JP2012019240A - Resin composite, insulation sheet with substrate and multilayer printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composite enables manufacture of a multilayer printed wiring board in which peeling and a crack do not occur in a thermal shock test such as a cold and heat cycle and which has high thermal resistance, low thermal expansion property and flame retardancy when the resin composite is used for an insulating layer of the multilayer printed wiring board, and to provide an insulation sheet with a substrate using the resin composite and a multilayer printed wiring board.SOLUTION: A resin composite used for forming an insulating layer of a multilayer printed wiring board includes (A) cyanate resin and/or its prepolymer, (B) epoxy resin, (C) phenoxy resin, (D) imidazole compound, and (E) inorganic filler. The (D) imidazole compound has mutual solubility with (A) to (C) components.

Description

  The present invention relates to a resin composition, an insulating sheet with a substrate, and a multilayer printed wiring board.

  In recent years, with the demand for higher functionality of electronic devices, etc., high-density integration of electronic components, and further high-density mounting, etc. are progressing. Compared to the conventional technology, miniaturization and high density are progressing. As a measure for increasing the density of printed wiring boards and the like, a multilayer printed wiring board using a build-up method is often employed (for example, see Patent Document 1).

  A multilayer printed wiring board by a build-up method is usually manufactured by laminating an insulating layer made of a resin composition and having a thickness of 100 μm or less and a conductor circuit layer. Moreover, as a connection method between conductor circuit layers, the formation of a via hole by a laser method, a photo method, or the like can be cited instead of the conventional drilling process. These methods achieve high density by freely arranging small-diameter via holes, and various build-up interlayer insulating materials corresponding to each method have been proposed.

Furthermore, fine circuit formation is necessary for increasing the density, and a semi-additive method is widely known as a technique for achieving this. In the semi-additive method, following the roughening treatment of the surface of the insulating layer, the substrate is subjected to electroless plating treatment, the circuit formation portion is protected with a plating resist, and then the copper thickness of the circuit formation portion is increased by electroplating, In this method, a conductor circuit is formed on an insulating layer by resist removal and soft etching.
At this time, the adhesion between the insulating layer and the plated metal is largely due to the uneven shape of the surface of the insulating layer formed by the roughening treatment. If the unevenness is too large, it is difficult to form a fine circuit, and the adhesion of the plated metal is difficult. The nature is also reduced.
Also, in the method using the build-up multilayer wiring board, the conductive circuit layers are connected by fine vias, so that the connection strength is lowered, and in some cases, the resin composition and the conductive circuit that form an insulating layer when subjected to thermal shock There was a problem that cracks and disconnections occurred in the conductor circuit due to the stress generated from the difference in thermal expansion from the metal to be formed.

Japanese Patent Application Laid-Open No. 07-106767

  The present invention, when used in an insulating layer of a multilayer printed wiring board, has high heat resistance and low thermal expansion properties that cause no peeling or cracking of the conductor circuit layer, and has flame retardancy by a thermal shock test such as a thermal cycle. The present invention provides a resin composition capable of producing a multilayer printed wiring board capable of forming a high-density fine circuit, an insulating sheet with a base material using the resin composition, and a multilayer printed wiring board.

Such an object is achieved by the following present inventions (1) to (7).
(1) A resin composition used for forming an insulating layer of a multilayer printed wiring board,
(A) cyanate resin and / or prepolymer thereof,
(B) epoxy resin,
(C) phenoxy resin,
(D) an imidazole compound, and
(E) inorganic filler,
And the (D) imidazole compound is compatible with the components (A) to (C).
(2) The resin composition according to (1), wherein the (A) cyanate resin is a novolak cyanate resin.
(3) The resin composition according to (1) or (2), wherein the (B) epoxy resin is an arylalkylene type epoxy resin.
(4) The (D) imidazole compound is selected from 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, and 2-ethyl-4-methylimidazole. (3) The resin composition in any one of.
(5) The resin composition according to any one of (1) to (4), wherein the (B) epoxy resin and (C) phenoxy resin do not substantially contain a halogen atom.
(6) An insulating sheet with a base material, wherein the resin composition according to any one of (1) to (5) is carried on a base material.
(7) A multilayer printed wiring board obtained by heating and press-molding the insulating sheet with a base material according to (6) above on one side or both sides of an inner layer circuit board.

