JPH08259668A - Resin composition for printed circuit board - Google Patents

Abstract

PURPOSE: To obtain a resing composition containing as the main component a polymaleimide resin modified with different kinds of specific resins and a compound, and useful as a resin material for laminates excellent in heat resistance, high in high temperature Barcol hardness, and extremely excellent in wire-bonding reliability. CONSTITUTION: This composition contains as the main component a polymaleimide resin obtained by modifying a polymaleimide resin of the formula [R1 is a n-valent 2-27C (cyclic)aliphatic group, a n-valent monocyclic aromatic group or a n-valent condensed polycyclic aromatic group (wherein the aromatic groups are connected to each other directly or through crosslinking members); Xa, Xb are H, a halogen, a 1-4C hydrocarbon group; n >=2] with (A) an epoxy resin having a naphthalene skeleton and two or more epoxy groups in the molecule, (B) a phenolic resin having two or more naphthalene skeletons and two or more OH groups in the molecule, and (C) a compound having an alcoholic or phenolic OH and one or more epoxy groups in the molecule and having a mol. wt. of <=300.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Wire bonding is widely used for connecting semiconductor elements. Wire bonding is a method of connecting semiconductor chips to each other or a semiconductor chip to a package with a thin wire when connecting a semiconductor element and a printed wiring board. Chip on board (hereinafter referred to as COB) is a method of directly attaching a semiconductor element by using wire bonding. In addition, a multi-chip module (hereinafter, referred to as MC) in which two or more semiconductor elements are connected to the substrate by wire bonding or the like.
It is called M. ) Is one such example. Furthermore, wire bonding is also used for connection of a ball grid array (hereinafter referred to as BGA) in which semiconductor elements are directly connected to a substrate and solder balls are arranged on the back surface thereof. In recent years, such a new mounting method has been in the limelight for the purpose of cost reduction for mounting. The present invention is COB, BGA, MCM
The present invention relates to a substrate material having excellent wire bonding properties, which are particularly important properties for substrates and the like. It is possible to provide a substrate material having a very high barcol, especially at high temperatures.

[0002]

2. Description of the Related Art With regard to printed wiring boards widely used in electric / electronic devices, communication devices, computing devices, etc., the wiring density has become more sophisticated and highly integrated.
There is an increasing demand for improved reliability by improving the heat resistance of laminated wiring boards. Especially, at the present time when surface mounting type mounting methods such as COB, BGA and MCM boards are becoming mainstream, wire bonding is an indispensable elemental technology, and improving the reliability of wire bonding is an urgent and serious requirement. is there. The characteristic required for a copper-clad laminate suitable for applications such as COB is that it has a high Barcol hardness at high temperatures and does not cause poor connection during bonding due to softening of the resin. More specifically, when high-speed wire bonding is performed, the temperature of the printed wiring board rises and the softening of the resin on the substrate causes defects in the wire bonding portion.
Therefore, for the purpose of wire-bonding a gold wire to a bonding pad on a printed wiring board at high speed with heat or ultrasonic waves, a material having a high heat resistance of Tg of 170 ° C. or more and a resin that does not easily soften at high temperature is used. Is preferred. BACKGROUND ART Conventionally, epoxy resins, unsaturated polyester resins, polyimide resins, phenol resins, etc. have been used as resin materials for forming laminated boards for printed wiring boards. Of these resins, epoxy resins and bismaleimides have been used. The polyamino bismaleimide resin obtained by reacting a diamine with an aromatic diamine is widely used for high-density packaging and high-multilayer laminates. However, the conventional epoxy resin glass cloth substrate copper-clad laminate (hereinafter referred to as FR-4) for general use has not been a particular problem in a field where heat resistance is not required, but as described above, It is impossible to meet the demand for higher heat resistance associated with high-density mounting and high-layer structure of the printed wiring board. FR-4 has a glass transition temperature of 120 to 145 ° C.
If the temperature exceeds this temperature, the resin becomes rubber and absorbs the pressure at the tip of the wire bonding machine, and the gold wire is not bonded to the bonding pad, resulting in a defect. The Barcol hardness referred to here is a measurement method for determining the degree of softening of the substrate in wire bonding, and bar
Using a GYZJ 934-1 Barcol hardness tester manufactured by Ber Colman, a needle is press-fitted onto the material and the hardness is measured by the ease with which the needle is inserted. On page 121 (Kurokawa et al.) Of the Proceedings of the 3rd Academic Lecture Meeting of the Printed Circuit Society, the description of the Barcol hardness measured by the same method is recognized. The barcol hardness of the copper-clad laminate mainly composed of epoxy resin shows a rapid decrease from around 100 ° C,
At 120 ° C to 150 ° C, it has reached a level at which it cannot be used. Specifically, the Barcol hardness at 200 ° C. is about 10. (Kurokawa et al., Above.) In addition, in the case of polyamino bismaleimide resin, although its heat resistance is very excellent, it has high hygroscopicity and has a problem in adhesiveness. It is necessary to use a high boiling point solvent such as dimethylformamide, the amount of residual solvent is large in the prepreg, and voids are likely to occur during lamination. Furthermore, there is a problem in that the cost becomes high because higher temperature and longer time are required for stacking than the epoxy resin. Also,
In order to compensate for the drawbacks of this polyamino bismaleimide resin,
There is an imide-modified epoxy resin obtained by adding an epoxy resin to a polyaminobismaleimide resin, but this resin also requires a high boiling point solvent, and there is a problem that the residual solvent increases in the prepreg, and the heat resistance of polyaminobismaleimide resin is high. There was a problem that it was significantly inferior to the maleimide resin. Further, even if the glass transition temperature is 180 ° C to 200 ° C, the barcol hardness at high temperature is higher than that of epoxy resin, but 60
It was not satisfactory for improving the reliability of wire bonding. JP 06-06
JP-A-263843 discloses a composition having a high Tg, a water absorption rate, an adhesive property, and a solder heat resistance, but the barcol hardness intended by the present invention is low, and an epoxy is used in the sense of ensuring the reliability of wire bonding. Although improved compared to resin, it was not satisfactory. As described above, each of the epoxy resin, the polyimide resin, and the imide-modified epoxy resin has defects, and no satisfactory material can be found for improving the wire bonding reliability.

