JP2013036042A - Thermosetting resin composition for interlayer insulating material of multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a thermosetting resin composition that can form an interlayer insulating layer high in bond strength to a plated conductive layer, and excellent in insulation reliability; a dry film using the same; and a multilayer printed wiring board having the interlayer insulating layer formed through these.SOLUTION: This thermosetting resin composition for the interlayer insulation material of the multilayer printed wiring board includes as essential components, (A) an epoxy resin having two or more epoxy groups in one molecule, and liquid at 20°C, (B) a solid epoxy resin having three or more epoxy groups in one molecule, and solid at 40°C; (C) a semi-solid epoxy resin having two or more epoxy groups in one molecule, and showing solid state at 20°C and liquid state at 40°C; (D) an epoxy curing agent; and (E) a filler. The three epoxy resins are contained, in mass ratio, (A):(B+C)=1:1 to 1:10, and (B):(C)=1:0.5 to 1:2. Preferably the component (A) and the component (B) are contained, in mass ratio, (A):(B)=1:0.5 to 1:5.

Description

  The present invention is a build-up multilayer printed wiring board in which conductor circuit layers and insulating layers are alternately stacked, and exhibits excellent adhesion to a substrate and a conductor, and the cured film has a relatively low coefficient of thermal expansion. A thermosetting resin composition for an interlayer insulating material having a high peel strength (peeling strength) of a conductor layer formed by plating and having both high heat resistance and roughening properties by roughening treatment, The present invention relates to a dry film used and a multilayer printed wiring board in which an interlayer insulating layer is formed using the dry film.

  In recent years, as a method for producing a multilayer printed wiring board, a build-up production technique in which an organic insulating layer and a conductor layer are alternately stacked on a conductor layer of an inner circuit board has attracted attention. For example, a multilayer printed wiring board in which an epoxy resin composition is applied to a circuit-formed inner layer circuit board, heat-cured, a roughened surface is formed on the surface with a roughening agent, and a conductor layer is formed by plating Has been proposed (see Patent Document 1 and Patent Document 2). Also, after laminating an adhesive sheet of an epoxy resin composition on a circuit-formed inner layer circuit board and heat-curing it, a roughening surface is formed on the surface with a roughening agent, and a conductor layer is formed by plating A method for manufacturing a printed wiring board has been proposed (see Patent Document 3).

  An example of a conventional method for producing a multilayer printed wiring board by a build-up method will be described with reference to FIG. 1. First, a multilayer substrate in which an inner layer conductor pattern 3 and a resin insulating layer 4 are formed in advance on both surfaces of an insulating substrate 1. The outer conductor pattern 8 is formed on both sides of X, and an epoxy resin composition is applied thereon by an appropriate method such as a screen printing method, a spray coating method, or a curtain coating method, and then cured by heating to form a resin insulating layer 9 Form. (When using a dry film or a prepreg, the resin insulation layer 9 is formed by laminating or hot plate pressing and heat curing.)

  Next, a through-hole hole 21 that penetrates the resin insulating layer 9 and the laminated substrate X and a via hole (not shown) for electrically connecting the connection portions of the conductor layers are formed. Drilling can be performed by a suitable means such as a drill, a die punch, or a laser beam. Thereafter, the surface of each resin insulating layer 9 is roughened and the holes are desmeared using a roughening agent. In general, the roughening treatment of the cured film of the epoxy resin composition on the inner layer circuit board is performed by treating the entire surface of the cured composition with an organic material such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, or methoxypropanol. It is carried out by swelling with a solvent or an alkaline aqueous solution such as caustic soda or caustic potash, and roughening using an oxidizing agent such as dichromate, permanganate, ozone, hydrogen peroxide / sulfuric acid, nitric acid.

  Next, a conductor layer is formed on the surface of the resin insulating layer 9 by electroless plating, electrolytic plating, a combination of electroless plating and electrolytic plating, or the like. The step of forming the conductor layer by electroless plating is a step of immersing the entire surface of the cured composition in an aqueous solution containing a catalyst for plating, adsorbing the catalyst, and then immersing in a plating solution to deposit the plating. It is. At this time, the conductor layer is covered not only on the surface of the resin insulating layer 9 but also on the entire surface of the through hole 21 and the blind hole. Next, a predetermined circuit pattern is formed on the conductor layer on the surface of the resin insulating layer 9 according to a conventional method (subtractive method, semi-additive method, etc.), and outermost layer conductor patterns 10 are formed on both sides as shown in FIG. . At this time, the plated layer is also formed in the through-hole 21 as described above. As a result, the connection portion 22 of the outermost layer conductor pattern 10 and the connection portion 3a of the inner layer conductor pattern 3 of the multilayer printed wiring board are formed. They are electrically connected to each other, and a through hole 20 is formed. In the case of manufacturing a multilayer printed wiring board, the resin insulating layer and the conductor layer may be built up alternately. In the above build-up, an example in which the resin insulating layer and the conductor layer are formed on the multilayer substrate has been described. However, a single-sided substrate or a double-sided substrate may be used instead of the multilayer substrate.

