and a compatibilizer. In addition, an intermediate layer is preferably provided between the base sheet and the seal layer, and at least a bonding surface of the intermediate layer with the seal layer is preferably a π-electron conjugated conductive polymer. The total light transmittance of the cover tape is 85% or more and haze 5% or less.
[0013]
The package of the present invention is characterized in that the cover tape is used to seal a carrier tape that houses electronic components. The adhesive surface of the carrier tape at least with the cover tape is preferably formed of a styrene resin, an ester resin, a urethane resin, or an acrylic resin.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The cover tape of the present invention comprises a base sheet as a base material and a seal layer provided on the base sheet, and the base sheet has a strength that is not cut at the time of peeling and is resistant to the environment and heat. Insulating polymer film with high dimensional stability is used.
Examples of the base sheet include polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, polyamide, polycarbonate, polyimide, polyetherimide, polyamideimide, polyethersulfone, polysulfone, polyphenylene sulfide, and polyarylate.
Of these, polyethylene terephthalate is most suitable in terms of strength, heat resistance, and transparency, but a modified product of the above film or a composite film can also be used.
[0015]
When compositing the film, the bonding surface can be roughened, or can be processed using a known technique such as corona discharge treatment, plasma discharge treatment, primer treatment, or anchor coat treatment.
[0016]
The thickness of the base sheet is approximately 12 to 150 μm. If it is thinner than 12 μm, there is not sufficient strength, and if peeling is performed intermittently at a speed of 20 to 50 m / sec, it will be cut. On the other hand, if it is thicker than 150 μm, rigidity is increased, handling is difficult, and heat conduction during sealing takes time, which is disadvantageous for high-speed sealing.
It is also optional to provide an antistatic layer made of a surfactant, a moisture permeation preventing layer made of a silicon dioxide thin film, or the like on the outer surface of the base sheet.
[0017]
Next, the seal layer is an adhesive layer made of a thermoplastic resin necessary for thermocompression bonding of the cover tape to a carrier tape to be described later, and is thermocompression bonded (size example: width 0.3 to 1 mm, length 10-50mm), etc., surface temperature is 120-200 ° C, pressure is 1-5g / mm²Therefore, it is necessary to activate the adhesion under the sealing condition of 1 to 5 times of repeated pressing at a cycle of 50 to 100 times per minute. The film thickness as the sealing layer is preferably 0.5 to 50 μm, and if it is thinner than this, sufficient adhesive strength cannot be maintained and peeled off, and if it is thick, the adhesive flows and stable peeling strength cannot be obtained. .
[0018]
The sealing material that forms the sealing layer includes polyamide, polyurethane, polyester, styrene thermoplastic elastomer, ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol, ethylene / vinyl acetate / acrylate copolymer, ethylene -(Meth) acrylic acid copolymer, ethylene / methyl (meth) acrylate copolymer, ethylene / ethyl acrylate copolymer and the like can be exemplified.
[0019]
The form before these sealing materials are formed on the sealing layer can be used in a solution state dissolved in a solvent or an emulsion solution state. The solution state is preferable because it is easy to dissolve and mix with a π-electron conjugated conductive polymer described later.
Among the sealing materials, an acrylic copolymer that has high compatibility with the π-electron conjugated conductive polymer and can be adjusted for various carrier tape materials is particularly preferable.
[0020]
This acrylic copolymer includes isononyl acrylate, 2-ethylhexyl acrylate, n-butyl acrylate, ethyl acrylate, methyl (meth) acrylate, diethylaminoethyl methacrylate, butyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, diacetone. In addition to two-dimensional copolymers of monomers selected from acrylamide, 2-hydroxypropyl methacrylate, (meth) acrylic acid, acrylamide, etc., vinyl acetate, styrene, ethylene, propylene, butene-1, acrylonitrile, maleic acid, succinic acid Examples thereof include a two-dimensional or higher copolymer composed of an ethylenically unsaturated carboxylic acid such as an acid or an anhydride thereof. The monomer can be selected depending on the sealing conditions, as well as those having different glass transition points Tg, and can also be selected in consideration of the polarity of the adherend.