[0003]

In recent years, in the printed wiring board industry, high heat resistance, high Barcol hardness, and good adhesiveness and the like can be applied to the progress of high-density mounting and multi-layering. , Voids are less likely to occur during stacking,
There has been a strong demand for resin materials for laminated boards at low cost. The present invention has been made in view of such circumstances, eliminates the drawbacks of conventional epoxy resins, polyimide resins, and imide-modified epoxy resins, has excellent heat resistance, high-temperature Barcol hardness, and high wire bonding reliability. Aims to provide an extremely excellent new resin material for laminated plates. As a result, the purpose is to provide a printed wiring board material such as COB.

[0004]

[Means for Solving the Problems] The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, the polymaleimide resin represented by the general formula (1)

[0005]

Embedded image (In the formula, R ₁ has 2 to 27 carbon atoms, and an aliphatic group, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, and an aromatic group are mutually directly or by a crosslinking member. N-valent groups, which are linked fused polycyclic aromatic groups, Xa and Xb are the same or different monovalent atoms or groups selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 4 carbon atoms, (n represents an integer of 2 or more), (a) an epoxy resin having at least two or more epoxy groups in the molecule and having at least one naphthalene skeleton, (b) at least two or more in the molecule. A phenolic resin having an OH group and having at least two naphthalene skeletons, and (c) a compound having a molecular weight of 300 or less and having one alcoholic or phenolic OH group in the molecule and one or more epoxy groups. Degenerate A thermosetting resin composition for a printed wiring board material containing a reimide resin as a main component, a prepreg in which a base material is impregnated with the imide resin, a plurality of the prepregs and a metal foil laminated on the outermost layer, and a temperature of 180 ° C. or higher. A thermosetting resin laminated board characterized by being molded, and a printed wiring board suitable for wire bonding, characterized by having a Barcol hardness at 200 ° C. of 60 or more, comprising the thermosetting resin laminated board It is a material.