As described above, an epoxy resin composition is generally used as a composition used for forming an interlayer insulating layer of a multilayer printed wiring board. However, the conventional cured film of the epoxy resin composition has a problem that the adhesion strength with the conductor layer is low because it is difficult to form a good uneven surface by roughening treatment.
In addition, with the progress of miniaturization and higher performance of electronic equipment, the build-up layer of multilayer printed wiring boards has become multi-layered, and staggered vias and stacked vias in which via holes are connected across multiple build-up insulating layers There is an increasing demand for multilayer printed wiring boards having a multi-stage via structure called “A”. In the multilayer printed wiring board having such a multi-stage via structure, the thermal expansion coefficient of the copper wiring connecting the via hole and the insulating layer is greatly different. Therefore, when a reliability test such as a thermal cycle is performed, the copper wiring or the insulating layer Problems such as cracks occurred.

  Therefore, in order to suppress the thermal expansion coefficient of the resin composition constituting the insulating layer and increase the peel strength (peeling strength) of the conductor layer formed by plating, (a) two or more epoxy groups in one molecule An epoxy resin which is liquid at a temperature of 20 ° C., (b) an aromatic solid epoxy resin having 3 or more epoxy groups in one molecule and an epoxy equivalent of 200 or less, and (c) a phenolic resin A curing agent, (d) one or more resins selected from the group consisting of a phenoxy resin, a polyvinyl acetal resin, a polyamide resin and a polyamideimide resin, having a glass transition temperature of 100 ° C. or higher, and comprising component (a) and component (b ) Epoxy resin in a weight ratio of 1: 0.3 to 1: 2, and the ratio of the epoxy group in the resin composition to the phenolic hydroxyl group of the phenolic curing agent in component (c) is 1: A resin composition for interlayer insulation of a multilayer printed wiring board in which the content ratio of the resin of component (d) is 2 to 20% by weight of the resin composition is proposed (patent) Reference 4).

  Heat obtained by containing two types of epoxy resins, a liquid epoxy resin and a solid epoxy resin, and a phenoxy resin having a glass transition temperature of 100 ° C. or higher, as in the resin composition for interlayer insulation. The coefficient of thermal expansion of the curable resin composition can be kept low. However, in the state before curing (dry coating film or dry film or prepreg), the measured value by the Erichsen tester shows a relatively high value when the test speed is slow, but the blending ratio of the solid epoxy resin is low, When the test speed was high, it showed a low value, and there were still points to be improved in the handling surface when processing the substrate.

JP-A-7-304931 (Claims) JP-A-7-304933 (Claims) JP-A-11-87927 (Claims) JP 2005-154727 A (Claims)

Therefore, the object of the present invention is to show excellent adhesion to the substrate and the conductor, the cured film exhibits a relatively low coefficient of thermal expansion, and the peel strength (peeling strength) of the conductor layer formed by plating. It is an object of the present invention to provide a thermosetting resin composition that can form an interlayer insulating layer of a multilayer printed wiring board having high insulation reliability and that is excellent in handling reliability, and a dry film using the same.
Another object of the present invention is to use these to build up a multilayer printed wiring board in which conductor circuit layers and insulating layers are alternately stacked, in which the peel strength of the plated conductor layer is high and reliability such as thermal cycle is reliable. It is an object of the present invention to provide a multilayer printed wiring board in which an interlayer insulating layer having excellent heat resistance and electrical insulation properties is formed without causing cracks in the property test.

  In order to achieve the above object, according to the present invention, (A) an epoxy resin having two or more epoxy groups in one molecule and being liquid at 20 ° C., (B) three or more epoxies in one molecule A solid epoxy having a group and solid at 40 ° C., (C) a semi-solid epoxy resin having two or more epoxy groups in one molecule of resin, solid at 20 ° C. and liquid at 40 ° C. , (D) an epoxy curing agent, and (E) a filler as essential components, and the above three types of epoxy resins in a mass ratio of (A) :( B + C) = 1: 1 to 1:10, (B) : (C) = 1: 0.5-1: 2 The thermosetting resin composition for interlayer insulation materials of a multilayer printed wiring board characterized by the above-mentioned is provided.

  In a preferred embodiment, the liquid epoxy resin (A) and the solid epoxy resin (B) are contained in a mass ratio of (A) :( B) = 1: 0.5 to 1: 5. In still another preferred embodiment, (F) a thermoplastic resin having a glass transition temperature of 100 ° C. or higher, preferably a thermoplastic polyhydroxy polyether resin having a fluorene skeleton is contained.

Furthermore, according to this invention, the dry film formed by forming the thin film of the said thermosetting resin composition on a support base film is also provided.
Furthermore, according to the present invention, in the multilayer printed wiring board in which the resin insulating layer and the conductor layer of the circuit pattern are sequentially formed on the inner circuit board, the resin insulating layer is a cured resin of the thermosetting resin composition. It consists of a film or a dry film, and the interface with the conductor layer on the surface is formed on a rough surface with fine irregularities by roughening treatment, and the conductor layer is bonded to the resin insulating layer via the roughened surface. Thus, a multilayer printed wiring board is provided.