[0021]
Its adhesive strength is approximately 100 to 1000 g / cm (180 ° peeling), does not vary depending on the conditions of thermocompression bonding, and has a low dependence on the sealing temperature. Adhesion during low temperature bonding and high temperature bonding Even when the temperature difference between the conditions is 60 ° C. or more, the variation in the adhesive strength is 4 times or less, preferably 3 times or less of the strength at the time of high temperature adhesion and low temperature adhesion.
[0022]
The π-electron conjugated conductive polymer contained in the seal layer is a polymer having a conjugated double bond in the molecular structure, and the conduction mechanism is not ionic conduction, so it is stable even with changes in humidity. Conductivity can be obtained. Moreover, since it is an organic compound, it is softer than an inorganic conductive material and does not damage the substrate sheet.
Examples of the monomer before polymerization of the conductive polymer include aniline derivatives such as aniline, sulfonated aniline, and alkylated aniline, or heterocyclic 5-membered ring compounds.
[0023]
Examples of the heterocyclic 5-membered ring compounds include pyrrole, thiophene, furan, indole and derivatives thereof such as N-methylpyrrole, N-ethylpyrrole, 3-methylpyrrole, 3-methoxypyrrole, 3-octylpyrrole, 3-decylpyrrole, 3,4-dimethylpyrrole, 3-hexylpyrrole, methyl 3-methyl-4-pyrrolecarboxylate, 3-methylthiophene, 3-methoxythiophene, 3-butylthiophene, 3,4-dimethylthiophene, Examples include 3-dodecylthiophene, 3-thiophene-β-ethanesulfonate, 2,3-dihydrothieno (3,4-b) -1,4-dioxin, 3-methylfuran, and 3-methylindole. However, it is not limited to these, and a single monomer or a plurality of monomers can be copolymerized and used. In particular, a derivative having a long side chain of 3 or more carbon atoms at the β-position of the heterocyclic 5-membered ring compound is characterized by excellent compatibility although it is not high in conductivity.
[0024]
Further, a so-called self-doping type water-soluble one having a sulfonic acid group covalently bonded thereto can also be used. Water-soluble ones are preferable when mixed with a sealing material in an emulsion state.
[0025]
The monomer before polymerization of the conductive polymer is polymerized into a polymer having a polymerization degree of about 10 to 1000 using an oxidation polymerization catalyst. If the degree of polymerization is low, the conductivity is low, so a large amount of conductive polymer must be added to the seal layer, which is disadvantageous for transparency. On the other hand, when the degree of polymerization is high, the compatibility with the seal layer is lowered, so the above-mentioned range is appropriate.
[0026]
The oxidation polymerization catalyst used for this includes transition metal chlorides such as ferric chloride, cupric chloride and stannic chloride, hydrogen peroxide, ozone, peroxides such as benzoyl peroxide, and silver oxide. Metal oxides such as inorganic acids such as permanganic acid, chromic acid and hypochlorous acid and their salts, perchlorates such as ferric perchlorate and cupric perchlorate, ammonium persulfate, Examples thereof include persulfides such as sodium sulfide and potassium persulfide.
If the polymerization catalyst remains, the electronic component may be corroded. Therefore, it is necessary to remove the polymerization catalyst by washing or ion exchange after completion of the polymerization. The residual ion concentration is 10 ppm or less, preferably 3 ppm or less.
[0027]
In order to improve the conductivity of the π-electron conjugated conductive polymer, a dopant may be added. For this, organic electron donating compounds such as fullerene, tetracyanoquinodimethane, tetracyanotetraazanaphthalene and the like can be used, and it is very preferable that there is no residual ion. Of the oxidation polymerization catalysts mentioned above, halogens and transition metal chlorides also function as dopants.
[0028]
  The π-electron conjugated conductive polymer must be substantially dissolved and mixed in the seal layer in order to improve transparency and obtain stable adhesiveness and peelability. In addition, substantially dissolved and mixed here means that the π-electron conjugated conductive polymer isIt is dissolved in the seal layer or it is dispersed in a microgel state of 200 nm or less,The conductive polymer is not present in the form of aggregates, that is, fillers. When dispersed, conductive polymer microgelIs preferably 100 nm or less.
