JPH0477555A - Polyimide resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition capable of lowering the dielectric constant of laminates therefrom and also reducing the thermal expansion coefficient in the width direction of said laminates, thus suitable for printed wiring boards etc. by incorporating a polyimide resin with a specified amount of inorganic microballoons. CONSTITUTION:The objective composition can be obtained by incorporating (A) a polyimide resin prepared by reaction between (1) a unsaturated bis-imide (e.g. maleic acid N,N'-ethylene-bis-imide) and (2) a diamine (e.g. 4,4'- diaminodicyclohexylmethane) with (B) 10 - 50pts.vol., based on 100pts.vol. of the component A, of inorganic microballoons, and pref. (C) 10 - 200pts.wt., based on 100pts.wt. of the component A, of a triallyl isocyanurate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to polyimide resin compositions used for manufacturing printed wiring boards and the like.

[Prior Art] Polyimide resins, epoxy resins, and the like have been widely used as resins for laminated boards constituting printed wiring boards. Among them, polyimide resin is disclosed in Japanese Patent Application Laid-Open No. 59-20659.
As disclosed in Japanese Patent Application Laid-open No. 61-40322, it is used in laminates of high-multilayer printed wiring boards for high-density packaging.

Polyimide resin is used in laminates for high-density packaging because it has the following characteristics.

■High-precision processing such as miniaturization of wiring conductors and fine hole drilling for high-density packaging is possible.

■The coefficient of thermal expansion in the thickness direction of the plate is small, and the through-hole plating has high continuity reliability.

■Less smear generation during the drilling process.

0 High conductor adhesion and hardness at high temperatures, and good mounting performance.

- Can withstand continuous use at high temperatures (e.g. 200°C), etc. [Problems to be solved by the invention] However, in recent years, printed wiring boards made of polyimide resin In response to the increasing speed of semiconductors, there is currently a strong desire to further increase the propagation speed of electrical signals in laminated plates. In addition, when creating multiple layers for high-density packaging, there are problems such as through-hole plating breaking due to thermal expansion in the thickness direction as the board becomes thicker. At present, there is a strong desire to improve the reliability of

The present invention has been made in view of the above points, and is intended to reduce the dielectric constant of a laminate in order to adapt to the increase in the propagation speed of electric signals, and to further improve reliability in multilayering. An object of the present invention is to provide a polyimide resin composition that can reduce the coefficient of thermal expansion in the thickness direction of a laminate.

[Means for Solving the Problems] The polyimide resin composition according to the present invention is characterized by blending inorganic micro hollow bodies into a polyimide resin. In the present invention, 10 to 10 parts by weight of triallyl isocyanurates are added to 100 parts by weight of polyimide resin.
It is preferable to blend 200 parts by weight.

The present invention will be explained in detail below.

The polyimide resin used in the present invention can be obtained by reacting unsaturated bisimides and diamines. In order to lower the dielectric constant of the polyimide resin, the polyimide resin thus obtained preferably contains at least 11% by weight of at least one of an alkyl group and an alkylene group other than a methylene group.

The general formula of the unsaturated bis-imides is <r>co
c.

It is expressed as [The formula (1) represents a divalent group containing a carbon-carbon double bond, and A represents a divalent group containing at least two carbon atoms.] Diamines also have a general formula of (
It) H2N-B-NH2, (If). [In formula (]I), B represents a divalent group having 30 or less carbon atoms," and A and B in 2 (■) (■) may be the same or different, and 13 a straight-chain or branched alkylene group having fewer than 1 carbon atoms,
A cyclic alkylene group having 5 or 6 carbon atoms in the ring can also be a heterocyclic group containing at least one O, N and S atom, or a phenylene or polycyclic aromatic group. can. These various groups may have substituents that do not cause unnecessary side reactions under the reaction conditions of a reaction temperature of 70 to 170°C and a reaction time of 30 to 350 minutes. They can be a number of phenylene groups, or they can be directly divalent atoms or alicyclic groups bonded in groups such as, for example, they can be oxygen or sulfur, or groups with 1 to 3 carbon atoms. Alkylene group or one of the following groups:

