JPH06333994A - Tape for tab and its manufacture - Google Patents

Abstract

PURPOSE:To make possible a tape for TAB using a base film which has high elasticity and low moisture absorption and specified property of thermal expansion coefficient by providing an adhesive layer and a protective layer on a specified polyimide film. CONSTITUTION:A tape for TAB is constituted of a polymide film expressed by the formula. An adhesive film layer and a protective film are provided on this polyimide film. Further, it is to be desired that the thermal expansion coefficient of the base film should be about 0.4-2.0X10<-5> deg.C-<1>. Among the formula, R1 is a linear diamine residual group, and R2 is a flexural diamine residual group, and n expresses the integer not less than 1. Since the tape for TAB is constituted with this polyimide film as a base film hereby, this does not cause any warp or any curl, and since the dimensional change in processing and mounting is small, this becomes a material suitable for a tape carrier package in multipin and high density pattern.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective layer, an adhesive layer, and a protective layer used in a TAB (Tape Automated Bonding) technique, which is attracting attention as a technique capable of accommodating multi-pins, miniaturization and high-density mounting of semiconductor devices. The present invention relates to a tape having a three-layer structure of an organic insulating film (hereinafter referred to as TAB tape) and a method for manufacturing the same.

[0002]

2. Description of the Related Art Processing steps for processing a TAB tape and mounting an LSI include the steps of forming sprocket holes and device holes by punching, removing a protective layer, and then removing a copper foil. Laminating, curing adhesive, forming wiring pattern (resist coating, copper foil etching, resist peeling),
There are several types of processes such as plating, inner lead bonding of LSI chips, resin sealing, punching, and outer lead bonding to a substrate, and the LSI is mounted on the substrate through the above processing steps. Therefore, T
In order to mount the LSI on the AB tape, the base film needs to have a “brush” that supports the LSI, that is, high elasticity.

Of these processing steps, the processing steps of copper foil laminating, adhesive curing, inner lead bonding, resin encapsulation, and outer lead bonding are exposed to heat during the process.
If the difference between the coefficient of thermal expansion of the base film of the tape for B and the coefficient of thermal expansion of other materials such as LSI, copper foil, and substrate is extremely large, inconvenience occurs. That is, in the processing step of inner lead bonding, a difference in thermal expansion between the base film and the LSI causes a shift in the bonding position between the inner lead and the LSI. Similarly, in the outer lead bonding processing step, a deviation occurs in the bonding position between the outer lead and the substrate.

Further, in the copper foil laminating process, the TAB tape is heat-pressed together with the copper foil. Therefore, if the difference in the coefficient of thermal expansion between the TAB tape base film and the copper foil is extremely large, The copper foil causes warping and curling of the laminated film.

Therefore, in the process of inner lead bonding, LSI (silicon wafer) is used.
And the thermal expansion coefficient of the base film are close to each other (the thermal expansion coefficient of the LSI is 0.4 × 10 ^-5 ° C ^-1 ), and in the outer lead bonding processing step, the thermal expansion coefficient of the substrate to be joined and the base film is large. Are preferably close to each other, and in the processing step of copper foil laminating, the thermal expansion coefficients of the copper foil and the base film (the thermal expansion coefficient of the copper foil 1.6 × 10 ⁻⁵ ° C. ⁻¹ ) are preferably close to each other.

When the moisture absorption rate of the base film is high, the electrical characteristics are deteriorated, and the dimensional change occurs between the processes due to the difference in the moisture absorption amount of the base film in each process, and the dimensional change due to the thermal expansion is caused. Similarly, the base film preferably has low hygroscopicity because warpage, curling, and poor bonding occur.

Therefore, it is desirable that the base film used for the TAB tape has high elasticity and low hygroscopicity, and has a coefficient of thermal expansion of about 0.4 to 2.0 × 10 ^-5 ° C ^-1. , TA using a base film having these properties
The advent of tapes for B has been awaited.