[0029]
The content of the conductive polymer in the seal layer is such that the resistance value on the surface of the seal layer is 10^Five~Ten^TenIt is set to 0.1 to 20% by weight so as to be Ω / mouth. If it is less than 0.1% by weight, sufficient conductivity cannot be obtained, and if it exceeds 20% by weight, transparency, particularly haze, is adversely affected.
[0030]
Depending on the type of sealing material that forms the sealing layer, even the π-electron conjugated conductive polymer solubilized like the above-mentioned derivatives can be separated and aggregated due to its polarity, intermolecular force, etc. In this case, the problem can be solved by using a compatibilizing agent.
[0031]
Examples of compatibilizers include compounds having a coordinate affinity with π electrons such as sulfonic acid group, cyano group, halogen, and quaternary ammonium. For example, dodecylbenzenesulfonic acid, pentadecylsulfonic acid, sulfonation Polystyrene, sulfonated polyisoprene, sulfonated polyimide, vinyl sulfonic acid copolymer, polyacrylonitrile, acrylonitrile-butadiene copolymer, cyanoacetanilide, cyanoacetyl urethane, butyl cyanoacetate, acetoxybenzonitrile, cyanoethyl pullulan, cyanoethylated ethylene -Vinyl alcohol copolymer, boron trifluoride ethyl ether, polyparabanic acid, soluble polyaramid, etc. are mentioned. The polymer type is preferable because it has a function of reducing the density of the microgel from the steric properties of the molecule itself, and can prevent aggregation.
[0032]
As the sealing material, the acrylic copolymers listed above can synthesize copolymers with a wide range of polarities by selecting monomers with low to high polarity, and have bulky groups in the side chain. High transparency due to low molecular density. Furthermore, the compatibility with various π-electron conjugated conductive polymers is also high, which is preferable.
[0033]
The cover tape of the present invention comprises a sealing layer having a good transparency and a base sheet. The base sheet has a total light transmittance of 85% or more and a haze of 5% or less, preferably a total light transmittance of 90% or more. The haze is 3% or less. If the transmittance is less than 85% and the haze is large, the contents stored through the cover tape cannot be confirmed, and in particular, there is a problem that it becomes impossible to recognize the part number, lot, etc. stamped on the electronic parts. In addition, the measuring method of transparency can be performed using a transmittance meter or a haze meter based on JIS K 7361-1 and JIS K 7136.
[0034]
It is considered that the generation of static electricity occurs when the carrier tape or the cover tape and the electronic component are rubbed together during transportation, or when the cover tape is peeled off when the cover tape is peeled off from the carrier tape. In the latter case, the peeling surface is the interface between the carrier tape and the seal layer, the seal layer due to cohesive failure in the seal layer, or the interface between the seal layer and the base sheet (in this case, strictly speaking, the seal layer is the seal part). Is present on the carrier tape side and the non-sealed part remains on the cover tape side, which causes cohesive failure of the seal layer). The charge can be quickly attenuated by being uniformly present not only on the surface of the layer but also in any part.
[0035]
In addition, the cover tape of this invention may have an intermediate | middle layer between a sealing layer and a base material sheet, and the thickness shall be 0.5-50 micrometers. This intermediate layer is provided in order to improve the contact with the thermocompression trowel and obtain stable adhesion at the time of sealing, and is preferably an elastic body having a lower elastic modulus than the shear modulus of the base sheet. Examples thereof include polyethylene, ethylene / vinyl alcohol copolymer, styrene-based, amide-based or ester-based thermoplastic elastomer.
[0036]
In addition, when this intermediate layer is used as a release layer for stabilizing the peel strength, a material that is different from the carrier tape and does not adhere well is selected, although it depends on the type of the sealing material. For this, an olefin-based film is selected. Further, in order to adjust the peelability, a compound such as wax, silicone, and acrylic silicone may be blended, but it is important that the transparency is not hindered.