As the polymaleimide compound used in the present invention, any compound having two or more maleimide groups in one molecule can be used. Examples of such a polymaleimide compound include N, N'-ethylene bismaleimide, N, N'-hexamethylene bismaleimide, and N, N '.
-(1,3-phenylene) bismaleimide, N, N '-[1,3- (2-methylphenylene)] bismaleimide, N, N'-(1,4-phenylene) bismaleimide, bis (4- Maleimidophenyl) methane, bis (3-methyl-4-maleimidophenyl) methane, bis (4-maleimidophenyl) ether, bis (4-
Maleimidophenyl) sulfone, bis (4-maleimidophenyl) sulfide, bis (4-maleimidophenyl) ketone, bis (4-maleimidocyclohexyl) methane, 1,
4-bis (4-maleimidophenyl) cyclohexane, 1,4-
Bis (maleimidomethyl) cyclohexane, 1,4-bis (
Maleimidomethyl) benzene, 1,3-bis (4-maleimidophenoxy) benzene, 1,3-bis (3-maleimidophenoxy) benzene, bis [4- (3-maleimidophenoxy) phenyl] methane, bis [4- ( 4-maleimidophenoxy) phenyl] methane, 1,1-bis [4- (3-maleimidophenoxy) phenyl] ethane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] ethane, 1,2-bis [4- (3-maleimidophenoxy) phenyl] ethane, 1,2-bis [4- (4-maleimidophenoxy) phenyl] ethane, 2,2-bis [4- (3-maleimidophenoxy) phenyl] propane, 2 , 2-bis [4
-(3-maleimidophenoxy) phenyl] propane, 2,2-
Bis [4- (3-maleimidophenoxy) phenyl] butane,
2,2-bis [4- (4-maleimidophenoxy) phenyl] butane, 2,2-bis [4- (3-maleimidophenoxy) phenyl
Le] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4
-(4-maleimidophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 4,4'-bis (3-maleimidophenoxy) biphenyl, 4,4'-bis (4-maleimide Phenoxy) biphenyl, bis [4- (3-maleimidophenoxy)
Phenyl] ketone, bis [4- (4-maleimidophenoxy)
Phenyl] ketone, bis [4- (3-maleimidophenoxy)
Phenyl] sulfide, bis [4- (4-maleimidophenoxy) phenyl] sulfide, bis [4- (3-maleimidophenoxy) phenyl] sulfoxide, bis [4- (4-maleimidophenoxy) phenyl] sulfoxide, bis [4- (3-
Maleimidophenoxy) phenyl] sulfone, bis [4-
(4-maleimidophenoxy) phenyl] sulfone, bis
[4- (3-maleimidophenoxy) phenyl] ether, bis [4- (4-maleimidophenoxy) phenyl] ether,
1,4-bis [4- (4-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1, 4-bis [4- (3-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (3-maleimidophenoxy) -α, α-dimethylbenzyl] benzene, 1,4- Screw [4
-(4-maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-maleimidophenoxy) -3,5-dimethyl-α, α-dimethylbenzyl ] Benzene, 1,4-bis [4- (3-maleimidophenoxy)-
3,5-dimethyl-α, α-dimethylbenzyl] benzene,
1,3-bis [4- (3-maleimidophenoxy) -3,5-dimethyl-
α, α-Dimethylbenzyl] benzene, general formula (2)
[Chemical Formula 3];

[0007]

Embedded image (In the formula, n is an average value of 0 to 10), and a polymaleimide compound represented by the general formula (3) [Chemical Formula 4];

[0008]

[Chemical 4] (In the formula, m is an average value of 0 to 10) and the like. These polymaleimide compounds may be used alone or in combination of two or more.

As the epoxy resin of the component (a) used in the present invention, any epoxy resin having at least two epoxy groups in one molecule and having at least one naphthalene skeleton can be used. These are illustrated below. From a novolak resin which is a reaction product of naphthols such as naphthol and dihydroxynaphthalene and naphthols or phenols such as phenol, cresol and resorcinol, and aldehydes such as formaldehyde, acetaldehyde, benzaldehyde, hydroxybenzaldehyde, gluoxal and alkanedial. Derived novolak type epoxy resins and aralkyl type epoxy resins derived from aralkyl resins which are reaction products of the above naphthols, phenols and aralkyl alcohol derivatives. In addition, an epoxy resin derived from a compound having two or more active hydrogens and a naphthalene skeleton in one molecule, for example, an epoxy resin obtained by reacting dihydroxynaphthalene, diaminonaphthalene and the like with epichlorohydrin or 2-methylepichlorohydrin One or two or more of these epoxy resins are used.

As the component (b), any phenol resin having at least two OH groups in the molecule and having at least two naphthalene skeletons can be used. For example, naphthol Zyloc and naphthalene-containing phenol resin. As the component (c), glycidol, glycerin diglycidyl ether, ethylene glycol monoglycidyl ether, resorcinol monoglycidyl ether, naphthresorcinol monoglycidyl ether, etc., one alcoholic or phenolic OH group in one molecule, and one Examples thereof include compounds having a molecular weight of 300 or less and containing the above epoxy groups. Even if the compound contains one alcoholic or phenolic OH group and one or more epoxy group in one molecule, if the molecular weight is 300 or more, the main component is maleimide soluble in a general-purpose solvent such as target methyl ethyl ketone. It is impossible to produce a resin that does.

