JPH0673348A - Tab tape with adhesive - Google Patents

Abstract

PURPOSE:To obtain a high-quality TAB tape provided with an adhesive layer and not causative of embedment of an electric conductor into the adhesive in the course of heat-bonding, under pressure, a TAB package to a liq. crystal glass panel via an anisotropically conductive thermosetting adhesive tape or in the course of sealing the TAB package with a resin according to transfer molding. CONSTITUTION:This TAB tape is basically constituted of either an org. electrical-insulating film and an adhesive layer, or an org. electrical-insulating film, an adhesive layer and a protective film laminated in this order, where the adhesive layer comprises as the indispensable components a polyamide resin, an epoxy resin, and an aliph. sulfonium salt curing agent for the epoxy resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape with an adhesive used for a semiconductor integrated circuit mounting tape called a TAB (Tape Automated Bonding) system (hereinafter abbreviated as TAB tape).

[0002]

2. Description of the Related Art The basic structure of a TAB tape is usually shown in FIG.
As shown in, a heat-resistant organic insulating film 1 made of polyimide or the like is used as a base material, and a mixed system of polyamide and epoxy is formed on the base material (abbreviated as “polyamide / epoxy system”, the same applies to “□
□□ / △△△ system "means a mixed system of □□□ and △△△) consisting of a conductor 4 such as a copper foil adhered via a thermosetting adhesive 2 such as an adhesive. ing. These adhesives are required to have various properties such as adhesiveness, insulation and chemical resistance.

A liquid crystal driving IC (hereinafter referred to as "driver I"
In order to connect a tape carrier package (hereinafter abbreviated as “TCP”) equipped with “C”) to a liquid crystal display panel, a thermocompression bonding method using an anisotropic conductive adhesive is usually adopted. The adhesive for the TAB tape used in the method requires new performance in addition to the above characteristics. That is, the anisotropic conductive adhesive is a thermosetting type adhesive in order to obtain a sufficiently reliable electrical and mechanical connection between the outer lead of the TCP and the transparent electrode formed on the glass surface of the liquid crystal display panel. As the thermocompression bonding conditions are becoming stronger, it is necessary to have strong conditions for temperature, pressure and time. Conventionally, it has been known that polyamide / epoxy type, polyamide / epoxy / phenol type adhesives for TAB tapes and imidazole type adhesives for curing agents are used. When thermosetting is performed on a liquid crystal panel using a curable anisotropic conductive adhesive, there is a problem that the conductor of the TAB tape is buried in the adhesive due to thermal pressure. FIG. 3 shows a model in which the conductor 4 is buried in the adhesive 2. In such a state, the original performance expected of the anisotropic conductive adhesive cannot be exhibited at all.

In addition, in TCP, the resin molding by the transfer molding method is being studied from the viewpoint of improving the reliability of the IC or making the package form such as the QFP type the same as that of the normal wire bonding method. In this case, the TCP using the conventional adhesive also has a problem that the conductor of the TAB tape is buried in the adhesive as shown in FIG. 3 due to heat and pressure during molding, and the original purpose cannot be achieved.

The TAB tape is the same as the flexible printed circuit board (FPC) in terms of material composition, and a nylon (polyamide) / epoxy adhesive has long been known as an adhesive for FPC ("Adhesion" Vol. 17, No7, pp31 ~
38 (1973)). It is well known that polyamide / epoxy type adhesives (including curing agents such as phenolic resin and dicyandiamide (DICY)) exhibit excellent performance as adhesives for TAB tapes (JP-A-53-1343).
65, Japanese Patent Publication No. 58-30755, Japanese Patent Publication No. 6
1-3101), and more recently, polyamide / epoxy / polyparavinylphenol-based (including imidazole-based curing agents) (JP-A-2-15664) and polyamide / epoxy / phenolic resin-based (imidazole-based curing agents). (Including JP-A-2-143447 and JP-A-3-217035).

