JP2584895B2 - Polyimide adhesive composition - Google Patents

Description

The present invention relates to a polyimide adhesive composition, and more particularly, to the use of a highly adhesive polyimide composition as a substrate material that is directly adhered to copper foil. These materials are used for flexible printed circuit boards and tape automated tapes.
Suitable for manufacturing bonding) (TAB). They are also applicable to polyimide thin film packaging technology.

[Background of the Invention]

Polyimides have found wide application in the electronics industry, such as flexible printed circuit boards, self-adhesive tapes (TABs), and thin film packages, due to their high heat resistance and low dielectric constant. However, polyimide has the disadvantage of lower adhesion to copper. Additionally, an adhesive is applied between the copper foil and the polyimide film, usually to improve the bond strength. The resulting flexible printed circuit boards and self-adhesive tapes (TAB) are of poor quality because the heat resistance of the adhesive used is weaker than that of the polyimide substrate. Adhesiveless assembly greatly improves overall performance.

The use of modified polyimides to increase the bond strength between the polyimide substrate and the copper foil has been disclosed by the prior art, such as JP-A-62-278687 and SAMPLE Journal July / August 1988. These known references disclosed that the adhesion of the polyimide substrate was improved by including siloxane segments in the polyimide backbone polymer.
However, the inclusion of siloxane greatly reduces the glass transition temperature of the polyimide and causes phase-separation. Therefore, a homogeneous polyimide film cannot be produced.

JP-A-61-48318 and JP-A-6-141077,
It has been disclosed to incorporate bismaleimide into a polyimide material to improve the heat resistance of the final product. But,
These prior patents do not effectively increase the adhesion between the copper foil and the polyimide substrate.

(Summary of the Invention)

Accordingly, a primary object of the present invention is to provide a flexible printed circuit board,
The object is to provide a high adhesion and high heat resistant polyimide that can eliminate the need for an adhesive between copper foil and a polyimide substrate when fabricating automatic adhesive tape (TAB) and thin film packages.

The polyimide adhesive composition of the present invention includes a product obtained by reacting a reaction product of barbituric acid and bismaleimide with a polyamic acid. The reaction between barbituric acid and bismaleimide is performed at a molar ratio of barbituric acid to bismaleimide of 1/3 to 1/10, a reaction temperature of 100 to 130 ° C., and 0.5
The reaction was performed under the condition of a reaction time of ６6 hours.

The polyamic acid used in the present invention is a product of a reaction between a dianhydride and a diamine performed by a known method.
The reaction product of barbituric acid and bismaleimide was mixed with polyamic acid at room temperature to form a new composition with 10-15% solids content. The solids percentage of the reaction product of barbituric acid and bismaleimide before reacting with the polyamic acid was 5 to 15 weight percent of the resulting composition.

The polyamic acid suitably used in the present invention was the reaction product of a dianhydride and a diamine. The dianhydride has the general formula: (Wherein R ⁴ is a tetravalent radical consisting of at least two carbon atoms, and is a substituted or unsubstituted aromatic group, aliphatic group, alicyclic group, directly or the following radical: alkylene, dioxy alkylene, arylene, -SO ₂ -, - O
−, −CO−, -NY-CO-X-CO-NY-, -CO-NY-X-NY-CO-,-
CO-OXO-CO-, -O-CO-X-XO-O-, and -CO-NY-NY-CO- (wherein X is a divalent alkylene radical, a dioxyalkylene radical, or An arylene radical, Y
And Y 'are an alkyl radical, an aryl radical, or an alicyclic radical. At least one atom bonded by one of the following:
It may be a heterocyclic group containing N, O, or S, or a different radical. ). A dianhydride is a carbonylated compound capable of forming an internal diimide having two sets of carbonylate groups, so that a single set of carbonylate groups is separated by up to three carbon atoms. And each group on one side is a carbon atom of a single tetravalent radical,
On the other side it is attached to an oxygen atom.