The thermosetting resin composition of the present invention has (A) an epoxy resin having two or more epoxy groups in one molecule and being liquid at 20 ° C., and (B) having three or more epoxy groups in one molecule. A solid epoxy resin that is solid at 40 ° C., (C) a semi-solid epoxy resin that has two or more epoxy groups in one molecule, is solid at 20 ° C., and is liquid at 40 ° C. Since it is contained in combination at a specific blending ratio, it exhibits excellent adhesion to the substrate and the conductor, its cured film exhibits a relatively low coefficient of thermal expansion, and the peel strength of the conductor layer formed by plating ( It is possible to form an interlayer insulating layer having high peel strength and excellent insulation reliability. Therefore, it is optimal as an interlayer insulating layer of a multilayer printed wiring board.
Therefore, by using the thermosetting resin composition of the present invention or a dry film thereof in a build-up method in which conductor circuit layers and insulating layers are alternately stacked, the peel strength of the plated conductor layer is high, and reliability such as thermal cycle is ensured. It is possible to produce a multilayer printed wiring board on which an interlayer insulating layer having excellent heat resistance and electrical insulation properties is formed without causing cracks in the property test.

It is a fragmentary sectional view which shows schematic structure of the multilayer printed wiring board produced by the conventional buildup method. It is a schematic side view which shows the two test tubes used for the liquid determination of the epoxy resin.

  As a result of diligent research to solve the above problems, the present inventors have (A) an epoxy resin having two or more epoxy groups in one molecule and being liquid at 20 ° C., and (B) in one molecule. Solid epoxy resin having 3 or more epoxy groups and solid at 40 ° C., (C) 2 or more epoxy groups in one molecule, solid at 20 ° C. and liquid at 40 ° C. When a semi-solid epoxy resin is contained in combination with the above-mentioned specific blending ratio, it exhibits excellent adhesion to the substrate and conductor, and its cured film exhibits a relatively low coefficient of thermal expansion and is formed by plating. In order to complete the present invention, it is found that the conductor layer has a high peel strength (peeling strength) and is optimal as an interlayer insulating layer of a multilayer printed wiring board having both high heat resistance and roughening properties by roughening treatment. It has come. That is, in the case of a combination of a bifunctional liquid epoxy resin (A) and a trifunctional or higher functional solid epoxy resin (B), when the blending ratio of the liquid epoxy resin (A) is high, the resin composition is applied to the substrate. The adhesiveness of the resin becomes high, and the resin oozes out more when it is laminated on a substrate as a dry film. Conversely, if the blending ratio of the solid epoxy resin (B) is high, sufficient flexibility of the dried film cannot be obtained, and cracks and powder fall off in the dried film, or peeling off when measuring the adhesion strength by the Eriksen test. Or cracks. In addition, when laminating to a circuit board, sufficient fluidity of the resin composition sufficient to fill the via hole or the through hole tends not to be obtained. According to the study by the present inventors, these bifunctional liquid epoxy resin (A) and trifunctional or higher solid epoxy resin (B) have two or more epoxy groups in one molecule, and at 20 ° C. If the semi-solid epoxy resin (C) that is solid and is liquid at 40 ° C. is used in combination at the above-described specific blending ratio, the obtained thermosetting resin composition is a base material without the above-mentioned problems. Excellent adhesion to the conductor, the cured film maintains a relatively low coefficient of thermal expansion, the peel strength of the conductor layer formed by plating is high, and the insulation reliability is excellent It has been found that an interlayer insulating layer can be formed. In addition, the inclusion of the thermoplastic resin (F) facilitates the removal of the filler during the roughening treatment, can form a stable roughened surface, and the anchor effect increases the peel strength of the plated conductor layer. A multilayer printed wiring board on which an interlayer insulating layer that is high and excellent in heat resistance, electrical insulation and the like is formed can be manufactured.

Hereinafter, each component of the thermosetting resin composition of the present invention will be described in detail.
First, as described above, as an epoxy resin, (A) an epoxy resin having two or more epoxy groups in one molecule and being liquid at 20 ° C., and (B) three or more epoxy groups in one molecule. A solid epoxy resin that is solid at 40 ° C., (C) a semi-solid epoxy resin that has two or more epoxy groups in one molecule, is solid at 20 ° C., and is liquid at 40 ° C. Must be used in combination. Here, the “liquid” determination method referred to in this specification will be described.

Judgment of liquid state shall be made in accordance with the second “Liquid Confirmation Method” of the Ministerial Ordinance on Dangerous Goods Testing and Properties (Ministry of Local Government Ordinance No. 1 of 1989).
(1) Apparatus Constant-temperature water bath: A device equipped with a stirrer, a heater, a thermometer, and an automatic temperature controller (with temperature control at ± 0.1 ° C.) having a depth of 150 mm or more.
In the determination of the epoxy resin used in the examples to be described later, a combination of a low temperature thermostatic water tank (model BU300) manufactured by Yamato Scientific Co., Ltd. and a thermostat (model BF500) of the input type thermostatic apparatus (model BF500) is used. Put 22 liters in a low temperature constant temperature water bath (model BU300), turn on the thermomate (model BF500) assembled to it and set it to the set temperature (20 ° C or 40 ° C), and set the water temperature to the set temperature ± 0.1 Although fine adjustment was performed with a thermomate (model BF500) at 0 ° C., any apparatus capable of the same adjustment can be used.

