JPH0359106B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to addition-type imide resin prepolymers used for manufacturing printed wiring boards and the like. [Background technology] Conventionally, epoxy resin materials with excellent adhesive properties, chemical resistance, electrical properties, mechanical properties, etc. have often been used as resins for manufacturing multilayer printed wiring boards. When used in a multilayer printed wiring board, there are problems with heat resistance during the mounting process and a decrease in continuity reliability due to thermal expansion in the thickness direction of the resin smear. In order to solve these problems from a material perspective, heat-resistant materials such as imide resins have been developed and put into practical use. In particular, addition-type imide resin, which is made by reacting unsaturated bis-imide with diamine, has a small coefficient of thermal expansion in the thickness direction, making it possible to perform high-precision processing such as thinning wires for high density and drilling micro holes. , high conductivity reliability due to through-hole plating, no smearing during the drilling process, high conductor adhesion and hardness at high temperatures, improving mounting performance, withstands continuous use at high temperatures (200℃), etc. Due to these characteristics, it has come to be widely used as a material for multilayer printed wiring boards. However, in recent years, multilayer printed circuit boards for large computers and the like are becoming more densely packaged and more multilayered, and there is therefore a strong demand for miniaturization of circuits and reduction in the diameter of through holes. In order to meet this requirement, substrates are now required to have even higher levels of dimensional stability and adhesion than before.
That is, the dimensional change of the board directly affects the positional deviation of the circuits in the outer layers of the multilayer board, and when the multilayer board size is increased, the variation in the dimensional change must be kept to a minimum, especially when the multilayer board size is increased. For this reason, when manufacturing the substrate, it is preferable to perform the molding process at low pressure. This is because dimensional stability deteriorates when molding is performed under high pressure. On the other hand, with regard to adhesion, with the miniaturization of circuits, the adhesion between the circuit and the resin must naturally be high, but the adhesion between the substrate and the resin must also be high, and the bond between the layers must also be high. Adhesion must also be high. This is because if the adhesion is low, minute peeling may occur between the substrate and resin during various processing steps such as drilling holes in a multilayer board, or separation may occur between layers inside the substrate. This is because Generally known addition-type imide resins have insufficient adhesion to substrates when viewed at the level of multilayer boards for large-scale computers, etc., so minute peeling tends to occur during the drilling process. Furthermore, when producing a substrate, if the prepreg is molded at low pressure, voids will occur and a uniform substrate cannot be obtained, so molding must necessarily be performed at high pressure. This also results in insufficient dimensional stability of the substrate. [Object of the Invention] The object of the present invention is to provide an addition-type imide resin prepolymer that can produce a high-density, high-multilayer printed board that enables high-density mounting of electronic components. [Disclosure of the Invention] In order to achieve the above object, the inventors first used a generally known addition-type imide resin prepolymer to solve the problem of insufficient adhesion between the circuit and the resin and between the substrate and the resin. We researched the causes of this.