[0008]

SUMMARY OF THE INVENTION The present inventors have proposed a conventional TA
TAB which solved the above problems in B tape
As a result of repeated studies for the purpose of providing tapes for
The present invention has been accomplished by finding a TAB tape in which an adhesive layer and a protective layer are provided on a predetermined polyimide film.

The gist of the TAB tape according to the present invention is as follows:

[Chemical 4] (In the formula, R ₁ is a linear diamine residue, R ₂ is a flexible diamine residue, and n is an integer of 1 or more.).

In the TAB tape, an adhesive layer and a protective layer are provided on the polyimide film.

Next, the gist of the method for producing a TAB tape according to the present invention is to add 4,4'-oxydiphthalic anhydride to at least one linear diamine,
Then, at least one flexible diamine is added to the 4,4 '
-Added so that the molar amount of oxydiphthalic anhydride and the total molar amount of each diamine are substantially equimolar,

[Chemical 5] (In the formula, R ₁ is a linear diamine residue, R ₂ is a flexible diamine residue, and n is an integer of 1 or more.) A polyamic acid copolymer having a structural unit represented by the following formula is polymerized: Further, a compound obtained by dehydration ring closure of the polyamic acid copolymer

[Chemical 6] (In the formula, R ₁ is a linear diamine residue, R ₂ is a flexible diamine residue, and n is an integer of 1 or more.).

In the method for producing the TAB tape, an adhesive layer and a protective layer are laminated on the obtained polyimide film.

Further, in the method for producing a tape for TAB, the linear diamine comprises 50 to 9 of all diamine components.
9 mol%, the flexible diamine is 1 to 1 of all diamine components.
It is in the ratio of 50 mol%, more preferably linear diamine in the ratio of 75 to 95 mol% of the total diamine component, and flexible diamine in the ratio of 5 to 25 mol% of the total diamine component.

[0014]

EXAMPLES Examples of the TAB tape and the method for producing the same according to the present invention will be described in detail below.

The TAB tape according to the present invention comprises a predetermined polyimide film provided with an adhesive layer and a protective layer. And this predetermined polyimide film is

[Chemical 7] (In the formula, R ₁ is a linear diamine residue, R ₂ is a flexible diamine residue, and n is an integer of 1 or more.) Obtained by dehydrating and ring-closing a polyamic acid copolymer. .

Here, the linear diamine used in the present invention does not include a bending group such as an ether group, a methylene group, a propargyl group, a hexafluoropropargyl group, and a carbonyl group in the main chain, and is composed of two linear diamines. A diamine compound having a structure in which the nitrogen atom of an amino group and the carbon atom to which they are bound are aligned. For example,

[Chemical 8] (However, in the formula, X is F, Cl, Br, CH ₃ , CH ₃
O and CF ₃ are shown. The diamine etc. which are shown to these can be illustrated.

On the other hand, the flexible diamine is an ether group,
A diamine containing a bending group such as a methylene group, a propargyl group, a hexafluoropropargyl group, and a carbonyl group in the main chain, or, in the case of not containing a bending group, nitrogen atoms of two amino groups and carbons bonded to them. A diamine compound having a structure in which the atoms are not aligned. For example, chemical formula 9, chemical formula 10, and chemical formula 11

[Chemical 9]

[Chemical 10]

[Chemical 11] (However, in the formula, X is H, F, Cl, Br, CH ₃ , C
H ₃ O and CF are shown. The diamine etc. which are shown to these can be illustrated.

The polyimide film used in the TAB tape of the present invention is obtained from the polyamic acid copolymer solution which is the precursor thereof shown in the above chemical formula 5, and the polyamic acid copolymer solution contains the acid dianhydride component. It is obtained by polymerizing in a polar organic solvent, using substantially equimolar amounts of the diamine component.