Test tube:
As shown in FIG. 2, the examiner is made of a flat bottom cylindrical transparent glass having an inner diameter of 30 mm and a height of 120 mm, and marked lines 31 and 32 are respectively provided at heights of 55 mm and 85 mm from the tube bottom. The test tube 30a for liquid judgment with the test tube 30a sealed with a rubber plug 33a is the same size as that of the test tube 30a. The rubber plug 33b is similarly provided with a marked line and a hole for inserting and supporting a thermometer in the center. A test tube 30b for temperature measurement in which the mouth of the test tube is sealed and a thermometer 34 is inserted into the rubber plug 33b is used. Hereinafter, a marked line having a height of 55 mm from the tube bottom is referred to as “A line”, and a marked line having a height of 85 mm from the tube bottom is referred to as “B line”.
As the thermometer 34, the one for freezing point measurement (SOP-58 scale range 20-50 ° C) specified in JIS B7410 (1982) "Petroleum test glass thermometer" is used, but the temperature is 0-50 ° C. It is sufficient if the range can be measured.

(2) Test procedure The liquid test tube 30a shown in FIG. 2 (a) and the temperature measurement test shown in FIG. 2 (b) were prepared for 24 hours or more at atmospheric pressure of 20 ± 5 ° C. Insert up to line A in each tube 30b. The two test tubes 30a and 30b are left standing in a low temperature constant temperature water bath so that the line B is below the water surface. The thermometer has its lower end 30 mm below the A line.
The state is maintained as it is for 10 minutes after the sample temperature reaches the set temperature ± 0.1 ° C. Ten minutes later, the test tube 30a for liquid judgment is taken out of the low-temperature water bath and immediately tilted horizontally on a horizontal test stand, and the time when the tip of the liquid level in the test tube has moved from the A line to the B line is measured with a stopwatch. Measure and record. A sample is determined to be liquid when the measured temperature is 90 seconds or less at a set temperature, and solid when it exceeds 90 seconds.

  The epoxy resin (A) having two or more epoxy groups in one molecule and being liquid at a temperature of 20 ° C. includes bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, tert-butyl. -A catechol type epoxy resin, a glycidyl amine type epoxy resin, an aminophenol type epoxy resin, an alicyclic epoxy resin, etc. are mentioned. Of course, the epoxy resin of component (A) may be liquid at a temperature of less than 20 ° C. The epoxy resin is preferably an aromatic epoxy resin from the viewpoint of preferable physical properties of the cured product. In the present specification, the aromatic epoxy resin means an epoxy resin having an aromatic ring skeleton in the molecule. Therefore, as the component (A), “an aromatic epoxy resin having two or more epoxy groups in one molecule and being liquid at a temperature of 20 ° C.” is more preferable. These epoxy resins may be used alone or in combination of two or more.

  As the solid epoxy resin (B) having 3 or more epoxy groups in one molecule and solid at 40 ° C., EXA4700 (tetrafunctional naphthalene type epoxy resin) manufactured by DIC Corporation, Nippon Kayaku Co., Ltd. ) NC-7000 (Naphthalene skeleton-containing polyfunctional solid epoxy resin) and other naphthalene type epoxy resins; Nippon Kayaku Co., Ltd. EPPN-502H (trisphenol epoxy resin) and other phenols and aromatic aldehydes having a phenolic hydroxyl group Condensate epoxidized product (trisphenol type epoxy resin); Dicyclopentadiene aralkyl type epoxy resin such as Epiklon HP-7200H (dicyclopentadiene skeleton-containing polyfunctional solid epoxy resin) manufactured by DIC Corporation; Nippon Kayaku ( NC-3000H (polyfunctional solid epoxy resin containing biphenyl skeleton), etc. Biphenyl aralkyl type epoxy resins; DIC Corporation Epicron N660, Epicron N690, Nippon Kayaku Co., Ltd. EOCN-104S and other novolak type epoxy resins; Nissan Chemical Industries, Ltd. TEPIC etc. Tris (2,3- And epoxypropyl) isocyanurate. These epoxy resins may be used alone or in combination of two or more. In order to impart particularly low thermal expansion properties, it is preferable to use an epoxy resin containing a naphthalene skeleton.

  As the semi-solid epoxy resin (C) having two or more epoxy groups in one molecule, solid at 20 ° C. and liquid at 40 ° C., DIC Corporation Epicron 860, Epicron 900-IM , Epicron EXA-4816, Epicron EXA-4822, Araldite AER280 manufactured by Asahi Ciba Co., Ltd., Epototo YD-134 manufactured by Tohto Kasei Co., Ltd. JER834, JER872 manufactured by Japan Epoxy Resin Co., Ltd., ELA manufactured by Sumitomo Chemical Co., Ltd. Bisphenol A type epoxy resins such as -134; naphthalene type epoxy resins such as Epicron HP-4032 manufactured by DIC Corporation; and phenol novolac epoxy resins such as Epicron N-740 manufactured by DIC Corporation. These epoxy resins may be used alone or in combination of two or more.

  (A) The epoxy resin which has two or more epoxy groups in one molecule and is liquid at 20 ° C., and (B) has three or more epoxy groups in one molecule and is used at 40 ° C. Solid epoxy resin that is solid, and (C) three types of epoxy resins that have two or more epoxy groups in one molecule, are solid at 20 ° C., and are liquid at 40 ° C. The blending ratio in the composition is (A) :( B + C) = 1: 1 to 1:10, preferably 1: 2 to 1:10, (B) :( C) = 1: 0.5 by mass ratio. A ratio of ˜1: 2 is desirable. The blending ratio of the liquid epoxy resin (A) and the solid epoxy resin (B) is preferably a ratio of (A) :( B) = 1: 0.5 to 1: 5 in terms of mass ratio. If the amount of the liquid epoxy resin (A) exceeds the above ratio, the adhesiveness of the resin composition becomes high, and the resin oozes out when laminated as a dry film on a substrate. On the other hand, if the amount of the solid epoxy resin (B) is too much in excess of the above ratio, sufficient flexibility of the dry film cannot be obtained, and cracks and powder fall off may occur in the dry film, or when measuring the adhesion strength by the Eriksen test. Will cause peeling or cracking. Moreover, when a semi-solid epoxy resin (C) remove | deviates from the said ratio, the problem by liquid epoxy resin (A) or solid epoxy resin (B) use will arise easily. In addition, since a liquid epoxy resin (A) contributes to the adhesive improvement of the cured film obtained, and a solid epoxy resin (B) contributes to raising a glass transition point, adjusting these ratios. It becomes possible to adjust the balance of the above characteristics.