The present invention is a resin composition used for forming an insulating layer of a multilayer printed wiring board,
(A) cyanate resin and / or prepolymer thereof,
(B) epoxy resin,
(C) phenoxy resin,
(D) an imidazole compound, and
(E) inorganic filler,
The (D) imidazole compound is a resin composition characterized by having compatibility with the components (A) to (C).
By using the resin composition of the present invention for an insulating layer of a multilayer printed wiring board, in addition to high heat resistance and low thermal expansion that do not cause peeling or cracking of the conductor circuit layer in a thermal shock test such as a thermal cycle, it has flame resistance. It is possible to manufacture a multilayer printed wiring board having a high density and fine circuit formation.

Below, the resin composition of this invention, the insulating sheet with a base material, and a multilayer printed wiring board are demonstrated in detail.
The resin composition of the present invention is a resin composition used for forming an insulating layer of a multilayer printed wiring board,
(A) cyanate resin and / or prepolymer thereof,
(B) epoxy resin,
(C) phenoxy resin,
(D) an imidazole compound, and
(E) inorganic filler,
And the (D) imidazole compound has a compatibility with the components (A) to (C).
Moreover, the insulating sheet with a base material of the present invention is characterized in that the resin composition of the present invention is supported on a base material.
The multilayer printed wiring board of the present invention is characterized in that the above-mentioned insulating sheet with a substrate of the present invention is formed by heating and press-molding on one or both sides of the inner layer circuit board.

First, the resin composition of the present invention will be described.
The resin composition of the present invention contains (A) a cyanate resin and / or a prepolymer thereof. Thereby, a flame retardance can be improved.
The method for obtaining the cyanate resin and / or its prepolymer is not particularly limited. For example, the cyanate resin can be obtained by reacting a cyanogen halide with a phenol and prepolymerizing it by a method such as heating as necessary. it can. Moreover, the commercial item prepared in this way can also be used.

Although it does not specifically limit as a kind of cyanate resin, For example, bisphenol-type cyanate resin, such as a novolak-type cyanate resin, bisphenol A-type cyanate resin, bisphenol E-type cyanate resin, tetramethylbisphenol F-type cyanate resin, etc. can be mentioned.
Among these, a novolak type cyanate resin is preferable. Thereby, while being able to improve heat resistance by the increase in a crosslinking density, a flame retardance can further be improved. The novolak-type cyanate resin is considered to have a high proportion of benzene rings due to its structure and easily carbonize.
The novolak type cyanate resin can be obtained, for example, by reacting a novolak type phenol resin with a compound such as cyanogen chloride or cyanogen bromide. Moreover, the commercial item prepared in this way can also be used.

  Here, as the novolac type cyanate resin, for example, those represented by the following general formula (I) can be used.

Although it does not specifically limit as a weight average molecular weight of the novolak-type cyanate resin shown by the said general formula (I), It is preferable that it is 500-4,500. More preferably, it is 600-3,000.
If the weight average molecular weight is less than the lower limit, the mechanical strength may be lowered. Moreover, when the said upper limit is exceeded, since the cure rate of a resin composition will become quick, preservability may fall.

In addition, as said cyanate resin, what prepolymerized this can also be used.
Here, the prepolymer is usually obtained by, for example, trimerizing the cyanate resin by a heat reaction or the like, and is preferably used for adjusting the moldability and fluidity of the resin composition. is there.
Although it does not specifically limit as a prepolymer here, For example, what a trimerization rate is 20 to 50 weight% can be used. This trimerization rate can be determined using, for example, an infrared spectroscopic analyzer.

  Thus, as a novolac type cyanate resin, one kind can be used alone, two or more kinds having different weight average molecular weights are used together, or one kind or two kinds or more and those prepolymers are used together. You can also do it.

In the composition of the present invention, the content of the cyanate resin is not particularly limited, but is preferably 5 to 50% by weight with respect to the entire resin composition. More preferably, it is 10 to 40% by weight. Thereby, the heat resistance which a cyanate resin has, and the flame retardance improvement effect | action can be expressed more effectively.
If the content of the cyanate resin is less than the lower limit, the effect of increasing the heat resistance may be reduced. On the other hand, when the above upper limit is exceeded, the crosslinking density increases and the free volume increases, so that the moisture resistance may decrease.

  The resin composition of the present invention contains (B) an epoxy resin. As a result, heat resistance and low heat decomposability can be imparted, and film forming properties when manufacturing an insulating sheet with a base material and adhesion to an inner circuit board when manufacturing a multilayer printed wiring board are improved. Can do.

