JPH05114673A - Back fixing agent for manufacturing tab tape carrier - Google Patents

Abstract

PURPOSE:To prevent the deformation and melting of leads by using a polymer selected output of one or two kinds among the copolymer of alkylacrylate and acrylic acid, a cresol novolak type resin, and the copolymer of alkylacrylate and alkylmethacrylate. CONSTITUTION:A copolymer selected out of one or two kinds selected from among the copolymer of alkylacrylate and acrylic acid, a cresol novolak type resin, and the copolymer of alkylacrylate and alkylmethacrylate is used. It is preferable to use copolymers of alkylacrylate and acrylic acid and alkylacrylate and alkylmethacrylate respectively having 3 to 50 degrees of polymerization degrees and 5:1 to 1:5 molar ratio. Therefore, the deformation and melting of leads can be prevented, since a resist on copper foil is not broken by a stripped off and falling down lump of a resist.

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]

2. Description of the Related Art As a TAB tape carrier, a three-layer structure of a base film, an adhesive and a conductive layer in which a conductive layer such as a copper foil is laminated 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.

Among them, in the step of etching the copper foil to form the conductor pattern, the device is formed in order to prevent the penetration of the etching solution from the device hole side and the deformation of the lead due to the spray pressure of the etching solution during the 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 is peeled off and falls off, whereby the resist on the copper foil is cracked and a prescribed lead pattern cannot be obtained.

Therefore, a method has been proposed in which a protective film such as a dry film is joined to the surface of the dry film opposite to the surface laminated with the copper foil to reinforce the dry film (Japanese Patent Laid-Open No. 2-2).
No. 03545). However, this method has a problem in that a void remains at the end of the device hole, and the etching liquid stays in that portion to dissolve the lead. 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 withstand m ² ), is naturally insoluble in an etching solution (ferric chloride or cupric chloride), and is required to have good adhesive strength with a copper foil. It

[0006]

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

[0007]

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

That is, the present invention comprises one or more of a copolymer of alkyl acrylate and acrylic acid, a cresol novolac type resin, or a copolymer of alkyl acrylate and alkyl methacrylate as a backing agent for producing a tape carrier for TAB. It consists of using the selected polymer.

The above-mentioned copolymer of alkyl acrylate and acrylic acid has a degree of polymerization of 3 to 50, particularly 6 to 12.
With alkyl acrylate: acrylic acid 5: 1
A molar ratio of ˜1: 5 is preferred, and as the alkyl group in the alkyl acrylate, a methyl group or an ethyl group is particularly desirable for the viscosity of the solution and the shortening of dissolution removal.

On the other hand, as the cresol novolac type resin, one 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. is particularly preferable.

Further, the copolymer of alkyl acrylate and alkyl methacrylate has a degree of polymerization of 3-5.
0, especially 6 to 11, alkyl acrylates:
Alkyl methacrylate having a molar ratio of 5: 1 to 1: 5 is particularly preferable, and a methyl group or an ethyl group is used as an alkyl group in the alkyl acrylate and the alkyl methacrylate in order to reduce the viscosity of the solution and the dissolution removal. , Especially desirable.

These resins can be used alone or as a mixture with other resins. Particularly, when a copolymer of alkyl acrylate and acrylic acid and a cresol novolac type resin are used as a mixture, the film strength is improved. It is excellent and can withstand fairly powerful etching sprays.

These resins are used after being dissolved or dispersed in a solvent. In this case, it is desirable to adjust the amount of solvent so that the solid content is 10 to 30%. Solid content is 10
If it is less than 30%, uneven coating tends to occur, and if it exceeds 30%, it becomes difficult to dry. As the solvent, solvents of these commonly used resins such as alcohols such as methanol and ethanol, ketones such as MEK, and glycols can be used.

The backing agent is removed before and after the removal of the resist for pattern formation after the etching is completed. The copolymer of alkyl acrylate and acrylic acid and the cresol novolac type resin are used in an aqueous NaOH solution, and the alkyl acrylate and alkyl methacrylate are used. Since the copolymer (1) is soluble in a solvent such as acetone or methanol, it can be dissolved and removed simultaneously with the pattern forming resist.

When the backing agent of the present invention is used, the film thickness is preferably 10 to 30 μm, and if it is less than 10 μm, it cannot withstand the spray pressure of the etching solution, and if it exceeds 30 μm, peeling becomes difficult, which is not desirable.

[0016]

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 0.025 mm thick rolled copper foil. Positive type photoresist is applied on the surface of copper foil, and the length is 0.6mm on the device hole.
A lead pattern having a width of 0.08 mm and a number of 40 was exposed and developed. Then, the backing agent shown in Table 1 was applied inside the device hole and dried. As a comparison, a method of joining dry films was performed in Comparative Example 2, but in this case, lamination was performed at a roll temperature of 140 ° C. These are further etched by immersing the copper foil in an etching solution consisting of an aqueous solution of ferric chloride, and checking the presence or absence of lead deformation and dissolution with an optical microscope (5
0 times). Then, the remaining positive photoresist was exposed again (1000 mJ / cm ² ) to obtain a 9% Na solution.
The tape and the backing agent were dissolved and removed by immersing the tape in an OH aqueous solution (acetone was used in Example 3) at 25 ° C. for 4 minutes, and the presence or absence of the backing agent was checked by an optical microscope.
(50 times) confirmed. The results are shown in Table 2.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

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

Claims (1)

[Claims] 1. A copolymer of alkyl acrylate and acrylic acid, a cresol novolac type resin, or a copolymer of alkyl acrylate and alkyl methacrylate.
A backing agent for producing a tape carrier for TAB, which contains a polymer selected from two or more kinds.