N R4;P, (0) R3--N = N,,N
=N--CO-0-1-8O□ ↓ 5iR3R<-1-CONH -NY-Co-X-Co-NY o-co-x-co-o- In the above formula, R2, R1 and Y are each carbon represents an alkyl group with 1 to 4 atoms, a cyclic alkyl group with 5 or 6 carbon atoms in the ring, or a phenyl or polycyclic aromatic group, where X has fewer than 13 carbon atoms 1 [Chained or branched alkylene group, cyclic alkylene group having 5 or 6 carbon atoms in the ring,
Or represents a monocyclic or polycyclic arylene group.

The group in the above formula <1) is derived from an ethylene anhydride of the formula (I[[)CO2, such as maleic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, itaconic anhydride. , and the products of the Diels-Alder reaction between a cyclodiene and one of these anhydrides.

Preferred unsaturated bis- of formula (I) that can be used
The following can be mentioned as imide. Maleic acid N-N-monoethylene-bisimide, Maleic acid N
-N--hexamethylene-bis-imide, maleic acid N
-N--Metaphenylene-bis-imide, maleic acid N
-N--paraphenylene-bis-imide, maleic acid N
-N"4.4"-diphenylmethane-bis-imide, [
N.N--methylenebis (also called N-phenylmaleimide)], maleic acid N-N--4.4-diphenyl ether-bis-imide, maleic acid N.N--4.4
″-diphenylsulfone-bisimide, maleic acid N-
N--4.4--dicyclohexylmethane-bis-imide, maleic acid N.N-1α.α゛-4.4--dimethylenecyclohexane-bis-imide, maleic acid N-N
- metaxylylene-bis-imide, maleic acid N/N-
1-diphenylcyclohexane-bis-imide 3-bis(2-p-anilinopropylidene)benzene-bis-imide, 1,4-bis(2-P-anilinopropylidene)
Benzene-bis-imide, 1,4-bis(2-m-anilinopropylidene)benzene-bis-imide, 4,4-
methylene di-2,6-xylysine-bis-imide, 4.
4'-methylenedi-2,6-dinithylaniline-bis-imide, 4,4--diamino-3,3-1diethyl-5
．． 5-dimethyldiphenylmethane-bis-imide, 4
・4゛-methylenedi2,6-diituprobylaniline-bis-imide, 2,5-dimethyl-p-phenylenediamine-bis-imide, 2,2-bis<4-aminophenyl)propane-bis-imide, Preferred diamines of formula (It) which may also be used include 2,4-diaminomesitylene-bis-imide, 3,5-diethyl-2,4-tolylenediamine-bis-imide, etc. can be mentioned.

4,4゛-diaminodicyclohexylmethane, 1,4゛-diaminocyclohexane, 2,6-diamitupyridine, metaphenylenediamine, paraphenylenediamine,
4,4-diamino-diphenylmethane, 2,2-bis-(4-aminophenyl)propane, benzidine, 4.
4'-Diamino diphenyl oxide, 4,4-diaminodiphenyl sulfide, 4,4-diaminodiphenylsulfone, bis-(4-aminophenyl)
Diphenylsilane, bis-(4-7minophenyl)methylphosphine oxide, bis-(3-aminophenyl)methylphosphine oxide, bis-<4-naminophenyl)phenylphosphine oxide, bis-
(4-aminophenyl)pheniramine, 1,5-diaminonaphthalene, meta-xylylene diamine, para-xylylene diamine, 1,1-bis(para-aminophenyl)phthalane, hexamethylene diamine, 1,3-bis(2-
p-anilinopropylidene)benzene, 1,4-bis(
2-p-anilinopropylidene)benzene, 1,4-bis(2-m-anilinopropylidene)benzene, 4.4
"-Methylenedi-2,6-xylidine, 4,4-1methylenedi-2,6-dinitylaniline, 4,4-diamino-3,3"-diethyl-5,5-dimethyldiphenylmethane, 4,4" -methylenedi-2,6-diituprobylaniline, 2,5-dimethyl-p-phenylenediamine, 2,2-bis(4-aminophenyl)propane,
2,4-diaminomesitylene, 3,5-diethyl-2.
4-tolylene diamine and the like.