Although it does not specifically limit as an epoxy resin used with the resin composition of this invention, For example, a phenol novolak type epoxy resin, a bisphenol type epoxy resin, a naphthalene type epoxy resin, an aryl alkylene type epoxy resin etc. are mentioned. Among these, aryl alkylene type epoxy resins are preferable. Thereby, a flame retardance and moisture absorption solder heat resistance can be improved.
Here, the aryl alkylene type epoxy resin refers to an epoxy resin having one or more aryl alkylene groups in the repeating unit, and examples thereof include a xylylene type epoxy resin and a biphenyl dimethylene type epoxy resin. Among these, a biphenyl dimethylene type epoxy resin is preferable. Thereby, a flame retardance can be improved further.
As the biphenyldimethylene type epoxy resin, for example, those represented by the following general formula (II) can be used.

Although n of the biphenyl dimethylene type epoxy resin represented by the general formula (II) is not particularly limited, 1 to 10 is preferable, and 2 to 5 is particularly preferable.
When the number of n is smaller than this, the biphenyldimethylene type epoxy resin is easily crystallized, and the solubility in a general-purpose solvent tends to be small, so that the handleability may be lowered. On the other hand, when more than this, the fluidity | liquidity of an epoxy resin will fall and a moldability may fall. By setting the number of n in the above range, the balance of these characteristics can be excellent.

Although it does not specifically limit as a weight average molecular weight of the said epoxy resin, It is preferable that it is 4,000 or less. More preferably, it is 500-4,000, Most preferably, it is 800-3,000.
When the weight average molecular weight is less than the above lower limit, when an insulating sheet with a substrate is produced, tackiness may be generated on the surface of the insulating resin layer, and the handleability may be reduced. On the other hand, when the above upper limit is exceeded, solder heat resistance may decrease. By setting the weight average molecular weight within the above range, it is possible to achieve an excellent balance of these characteristics.

Although it does not specifically limit as content of the said epoxy resin, It is preferable that it is 5 to 50 weight% with respect to the whole resin composition. More preferably, it is 10 to 40% by weight.
If the content of the epoxy resin is less than the lower limit, the effect of improving moisture-absorbing solder heat resistance and adhesion may be reduced. Moreover, since content of cyanate resin will decrease relatively when the said upper limit is exceeded, low thermal expansibility may fall. By setting the content of the epoxy resin within the above range, it is possible to achieve an excellent balance of these characteristics.

  The resin composition of the present invention contains (C) a phenoxy resin. Thereby, the film formability at the time of manufacturing the insulating sheet with a base material can be further improved.

  The phenoxy resin is not particularly limited, and examples thereof include a phenoxy resin having a bisphenol skeleton, a phenoxy resin having a novolak skeleton, a phenoxy resin having a naphthalene skeleton, and a phenoxy resin having a biphenyl skeleton. A phenoxy resin having a structure having a plurality of these skeletons can also be used.

Among these, those having a biphenyl skeleton and a bisphenol S skeleton can be used. Thereby, the glass transition temperature can be increased due to the rigidity of the biphenyl skeleton, and the adhesion of the plated metal when the multilayer printed wiring board is manufactured can be improved by the bisphenol S skeleton.
Further, those having a bisphenol A skeleton and a bisphenol F skeleton can be used. Thereby, the adhesiveness to an inner-layer circuit board can be improved at the time of manufacture of a multilayer printed wiring board.
Furthermore, those having the biphenyl skeleton and the bisphenol S skeleton and those having the bisphenol A skeleton and the bisphenol F skeleton can be used in combination. Thereby, these characteristics can be expressed with good balance.
When using the combination (1) having the bisphenol A skeleton and the bisphenol F skeleton and the combination (2) having the biphenyl skeleton and the bisphenol S skeleton, the combination ratio (weight) is not particularly limited. For example, (1) :( 2) = 2: 8 to 9: 1 can be set.

Although it does not specifically limit as molecular weight of the said phenoxy resin, It is preferable that a weight average molecular weight is 5000-70000. More preferably, it is 10,000 to 60000.
If the weight average molecular weight of the phenoxy resin is less than the lower limit, the effect of improving the film forming property may not be sufficient. On the other hand, when the above upper limit is exceeded, the solubility of the phenoxy resin may decrease. By making the weight average molecular weight of the phenoxy resin within the above range, it is possible to achieve an excellent balance of these characteristics.

Although it does not specifically limit as content of a phenoxy resin, It is preferable that it is 1 to 40 weight% of the whole resin composition. More preferably, it is 5 to 30% by weight.
If the content of the phenoxy resin is less than the above lower limit, the effect of improving the film forming property may not be sufficient. On the other hand, when the above upper limit is exceeded, the content of the cyanate resin is relatively reduced, and thus the effect of imparting low thermal expansion may be reduced. By making content of a phenoxy resin into the said range, it can be excellent in the balance of these characteristics.