Here, 4,4'-oxydiphthalic anhydride is used as the acid dianhydride. By using this acid dianhydride, the water absorption of the obtained polyimide film can be suppressed low. This is because the electron-donating ether group contained in the 4,4′-oxydiphthalic anhydride residue suppresses the polarizability of the imide group to a low level, and as a result, the amount of water molecules adsorbed on the imide group may be reduced. Probably the cause.

As the diamine component, one or more kinds of linear diamines and one or more kinds of flexible diamines can be used in combination at an arbitrary ratio, and preferably the linear diamine is 50 to 50% of all diamine components. 99 mol%, flexible diamine is 1 to 50 mol% of all diamine components, and more preferably linear diamine is 75 to 95 of all diamine components.
mol%, flexible diamine is 5 to 25 m of all diamine components
Used in the ratio of ol%. When the ratio of the linear diamine is larger than this, the polyimide film becomes brittle,
Further, the coefficient of linear expansion becomes too low. On the other hand, if the ratio of the flexible diamine is larger than this, the elastic modulus becomes small.

Of the diamine components, paraphenylenediamine is more preferably used as the linear diamine. Paraphenylenediamine does not have an aliphatic substituent, and therefore has excellent heat resistance. Further, it is more preferable to use 4,4′-diaminodiphenyl ether as the flexible diamine. Among the flexible diamines, 4,4′-diaminodiphenyl ether has relatively high heat resistance and excellent chemical stability.

Next, examples of the organic polar solvent used in the reaction for producing the polyamic acid copolymer include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N-dimethylformamide and N, N-diethylformamide. Formamide solvents such as N, N-
Acetamide solvents such as dimethylacetamide and N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, m-, or p-cresol, xylenol , Halogenated phenols, phenolic solvents such as catechol, hexamethylphosphoramide, γ-butyrolactone, and the like. It is preferable to use these singly or as a mixture, but it is also possible to partially use an aromatic hydrocarbon such as xylene or toluene.

The polyamic acid copolymer solution obtained by polymerizing the acid dianhydride component and the diamine component in substantially equimolar amounts in an organic polar solvent in this way is dehydrated and ring-closed.
Converted to polyimide. The average molecular weight of this polyimide is preferably 10,000 to 1,000,000. If the average molecular weight is less than 10,000, the resulting film becomes brittle, while if it exceeds 1,000,000, the viscosity of the polyamic acid varnish, which is the polyimide precursor, becomes too high, which is not preferable because it is difficult to handle.

It is also possible to compound various organic additives or inorganic fillers or various reinforcing materials with this polyimide film.

Next, a method for synthesizing a polyamic acid copolymer solution will be specifically shown. First, an organic polar solvent and at least one linear diamine are placed in a container, and the mixture is cooled and stirred. Next, an excess amount of 4,4′-oxydiphthalic anhydride, which is in excess of the molar amount of the linear diamine, is added to the above reaction solution, and the mixture is cooled and stirred for preferably 20 minutes or more. Then, one or more kinds of flexible diamines are gradually added as a shortage diamine component while cooling and stirring so that the molar amount of 4,4′-oxydiphthalic anhydride and the molar amount of all diamine components become equal, Thus, a polyamic acid copolymer solution represented by the above chemical formula is obtained.

The obtained polyamic acid copolymer is preferably dissolved in the organic polar solvent in an amount of 5 to 40% by weight, preferably 10 to 30% by weight, from the viewpoint of handling.

From the aromatic polyamic acid copolymer solution represented by the chemical formula 7, the chemical formula 12 according to the present invention can be obtained.

[Chemical 12] (In the formula, R ₁ is a linear diamine residue, R ₂ is a flexible diamine residue, and n is an integer of 1 or more.) A chemical method or a chemical method using a dehydrating agent may be used, but the chemical method is preferable because the resulting polyimide film has excellent mechanical properties such as elongation and tensile strength.