As a result, it was found that the main cause was that general addition-type imide resin prepolymers contained a large amount of high molecular weight components. As a result of further research, the inventors discovered that although it is preferable for the absolute amount of high molecular weight components to be small, not only the absolute amount but also the relative ratio to the unreacted raw material is an important factor. Completed two inventions. That is, the gist of the first invention is an addition-type imide resin prepolymer composition characterized in that N.N'-methylenebis (N-phenylmaleimide) is added to the addition-type imide resin prepolymer. The second invention is an addition-type imide resin prepolymer characterized in that N.N'-methylenebis (N-phenylmaleimide) is added together with 4,4'-diaminodiphenylmethane. The gist is imide resin prepolymer compositions. These inventions will be explained in detail below. These inventions are characterized in that N・N′-methylenebis(N-phenylmaleimide) is added to the addition-type imide resin prepolymer alone or in combination with 4・4′-diaminodiphenylmethane. It is. The amount of these additions needs to be selected within the following range. That is _, for 100 parts by weight of addition-type imide resin prepolymer (hereinafter abbreviated _as parts), X _T = When adding _maleimide ) alone, 5≦ _{XT =} Department]... is. And N・N′-methylenebis(N-
When using phenylmaleimide ₎ and 4,4'-diaminodiphenylmethane in combination, _the preferred range of the blending ratio _of both _{is :} be. _Where , X _T :Total amount _of additives (number of parts) (number of parts) _{X M} : _{molar ratio} of _additives That is, N・N′-methylenebis(N
- phenylmaleimide) is added alone, it is preferable that the relationship of the formula is satisfied,
When added together with 4,4'-diaminodiphenylmethane, it is preferable that the formula and the relationship of the formula are satisfied at the same time. Note that in the formula or formula, in a region where X _T is smaller than 5, the effect of addition may not be observed. In a region where X _T is greater than 60 in the formula, or in a region where X _T is greater than 150 in the formula, there is a risk that unreacted components will increase too much and precipitate will easily precipitate when stored in solution. X _M
If it is smaller than 1.1, the time to cure will be shortened and it will be difficult to handle, and if X _M exceeds 10.0, a large amount of unsaturated bisimide components [especially N・N′-methylenebis(N-phenylmaleimide)] will likely remain. Therefore, when the prepolymer composition is stored as a solution, there is a possibility that precipitates are likely to precipitate. That is, it becomes difficult to uniformly impregnate the substrate. There are no particular restrictions on the timing of adding N・N′-methylenebis(N-phenylmaleimide) to the addition type imide resin prepolymer alone or in combination with 4・4′-diaminodiphenylmethane, but the following Two methods are preferred. (a) Add a specified amount to the powder addition type imide resin prepolymer, dissolve in a solvent, and mix thoroughly. (b) Powdered addition type imide resin prepolymer is dissolved in a solvent, diluted to form a varnish, and a predetermined amount of additives are added to this. Further, after performing the operations (a) and (b) above, the solution may be heated to, for example, about 80°C and aged for 0.5 to 2 hours. Moreover, the obtained prepolymer composition solution can be powdered and used for applications such as molding materials. The above solvent is not particularly limited as long as it completely dissolves the addition type imide resin prepolymer, but polar solvents such as N-methylpyrrolidone, dimethylacetamide, dimethylformamide, and dimethylsulfamide are preferred. The amount of solvent used for dissolution is not particularly limited. The addition type imide resin prepolymer used in this invention is obtained by reacting an unsaturated bisimide represented by the following formula () with a diamine represented by the following formula (). (In the formula, D represents a divalent group containing carbon-carbon and double bonds, and A represents a divalent group containing at least two carbon atoms.) H ₂ N-B-NH ₂ ...() (wherein B is a divalent group having up to 30 carbon atoms) The symbols A and B can be the same or different and each has a straight chain with less than 13 carbon atoms. a branched or branched alkylene group, a cyclic alkylene group having 5 or 6 carbon atoms in the ring, a heterocyclic group containing at least one of O, N and S atoms, or
It can also be a phenylene or polycyclic aromatic group. These various groups may have substituents that do not give rise to unnecessary side reactions under the reaction conditions. The symbols A and B can also represent a number of phenylene groups or alicyclic groups.
In this case, the adjacent phenylene groups or alicyclic groups may be bonded directly, or may be bonded via a divalent atom such as oxygen or sulfur, or
Alternatively, it may be bonded through an alkylene group of 1 to 3 carbon atoms or one of the groups shown below. When a plurality of these atoms or groups exist, they may be the same or different. −NR ⁴ −, −P(O)R ³ −, −N=N−,