The component (c) is 5 to 100 parts by weight, preferably 15 to 5 parts by weight, relative to 100 parts by weight of the polymaleimide resin, from the viewpoint of obtaining heat resistance and high barcol hardness.
It is preferred to use 0 parts by weight. If it is 5 parts by weight or less, the Barcol hardness does not exceed 60. If it is 15 parts by weight or more, the Barcol hardness is 70 or more, and it is more preferable. Even if the amount is 50 parts or more, the performance is not adversely affected, but the effect hardly appears. The epoxy resin as the component (a) is preferably 10 to 500 parts by weight, more preferably 10 to 200 parts by weight, based on 100 parts by weight of the polymaleimide resin, from the viewpoint of obtaining heat resistance and high Barcol hardness. When the amount is 500 parts by weight or more, the imide component decreases, and the heat resistance and the barcol hardness decrease. If the amount is 10 parts by weight or less, not only the effect of improving heat resistance is small but also stable production of varnish becomes difficult. 1
If it is 0 to 200 parts by weight, the Barcol hardness will be 70 or more.

The amount of the phenol resin as the component (b) is in the range of 1 to 500 parts by weight, preferably 10 to 200 parts by weight, based on 100 parts by weight of the epoxy resin of the component (a). If the amount is less than 1 part by weight, the effect of the phenol resin, which is the greatest point of the present invention, is lost, and heat resistance and high barcol cannot be maintained. If the amount is 500 parts by weight or more, the performance is not adversely affected, but the effect is lost. In addition, the varnish cannot be manufactured stably.

The resin composition of the present invention contains the maleimide resin as a main component, and if necessary, an epoxy containing no naphthalene skeleton such as cresol novolac type epoxy and bisphenol type epoxy, and / or Use in combination with phenol novolac resins, phenol aralkyl resins, and other phenol resins that do not contain a naphthalene skeleton, amines represented by diaminodiphenylmethane, diaminodiphenylsulfone, dicyandiamide, and acid anhydrides such as phthalic anhydride and pyromellitic dianhydride. You can also

In the present invention, when curing the resin composition, it is desirable to include a curing accelerator,
As such a curing accelerator, 2-methylimidazole,
Imidazoles such as 2-methyl-4-ethylimidazole and 2-heptadecylimidazole; amines such as triethanolamine, triethylenediamine and N-methylmorpholine; organic phosphines such as tributylphosphine, triphenylphosphine and tritolylphosphine ;
Tetraphenylphosphonium tetraphenylborate,
And tetraphenylboron salts such as triethylammonium tetraphenylborate; 1,8-diaza-bicyclo (5,4,0) undecene-7 and its derivatives. These curing accelerators may be used alone or in combination of two or more, and if necessary, an organic peroxide or an azo compound may be used in combination. The content of these curing accelerators is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the resin. When the resin composition of the present invention as described above is used as a resin material for laminates, the resin is dissolved in a solvent to form a resin varnish, the base material is impregnated and dried, and a prepreg is prepared. A predetermined laminated plate can be obtained by pressurizing and laminating and integrating.

As the base material, any suitable material such as glass mat, glass sheet, non-woven fabric, paper, etc. can be used, and in the laminate molding, a metal foil such as copper, aluminum or stainless steel is placed as the outermost layer for molding and printing. It can be a laminate for wiring boards. You may use it as a laminated board for multilayer printed wiring boards using an inner layer core material. The molding temperature is 180 ° C or higher, preferably 180 ° C to 230 ° C. When the temperature is 180 ° C or lower, the Barcol hardness is low and 50 or lower. On the other hand, when the temperature is 230 ° C. or higher, not only the barcol hardness reaches a ceiling but also decomposition starts to adversely affect the substrate itself.

[0016]

EXAMPLES The present invention will be specifically described below with reference to examples. The test method of the performance in the examples is as follows.・ Barcol hardness: G manufactured by BARBER COLMAN
YZJ 934-1 A sample (thickness: 1.6 mm) is placed on a 200 ° C. hot plate, and after confirming that the temperature of the sample surface is 200 ° C. by a surface thermometer, a hardness meter is pressed to measure. The following materials were used as the raw materials used in the examples and comparative examples.・ Polymaleimide compound; bis (4-maleimidophenyl) methane (manufactured by Mitsui Toatsu Chemicals, Inc.) ・ Epoxy resin; naphthalene-containing epoxy resin (EOCN-7)
000, manufactured by Nippon Kayaku Co., Ltd.)