Then, an addition type polyimide resin can be prepared by reacting the unsaturation, soimide, and diamine. The blending ratio of bis-imide and diamine is
The molar ratio is 1.7 to 2 bis-imides to 1 diamine.
．． A range of 5 is preferred. If the amount of bis-imide is less than 1.7, more polymer violet will be produced, shortening the curing time and causing problems in handling.If the amount of bis-imide is more than 2 or 5, a large amount of unreacted raw material will remain. One reaction that tends to be easier is to combine bis-imides and diamines with N-methylpyrrolidone (NMP) or N,N dimethylacetamide (
The reaction can be carried out in a state dissolved in a solvent such as DMAC>, and the heating temperature during the reaction is 70 to 170℃.
It is preferable to carry out the reaction at a temperature of about 30°C, and the reaction time is about 30°C.
It is preferable to carry out the process for about 350 minutes.

Inorganic micro hollow bodies are blended into the polyimide resin prepared as described above, triallyl isocyanurate (hereinafter abbreviated as TAIC) is further blended, and if necessary,
2-ethyl-4-methylimidazole (2
Dimethylformamide (DMF>, DM
Ac, dioxane, NMP, methyl ethyl getone (ME
K) and the like, and by mixing these, the polyimide resin composition according to the present invention can be obtained.

The above-mentioned inorganic micro-hollow bodies (commonly known as ceramic microballoons, etc.) are made of "phyllite," which is an inert and stable aluminosilicate-based micro-hollow filler.
(Product name Nippon Philite Co., Ltd., diameter 30-30
0 micron, average bulk specific gravity 0.7), "Nipcell" is a micro hollow spherical filler with borosilicate glass composition or silica composition (product name: Nippon Silikani Gyo Co., Ltd., average particle size 3)
5 to 55 microns, bulk density 0.14 to 0.68), etc. can be used. Since this inorganic minute hollow body is hollow, the particle dielectric constant is 1. The process rate is low and the effect of lowering the dielectric constant of the laminate can be obtained. In addition, since it is an inorganic material (ceramic), it has high heat resistance and a low coefficient of thermal expansion of about 10 ppm, so that it can also have the effect of lowering the coefficient of thermal expansion in the thickness direction of the laminate. In addition, since these inorganic minute hollow bodies have very small particle diameters, there is no fear that they will have an adverse effect when forming through holes in a laminate. The blending amount of the inorganic micro hollow bodies is 10 to 10% by volume relative to the polyimide resin.
The weight fraction is preferably in the range of 50 parts (3.6 to 18 parts per 100 parts of polyimide resin). If the amount is less than this range, the effect of lowering the dielectric constant will be insufficient, and if it is more than this range, the laminate will be hard and brittle, which is not preferable.

In addition to TAIC monomers, TAICs include TAIC monomers.
IC polymer can be used, and 10 to 20 parts of TAIC is added to 100 parts by weight of polyimide resin.
It is preferable to mix 0 parts by weight of TAICs, which can reduce the dielectric constant of the laminate, and if the amount of TAICs is less than 10 parts by weight, the effect of lowering the dielectric constant will decrease. If it exceeds 200 parts by weight, the dielectric constant decreases, but the laminate becomes hard and brittle, which is not preferable. It is preferable to use a mixture containing parts by weight. Adding a TAIC polymer can suppress the intense volatilization of the TAIC monomer during the drying process during the production of Bleprig, and it is also possible to use only TA and IC polymers. The TAIC polymer preferably has a weight average molecular weight of 500 to 10,000, particularly preferably 500 to 3,000. Therefore, in the present invention, the TAIC polymer also includes the TAIC prepolymer.In order to ensure the flame retardancy required for the safety of electronic devices, bromine having a reactive group is used as a flame retardant. It is preferable to blend a brominated resin with the polyimide resin, because this brominated resin having a reactive group reacts with the side chains and terminal groups of the polyimide resin and is incorporated into the skeleton of the polyimide resin structure. In addition to flame retardancy, it is also possible to improve interlayer adhesion, through-hole reliability, heat resistance, etc. Therefore, as a reactive group of a brominated resin, an alkyl having 1 to 4 carbon atoms having an epoxy group, an allyl group, a vinyl group, etc., a cyclic alkyl having 5 or 6 carbon atoms in the ring, or a phenyl or polycyclic aromatic, or straight-chain or branched alkylene with less than 13 carbon atoms, cyclic alkylene with 5 or 6 carbon atoms in the ring, or monocyclic or polycyclic arylene etc. are preferred, and epoxy resin is particularly preferred.