These adhesives are based on the excellent adhesiveness, toughness, and chemical resistance of nylon (polyamide) resin, and the epoxy resin and the active terminal group (-NH
₍₂ , -COOH) forms a cross-linked structure with each other, and at the same time increases the cross-link density of the epoxy resin itself with an epoxy curing agent such as DICY or imidazole to improve heat resistance, chemical resistance, and electrical insulation. The basic idea is to raise the level to the desired level. It is well known that the phenolic hydroxyl group in the molecular structure of a phenol resin or polyparavinylphenol acts as a curing agent for an epoxy resin to form a cured product excellent in heat resistance and electric insulation. Therefore, the adhesive for TAB also has an effect of further modifying the properties of the polyamide / epoxy system.

However, these conventionally known adhesives cannot withstand the thermocompression bonding conditions of thermosetting anisotropic conductive adhesives and transfer molding conditions, and the conductors are buried in the adhesives. There is a drawback that the initial purpose cannot be achieved.

As a method for increasing the heat resistance (Tg, HDT, etc.) of an epoxy resin, an acid anhydride system such as trimellitic acid anhydride, pyromellitic acid anhydride, benzophenonetetracarboxylic acid anhydride, diaminodiphenylmethane, diaminocyphenyl, etc. Aromatic diamines such as sulfone,
Phenolic resins and polyparavinylphenol are well known, but even if these high heat resistant epoxy curing agents are used in a composition based on polyamide / epoxy, the burial phenomenon of the target TAB tape conductor will occur. Can not be suppressed at all, and even if an aromatic diamine such as DDS or an acid anhydride such as trimellitic anhydride is applied to the polyamide / epoxy / phenol system, almost no effect is observed.

As a result of intensive studies to solve this problem, the present inventors have found that among these polyamide / epoxy adhesives, the aliphatic sulfonium salt-based epoxy resin curing agent exhibits a specific action. Reached

[0010]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to have the adhesiveness, insulating property, chemical resistance, etc., which have been conventionally required as an adhesive for TAB tape.
With a high-quality TAB adhesive that can withstand the heat pressure of TCP and liquid crystal panel connection with thermosetting anisotropic conductive adhesive, or transfer molding of TAB type IC, and the conductor will not be buried in the adhesive. To provide the tape.

[0011]

The object of the present invention is as follows.
A tape having a basic structure, which comprises an organic insulating film and an adhesive layer, or an organic insulating film, an adhesive layer and a protective film laminated in this order, wherein the adhesive layer comprises (a) a polyamide resin, This is achieved by a tape with an adhesive for TAB, which comprises (b) an epoxy resin and (c) a curing agent for an aliphatic sulfonium salt epoxy as an essential component. Furthermore, the polyamide resin contains a dicarboxylic acid having 36 carbon atoms as an essential component, and the aliphatic sulfonium salt-based epoxy curing agent has the general formula (1).

[Chemical 2] (In the formula, R ₁ , R ₂ , and R ₃ each represent a hydrocarbon group having 1 to 6 carbon atoms.) is there. Further, an adhesive resin component additionally containing a phenol resin can be preferably used because the objective performance of the present invention is further improved.

As the organic insulating film used in the present invention, a so-called heat resistant film made of polyimide, polyetherimide, aromatic polyamide, or a composite material made of flexible epoxy / glass cloth can be preferably used.

The polyamide resin which is the component a of the adhesive is obtained by thermally polymerizing a mixture of an acid and a diamine, and known ones can be used. Those containing a dicarboxylic acid having a number of 36 (so-called "dimer acid") (commonly called "dimer acid-based polyamide") are preferable. The dimer acid-based polyamide can be obtained by thermally polymerizing an equimolar mixture of dimer acid and diamine. Not only dimer acid as the dicarboxylic acid component, but also azelaic acid,
It may contain other dicarboxylic acid such as sebacic acid as a copolymerization component. At this time, the dimer acid content is more preferably 70 mol% or more in the acid component.

As the diamine component, hexamethylenediamine, ethylenediamine, piperazine, bis (4-aminocyclohexyl) methane, bis (4-amino, 1,1)
2-Methylcyclohexyl) methane and the like can be mentioned, but particularly preferable one is hexamethylenediamine. Dimer acid-based polyamides containing hexamethylenediamine as a main component are particularly preferable because they exhibit excellent properties in overall performance. Further, the diamine component may be used not only in one kind but also in a mixture of two or more kinds. Among the dimer acid-based polyamides, those having a high degree of polymerization are preferable because they have a relatively low water absorption rate and are likely to have high electric insulation even in a high humidity atmosphere.