[Formula] -CO-O-, -SO ₂ -, -SiR ³ R ⁴ -, -CONH-, -NY-CO-X-CO-
NY-, -O-CO-X-CO-O-,

【formula】

【formula】

[expression] and In the above formula, R ³ , R ⁴ and Y are each an alkyl group having 1 to 4 carbon atoms, a cyclic alkyl group having 5 or 6 carbon atoms in the ring, a phenyl group, or a polycyclic aromatic group. Represents a group group, X
is a straight-chain or branched alkylene group having fewer than 13 carbon atoms, a cyclic alkylene group having 5 or 6 carbon atoms in the ring,
Alternatively, it represents a monocyclic or polycyclic arylene group. The group D has the formula: derived from ethylenic anhydrides (such as unsaturated dicarboxylic anhydrides), such as maleic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, itaconic anhydride, and cyclodienes and their anhydrides. It can also represent the product of a Diels-Alder reaction that occurs between one of the following: Preferred examples of the unsaturated bisimide represented by formula () include the following. Maleic acid N・N′-ethylene-bis-imide, maleic acid N・N′-hexamethylene-bis-imide, maleic acid N・N′-metaphenylene-bis-imide, maleic acid N・N′-paraphenylene-bis-imide -imide, maleic acid N・N′-4・4′-diphenylmethane-bis-imide [also called N・N′-methylenebis (N-phenylmaleimide)], maleic acid N・N′-4・4′- Diphenyl ether-bis-imide, maleic acid N・N′-4・4′-diphenylsulfon-bis-imide, maleic acid N・
N'-4,4'-dicyclohexylmethane-bis-imide, maleic acid N, N'-α, α'-4,4'-dimethylenecyclohexane-bis-imide, maleic acid N, N'-methaxylylene-bis-imide -imide, and N.N'-diphenylcyclohexane-bis-imide maleate. Preferred examples of diamines represented by formula () include the following. 4,4'-diaminodicyclohexylmethane, 1,4'-diaminocyclohexane, 2,6-diaminopyridine, metaphenylenediamine, paraphenylenediamine, 4,
4'-diamino-diphenylmethane, 2,2-bis-(4-aminophenyl)propane, benzidine,
4,4'-diaminophenyl oxide, 4,4'-
Diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, bis-(4-aminophenyl) diphenylsilane, bis-(4-aminophenyl)methylphosphine oxide, bis-(3-aminophenyl)methylphosphine oxide, Bis-(4-aminophenyl)-phenylphosphine oxide, bis-(4-aminophenyl) phenylamine, 1,5-diaminonaphthalene, metaxylylene diamine, paraxylylene diamine, 1,1-bis-(paraiminophenyl) ) Phthalane and hexamethylene diamine. The addition-type imide resin prepolymer used in the above two inventions is one obtained by reacting the above-mentioned unsaturated bisimide and diamine as is, heated and melted, or reacted in a polar solvent. Furthermore, it includes those reacted in the presence of a reaction catalyst. Reactions typically range from 50 to 200
It is carried out in a temperature range of ℃. Here, the catalyst is preferably one that acts as a proton donor in the polar solvent used and promotes Michael addition. Examples of catalysts are shown below. Examples of catalysts triethylamine, tripropylamine, tributylamine, N/N-tetramethylethylenediamine, N/N-tetramethyl-1,3-butanediamine, triethylenediamine, N-methylmorpholine, pyridine, α-picoline, quinoline,
Tertiary amines such as N/N'-dimethylaniline, N/N'-diethylaniline, dimethylbenzylamine, formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, benzoic acid, phthalic acid, isophthalic acid , organic acids such as terephthalic acid, and water. Note that it is also possible to use a commercially available addition type imide resin prepolymer. Examples of commercially available products are listed below. Kerimid 601 (manufactured by Rhône-Poulenc, France). This is a prepolymer obtained by heat-melting reaction of unsaturated bisimide and diamine, and is widely commercially available. Compimid X183 (manufactured by Technochem, West Germany)
MS-2040 (manufactured by Mitsubishi Yuka Co., Ltd.) These are polymaleimides made by reacting maleic anhydride with a polyamine. Note that it is also possible to use modified products of the above commercial products. There are no particular limitations on the molecular weight distribution of the addition-type imide resin prepolymer, but even if it contains 7% or more of components with a molecular weight exceeding 15,000, the viscosity of the prepolymer composition will not become too high and the curing time will be shortened. There are no inconveniences such as no shortening of the pot life due to the shortening. Also, the molecular weight
When synthesized to contain 7% or more of components exceeding 15,000, the proportion of components with lower molecular weights, good solubility, high activity, and good adhesion to the base material increases, and it becomes difficult to bond with the base material. preferred in terms of adhesion, solubility, etc. Here, the molecular weight distribution is determined using, for example, a DMF solvent and a separation column manufactured by Showa Denko AD-
Gel permeation chromatograph (manufactured by Toyo Soda) equipped with two 803/S (8.0 x 250 mm, 6000 theoretical plates)
HLC-803D). Calculation of molecular weight is