The amount of the brominated resin having this reactive group is preferably in the range of 1 to 50 parts by weight based on bromine content based on 100 parts by weight of the polyimide resin. If it is less than 1 part by weight, the effect of improving flame retardancy will be insufficient, and if it exceeds 50 parts by weight, the heat resistance and dielectric constant of the laminate may deteriorate, which is not preferable.

When creating a laminate using the polyimide resin composition obtained as described above, first, the base material is impregnated with the polyimide resin composition, and then heated to dry and evaporate the diluent solvent to half the resin content. A prepreg is created by curing. At this time, the reaction between the polyimide and TAICs proceeds, and the brominated resin having a reactive group also reacts with the reactive group or the side chain or terminal group of the polyimide resin, and is incorporated into the skeleton of the polyimide resin structure. The type of base material impregnated with polyimide resin is not particularly limited. Glass cloth is usually used, but other highly heat-resistant fiber cloths such as inorganic fiber cloth such as quartz fiber cloth, Kevlar fiber cloth, and polyimide fiber cloth can also be used. The temperature during semi-curing is preferably set in a range of about 110 to 155°C. If the temperature exceeds 155℃, the TAIC monomer will easily volatilize, the reaction will proceed too much, the interlayer adhesion of the obtained prepreg will decrease, and the effect of lowering the dielectric constant may be reduced. It is impractical as it takes too much time. One or more sheets of prepreg prepared in this way are stacked, and if necessary, a metal foil such as copper, niragel, or aluminum or an inner layer material with a circuit formed thereon is stacked, and then A laminate can be obtained by laminating and molding under heat and pressure.

[Examples] Next, Table 1.2 explains the present invention using Examples and Comparative Examples.
A polyimide resin composition was prepared by mixing the following formulations.

Here, as the inorganic micro hollow bodies, "Fillite 200/7 J" manufactured by Nippon Phyllite Co., Ltd. and "Nip Cell ni 330" manufactured by Nippon Silikani Gyo Co., Ltd. were used.

The following polyimide resins #1 to #4 were used.

・#1...Polyimide resin synthesized from maleic acid N-N--4,4゛-diphenylmethane-bis-imide and 4,4°-diaminodiphenylmethane, containing an alkyl group or an alkylene group in the resin molecule do not.

・#2...Polyimide resin synthesized from 4,4'-methylene di-2,6-xylysine-bis-imide and 4,4-diaminodiphenylmethane. The resin molecule contains 13% by weight of alkyl groups.

- #3: A polyimide resin synthesized from 4,4--methylene di-2,6-dinitylaniline-bis-imide and 1,4-bis(2p-anilinopropylidene)benzene. The resin molecule contains 24.5% by weight of alkyl groups.

・#4...4,4--methylene di-2,6-diinpropylaniline-bis-imide and 1,4-bis(2-p
- anilinopropylidene) benzene. The resin molecule contains 30% by weight of alkyl groups.

In addition, brominated resins are represented by the following chemical structural formula:
Reactive brominated phenol novolac type epoxy resin (
BREN-8) manufactured by Nippon Kayaku Co., Ltd. was used.

n=3 to 4 Further, 2E4MZ (manufactured by Shikoku Kasei Kogyo Co., Ltd.) was used as an accelerator, and DMF was used as a diluting solvent so that the resin solid content was about 60% by weight.