As the component b epoxy resin, glycidyl ether type epoxies such as bisphenol, phenol novolac and cresol novolac, or known various epoxy resins such as cycloaliphatic epoxy, glycidyl ester type epoxy and glycidyl amine type epoxy can be used. Is.

Examples of the aliphatic sulfonium salt-based epoxy curing agent of the component c are those represented by the following general formulas [A] and [B] (wherein A is a sulfonium ion and B is a counter ion).
What is represented by is preferable.

The sulfonium ion of the above A is represented by the general formula (2)

[Chemical 3] (In the formula, each of R ₁ , R ₂ , and R ₃ represents a hydrocarbon group having 1 to 6 carbon atoms.).

Examples of the counter ions of the B, BF ₄ ^-, P
F ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , ZnCl ₂ ⁻ , Sn
Examples include Cl ₅ ⁻ , FeCl ₄ ⁻ , AlCl ₄ ^{− and the} like. Of these, SbF ₆ ⁻ is particularly preferable.

As the phenol resin, all known phenol resins can be used. Specific examples thereof include a phenol resin (novolak type and resol type), an alkylphenol resin (novolak type and resol type), and a polyparavinylphenol resin.

The ratio of each component is preferably 10 to 180 parts by weight of the epoxy resin of component b, more preferably 2 when the polyamide resin of component a is 100 parts by weight.
The amount is preferably 0 to 130 parts by weight, more preferably 60 to 100 parts by weight. If the amount of epoxy resin is too small, it tends to be weak against thermocompression bonding. If the amount of the epoxy resin is too large, the adhesive force will be reduced and it will be difficult. The component c aliphatic sulfonium salt-based curing agent is preferably in the range of 0.01 to 40 parts by weight,
The amount is more preferably 0.1 to 20 parts by weight, still more preferably 0.5 to 8 parts by weight. If the amount of the aliphatic sulfonium salt-based curing agent is too small, it tends to be weak against thermocompression bonding. Further, if the amount of the aliphatic sulfonium salt-based curing agent is too large, problems such as precipitation of the aliphatic sulfonium salt-based curing agent in the adhesive solution are likely to occur. 10 to 10 phenolic resins
It is preferably used in the range of 100 parts by weight. If the amount of phenolic resin is too much, the adhesive strength will be poor.

An adhesive resin mixture solution is obtained by dissolving the above components in a solvent. As a solvent for dissolving each component of the adhesive, a mixed solvent of an aromatic solvent such as toluene, xylene, chlorobenzene, and benzyl alcohol and an alcohol solvent such as methanol, ethanol, isopropyl alcohol, and butyl alcohol is suitable.

Further, in the present invention, a protective film is formed on the adhesive layer, if necessary. The protective film is used for the purpose of dust prevention or handling,
Polyethylene, polypropylene, polyethylene terephthalate, polyphenylene sulfide, etc. are preferably used.

The adhesive tape for TAB is usually produced by any of the following methods (1) and (2).

(1) The adhesive resin mixture solution is applied to an organic insulating film and dried. At this time, it is preferable to apply so that the film thickness after drying is about 10 to 25 μm. The drying condition is usually 100 to 200.
C., in the range of 1 to 5 minutes. If necessary, a protective film having releasability is laminated on the film and slit to a desired width. Its width is usually about 35 to 158 cm.

(2) The adhesive resin mixed solution is applied and dried on a releasable film to be a protective film.
The coating film thickness at this time is 10 to 25 μm after drying.
It is preferably in the range of. The drying conditions are usually 100 to 200 ° C. and 1 to 5 minutes. If necessary, a second release film is laminated on the adhesive layer and similarly slit to a desired width. Then, the second release film is peeled off from the organic insulating film such as polyimide which is slit in advance to a desired width, and the adhesive surface is attached. Usually, the width of the organic insulating film that is the base material is set wider than the width of the adhesive.