A cubic regression curve is obtained from the common logarithm of the retention time and molecular weight of five types of monodisperse polyethylene glycol and ethylene glycol monomer, and this is applied to the sample, and the molecular weight is calculated inversely from the retention time of the sample. I went by method. In addition, the ratio (%) of each component was determined using a differential refractometer (128 × 10 ^-8 RI unit), and the sample concentration was determined to be 0.5±0.2.
%, the sample injection amount was 100 μ, the refractometer output was 0 to 1 V, the recorder output was 0 to 10 mV, and the chart speed was 5 mm/min. The respective ratios were determined. When the prepolymer compositions according to the first and second inventions are dissolved in a polar solvent such as N-methylpyrrolidone or dimethylacetamide to prepare a varnish, precipitation of unreacted raw materials and high-molecular-weight undissolved substances occur in the varnish. It is a clear varnish that does not contain any substances, and since it takes a long time for the varnish to harden, the pot life of the varnish is also extended. The addition-type imide resin prepolymers of the above two inventions can be used not only for printed wiring board laminates, but also for semiconductor encapsulation materials, high-strength, high-modulus structural materials for electrical equipment, and electromagnetic shielding materials when combined with various fillers. It can be used in a wide range of electrical applications such as molding materials such as molding materials, adhesives for die bonding of semiconductor elements and mounting of chip parts, and pastes for circuit printing.
It becomes possible to obtain a molded article with high adhesion and good flexibility. Furthermore, low pressure molding is possible. When producing a prepreg by impregnating a base material with the addition-type imide resin prepolymer composition of the above two inventions and semi-curing each, the type of base material impregnated with the addition-type imide resin prepolymer composition is not particularly limited. . Usually, glass cloth or the like is used. In addition, inorganic fiber cloth such as quartz fiber cloth, highly heat-resistant organic fiber cloth such as aramid resin (Kevlar etc.) cloth, etc. may be used. These base materials are usually used after surface treatment with a coupling agent or the like. The temperature during semi-curing is preferably 130 to 155°C. When the temperature exceeds 155°C, the production of components with a molecular weight exceeding 15,000 is promoted, and when the temperature is below 130°C, prepreg cannot be efficiently produced. molecular weight
If there are too many components exceeding 15,000, the viscosity of the resin will become too high. Therefore, voids occur during low-pressure molding. Furthermore, the time required for curing is too short, making it difficult to obtain large laminates (molded plates). A prepreg using at least one of the prepolymer compositions according to the first and second inventions includes:
It takes a long time for the varnish to harden, allowing sufficient drying, and less volatile matter remains in the prepreg. Furthermore, since the melt viscosity of the resin is low, this prepreg does not cause fading even when molded at low pressure, making it suitable for molding large-sized laminates. The laminate is made, for example, by laminating and molding a predetermined number of the above prepregs, or by laminating and molding the above prepregs together with a metal foil such as copper or nickel, or an inner layer material having a circuit formed thereon, if necessary.
Since the prepreg uses at least one of the prepolymer compositions of the two inventions described above, it can be molded at low pressure without generating voids. Therefore, this laminate can be made very dimensionally stable. In addition, since this laminate uses at least one of the prepolymer compositions according to the above two inventions, it also has good adhesion between the resin and the base material, adhesion between the circuit and the resin, and an excellent relationship between the layers. High adhesion. Therefore, by using this laminate, it is possible to obtain a high-density multilayer printed board. Next, examples and comparative examples of the first and second inventions will be described. Examples 1 to 14 and Comparative Examples 1 to 3 In Examples 1 to 14 and Comparative Examples 1 to 3, prepolymer composition solutions having the formulations shown in Table 1 were prepared. The gelation time (minutes) at 160° C. and the formation of precipitate during storage at room temperature were investigated for each prepolymer composition solution, and the results are also shown in Table 1. The BMI-DDM reactants shown in Table 1 were prepared as follows. (Preparation of BMI-DDM reactant) In a stainless steel container that has been sufficiently heated with an electric heater, the molar ratio of N・N′-methylenebis(N-phenylmaleimide) and 4・4′-diaminodiphenylmethane ( BMI/DDM) 2.5 was added in the prescribed amount. Next, stir as the contents melt,
It was kept at 160°C for 8 minutes. Thereafter, the mixture was spread on a sufficiently cooled wide iron plate and cooled to obtain a yellow solid BMI-DDM reaction product.