Next, Table 1. A prepreg was prepared by impregnating an E glass cloth of 95 g/m2 with a thickness of 0.1 mm with the polyimide resin composition prepared according to the second composition, and heating and drying it in a dryer at 140° C. for 40 minutes. The volatile content of each prepreg was measured. The volatile content of the prepreg was determined by measuring the weight Wl of the prepreg before drying and the weight W2 after drying by heating at 180°C for 30 minutes, and using the formula (Wl-W2)/WIX100. The results are shown in Tables 1 and 2.

Both sides of the prepreg prepared in this way have a thickness of 18 μm.
A double-sided copper-clad laminate for an inner-layer printed wiring board was obtained by stacking two double-sided roughened copper foils of 2.0 m and lamination molding under the conditions of a molding temperature of 130° C., a molding pressure of 30 kg, and 2.90 minutes per cm. An inner layer printed wiring board is created by etching the copper foil of this double-sided copper-clad laminate to form a circuit.
Then, 35 inner-layer printed wiring boards are stacked with the same 4 prepregs as above interposed between each one, and 4 more prepregs are placed above and below them to a thickness of 35 μm.
Copper foils were layered, and this was placed in a 6 mm thick mold for lamination molding. This laminated molding is performed by immediately heating to 130°C while applying a pressure of 5 kg/cm2 and holding it for 20 minutes, then heating it to 200°C with a pressure of 30 kg/cm2, holding it for 120 minutes, and then leaving it at room temperature while applying pressure. The test was carried out under conditions of cooling to .

Regarding the double-sided copper-clad multilayer laminate obtained in this way, "dielectric constant", "r interlayer adhesion strength", "through-hole plating penetration length", "through-hole wall surface roughness", and "flame retardancy" , "heat resistance" and "coefficient of thermal expansion in the thickness direction" were measured. The results are shown in Table 1.2. "Permittivity" is JIS
Based on C6481, "flame retardancy" was measured in accordance with the UL standard. "Interlayer adhesive strength J was measured by measuring the adhesive strength when the layers of the multilayer laminate were peeled off in a 90° direction. Also, using a drill bit of 0° 4 mmφ on the multilayer laminate, the adhesive strength was measured at 40000 rpm. 100 through-holes were drilled under the conditions of a rotational speed of 50μm/rev and a feed rate per rotation of 50μm/rev, and the through-holes were plated using a combination of electroless plating and electrolytic plating. Observe the cross section of the through-hole with a microscope and measure the "through-hole plating penetration length" that occurs during through-hole plating and the "through-hole wall roughness" on the inside of the through-hole. did.

As shown in Table 1.2, it is confirmed that the dielectric constant and the coefficient of thermal expansion in the thickness direction can be lowered by blending inorganic micro hollow bodies. It is also confirmed that by blending together with TAIC, the effect of lowering the dielectric constant is enhanced.

U Effect of the invention] As described above, in the present invention, the inorganic micro hollow bodies are blended into the polyimide resin, so the inorganic micro hollow bodies have a low particle permittivity and are effective in reducing the dielectric constant of the laminate. Therefore, it can be adapted to increase the propagation speed of electric signals, and the inorganic micro hollow bodies have a low coefficient of thermal expansion, and have the effect of reducing the coefficient of thermal expansion in the thickness direction of the laminate. This makes it possible to improve reliability in multi-layering.

Claims (3)

[Claims] (1) A polyimide resin composition comprising a polyimide resin mixed with inorganic microscopic hollow bodies. (2) The polyimide resin composition according to claim 1, characterized in that 10 to 200 parts by weight of triallyl isocyanurates are blended with 100 parts by weight of the polyimide resin. (3) The polyimide resin composition according to claim 1 or 2, wherein 10 to 50 parts of the inorganic micro hollow bodies are blended in a volume fraction of 100 parts of the polyimide resin.