In general, π-electron conjugated conductive polymers have poor adhesion, so that the peel strength can be adjusted by providing this π-electron conjugated conductive polymer on at least the interface of the intermediate layer with the seal layer. And antistatic treatment can be performed, which is preferable.
[0037]
This intermediate layer may be subjected to antistatic treatment if necessary. For this, a general antistatic agent may be used. However, if a π-electron conjugated conductive polymer having poor adhesion is selected, it is very preferable in terms of improving the releasability.
In addition, it is also possible to provide a hygroscopic function by attaching a polyamide film having a large hygroscopic property to the surface of the base sheet as an intermediate layer.
[0038]
In order to form the sealing layer on the base sheet, the sealing material may be coated using a known coating method such as gravure coating, comma coating, roll coating or the like. Adjustment of the sealing material is performed by dissolving and mixing the above-described adhesive made of the thermoplastic resin and the π-electron conjugated conductive polymer in a solvent. An appropriate solvent boiling point is selected in consideration of the coating line speed, but a solvent having a boiling point of approximately 80 to 150 ° C. is used.
[0039]
For the dissolution and mixing of the sealing material and the π-electron conjugated conductive polymer, a polymer blend method in which the conductive polymer is added directly to the sealing material solution or the conductive polymer solution is mixed with the solvent of the sealing material may be used. However, if necessary, the compatibilizer can be mixed at the same time. In addition, as a method of performing uniform dissolution and mixing at the molecular level by avoiding the aggregation of conductive polymers and increasing the compatibility with the sealing material, it can be used in a sealing material solvent or a solvent in which a compatibilizing agent is dissolved. There is a method of polymerizing a conductive polymer monomer.
After the coating, a raw tape obtained by drying is slit into a desired width of several to several tens of mm, and wound on a reel to obtain a cover tape.
[0040]
On the other hand, carrier tape, which is an adherend of cover tape, is made of polystyrene, polyester (A-PET, PET-G, etc.), polypropylene, polycarbonate, polyacrylonitrile, acrylonitrile / budadiene / styrene copolymer, etc. It is obtained by embossing according to the dimensions.
The film is preliminarily kneaded with an antistatic agent or a conductive filler, or is coated with an ink in which these conductivity-imparting substances are mixed in a urethane or acrylic binder.
[0041]
When using the cover tape, place the electronic parts in the cavity of the embossed carrier tape, and then match the cover tape with the cover tape. Both edges in the longitudinal direction of the cover tape are continuously 0.3 to 1 mm wide. Seal, wrap and wind on reel. Electronic components are stored or transported in this state.
[0042]
To remove the electronic components from the carrier tape, the cover tape is peeled off intermittently while being transported through the feed holes provided along both edges in the longitudinal direction of the carrier tape. Take out while checking the direction and position, and use. For this reason, it is calculated | required that a cover tape does not cut | disconnect during peeling but the content can be confirmed.
[0043]
Therefore, as the cover tape, an adhesive that stably adheres well even to different bonding surfaces and surface states of various carrier tape materials is selected, and a stable peeling state can be obtained even under different sealing conditions. By using the above-described intermediate layer as a release layer and selecting an intermediate layer that can be appropriately peeled, any carrier tape and any carrier condition can be used for various carrier tapes.
[0044]
【Example】
(Example 1)
A 50 μm thick polyethylene terephthalate film (trade name, Lumirror, single-side antistatic treatment product) is used as a base sheet, and the sealing material prepared as follows on the surface opposite to the antistatic surface A was provided with a thickness of 10 μm by a gravure coater to obtain a cover tape of the present invention. The evaluation results are shown in Table 1.
[0045]
Preparation of sealing material A;
Styrene thermoplastic elastomer (product name: Toughprene 315, manufactured by Asahi Kasei) 60 parts, partially hydrogenated styrene thermoplastic
Elastomer (Asahi Kasei, brand name Tuftec P1000) 40 parts, Alicyclic saturated hydrocarbon resin (Arakawa Chemical Industries, trade name Alcon M-90) 25 parts, α-methylstyrene resin (Hercules Japan, trade name Endex) 150) 15 parts are dissolved in 600 parts of a mixed solvent of MEK and toluene (weight ratio 50:50), and 0.05% by weight of Aerosil (Nippon Aerosil, trade name R972) is added to the solid content of this mixed solution. Stir to prepare an adhesive solution.