In the present invention, tetrahydrofurantetracarboxylic dianhydride, cyclopentanetetracarboxyl dianhydride, or bicyclo- [2,2,2] -octene- (7)
-2,3,5,6-Tetracarboxyl-2,3: 5,6-dianhydride may be used. Aromatic dianhydrides are preferred. Examples of suitable aromatic dianhydrides are: pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyltetracarboxylic dianhydride 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, bis (3,3-dicarboxyphenyl) sulfone dianhydride, and Bis (3,4-dicarboxyphenyl) ether dianhydride.

The diamine used in the present invention is represented by the following formula: H ₂ N—R ³ —NH ₂ (wherein R ³ is a group consisting of an aromatic group, an aliphatic group, a cycloaliphatic group, and an aliphatic group including siloxane. Selected from). Examples of typical diamines are as follows:
Ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2-ethylhexylenediamine, nonamethylenediamine, decamethylenediamine, 2,11-diamino-
Dodecane, etc .; meta-phenylenediamine, para-phenylenediamine, 2,2'-naphthalenediamine, 4,4'-biphenylenediamine, methylenedianiline- (4,4'-
Diaminodiphenylmethane), ethylenedianiline-
(4,4'-diaminodiphenylethane), propylene dianiline- (4,4'-diaminodiphenylpropane)
Bis- (para-amino-cyclohexyl) N-phenylamine, bis- (para-amino-cyclohexyl)
N-methylamine, hexafluoroisopropylidene-
Bis- (4-phenylamine), 4,4'-diamino-diphenylmethane, 4,4'-diamino-diphenylethane, 4,4'-diamino-diphenylpropane, 4,4'-diamino-diphenylbutane, 6-diamino-pyridine, bis- (4-amino-phenyl) diethylsilane,
Bis- (4-amino-phenyl) diphenylsilane, bis- (4-amino-phenyl) ethylphosphine oxide, bis- (4-amino-phenyl) phenylphosphine oxide, bis- (4-amino-phenyl) -N- Phenylamine, bis- (4-amino-phenyl) -N-
Methylamine, 3,3'-dimethyl-4,4'-diamino-biphenyl, 3,3'-dimethoxy-benzidine, 2,4-bis (o-amino-t-butyl) toluene, bis (para-o
-Amino-t-butyl-phenyl) ether, para-bis- (2-methyl-4-amino-phenyl) benzene,
Para-bis- (1,1-dimethyl-5-amino-pentyl) benzene, m-xylenediamine, p-xylenediamine, oxydianiline- (4,4'-diaminodiphenyl ether), ketodianiline, 4,4'- Diamino-
Diphenyl sulfide, 3,3′-diamino-diphenyl sulfide, 4,4′-diamino-diphenyl sulfone,
3,3'-diamino-diphenyl sulfone, bis- (para-amino-cyclohexyl) methane, bis- (para-amino-cyclohexyl) ethane, bis- (para-amino-cyclohexyl) propane, bis- (para-amino-
Cyclohexyl) sulfide, bis- (para-amino-
Cyclohexyl) sulfone, bis- (para-amino-cyclohexyl) ether, bis- (para-amino-cyclohexyl) diethylsilane, bis- (para-amino-
Cyclohexyl) diphenylsilane, bis- (para-amino-cyclohexyl) ethyl phosphine oxide, bis- (para-amino-cyclohexyl) phenyl phosphine oxide, 1,2-bis- (3-amino-propoxy) ethane, 2,2- Dimethylpropylenediamine, 3-
Methoxy-hexamethylenediamine, 2,5-dimethylheptamethhyrene (hylene) diamine, 5-methylnonamethylenediamine, 1,4-diamino-cyclohexane, 1,2
Diamino-octadecane, 2,5-diamino-1,3,4-oxadiazole.