  As said epoxy hardening | curing agent (D), conventionally well-known various epoxy resin hardening | curing agents or an epoxy resin hardening accelerator can be mix | blended. For example, phenol resins, imidazole compounds, acid anhydrides, aliphatic amines, alicyclic polyamines, aromatic polyamines, tertiary amines, dicyandiamide, guanidines, or epoxy adducts or microencapsulated products thereof, triphenyl Regardless of the curing agent or curing accelerator, such as organic phosphine compounds such as phosphine, tetraphenylphosphonium, tetraphenylborate, DBU or its derivatives, etc., any known and commonly used ones may be used alone or in combination of two or more. can do. These epoxy curing agents are preferably blended in the range of 0.1 to 50 parts by mass with respect to 100 parts by mass of the total amount of the epoxy resins (A) to (C). If the blending amount is less than the above range, curing will be insufficient.On the other hand, even if blended in a large amount exceeding the above range, the curing acceleration effect will not be increased, and on the contrary, the problem of impairing heat resistance and mechanical strength is likely to occur. It is not preferable.

  Of the above-described epoxy curing agents, phenol resins and imidazole compounds are preferable. As the phenolic resin, known or commonly used phenolic novolac resins, alkylphenolic volac resins, bisphenol A novolac resins, dicyclopentadiene type phenolic resins, Xylok type phenolic resins, terpene modified phenolic resins, polyvinylphenols, alone or 2 It can be used in combination of more than one species.

  In addition, the reaction of the imidazole compound is slow in the temperature range (80 ° C. to 130 ° C.) when drying the solvent in the composition, and sufficiently proceeds in the temperature range during curing (150 ° C. to 200 ° C.). This is preferable in that the physical properties of the cured product can be sufficiently expressed. Moreover, an imidazole compound is preferable also at the point which is excellent in adhesiveness with a copper circuit and copper foil. Specific examples of particularly preferable ones include 2-ethyl 4-methylimidazole, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, bis (2-ethyl-4-methyl-imidazole), 2- Examples include phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, triazine addition type imidazole, and the like. These can be used alone or in combination of two or more.

  Next, as the filler (E), all conventionally known inorganic fillers and organic fillers can be used, and the filler (E) is not limited to specific ones. The action to be formed is mainly due to the roughening liquid penetrating into the interface between the cured film and the filler and the filler on the surface of the cured film falling off, so that an inorganic filler having good affinity with the roughening liquid is preferable. Examples of inorganic fillers include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, and aluminum nitride. And extender pigments such as copper, tin, zinc, nickel, silver, palladium, aluminum, iron, cobalt, gold and platinum. These inorganic fillers contribute to the improvement of properties such as adhesion and hardness by suppressing the curing shrinkage of the coating film in addition to the action of forming a rough surface with fine irregularities by the roughening treatment. Among these inorganic fillers, silica and barium sulfate which are not easily attacked by the roughening liquid are preferable, and spherical silica is particularly preferable because it can be blended in a high ratio in the composition. The average particle size of the filler is preferably 3 μm or less, more preferably 1 μm or less.

  The proportion of the filler (E) is 40 to 200 parts by mass, preferably 50 to 150 parts by mass, with respect to 100 parts by mass of the total amount of the epoxy resins (A) to (C). When the blending amount of the filler is less than the above range, it is difficult to form a good rough surface having a rough surface, and when it exceeds the above range, the fluidity of the composition is deteriorated.

  The thermosetting resin composition of the present invention is a thermoplastic resin (F) having a glass transition temperature of 100 ° C. or higher, for example, a thermoplastic polyhydroxy polyether described later, in order to improve the mechanical strength of the resulting cured film. Resin, phenoxy resin which is a condensate of epichlorohydrin and various bifunctional phenol compounds, or phenoxy resin obtained by esterifying the hydroxyl group of the hydroxy ether moiety in the skeleton using various acid anhydrides or acid chlorides, polyvinyl acetal resin, Polyamide resins, polyamideimide resins and the like can be contained alone or in combination of two or more. When the glass transition temperature of the thermoplastic resin (F) is less than 100 ° C., the mechanical strength of the cured product is not sufficient, and the inorganic filler tends to precipitate on the surface of the cured product after roughening, and a sufficient plated conductor layer It becomes difficult to obtain peel strength. The glass transition temperature is determined according to the method described in JIS (Japanese Industrial Standard) K7197. In addition, since the glass transition temperature is higher than the decomposition temperature, the case where the glass transition temperature is not actually observed is also included in the definition of “the glass transition temperature is 100 ° C. or higher” in the present invention. The decomposition temperature is defined as a temperature at which the mass reduction rate is 5% when measured according to the method described in JIS K7120.