An example of a method for producing a polyimide film will be described below. A solution prepared by adding a stoichiometric or more stoichiometric dehydrating agent and a catalytic amount of a tertiary amine to the polyamic acid copolymer or a solution thereof is cast or coated on a support such as a drum or an endless belt to form a film, The film 150
The film is dried at a temperature of ℃ or less for about 5 to 90 minutes to obtain a self-supporting polyamic acid film. Then, this is peeled off from the support and the end is fixed. After that, about 100-500 ℃
It is imidized by gradually heating to, and after cooling it is removed to obtain a polyimide film used for the TAB tape of the present invention.

Examples of the dehydrating agent include aliphatic acid anhydrides such as acetic anhydride and aromatic acid anhydrides such as benzoic anhydride. Examples of the catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as pyridine, picoline, and isoquinoline.

The TAB tape of the present invention has a thickness of 2
A polyimide film having a thickness of about 5 μm to 180 μm is used, but 50 μm to 12 from the balance of convenience in handling, film strength, thinning requirement for downsizing, and the like.
5 μm is more preferable.

Next, as the adhesive used in the TAB tape of the present invention, for example, epoxy resin, polyamide resin, phenol resin, acrylic resin, polyimide resin,
A rubber-based resin or the like may be used alone or mixed in various proportions with a solvent, and may further contain additives such as a curing agent and a curing accelerator, if necessary.

As the protective film to be the protective layer of the adhesive layer, any film may be used as long as it has heat resistance to the extent that it does not soften or deteriorate when the adhesive is dried, but polyethylene terephthalate, etc. The polyester film or polyolefin film such as polypropylene is preferable.

The TAB tape according to the present invention is manufactured by providing the above-mentioned predetermined polyimide film with an adhesive layer and a protective film serving as a protective layer. More specifically, first,
An adhesive having a predetermined composition is uniformly applied onto the protective film so as to have a final film thickness of 8 to 40 μm, preferably 10 to 30 μm. Then, the adhesive solution is dried to bring the adhesive layer into a semi-cured state (B-staged state). After that, a polyimide film is overlaid on the adhesive layer on the protective film and pressure-bonded at ^{20 to} 180 ° C. under a condition of 0.1 kg / cm ² or more to obtain a TAB tape.

The obtained TAB tape was used for T
As mentioned above, in order to manufacture the AB tape, the TA is usually used.
The tape for B is subjected to predetermined punching, the protective film is peeled off, the copper foil is thermocompression-bonded, the adhesive is cured, and the copper foil is etched to form a circuit, whereby the TAB tape is manufactured. Of.

Next, examples of the present invention will be described in detail. Less than,
The present invention will be specifically described with reference to examples, but the present invention is not limited to these examples, and the present invention is variously changed based on the knowledge of those skilled in the art without departing from the spirit of the present invention. It can be implemented in a mode in which improvements, modifications and variations are added.

In the examples, ODA is 4,4'-diaminodiphenyl ether, p-PDA is paraphenylenediamine, m-PDA is metaphenylenediamine, PMDA is pyromellitic dianhydride, and ODPA is 4,4'-oxydiphthalate. Acid anhydride and DMF represent N, N-dimethylformamide.

Example 1 DMF and p-PDA (3 equivalents) were placed in a separable flask, well stirred at room temperature until the diamine compound was completely dissolved, and then cooled with ice. Then add ODPA4 to this solution.
An equivalent amount was added, and the mixture was cooled and stirred for 40 minutes. And ODA1
An equivalent amount was dissolved in DMF, this ODA solution was gradually added to the reaction solution, and then the mixture was cooled and stirred for 1 hour to obtain a DMF solution of polyamic acid. The amount of DMF used was such that the monomer charge concentration of diamines and aromatic tetracarboxylic dianhydrides was 18% by weight.