The bismaleimide used in the present invention has the following formula (In the above formula, R is an aliphatic group or Ph-R ⁵ -Ph, including aromatic groups, aliphatic groups, cycloaliphatic groups, siloxane, Ph is paraphenylene group, and R ⁵ is An aromatic group, an aliphatic group, a cycloaliphatic group, or an aliphatic group containing siloxane). Examples of typical bismaleimides are: N, N'-ethylene-bis-maleimide, N, N'-butylene-bis-maleimide, N, N'-phenylene-bis-maleimide, N, N '-Hexamethylene-bis-maleimide, N, N'-4,4'-diphenylmethane-bis-maleimide, N, N'-4,4'-diphenylether-bis-maleimide, N, N'-4,4' -Diphenylsulfone-bis-maleimide, N, N'-4,4'-dicyclohexylmethane-bis-maleimide, N, N'-xylylene-bis-maleimide, N, N'-diphenylcyclohexane-bis-maleimide and the like.

The barbituric acid used has the general formula: (Wherein R ¹ and R ² are independently -H, -CH ₃ , -C ₂ H ₅ , -C
_{6 H 5, -CH (CH 3} ) 2, -CH 2 CH (CH 3) 2, -CH 2 CH 2 CH
(CH ₃ ) ₂ , and —CH (CH ₃ ) CH ₂ CH ₂ CH ₃ .

[Description of the preferred embodiment]

Example 1 (A) Preparation of modified bismaleimide 8.66 g of N, N'-4,4'-diphenylmethane-bis-maleimide was dissolved in 20 g of butyrolactone. 1g
After addition of the barbituric acid, the resulting solution was stirred at 110 ° C. for 1 hour.

(B) Preparation of polyamic acid In a 500 ml four-necked reactor, 17.45 g of 4,4'-diaminodiphenyl-ether (DDE) was added, and 130 ml of NMP and 3 ml were added.
Dissolved in a mixture of 0 ml xylene. Under a nitrogen atmosphere, 18.55 g (0.085 mol) of pyromellitic dianhydride (P
MDA) was added, and the mixture was reacted for 3 hours while maintaining stirring. Further addition of 0.436 g (0.02 mol) of PMDA and reaction for 2 hours gave a polyamic acid solution having a solids content of 18.5%.

30 g of the modified bismaleimide obtained in method (A) was dissolved at room temperature in 1.88 g of polyamic acid formed in method (B). 8.9 g of NMP was added to the product solution to a solids content of 15%. The final product is electrophoretically applied to defatted Cu plates and baked according to the described conditions as listed below to form a smooth uniform film.
did.

a. First, raise the temperature to 100 ° C. within 30 minutes and maintain at 100 ° C. for 1 hour.

b. Second, raise the temperature from 100 ° C to 200 ° C within one hour,
Maintain at 200 ° C. for 1 hour.

c. Third, raise the temperature from 200 ° C to 300 ° C within one hour,
Maintain at 300 ° C. for 1 hour.

d. Fourth, raise the temperature from 300 ° C to 350 ° C for 30 minutes,
For 30 minutes.

e. Finally, cool the temperature to room temperature within 3 hours.

The Cu foil used in this example includes two types. One is TCPI
(Trademark of Nippon Mining Co. Ltd.) and other
Made by Copper Foil Co. Ltd. The adhesion of the copper to the polyimide substrate formed in this example was measured with a peel tester and the results are listed first. The physical properties of the final product obtained are similar to those of conventional polyimide substrates.

Example 2 (A) Preparation of Modified Bismaleimide 11.55 g of N, N'-4,4'-diphenylmethane-bis-maleimide was dissolved in 25 g of γ-butyrolactone. After the addition of 1 g of barbituric acid, the resulting solution was heated at 120 ° C. for 1 hour while maintaining stirring.

(B) Preparation of polyamic acid In a 500 ml four-necked reactor, 13.8 g of 4,4'-diaminodiphenyl-ether (DDE) was added, and 130 ml of NMP and 30 m
dissolved in a mixture of 1 xylene. Under a nitrogen atmosphere, 20.93 g (0.065 mol) of benzophenonetetracarboxylic dianhydride (BTDA) was added and reacted for 3 hours while maintaining stirring. 1.288 g (0.004 mol) of BTDA
And a reaction for 2 hours gave a polyamic acid solution having a solids content of 18.4%.