  Specific examples of the phenoxy resin include FX280, FX293 manufactured by Toto Kasei Co., Ltd., YX8100, YL6954, YL6974 manufactured by Japan Epoxy Resin Co., Ltd., and the like. Specific examples of the polyvinyl acetal resin include SLECK KS series manufactured by Sekisui Chemical Co., Ltd., as the polyamide resin, KS5000 series manufactured by Hitachi Chemical Co., Ltd., BP series manufactured by Nippon Kayaku Co., Ltd., and further as polyamideimide resin Examples include KS9000 series manufactured by Hitachi Chemical Co., Ltd.

  Among the above-described thermoplastic resins, a thermoplastic polyhydroxy polyether resin having a fluorene skeleton is preferable. The thermoplastic polyhydroxy polyether resin has a high glass transition point due to having a fluorene skeleton, and is excellent in heat resistance. Therefore, while maintaining a low coefficient of thermal expansion due to the epoxy resins (A) to (C), its glass transition. The cured film obtained by maintaining the point has a low thermal expansion coefficient and a high glass transition point in a well-balanced manner. In addition, since the thermoplastic polyhydroxypolyether resin has a hydroxyl group, it exhibits good adhesion to the substrate and the conductor, and the cured film obtained is not easily affected by the roughening agent, but the aqueous solution is roughened. Since the liquid easily penetrates into the interface between the cured film and the filler, the roughening treatment makes it easy for the filler on the surface of the cured film to come off, and it becomes easy to form a good roughened surface.

上記一般式（１）において、Ｘは下記一般式（２）又は（３）で示されるものであり、一般式（１）における全Ｘに対する一般式（３）の割合は８％以上であり、Ｚは水素原子又はグリシジル基であり、ｎは２１以上の整数である。 As the thermoplastic polyhydroxy polyether resin having the fluorene skeleton, for example, a thermoplastic polyhydroxy polyether resin represented by the following general formula (1) can be suitably used.

In the general formula (1), X is represented by the following general formula (2) or (3), the ratio of the general formula (3) to the total X in the general formula (1) is 8% or more, Z is a hydrogen atom or a glycidyl group, and n is an integer of 21 or more.

上記一般式（２）において、Ｒ^１、Ｒ^２は水素原子、炭素数１〜５のアルキル基、ハロゲン原子から選ばれるものであり、Ｙは−ＳＯ_２−、−ＣＨ_２−、−Ｃ（ＣＨ_３）_２−、又は−Ｏ−のいずれかであり、ｍは０又は１である。Ｒ^１とＲ^２は同一であってもよいし、異なっていてもよい。

In the general formula (2), R ¹ and R ² are selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a halogen atom, and Y is —SO ₂ —, —CH ₂ —, —C ( CH ₃ ) ₂ — or —O—, and m is 0 or 1. R ¹ and R ² may be the same or different.

  The molecular weight of the thermoplastic polyhydroxy polyether resin having the fluorene skeleton is in the range of 5,000 to 100,000 (weight average molecular weight in terms of standard polystyrene measured by gel permeation chromatography (GPC)). Preferably there is. If the molecular weight is less than 5,000, the thermoplasticity is lost. On the other hand, if the molecular weight exceeds 100,000, the solution viscosity when dissolved in a solvent is too high, and it becomes difficult to add a large amount of filler. It is not preferable.

  A halogen may be introduced into the thermoplastic polyhydroxy polyether resin having a fluorene skeleton in order to impart flame retardancy. When flame retardancy is imparted by halogen, it is difficult to impart sufficient flame retardancy if the halogen content is less than 5% by mass. On the other hand, even if the concentration exceeds 40% by mass, further flame retardancy is achieved. Since no improvement is observed, it is practical to control the halogen content in the range of 5 to 40% by mass. Any type of halogen element may be used, but from the viewpoint of commercial production, commercially available bromine compounds, chlorine compounds, and fluorine compounds are preferably used.

  As a method for producing the thermoplastic polyhydroxy polyether resin having the fluorene skeleton, there are a method by a direct reaction of a dihydric phenol and epichlorohydrin, and a method by an addition polymerization reaction of a diglycidyl ether of a dihydric phenol and a dihydric phenol. Although known, it may be obtained by any manufacturing method. In addition, since the manufacturing method of the said thermoplastic polyhydroxy polyether resin is described in detail in Unexamined-Japanese-Patent No. 11-269264, please refer to it.

  The amount of the thermoplastic resin (F) in the thermosetting resin composition of the present invention is 5 to 50 parts by mass, preferably 100 parts by mass of the total amount of the epoxy resins (A) to (C). Is preferably 10 to 40 parts by mass. If the blending amount of the thermoplastic resin (F) is out of the above range, it becomes difficult to obtain a uniform roughened surface state.

  In addition, polyimide resin, polyphenol resin, polycyanate resin, polyester resin, thermosetting polyphenylene ether resin, etc. should be added to the thermosetting resin composition of the present invention in a quantitative ratio that does not impair the effects of the present invention. You can also.

  Furthermore, the thermosetting resin composition of this invention can contain an organic solvent as needed. Examples of the organic solvent include ordinary solvents such as ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and cellosolves such as cellosolve and butylcellosolve. In addition to carbitols such as carbitol and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide and the like can be used alone or in combination of two or more.

