JPH0770537A - Backing agent for production of tape carrier for tab - Google Patents

Abstract

PURPOSE:To obtain a backing agent for production of a tape carrier for TAB which does not cause the resist on a copper foil to crack during etching, does not cause the deformation or dissolution of leads, and can give a prescribed lead pattern with good precision by mixing a specified ester compound with a cresol novolac resin. CONSTITUTION:This backing agent is prepared by mixing an ester compound (e.g. Paogen PP-15, a product of Dai-ichi Kogyo Seiyaku KK) which is a reaction product of a polyhydroxy compound prepared by addition-polymerizing an alkylene oxide component desirably of an ethylene oxide content of 70wt.% or above with a compound having two active hydrogen groups and desirably having an average molecular weight of 1000 or above with a dicarboxylic acid with a cresol novolac resin (e.g. Sumilite Resin PR-51767, a product of Sumitomo Bakelite KK) desirably in a ratio of the former to the latter of 4:6 to 2:8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backing agent for manufacturing a tape carrier for TAB.

[0002]

As a tape carrier for TAB, a three-layer structure of a base film, an adhesive and a conductive layer, which is obtained by laminating a conductive layer such as a copper foil with an adhesive on a base film made of polyimide, epoxy containing glass, polyester or the like. Is used. This 3-layer TA
The tape carrier for B is generally manufactured by the following manufacturing process. That is, a step of forming required holes such as device holes and sprocket holes in a base film coated with an adhesive for laminating copper foil. Step of laminating copper foil on this film. A step of forming a resist pattern by applying a resist on a copper foil, exposing it, and developing it. A step of etching a copper foil to form a lead pattern. The process of plating the lead surface. Step of stripping the resist.

Of these, in the step of etching the copper foil to form a conductor pattern, the device is formed for the purpose of preventing the penetration of the etching liquid from the device hole side and the deformation of the leads due to the spray pressure of the etching liquid during etching. A method of filling a hole with a backing agent such as an etching resist is generally performed. However, the etching resist has a problem in that during etching, the resist used as the backing agent peels off and falls off, which breaks the resist on the copper foil and a prescribed lead pattern cannot be obtained.

For this reason, a method has been proposed in which a protective film such as a dry film is joined to the surface opposite to the surface laminated with the copper foil to reinforce it (JP-A-2-203545). However, this method has a problem in that voids remain at the ends of the device holes, and the etching liquid stays in those portions to dissolve the leads. In addition, the method of joining the protective film after filling the backing agent is not preferable because the number of steps is increased by one.

On the other hand, as this kind of backing agent, it is possible to form a film without leaving voids at the end of the hole simply by dissolving it in a solvent and coating and drying it on the device hole. Spray pressure (usually 1 kg / c
m ² ), which is tough enough to endure, is naturally insoluble in an etching solution (ferric chloride or cupric chloride), and is required to have good adhesion strength with a copper foil. It

[0006]

SUMMARY OF THE INVENTION The present invention has solved the above problems, and an object of the present invention is to prevent the backing agent from peeling off during etching and satisfying the above requirements. To provide a backing agent for manufacturing a tape carrier for TAB.

[0007]

As a result of earnest research, the present inventor has found that the above-mentioned problems can be achieved by using a specific compound as a backing agent.

That is, according to the present invention, as a backing agent for producing a tape carrier for TAB, (1) a reaction product of a polyhydroxyl compound obtained by addition-polymerizing an alkylene oxide with an organic compound having two active hydrogen groups and a divalent carboxylic acid. It is characterized by containing an ester compound which is a product and (2) a cresol-novolak type resin.

In the present invention, an ester compound which is a reaction product of a polyhydroxyl compound obtained by addition-polymerizing an alkylene oxide with an organic compound having two active hydrogen groups and a divalent carboxylic acid (hereinafter, in the present invention,
(Referred to simply as “ester compound”) is disclosed in JP-A-4-35.
The high molecular weight compounds described in 6526 and JP-A-5-5031 are preferred.

This high molecular weight compound has an ethylene oxide content of 70 in addition to an organic compound having two active hydrogen groups.
A reaction product of a polyhydroxyl compound having an average molecular weight of 1000 or more and an ethylene oxide content of 68% by weight or more obtained by addition polymerization of alkylene oxide in an amount of at least% by weight, and a dicarboxylic acid having a degree of polymerization of 4.5. ~ 21,
It is a water-soluble and moldable ester compound having an average molecular weight of more than 20,000.

When an alkylene oxide having an ethylene oxide content of less than 70% by weight is used, the product is water-swellable and is not completely dissolved in water, which is not preferable. When the average molecular weight of ethylene oxide obtained by addition polymerization of alkylene oxide having an ethylene oxide content of 70% by weight or more is less than 1,000,
It is not preferable because it has no film forming ability.

If the degree of polymerization is less than 4.5, there is no film-forming ability, and if the degree of polymerization exceeds 21, it becomes insoluble in water, which is not preferable. On the other hand, the average molecular weight of the ester compound is larger than 20,000, preferably 30,000.
More preferably, it is 50,000 or more. 2000
A value of 0 or less is not preferable because it has no film forming ability.