100 parts of butyl 3-methyl-4-pyrrolecarboxylate (manufactured by Nippon Soda Co., Ltd., pyrrole derivative) as a π-electron conjugated conductive polymer, and 2,3,6,7-tetracyano-1,4,5, as a dopant 25 parts of 8-tetraazanaphthalene (manufactured by Nippon Soda) and 10 parts of polyacrylonitrile (made by Mitsui Chemicals, trade name Barex # 1000) as a compatibilizer are mixed with 900 parts of a mixed solvent of dimethylacetamide and toluene (weight ratio 80:20). It melt | dissolved and obtained the pi-electron child system conductive polymer solution.
The π-electron child conductive polymer solution is added to the adhesive solution so that the π-electron child conductive polymer is 10% by weight with respect to the solid content of the adhesive solution, and a brown transparent seal is added. Material A was prepared.
[0046]
(Example 2)
A 50 μm thick polyethylene terephthalate film (product name: Lumirror, single-side antistatic treatment product) is used as the base sheet, and the polyurethane emulsion (first The product name F-8582D manufactured by Kogyo Seiyaku Co., Ltd. was provided with a thickness of 2 μm by a gravure coater, and the following sealing material B was further provided with a thickness of 10 μm by a gravure coater to obtain the cover tape of the present invention. The evaluation results are shown in Table 1.
[0047]
Preparation of sealing material B;
100 parts of a polyester emulsion (Daiichi Kogyo Seiyaku Co., Ltd., trade name Superflex 460, solid content: 38% by weight) is washed three times in advance with a mixed solvent of MEK and pure water as a π-electron child conductive polymer. Then, 4.5 parts of dried sulfonated aniline (manufactured by Toyobo Co., Ltd.) was dissolved and mixed to prepare a sealing material B containing a green transparent π-electron child conductive polymer.
[0048]
Example 3
A 25 μm-thick polyethylene terephthalate film (product name: Lumirror, single-side antistatic treatment product) was dry-laminated with a 30 μm-thick polyethylene film to obtain a base sheet. After subjecting the polyethylene surface to corona discharge treatment, the following sealing material C was provided with a thickness of 3 μm by a gravure coater to obtain the cover tape of the present invention. The evaluation results are shown in Table 1.
[0049]
Preparation of sealing material C;
Acrylic copolymer (methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, acrylonitrile, molar ratio 2: 3: 3: 2) was dissolved in dimethylacetamide to obtain an adhesive solution having a solid content of 10% by weight.
To 100 parts of the adhesive solution, add 15 parts of aniline as a π-electron-conducting conductive polymer, and after stirring well, ventilate oxygen containing 1% by weight of ozone and allow it to react at room temperature for 3 hours. A sealing material C was prepared.
[0050]
Example 4
A 36μm thick polyethylene terephthalate film (trade name, Lumirror, single-side antistatic treatment product) is used as the base sheet, and the water-soluble polyester (Imperial) is used as the intermediate layer on the opposite side of the antistatic surface. After using a solution of 2% by weight polyethylene dioxythiophene aqueous solution (trade name Denatron P-502S manufactured by Nagase Sangyo Co., Ltd., trade name Gabsen ES-901A) made by Chemical Industry, and 2 μm thick by a gravure coater, The seal material D was provided with a thickness of 2 μm by a gravure coater to obtain the cover tape of the present invention. The evaluation results are shown in Table 1.
[0051]
Preparation of sealing material D;
Acrylic copolymer (methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, acrylonitrile, molar ratio 4: 3: 3) is dissolved in a mixed solvent of MEK and toluene (weight ratio 50:50), and the solid content is 10% by weight. An adhesive solution was obtained.