The (B) epoxy resin and (C) phenoxy resin used in the composition of the present invention are preferably substantially free of halogen atoms. Thereby, a flame retardance can be provided, without using a halogen compound.
Here, “substantially free of halogen atoms” means, for example, those in which the content of halogen atoms in the epoxy resin or phenoxy resin is 1% by weight or less.

The resin composition of the present invention contains (D) an imidazole compound.
And the said imidazole compound has compatibility with the (A)-(C) component demonstrated above, It is characterized by the above-mentioned.
Here, having compatibility with the components (A) to (C) means that the imidazole compound is mixed with the components (A) to (C), or the imidazole compound is mixed with the components (A) to (C) and the organic solvent. When mixed together, it refers to such a property that it can be substantially dissolved or dispersed to a molecular level.

By using such an imidazole compound, the resin composition of the present invention can effectively promote the reaction of a cyanate resin or an epoxy resin, and equivalent characteristics even if the amount of the imidazole compound is reduced. Can be granted.
Furthermore, a resin composition using such an imidazole compound can be cured with high uniformity from a minute matrix unit with a resin component. Thereby, the insulation of the resin layer formed in the multilayer printed wiring board, and heat resistance can be improved.

And the insulating resin layer formed from such a resin composition of the present invention is subjected to a roughening treatment on the surface using an oxidizing agent such as permanganate or dichromate, after the roughening treatment. A large number of minute uneven shapes with high uniformity can be formed on the surface of the insulating layer.
When a metal plating process is performed on the surface of the insulating resin layer after such a roughening process, the smoothness of the roughened surface is high, so that a fine conductor circuit can be accurately formed. Further, the anchor effect can be enhanced by the minute uneven shape, and high adhesion can be imparted between the insulating resin layer and the plated metal.

  Examples of the imidazole compound used in the resin composition of the present invention include 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4- Methylimidazole, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- (2'-undecylimidazolyl) -ethyl-s -Triazine, 2,4-diamino-6- [2'-ethyl-4-methylimidazolyl- (1 ')]-ethyl-s-triazine, and the like.

  Among these, an imidazole compound selected from 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, and 2-ethyl-4-methylimidazole is preferable. These imidazole compounds have particularly excellent compatibility, so that a highly uniform cured product can be obtained and a fine and uniform roughened surface can be formed, so that a fine conductor circuit can be easily formed. In addition, the multilayer printed wiring board can exhibit high heat resistance.

Although it does not specifically limit as content of the said imidazole compound, 0.01 to 5 weight% is preferable with respect to the sum total of the said cyanate resin and an epoxy resin, and 0.05 to 3 weight% is especially preferable. Thereby, especially heat resistance can be improved.

  The resin composition of the present invention contains (E) an inorganic filler. Thereby, improvement of low thermal expansibility and a flame retardance can be aimed at. Moreover, an elastic modulus can be improved with the combination of the said cyanate resin and / or its prepolymer (especially novolak-type cyanate resin) and an inorganic filler.

Although it does not specifically limit as said inorganic filler, For example, a talc, an alumina, glass, a silica, mica etc. are mentioned. Among these, silica is preferable, and fused silica is preferable in that it has excellent low expansibility.
Examples of the shape of the fused silica include a crushed shape and a spherical shape, but a spherical shape is preferable. Thereby, content in a resin composition can be increased and favorable fluidity | liquidity can be provided even in that case.

Although it does not specifically limit as an average particle diameter of the said inorganic filler, It is preferable that it is 0.01-5 micrometers. More preferably, it is 0.2-2 micrometers.
When the average particle size of the inorganic filler is less than the above lower limit, the viscosity of the resin varnish increases when the resin varnish is prepared using the resin composition of the present invention, so that an insulating sheet with a substrate is produced. May affect the workability. On the other hand, if the upper limit is exceeded, phenomena such as sedimentation of the inorganic filler may occur in the resin varnish. By setting the average particle size of the inorganic filler within the above range, it is possible to achieve an excellent balance of these characteristics.