FIG. 1 is a schematic sectional view of the adhesive tape for TAB according to the present invention. It is composed of a base material composed of the organic insulating film 1 and a protective film 3 adhered on the base material via an adhesive 2.

The TAB tape for mounting the IC is the TAB described above.
The tape is prepared through the following steps, using the adhesive tape.

Punching process for sprocket holes, device holes, etc. Protective film removal / copper foil laminating process Adhesive heating curing process Photoresist application / pattern exposure / development process Copper foil pattern etching process Photoresist peeling process (solder resist application process if necessary) ) Plating process (tin, solder, gold, etc.) The IC is mounted on the TAB tape thus obtained.

The operation of the present invention will be described below.

It is not clear why the aliphatic sulfonium salt-based curing agent of the present invention exerts unique performance when applied to a polyamide / epoxy system, but as will be described in detail in Examples and Comparative Examples, for example, 25 kg / c for polyamide resin / epoxy resin / phenolic resin (or polyparavinylphenol resin) / imidazole curing agent system proposed as an adhesive for TAB tape
When pressing the TAB tape conductor with a pressure of m ² , 10
While the conductor is buried in the adhesive at a temperature of 0 to 120 ° C, the aliphatic sulfonium salt-based epoxy curing agent of the present invention, for example, the general formula (1)

[Chemical 4] (Wherein each of R ₁ , R ₂ , and R ₃ represents a hydrocarbon group having 1 to 6 carbon atoms), the curing agent is 190.
The remarkable effect is that no burial occurs even at ℃.

That is, the technical content seems to be a simple compositional improvement at first glance, but as a result, the present inventors have found that it has an extremely excellent action and effect which could not be expected at all. is there.

Although the burying phenomenon of the conductor does not occur due to the pressing force at high temperature, the adhesiveness, chemical resistance, electric insulation and the like required for the adhesive for TAB tape must be maintained in a well-balanced manner. It was confirmed that the adhesive of the present invention is at a satisfactory level in these performances, and it was found that it can play a very important role industrially in the TAB mounting field.

[0033]

EXAMPLES The contents of the present invention will be described in detail below with reference to examples.

Each test was conducted as follows.

<Heat-pressing test method> TAB tape for performance examination: conductor width 200 μm pattern pitch 300 μm Heat-pressing tester: Nippon Avionics PULSE HEATE BO
NDER MODEL TCW-125 Heater chip 3 × 30mm Head pressure is set to 25kg, pressurization time is set to 6 seconds, a heat pressing test is performed while changing the heater temperature in steps of 10 ℃, and the temperature at which the conductor begins to bury in the adhesive. (This temperature is referred to as "heat distortion temperature") is measured. Practically, the heat distortion temperature is preferably 180 ° C. or higher.

<Adhesive force measuring method> TAB tape for performance examination: conductor width 200 μm Measuring machine: Orientec tensile tester A conductor is peeled in 90 ° direction at a speed of 50 mm / min and the stress at that time is measured. Generally, 1.0 kg / cm or more is required.

Example 1 A 75 μm-thick polyimide film (“UPILEX” 75S manufactured by Ube Industries, Ltd.) was coated with an adhesive solution having the following composition so that the dry film thickness was 18 μm, and an air oven was used for 1 hour at 100 ° C. Min, dried at 150 ° C. for 2 minutes.

<Adhesive Composition> 100 parts by weight of polyamide resin (Nylon 6.36 “PRIADIT” 2053 manufactured by Unichema, polyamide composed mainly of dimer acid and hexamethylenediamine, weight average molecular weight of about 100,000, 175 ° C. MI value at 10 gr / min) Epoxy resin 80 parts by weight (Yukaka Shell Co. "Epicoat" 152, novolac type, epoxy equivalent 175) Aliphatic sulfonium salt-based epoxy curing agent 2.0 parts by weight (Asahi Denka Kogyo KK Epoxy curing agent "Adeka Opton" CP-66) An adhesive solution is obtained by dissolving the above components in a mixed solvent of monochlorobenzene and methanol at a solid concentration of 20% by weight.