  The thermosetting resin composition of the present invention may further include a known and commonly used colorant such as phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, etc. , Known and commonly used thickeners such as asbestos, olben, benton, fine silica, etc., defoamers and / or leveling agents such as silicones, fluorines and polymers, thiazoles, triazoles, silane coupling agents, etc. Adhesiveness imparting agents, titanate-based, and aluminum-based commonly used additives can be used.

The thermosetting resin composition of the present invention is easy to form a roughened surface by containing the filler (E), but on the other hand, deterioration such as surface smoothness easily occurs. In this regard, in the present invention, by blending the antifoaming agent and / or leveling agent (G) among the above additives, the surface smoothness is prevented from being deteriorated, and the interlayer insulation is deteriorated due to voids or pinholes. Can also be prevented.
As a specific example of the antifoaming agent and / or the leveling agent (G), BYK (registered trademark) − manufactured by BYK Japan Japan Co., Ltd. as an antifoaming agent comprising a commercially available non-silicone-based antifoaming polymer solution is used. 054, -055, -057, -1790, and the like. Examples of silicone-based antifoaming agents are BYK (registered trademark) -063, -065, -066N, -067A, and -077 manufactured by BYK Japan KK. And KS-66 (trade name) manufactured by Shin-Etsu Chemical Co., Ltd.
The blending amount of such an antifoaming agent and / or leveling agent (G) is 5 parts by weight or less with respect to a total of 100 parts by weight of the epoxy resins (A) to (C) and the thermoplastic resin (F). 0.01 to 5 parts by weight is preferable.

  The form of the thermosetting resin composition of the present invention may be provided as a coating material having an appropriately adjusted viscosity, or may be a dry material obtained by applying the thermosetting resin composition on a supporting base film and drying the solvent. It is good also as a film. Further, it may be a prepreg sheet which is semi-cured by coating and / or impregnating a sheet-like fibrous base material such as glass cloth, glass and aramid nonwoven fabric. Examples of the supporting base film include polyolefins such as polyethylene and polyvinyl chloride, polyesters such as polyethylene terephthalate, polycarbonates and polyimides, and metal foils such as release paper, copper foil, and aluminum foil. Note that the support base film may be subjected to a release treatment in addition to the mud treatment and the corona treatment.

  The coating material, dry film, or prepreg using the thermosetting resin composition is directly coated on the inner circuit board on which the circuit is formed, and then dried or cured, or the dry film is laminated by heating to be integrally formed. Then, it may be cured in an oven or cured by a hot plate press. In the case of a prepreg, it is placed on an inner circuit board, sandwiched between metal plates through a release film, and pressed by pressing and heating.

  Among the above steps, the method of laminating or hot plate pressing is preferable because the fine unevenness caused by the inner layer circuit is eliminated when heated and melted and is cured as it is, so that a multilayer plate having a flat surface state can be finally obtained. Further, when laminating or hot plate pressing the base material on which the inner layer circuit is formed and the film or prepreg of the thermosetting resin composition of the present invention, the copper foil or the base material on which the circuit is formed can be laminated simultaneously. .

A hole is made in the substrate thus obtained with a semiconductor laser such as a CO ₂ laser or a UV-YAG laser or a drill. The hole is a through hole (through hole) that is intended to connect the front and back of the substrate, but it is also a partial hole (conformal via) that is intended to connect the inner layer circuit and the circuit on the surface of the interlayer insulating layer. either will do.

  After drilling, in order to remove the residue (smear) present on the inner wall and bottom of the hole and to develop an anchor effect with the conductor layer (the metal plating layer to be formed thereafter), a rough surface with fine irregularities For the purpose of forming a chemical surface, a commercially available desmear liquid (roughening agent) or a roughening liquid containing an oxidizing agent such as permanganate, dichromate, ozone, hydrogen peroxide / sulfuric acid, nitric acid, etc. Do it at the same time.

  Next, a circuit is formed by a subtractive method, a semi-additive method, or the like after forming a hole from which a residue has been removed with a desmear liquid or a film surface having a fine uneven rough surface. In either method, after electroless plating or electrolytic plating, or after both plating, a heat treatment called annealing at about 80 to 180 ° C. for about 10 to 60 minutes for the purpose of removing stress from the metal and improving the strength. May be applied.

  As metal plating used here, there is no restriction | limiting in particular, such as copper, tin, solder, nickel, etc., It can also be used in multiple combination. Further, instead of the plating used here, metal sputtering or the like can be used instead.

  EXAMPLES Hereinafter, although an Example, a comparative example, and a test example of this invention are shown and this invention is demonstrated concretely, it cannot be overemphasized that this invention is not limited to the following Example. In the following, “parts” and “%” are based on mass unless otherwise specified.

Examples 1-6 and Comparative Examples 1-3
A thermosetting resin composition prepared by blending each component in the formulation shown in Table 1 below, kneading and dispersing with a three-roll mill, and adjusting the viscosity to 20 dPa · s ± 10 dPa · s (rotary viscometer 5 rpm, 25 ° C.) Obtained.

Production of adhesive film:
Each of the thermosetting resin compositions obtained as described above was applied to a PET film (manufactured by Toray Industries, Inc., Lumirror 38R75: 38 μm) using a bar coater so that the film thickness of the film became 63 μm after drying. And dried at 110 ° C. for 15 minutes to obtain an adhesive film.