Although it does not specifically limit as content of the said inorganic filler, It is preferable that it is 20 to 70 weight% of the whole resin composition. More preferably, it is 30 to 60% by weight.
If the content of the inorganic filler is less than the lower limit, the effect of imparting low thermal expansion and low water absorption may be reduced. Moreover, when the said upper limit is exceeded, a moldability may fall by the fall of the fluidity | liquidity of a resin composition. By making content of an inorganic filler into the said range, it can be set as the thing excellent in the balance of these characteristics.

  Although it does not specifically limit in the resin composition of this invention, It is preferable to contain a coupling agent further. Thereby, since the wettability of the interface of a resin component and an inorganic filler can be improved, heat resistance, especially moisture absorption solder heat resistance can be improved.

  Although it does not specifically limit as said coupling agent, 1 or more types of coupling agents chosen from an epoxy silane coupling agent, a titanate coupling agent, an aminosilane coupling agent, and a silicone oil type coupling agent are used. It is preferable to do. Thereby, especially the wettability of the interface of a resin component and an inorganic filler can be improved, and heat resistance can be improved more.

Although it does not specifically limit as content of the said coupling agent, It is preferable that it is 0.05-3 weight part with respect to 100 weight part of inorganic fillers.
When the content of the coupling agent is less than the lower limit, the effect of improving the heat resistance by covering the inorganic filler may not be sufficient. On the other hand, when the above upper limit is exceeded, the bending strength of the insulating sheet with a substrate may be lowered. By setting the content of the coupling agent within the above range, it is possible to achieve an excellent balance of these characteristics.

  In addition to the components described above, the resin composition of the present invention can contain additives such as an antifoaming agent and a leveling agent as necessary.

Next, the insulating sheet with a substrate of the present invention will be described.
The insulating sheet with a base material of the present invention is formed by supporting the resin composition of the present invention on a base material, and is composed of an insulating sheet formed from the resin composition and a base material supporting the insulating sheet. It is what.

Here, the method of supporting the resin composition on the substrate is not particularly limited. For example, the resin varnish is prepared by dissolving and dispersing the resin composition in a solvent or the like, and using various coater devices. The method of drying this after apply | coating to a base material, the method of spraying the resin varnish to a base material using a spray apparatus, and drying this are mentioned.
Among these, it is preferable to apply a resin varnish to a substrate using various coaters such as a comma coater and a die coater and then dry the resin varnish. Thereby, the insulating sheet with a base material which has no void and has a uniform thickness of the insulating sheet layer can be efficiently produced.

The solvent used for the preparation of the resin varnish is not particularly limited. For example, alcohols, ethers, acetals, ketones, esters, alcohol esters, ketone alcohols, ether alcohols, ketone ethers, ketones Esters and ester ethers can be used.
Although it does not specifically limit as solid content in the said resin varnish, 30 to 80 weight% is preferable and especially 40 to 70 weight% is preferable.

  In the insulating sheet with a substrate of the present invention, the thickness of the insulating sheet layer composed of the resin composition is not particularly limited, but is preferably 10 to 100 μm. More preferably, it is 20-80 micrometers. Thereby, when manufacturing a multilayer printed wiring board using this insulating sheet with a base material, while being able to fill and shape the unevenness | corrugation of an inner-layer circuit, suitable insulating layer thickness can be ensured. Moreover, in an insulating sheet with a base material, generation | occurrence | production of the crack of an insulating sheet layer can be suppressed and powder fall at the time of cutting can be decreased.

Although it does not specifically limit as a base material used for the insulating sheet with a base material of this invention, For example, polyester resin, such as a polyethylene terephthalate and a polybutylene terephthalate, a fluororesin, a thermoplastic resin film with heat resistance, such as a polyimide resin Alternatively, copper and / or a copper-based alloy, aluminum and / or an aluminum-based alloy, iron and / or an iron-based alloy, silver and / or a metal foil of a silver-based alloy, or the like can be used.
Although it does not specifically limit as thickness of the said base material, When the thing of 10-70 micrometers is used, the handleability at the time of manufacturing an insulating sheet with a base material is favorable, and it is preferable.
In manufacturing the insulating sheet with a base material of the present invention, it is preferable that the unevenness on the surface of the insulating base material to be joined to the insulating sheet is as small as possible. Thereby, the effect | action of this invention can be expressed effectively.