An electrolytic copper foil having a thickness of 35 μm was laminated on the adhesive-attached polyimide film obtained above by a roll laminating method. Then, in the air oven, 80 ℃
The adhesive was cured by heat treatment under the conditions of × 3 hours, 100 ° C × 5 hours, and 150 ° C × 5 hours.

Using the obtained TAB tape, a comb pattern was formed on the copper foil surface by a conventional method through photoresist coating, pattern exposure, development, copper foil pattern etching, and photoresist stripping steps. Further, a TAB tape for performance study was prepared by plating with a thickness of 0.5 μm using an immersion tin plating solution.

Example 2 A polyethylene terephthalate film having a thickness of 25 μm and subjected to a mold release treatment was coated with the same adhesive solution as in Example 1 by the same method as in Example 1 and dried. This thickness 125
120 ° C by roll laminating method on μm polyimide film (“Kapton” 500V manufactured by Toray DuPont)
A polyimide film with an adhesive was prepared by laminating at a temperature of. Using this, a TAB tape for performance study was produced in exactly the same manner as in Example 1.

Example 3 A TAB tape for performance study was prepared in the same manner as in Example 2 except that the adhesive components were as follows.

Polyamide resin 100 parts by weight (the same as Example 1 except that Henkel Nylon “MACROMELT” 6901, containing about 10% azelaic acid as a copolymerization component) Epoxy resin 80 parts by weight (same as Example 1) Phenol Resin 45 parts by weight (Sumitomo Chemical's "Sumilite Resin" PR50087, resole type) Curing agent for aliphatic sulfonium salt epoxy 2.5 parts by weight (Asahi Denka Kogyo's epoxy curing agent "Adeka Opton" CP-77) Comparative example 1-3 Example 1 except that the epoxy curing agent is Comparative Example 1: 2-methyl 4-ethylimidazole 0.5 parts by weight Comparative Example 2: diaminodiphenylmethane 1 part by weight Comparative Example 3: diaminodiphenylsulfone 1 part by weight. TA for performance study with exactly the same contents as
A B tape was produced.

Comparative Examples 4 to 6 The epoxy curing agent is Comparative Example 4: 2-methyl-4-ethylimidazole 0.5 part by weight Comparative Example 5: diaminodiphenylmethane 1 part by weight Comparative Example 6: diaminodiphenylsulfone 1 part by weight. Except for the above, the TA for performance examination has exactly the same contents as in Example 3.
A B tape was produced.

Table 1 shows the test results of the examples and comparative examples.

[0046]

[Table 1]

[0047]

The TAB tape made from the tape with adhesive for TAB according to the present invention has the same adhesiveness as the conventional one,
Insulation and chemical resistance, and I such as driver IC
When TCP mounted with C by TAB method is connected to liquid crystal display panel with thermosetting anisotropic conductive adhesive,
Since the IC mounted by the AB method can withstand the thermal stress when the resin molding is performed by the transfer molding method, the conductor is of high quality without being buried in the adhesive.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a tape with an adhesive for TAB of the present invention.

FIG. 2 is a schematic cross-sectional view of a TAB tape.

FIG. 3 is a schematic cross-sectional view showing a state in which a conductor of a TAB tape is embedded in an adhesive.

[Explanation of symbols]

 1: Organic insulating film 2: Adhesive 3: Protective film 4: Conductor

Claims (4)

[Claims] 1. A tape having an adhesive for TAB, which has a basic structure in which an organic insulating film and an adhesive layer or an organic insulating film, an adhesive layer and a protective film are laminated in this order, the adhesive layer comprising: a) polyamide resin,
An adhesive tape for TAB comprising (b) an epoxy resin and (c) a curing agent for an aliphatic sulfonium salt epoxy as an essential component. 2. The adhesive tape for TAB according to claim 1, wherein the polyamide resin contains a dicarboxylic acid having 36 carbon atoms as an essential component. 3. An aliphatic sulfonium salt-based epoxy curing agent is represented by the general formula (1): (In the formula, R ₁ , R ₂ , and R ₃ each represent a hydrocarbon group having 1 to 6 carbon atoms.) The tape with an adhesive for TAB according to claim 1 or 2, . 4. The TAB according to claim 1, wherein the adhesive layer further contains a phenol resin.
Adhesive tape.