Next, the polyamic acid solution thus obtained is cast-coated on a glass plate, dried at about 100 ° C. for about 30 minutes, and then the polyamic acid coating film is peeled off from the glass plate. The coating film of the polyamic acid is fixed to a support frame, and then heated at about 100 ° C. for about 30 minutes, about 200 ° C. for about 60 minutes, and about 300 ° C. for about 60 minutes to dehydrate and ring-close and dry, A polyimide film having a thickness of about 75 μm was obtained.

The physical properties of the obtained polyimide film are shown in Table 1.
Shown in.

[Table 1]

Then, 50 parts of a bisphenol A type epoxy resin (E1001 / made by Yuka Shell Epoxy Co.) on a polyethylene terephthalate (PET) film for a protective film having a surface treated with a release agent, and a cresol novolac type epoxy resin (180H65 / oil). Made by Epoxy Shell Epoxy Co., Ltd. 1
An adhesive consisting of 0 part, 40 parts of polyamide resin (M1276 / manufactured by Rilsan Japan), 7 parts of diaminodiphenylsulfone, 2 parts of dicyandiamide, 35 parts of toluene, and 15 parts of isopropyl alcohol was applied to a thickness of about 20 μm after drying. And dried at 150 ° C. for 10 minutes. This PET film with an adhesive was slit to a width of 27 mm, and this PET film was pressure-bonded to the above polyimide film slit to a width of 35 mm at 40 ° C. to obtain a TAB tape.

After removing the PET tape from the TAB tape, the adhesive surface and the copper foil (Low-profile manufactured by Mitsui Metal Co., Ltd.
Electrolytic copper foil VLP-3EC) was laminated at 120 ° C., the appearance was observed in this state, and the dimensional change rate after etching was measured according to the following method. That is, after laminating a copper foil on a base polyimide film, heating and curing it, two marking holes a and b for measuring the dimensional change rate are punched in the MD direction (machine manufacturing direction). The initial value L ₁ between a and b of was measured. Next, the entire surface of the copper foil was etched, and L ₂ between a and b was measured. Then, the dimensional change rate before and after etching was calculated based on the following calculation formula. The dimensional change rate = (L ₁ -
L ₂ ) / L ₁ × 100% The results are shown in Table 1.

Example 2 DMF and p-PDA (7 equivalents) were placed in a separable flask, stirred well at room temperature until the diamine compound was completely dissolved, and then cooled with ice. Then add ODPA8 to the solution.
An equivalent amount was added, and the mixture was cooled and stirred for 40 minutes. And ODA1
An equivalent amount was dissolved in DMF, the ODA solution was gradually added to the reaction solution, and then the mixture was cooled and stirred for 1 hour to obtain a DMF solution of polyamic acid. And it baked by the method similar to Example 1, and obtained a 75-micrometer polyimide film.

The physical properties of the obtained polyimide film are shown in Table 1.
Shown in. Using this polyimide film, a TAB tape was obtained in the same manner as in Example 1, laminated with a copper foil, and the appearance was observed and the dimensional change was measured. The results are shown in Table 1.

Example 3 DMF and p-PDA (3 equivalents) were placed in a separable flask, stirred well at room temperature until the diamine compound was completely dissolved, and then cooled with ice. Then add ODPA4 to the solution.
An equivalent amount was added, and the mixture was cooled and stirred for 40 minutes. And m-PD
A1 equivalent of A was dissolved in DMF, the m-PDA solution was gradually added to the reaction solution, and then the mixture was cooled and stirred for 1 hour to obtain a DMF solution of polyamic acid. And it baked by the method similar to Example 1, and the polyimide film was obtained.

The physical properties of the obtained polyimide film are shown in Table 1.
Shown in. Using this polyimide film, a TAB tape was obtained in the same manner as in Example 1, laminated with a copper foil, and the appearance was observed and the dimensional change was measured. The results are shown in Table 1.