Such an ester compound is water-soluble and has film-forming ability, but has a problem of poor adhesion. Therefore, in order to improve the adhesion, the present invention is characterized by adding a cresol novolac type resin to the above ester compound. Generally, a cresol novolac type resin has a problem in that it has good adhesion but the resulting film is brittle. By using the cresol novolac type resin in combination with the above ester compound, the advantages of both can be utilized and the problem can be solved.

As the cresol novolac type resin used in the present invention, metacresol and paracresol as the raw materials are 8: 2 to 4: 6, preferably 7: 3 to.
It is preferable to react one having a ratio of 5: 5, particularly preferably 6: 4. If it exceeds 8: 2, the adhesion will be poor, and if it is less than 4: 6, the solubility will be poor. And, those having a molecular weight of 1000 to 3000, a viscosity in a 50% ethanol solution of 50 to 100 cP, and a melting point of 50 to 100 ° C.
It is preferable to take into account the viscosity of the solution and the shortening of dissolution removal.

The mixing ratio of the cresol novolac type resin and the ester compound is 6: 4 to 8: 2, particularly preferably 7: 3. If it is less than 6: 4, the adhesion will be poor, while if it exceeds 8: 2, the film will be brittle.

The backing agent containing the ester compound of the present invention and the cresol-novolak type resin can be used by mixing with other compounds or resins, and especially when a tackifier, a plasticizer and the like are mixed and used. , Which is a backing agent having higher adhesiveness and flexibility.

Next, the ester compound of the present invention and cresol
The backing agent containing the Lunovolac type resin is used by being dissolved or dispersed in a solvent. In this case, the solid content is 10
It is desirable to adjust the amount of solvent so that the amount becomes 30%. If the solid content is less than 10%, uneven coating tends to occur,
Further, if it exceeds 30%, it becomes difficult to dry.

As the solvent, commonly used solvents such as alcohols such as methanol and ethanol, ketones such as MEK, glycols and the like can be used. In order to prevent precipitation even at 0 ° C., A mixed solution of ethyl carbitol, acetone and water is preferable, and the ratio thereof is 5 to 7: 2 to 4: 0.5 to 1, preferably 6 :.
It is 3: 1.

The backing agent is removed before and after the removal of the resist for pattern formation after the etching is completed. However, the ester compound is water-soluble and the cresol novolac type resin is soluble in an aqueous NaOH solution. Can be dissolved and removed simultaneously with the resist for use.

When the backing agent of the present invention is used, the film thickness is preferably 15 to 30 μm. If it is less than 15 μm, the spray pressure of the etching solution cannot be withstood, and if it exceeds 30 μm, peeling becomes difficult, which is not desirable.

[0021]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited thereto.

An epoxy adhesive was applied to a polyimide film having a width of 35 mm and a thickness of 0.1 mm to form a device hole having an area of 50 mm ² . This tape was laminated with a rolled copper foil having a thickness of 0.025 mm. Apply positive photoresist on the surface of copper foil, and make it 0.6mm long on the device hole.
A lead pattern having a width of 0.08 mm and a number of 40 was exposed and developed.

A cresol novolac type resin (Sumilite resin PR-51767, Sumitomo Beer Co., Ltd.) produced by using metacresol: paracresol = 6: 4 as a raw material.
Klite Co., Ltd. and ester compound (Paogen (PP
-15), manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) at a ratio of 7: 3, and a backing agent obtained by dissolving this in a solvent having a mixing ratio of ethylcarbitol: acetone: water = 6: 3: 1. After applying 70 μm in the device hole, it was dried. As a comparative example, a method of joining dry films was performed, but in this case, lamination was performed at a roll temperature of 140 ° C.

These were further immersed in an etching solution containing an aqueous solution of cupric chloride for etching, and the presence or absence of deformation and dissolution of the leads was confirmed by an optical microscope (50 times). Then, the remaining positive photoresist is exposed again (100
0 mJ / cm ² ) and immerse the film in a 2% NaOH aqueous solution at 25 ° C for 4 minutes to dissolve and remove the photoresist and the backing agent.
(50 times) confirmed.

As a result, when the backing agent of the present invention was used, film (resist) destruction and film peeling did not occur, lead deformation and lead dissolution did not occur, and the backing agent was completely removed. Although it was dissolved, when a dry film was used, a void remained at the end of the device hole, and the etching solution stayed in that portion, causing dissolution of the lead.

[0026]

As described above, by using the backing agent according to the present invention, during etching, the backing agent does not peel off and fall off, and the resist on the copper foil is not cracked. Can prevent dissolution,
A specified lead pattern can be obtained with high accuracy.

Claims (1)

[Claims] 1. An ester compound which is a reaction product of a polyhydroxyl compound obtained by addition-polymerizing an alkylene oxide to an organic compound having two active hydrogen groups and a divalent carboxylic acid, and (2) a cresol novolak type compound. A backing agent for producing a tape carrier for TAB, which contains a resin.