【table】

[Table] (Preparation of prepreg) Next, surface-treated glass cloth (105 g/cm ² ) was impregnated with each of the prepolymer composition solutions of Examples 1 to 14 and Comparative Examples 1 to 3, and
A prepreg with a resin content of 48-50% was obtained by drying at 150°C. Table 2 shows the gelation time (seconds) of each prepreg at 170°C. (Preparation of laminate board) The prepreg obtained earlier was made into a size of 30cm x 30cm, and 4 sheets were stacked, and 1/2 oz ft ² copper foil of the same size with surface treatment was placed on both sides. It was made into a laminate. This was placed in a 1.6 mm thick mold, and while applying a pressure of 5 kg/cm ² using a steam press, it was immediately heated to 130° C. and held for 20 minutes. After this,
Set the pressure to the pressure shown in Table 2 and 170
℃, and after 90 minutes was cooled to room temperature while keeping the pressure applied to obtain a double-sided copper-clad laminate. This material was subjected to after-cure at a temperature of 200°C for 120 minutes. The variation in peel strength and dimensional change of each of the obtained laminates is also shown in Table 2. Note that the peel strength is a value between laminated prepregs. Dimensional changes are measured at measurement intervals of 200
The amount of shrinkage in the vertical direction was measured in mm. The measurement method is shown below. (Measurement method of dimensional change) A primary molded double-sided copper-clad laminate was prepared in the same manner as above except that one prepreg sheet of 25 cm x 25 cm and two sheets of 1 oz/ft ² copper foil of the same size were used. I got it. After drilling reference point holes in this material at intervals of approximately 200 mm, the dimensions between the holes were accurately measured, and the copper foil on both sides was etched away using a conventional method. next,
On one side of this (inner layer material), two sheets of prepreg with the same dimensions as above and one sheet of copper foil of 1 oz/ft ² with the same size are laminated, and on the other side, two sheets of prepreg and one sheet of copper foil are laminated. were laminated and molded in the same manner as above, followed by after-curing at 200°C for 120 minutes to obtain a laminate (multilayer board). The copper foil on the reference point hole of the inner layer material of this laminate was mechanically removed and the dimensions were measured, and the dimensional change of the inner layer was measured. Based on this measurement method, the above measurements were performed 10 times. The variation in dimensional change (3δ) [%] at this time is
It is also shown in the table.

【table】

【table】

〔Effect of the invention〕

The addition-type imide resin prepolymer compositions according to the first and second inventions are as described above, so by using them, molded products with high adhesion can be obtained and low-pressure molding is possible. This makes it possible to obtain a molded article with high dimensional stability. Therefore, by using these, it becomes possible to obtain a high-density, high-multilayer printed board.

Claims (1)

[Claims] 1. 100 parts by weight of an addition type imide resin prepolymer made by reacting an unsaturated bisimide with a diamine,
An addition type imide resin prepolymer composition containing 5 to 60 parts by weight of N.N'-methylenebis(N-phenylmaleimide). 2 The addition type imide resin prepolymer has a molecular weight of
The addition type imide resin prepolymer composition according to claim 1, which contains 7% or more of a component exceeding 15,000. 3. To 100 parts by weight of an addition-type imide resin prepolymer made by reacting unsaturated bisimide and diamine,
An addition type imide resin prepolymer composition containing N.N'-methylenebis(N-phenylmaleimide) and 4.4'-diaminodiphenylmethane in a total amount of 5 to 150 parts by weight. 4 The addition type imide resin prepolymer has a molecular weight of
The addition type imide resin prepolymer composition according to claim 3, which contains 7% or more of a component exceeding 15,000.