[0017]

Embedded image -Phenolic resin; naphthalene-containing phenolic resin (OC
N-7000, manufactured by Nippon Kayaku Co., Ltd.

[0018]

[Chemical 6] -Phenol resin; Naphthol ziloc resin (NX, manufactured by Mitsui Toatsu Chemicals, Inc.)

[0019]

[Chemical 7]

[0020]

Embedded image ・ Glycidol; Epiol OH (produced by NOF Corporation)

[0021]

[Chemical Formula 9] Silicate skeleton epoxy resin

Examples 1 and 2 and Comparative Example 1 (Production of Resin Containing Maleimide as Main Component) In a reaction vessel equipped with a stirrer, a thermometer and a cooler, 20 parts by weight of glycidol per 100 parts of polymaleimide resin, EOCN
7000 50 parts by weight and 30 parts by weight of NX in Example 1, 30 parts by weight of OCN7000 in Example 2, and 30 parts by weight of a phenol resin containing one naphthalene skeleton in Comparative Example, 130 ° C, 3
The reaction was carried out for 0 minutes or 1 hour to obtain 3 kinds of resins containing maleimide as a main component.

(Production of copper-clad laminate) The resin varnish containing maleimide as a main component thus obtained was used in an amount of 104 k.
A glass cloth of g / m2 was impregnated and dried at 140 ° C for 5 minutes to obtain a prepreg of about 190 g / m2. Sixteen prepregs were stacked, copper foils were further arranged on the upper and lower outermost casings, and the prepregs were molded at a pressure of 40 kg / cm 2 at 170 ° C. for 60 minutes to obtain a copper-clad laminate having a thickness of 0.5 mm. .

(Evaluation of Laminated Plate) Based on the test results of the obtained prepreg and laminated plate, the Barcol hardness of Examples 1 and 2 was 65.
And the Barcol hardness of Comparative Example 1 was 50.

(Evaluation of Wire Bonding Reliability) Ni plating was applied on the surface of the copper-clad laminates of Example 1 and Comparative Example 3 by plating.
Micron Further gold plating was performed to 0.05 micron. After that, a wire bonding test was performed using a rotary head high-speed wire bonder M360C manufactured by Orthoda Inchea, USA. A wire bonding test was performed under the conditions of a capillary diameter of 150 μ and a bonding load of 200 g. Substrate temperature is 150 ° C and bonding interval is 5
Tested as 0 micron. As a result, out of 10,000 times, the adhesion failure was 0 times in Example 1 and 30 times in Comparative Example 1.

(Effect of molding temperature) The molding temperature was changed using the same prepreg. 160 ° C. (Comparative Example 2), 1
70 ° C. (Comparative Example 3), 180 ° C. (Example 3), 200 ° C.
(Example 4) The hardness at the time of molding at 230 ° C (Example 5) was measured. 60 in Example 3, 7 in Example 4
0 and 70 in Example 5. Further, it was 30 in Comparative Example 2 and 40 in Comparative Example 3. .

[0027]

INDUSTRIAL APPLICABILITY The present invention is a resin material for laminated plates, which has excellent heat resistance, high-temperature Barcol hardness, and extremely excellent wire bonding reliability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kotaro Asahina 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (4)

[Claims] 1. A polymaleimide resin represented by the general formula (1) [Chemical Formula 1] (In the formula, R ₁ has 2 to 27 carbon atoms, and an aliphatic group, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group is directly or by a cross-linking member. An n-valent group which is a condensed polycyclic aromatic group linked to, Xa and Xb are the same or different monovalent atoms or groups selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 4 carbon atoms. , N is 2
The above integers), (a) an epoxy resin having at least two epoxy groups in the molecule and having at least one naphthalene skeleton, and (b) at least two OH groups in the molecule. A phenolic resin having at least two naphthalene skeletons, and (c) one alcoholic or phenolic OH group in the molecule,
A thermosetting resin composition for a printed wiring board material, which comprises, as a main component, a maleimide resin modified with a compound having one or more epoxy groups and a molecular weight of 300 or less. 2. A prepreg obtained by impregnating a base material with the resin composition according to claim 1. 3. A thermosetting resin laminate comprising a plurality of the prepregs according to claim 2 and a metal foil laminated on the outermost layer and molded at a temperature of 180 ° C. or higher. 4. A thermosetting resin laminate according to claim 3,
A printed wiring board material suitable for wire bonding, which has a Barcol hardness of 60 or more at 200 ° C.