Test example:
The adhesive film was heat-laminated on a buffed 0.8 mm thick copper plate using a vacuum laminator (MELPI, MVLP-500) at 5 kgf / cm ² , 120 ° C., 1 minute, 1 Torr, After leveling with a hot plate press at 10 kgf / cm ² , 130 ° C. for 1 minute, it was cured with a hot air circulation dryer at 150 ° C. for 30 minutes.
The obtained samples were measured for adhesion strength and judged according to the following criteria. Moreover, about the obtained sample, it observed about the oozing-out of resin, and determined with the following references | standards. The results are also shown in Table 1.

Adhesion strength:
When using an Erichsen tester (Model 202-C, manufactured by Eriksen) at a test speed of 7 mm / min, the extruding length of the extruding pin when peeling or cracking is 3 mm or less x exceeds it The thing was made into (circle).
Resin oozing:
A sample with a bleeding of less than 5 mm was marked with ◯, and a sample with more than 5 mm was marked with ×.

  As is clear from the results shown in Table 1 above, in each of the examples using the thermoplastic resin composition of the present invention, the resin did not ooze and showed high adhesion strength. On the other hand, in the case of the comparative example 1 using the thermosetting resin composition which does not contain a semi-solid epoxy resin, it was inferior to adhesive strength. Moreover, in the case of the comparative example 2 which used the thermosetting resin composition in which the compounding ratio of a solid epoxy resin and a semi-solid epoxy resin is outside the range prescribed | regulated by this invention, and solid epoxy resin + semi-solid with respect to a liquid epoxy resin In the case of Comparative Example 3 using the thermosetting resin composition in which the blending ratio of the epoxy resin and the blending ratio of the solid epoxy resin to the liquid epoxy resin are out of the range specified in the present invention, both contain a semi-solid epoxy resin. Therefore, although there was not much problem in terms of adhesion strength, since the blending ratio of the liquid epoxy resin was high, the resin oozed out.

  The thermosetting resin composition of the present invention exhibits excellent adhesion to the base material and the conductor, and the cured film exhibits a relatively low coefficient of thermal expansion, and the peel strength of the conductor layer formed by plating ( High peel resistance), high heat resistance, and roughening by roughening treatment, so that it can be used to form an interlayer insulating layer in a multilayer printed wiring board of build-up system in which conductor circuit layers and insulating layers are stacked alternately In addition to being useful, it is useful for producing dry films and prepregs for interlayer insulating materials.

DESCRIPTION OF SYMBOLS 1 Insulating board 3 Inner layer conductor pattern 4,9 Resin insulating layer 8 Outer layer conductor pattern 10 Outermost layer conductor pattern 20 Through hole 30a Test tube for liquid determination 30b Test tube for temperature measurement 31 Mark (A line)
32 Mark (B line)
33a, 33b Rubber stopper 34 Thermometer X Multilayer substrate

Claims (7)

  (A) Epoxy resin having two or more epoxy groups in one molecule and being liquid at 20 ° C. (B) Solid epoxy having three or more epoxy groups in one molecule and being solid at 40 ° C. A resin, (C) a semi-solid epoxy resin having two or more epoxy groups in one molecule, solid at 20 ° C. and liquid at 40 ° C., (D) an epoxy curing agent, and (E) a filler. It is contained as an essential component, and the above three kinds of epoxy resins are (A) :( B + C) = 1: 1 to 1:10, (B) :( C) = 1: 0.5 to 1: 2 by mass ratio. A thermosetting resin composition for an interlayer insulating material of a multilayer printed wiring board, characterized by comprising:   The liquid epoxy resin (A) and the solid epoxy resin (B) are contained in a mass ratio of (A) :( B) = 1: 0.5 to 1: 5. The thermosetting resin composition for interlayer insulation materials of the multilayer printed wiring board as described.   The thermosetting resin composition for interlayer insulating materials for multilayer printed wiring boards according to claim 1, further comprising (F) a thermoplastic resin having a glass transition temperature of 100 ° C or higher.   The thermosetting resin composition for an interlayer insulating material of a multilayer printed wiring board according to claim 3, wherein the thermoplastic resin (F) is a thermoplastic polyhydroxy polyether resin having a fluorene skeleton.   A dry film comprising a thin film of a thermosetting resin composition for an interlayer insulating material for a multilayer printed wiring board according to any one of claims 1 to 4 formed on a support base film.   The multilayer printed wiring board by which the resin insulating layer and the conductor layer of a circuit pattern are formed in order on an inner layer circuit board, The said resin insulating layer is a multilayer printed wiring board as described in any one of Claims 1 thru | or 4. It is composed of a cured coating film of a thermosetting resin composition for interlayer insulating materials, and the interface with the conductor layer on the surface thereof is formed on a rough surface with fine irregularities by roughening treatment, and the conductor layer is formed of the roughened film. A multilayer printed wiring board characterized by being bonded to a resin insulating layer through a conversion surface.   In a multilayer printed wiring board in which a resin insulating layer and a conductor layer of a circuit pattern are sequentially formed on an inner layer circuit board, the resin insulating layer is made of the dry film according to claim 5 and has a conductor layer on the surface thereof. The multilayer printed wiring board is characterized in that the interface is formed on a rough surface with fine irregularities by a roughening treatment, and the conductor layer is bonded to the resin insulating layer through the roughened surface.

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