30 g of the modified bismaleimide obtained by the method (A) is
It was dissolved at room temperature in 1.8 g of the polyamic acid formed in method (B). 11 g of NMP was added to the resulting solution to a solids content of 15%. The final product was applied to degreased Cu foil and baked under the conditions described in Example 1 to form a smooth uniform film. The peel strength of the final product of this example is also listed in Table I.

Comparative Example 1 0.62 g of N, N'-4,4'-diphenyl-methane-bis-
Maleimide was dissolved in 10.5 g NMP. After the addition of 30 g of the polyamic acid obtained according to the method (B) of Example 1, the final product was applied to degreased Cu foil and baked under the conditions described in Example 1. The peel strength of the final product is listed in Table I.

Comparative Example 2 The polyamic acid obtained by the method (B) of Example 1 was directly applied to a degreased Cu foil and baked under the conditions described in Example 1. Example peel strengths are listed in Table I.

Comparative Example 3 0.61 g of N, N'-4,4'-diphenyl-methane-bis-
Maleimide was dissolved in 10.3 g NMP. After the addition of 30 g of polyamic acid obtained by method (B) of Example 2, the final product was applied to degreased Cu foil and baked under the conditions described in Example 1. The peel strength of the final product is listed in Table I.

Comparative Example 4 The polyamic acid obtained by the method (B) of Example 2 was directly applied to a degreased Cu foil and baked under the conditions described in Example 1. The peel strengths of the examples are listed in Table I.

Having described the invention in detail, it will be understood by those skilled in the art that various modifications may be made without departing from the spirit of the invention and the scope of the claims. Accordingly, it is not intended that the invention be limited, except as by the appended claims.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shiao Kuo Yui Taiwan, Shinchoshi Koanhuluo 2 Toan 958 Howe (72) Inventor Wang Zhong Taiwan, Thaibei Sien Woo Gusian Chong Shinru 2 Toan 178 Howe (72) Inventor Chang Wen Chang Taiwan, Thailand Bay Xian Yong Ho Shi Chong Shin Chie 65 Cyan 7 Howe 5 Row References: Kaihei 2-24323 (JP, A)

Claims (3)

(57) [Claims] [1] The following equation (In the above formula, R ¹ and R ² are independently -H, -CH ₃ , -C ₂ H ₅ , -C
_{6 H 5, -CH (CH 3} ) 2, -CH 2 CH (CH 3) 2, -CH 2 CH 2 CH
Selected from the group consisting of (CH ₃ ) ₂ and —CH (CH ₃ ) CH ₂ CH ₂ CH ₃ ). The reaction product of barbituric acid and bismaleimide is reacted with polyamic acid. Including things,
The molar ratio of the barbituric acid to the bismaleimide
1/3 to 1/10, wherein the solid percentage of the reaction product of the barbituric acid and the bismaleimide before reacting with the polyamic acid is 5 to 15 weight percent of the resulting composition;
Polyimide adhesive composition. 2. The polyamic acid according to claim 1, wherein (i) H ₂ N—R ³ —NH ₂ and (ii) (Wherein R ³ and R ⁴ are independently selected from the group consisting of aromatic groups, aliphatic groups, cycloaliphatic groups, and aliphatic groups containing siloxanes). The polyimide adhesive composition according to claim 1. 3. The bismaleimide according to claim 1, wherein (In the above formula, R is an aliphatic group or Ph-R ⁵ -Ph, including aromatic groups, aliphatic groups, cycloaliphatic groups, siloxane, Ph is paraphenylene group, and R ⁵ is The polyimide adhesive composition according to claim 1, which is an aromatic group, an aliphatic group, a cycloaliphatic group, or an aliphatic group containing siloxane.