To 1000 parts of pure water, add 10 parts of pyrrole as a π-electron-conducting conductive polymer, 55 parts of ferric chloride as an oxidation polymerization catalyst, and 10 parts of dodecylbenzenesulfonic acid as a compatibilizer, and stir well with a homogenizer. And reacted at room temperature for 60 minutes. Thereafter, 20 parts of xylene was added to the aqueous solution, and decanted to obtain a xylene solution of polypyrrole that shifted to the xylene phase. Further, pure water was added, washed and decanted. This was repeated three times to prepare a brown π-electron child conductive polymer solution (xylene solution).
The π-electron child conductive polymer solution is added to the adhesive solution so that the π-electron child conductive polymer is 1.5% by weight with respect to the solid content of the adhesive solution, and a brown transparent seal is added. Material D was prepared.
[0052]
(Comparative Example 1)
A cover tape was produced in the same manner as in Example 4 except that a polymer-type permanent antistatic agent (trade name: Perestat NC6321 manufactured by Sanyo Chemical Industries, Ltd.) was added in place of the π-electron child role conductive polymer. The evaluation results are shown in Table 1.
[0053]
(Comparative Example 2)
In place of the π-electron-conducting conductive polymer, antimony-doped tin oxide fine particles (manufactured by Nissan Chemical Industries, trade name Celnax CX-Z309K) were prepared by adding 50 parts by weight to the solid content of the adhesive solution. A cover tape was produced in the same manner as in Example 4 except that the conductive solution was provided on the seal layer with a thickness of 1 μm. The evaluation results are shown in Table 1.
[0054]
[Table 1]

[0055]
In addition, evaluation of the cover tape obtained by Examples 1-4 and Comparative Examples 1 and 2 was performed based on the following evaluation methods.
Evaluation methods:
a. Measurement of transparency (total light transmittance, haze); measured using HR-100 manufactured by Murakami Color Research Laboratory.
b. Surface resistance: measured using Hiresta UP, manufactured by Dia Instruments Co., Ltd. (measurement voltage 100 V).
c. Metal ion concentration: The sample was extracted by applying ultrasonic oscillation and then measured by an atomic absorption method.
d. High-temperature storage appearance: After storage at 60 ° C for 240H, changes in appearance were visually confirmed.
[0056]
【The invention's effect】
In the cover tape of the present invention, the sealing layer provided on the base sheet is formed by uniformly dissolving and mixing the π-electron conjugated conductive polymer in the sealing material. Therefore, the cover tape has high transparency and is included in the carrier tape. The electronic parts can be checked well. Furthermore, even if it peels in any site | part of a sealing layer, charge attenuation property is good, generation | occurrence | production of static electricity can be suppressed, and an electronic component is not damaged.
In addition, since the sealing layer is homogeneous and contains a π-electron conjugated conductive polymer that is an organic compound, the adhesive strength and thus the peel strength is stable, and the packaging body can smoothly take out the electronic components from the carrier tape. Can be supplied.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a cover tape.
FIG. 2 is a cross-sectional view of a cover tape including an intermediate layer.
[Explanation of symbols]
1 …… Base sheet,
2 …… Sealing layer,
3: Middle layer.

Claims (8)

A cover tape comprising a base sheet and a seal layer provided thereon, wherein the π electron conjugated conductive polymer is dissolved or dispersed in a microgel state of 200 nm or less in the seal layer . Cover tape to be used. The cover tape according to claim 1, wherein the seal layer contains a π-electron conjugated conductive polymer and a compatibilizing agent. The cover tape according to claim 1 or 2, wherein the seal material forming the seal layer is an acrylic copolymer. The cover tape according to any one of claims 1 to 3, further comprising an intermediate layer between the base sheet and the seal layer. The cover tape according to claim 4, wherein the intermediate layer has a π-electron conjugated conductive polymer on at least a joint surface with the seal layer. The cover tape according to any one of claims 1 to 5, wherein the cover tape has a total light transmittance of 85% or more and a haze of 5% or less. A package comprising the cover tape according to any one of claims 1 to 6 and sealed to a carrier tape that houses an electronic component. The package according to claim 7, wherein an adhesive surface of the carrier tape at least with the cover tape is made of a styrene resin, an ester resin, a urethane resin, or an acrylic resin.

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