Example 4 DMF and p-PDA (7 equivalents) were placed in a separable flask, stirred well at room temperature until the diamine compound was completely dissolved, and then cooled with ice. Then add ODPA8 to the solution.
An equivalent amount was added, and the mixture was cooled and stirred for 40 minutes. And m-PD
A1 equivalent of A was dissolved in DMF, this m-PDA solution was gradually added to the reaction solution, and then the mixture was cooled and stirred for 1 hour to obtain a DMF solution of a polyamic acid. And it baked by the method similar to Example 1, and the polyimide film was obtained.

The physical properties of the obtained polyimide film are shown in Table 1.
Shown in. Using this polyimide film, a TAB tape was obtained in the same manner as in Example 1, laminated with a copper foil, and the appearance was observed and the dimensional change was measured. The results are shown in Table 1.

Comparative Example 1 In the same manner as in Example 1 above, a polyimide film was obtained using PMDA and ODA in equimolar amounts.

The physical properties of the obtained polyimide film are shown in Table 1.
Shown in. Using this polyimide film, a TAB tape was obtained in the same manner as in Example 1, laminated with a copper foil, and the appearance was observed and the dimensional change was measured. The results are shown in Table 1.

Comparative Example 2 DMF and 1 equivalent of p-PDA were placed in a separable flask, well stirred at room temperature until the diamine compound was completely dissolved, and then cooled with ice. Then add PMDA2 to the solution.
An equivalent amount was added, and the mixture was cooled and stirred for 40 minutes. And ODA1
An equivalent amount was dissolved in DMF, this ODA solution was gradually added to the reaction solution, and then the mixture was cooled and stirred for 1 hour to obtain a DMF solution of polyamic acid. And it baked by the method similar to Example 1, and the polyimide film was obtained.

The physical properties of the obtained polyimide film are shown in Table 1.
Shown in. Using this polyimide film, a TAB tape was obtained in the same manner as in Example 1, laminated with a copper foil, and the appearance was observed and the dimensional change was measured. The results are shown in Table 1.

[0052]

As described above, the tape for TAB and the method for producing the same according to the present invention have a high elasticity and a suitable line by copolymerizing 4,4'-oxydiphthalic anhydride with a linear diamine and a flexible diamine. It is possible to obtain a polyimide film having a coefficient of expansion, appropriate flexibility and low hygroscopicity. Therefore, by constructing a TAB tape using this polyimide film as a base film, warping and curling do not occur, and the dimensional change during processing and mounting is small, making it a tape carrier package with a multi-pin high-density pattern. It becomes a suitable material.

Claims (5)

[Claims] 1. The following formula 1 (Wherein R ₁ is a linear diamine residue, R ₂ is a flexible diamine residue, and n is an integer of 1 or more).
AB tape. 2. The tape for TAB according to claim 1, wherein an adhesive layer and a protective layer are provided on the polyimide film. 3. At least one linear diamine,
4,4'-oxydiphthalic anhydride is added, and then at least one flexible diamine is added such that the molar amount of the 4,4'-oxydiphthalic anhydride and the total molar amount of each diamine are substantially. Add the following formula 2 (In the formula, R ₁ is a linear diamine residue, R ₂ is a flexible diamine residue, and n is an integer of 1 or more.) A polyamic acid copolymer having a structural unit represented by the following formula is polymerized: Furthermore, the polyamic acid copolymer is obtained by dehydration ring closure. (Wherein R ₁ is a linear diamine residue, R ₂ is a flexible diamine residue, and n is an integer of 1 or more.), And a TAB tape is produced. Manufacturing method. 4. An adhesive layer and a protective layer are laminated on the obtained polyimide film.
A method for manufacturing a TAB tape according to item 1. 5. The linear diamine is 50 to 99 mol% of the total diamine component, the flexible diamine is 1 to 50 mol% of the total diamine component, and more preferably the linear diamine is 75 to 95 mol% of the total diamine component. %, And the flexible diamine is a ratio of 5 to 25 mol% of the total diamine component, The method for producing a TAB tape according to claim 3 or 4, wherein