Next, the multilayer printed wiring board using the insulating sheet with a base material of the present invention will be described.
The multilayer printed circuit board is formed by heating and press-molding the insulating sheet with a base material on one side or both sides of the inner layer circuit board.
Specifically, the insulating sheet layer side of the insulating sheet with a base material according to the present invention and the inner circuit board are combined and vacuum-heated and pressure-molded using a vacuum-pressure laminator device or the like, and then a hot-air drying device or the like It can be obtained by heating and curing.
Although it does not specifically limit as conditions to heat-press form here, if an example is given, it can implement at the temperature of 60-160 degreeC, and the pressure of 0.2-3 MPa. Moreover, it is although it does not specifically limit as conditions to heat-harden, It can implement in temperature 140-240 degreeC and time 30-120 minutes.
Alternatively, the insulating sheet layer side of the insulating sheet with a base material of the present invention can be obtained by superimposing the inner layer circuit board on the inner layer circuit board, and heating and pressing it using a flat plate press apparatus or the like.
Although it does not specifically limit as conditions to heat-press form here, For example, it can implement at the temperature of 140-240 degreeC, and the pressure of 1-4 MPa.
The inner layer circuit board used for obtaining the multilayer printed wiring board is preferably, for example, one in which a predetermined conductor circuit is formed by etching or the like on both sides of a copper clad laminate and the conductor circuit portion is blackened. Can be used.

  The multilayer printed wiring board obtained above further peels and removes the base material, and after roughening the surface of the insulating resin layer with an oxidizing agent such as permanganate or dichromate, metal plating is performed. A new conductive wiring circuit can be formed. In the insulating resin layer formed from the resin composition of the present invention, a large number of fine irregularities can be formed with high uniformity in the roughening treatment step, and the smoothness of the surface of the insulating resin layer is high. A fine wiring circuit can be formed with high accuracy.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

The raw materials used in Examples and Comparative Examples are as follows.
(1) Cyanate resin A / Novolac type cyanate resin: “Primaset PT-30” manufactured by Lonza Corporation, weight average molecular weight 700
(2) Cyanate resin B / Novolac type cyanate resin: “Lima set PT-60” manufactured by Lonza Corporation, weight average molecular weight 2600
(3) Epoxy resin / biphenyl dimethylene type epoxy resin: “NC-3000” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 275, weight average molecular weight 2000
(4) Copolymer of phenoxy resin A / biphenyl epoxy resin and bisphenol S epoxy resin, and terminal portion has an epoxy group: “YX-8100H30” manufactured by Japan Epoxy Resin Co., Ltd., weight average molecular weight 30000 )
(5) Phenoxy resin B / A copolymer of bisphenol A type epoxy resin and bisphenol F type epoxy resin, having terminal epoxy groups: “Epicoat 4275” manufactured by Japan Epoxy Resin Co., Ltd., weight average (Molecular weight 60000)
(6) Curing Catalyst A / Imidazole Compound: “Cureazole 1B2PZ (1-benzyl-2-phenylimidazole)” manufactured by Shikoku Kasei Kogyo Co., Ltd.
(7) Curing catalyst B / Imidazole compound: “Cureazole C17Z (2-heptadecylimidazole)” manufactured by Shikoku Kasei Kogyo Co., Ltd.
(8) Inorganic filler / spherical fused silica: manufactured by Admatechs Co., Ltd. “SO-25H”, average particle size 0.5 μm
(9) Coupling agent / epoxysilane coupling agent: Nippon Unicar Co., Ltd. “A-187”

<Example 1>
(1) Preparation of resin varnish 25 parts by weight of cyanate resin A, 25 parts by weight of epoxy resin, 10 parts by weight of phenoxy resin A, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.

(2) Production of Insulating Sheet with Substrate The resin varnish obtained above is applied to one side of a PET (polyethylene terephthalate) film having a thickness of 25 μm, and the thickness of the insulating film after drying using a comma coater device is 60 μm. It coated so that it might become, and this was dried for 10 minutes with a 160 degreeC drying apparatus, and the insulating sheet with a base material was manufactured.

(3) Manufacture of multilayer printed wiring board 1 On the front and back of the inner layer circuit board on which the predetermined inner layer circuit is formed on both sides, the insulating sheet surface of the insulating sheet with the base material obtained above is overlapped, and this is laminated. Then, using a vacuum pressurizing laminator apparatus, vacuum heating and pressing were performed at a temperature of 100 ° C. and a pressure of 1 MPa, and then heat curing was performed at 170 ° C. for 60 minutes in a hot air drying apparatus.
In addition, the following were used as the inner layer circuit board.
-Insulating layer: Halogen-free FR-4 material, thickness 0.4mm
Conductor layer: copper foil thickness 18 μm, L / S = 120/180 μm, clearance holes 1 mmφ, 3 mmφ, slit 2 mm

(4) Manufacture of multilayer printed wiring board 2 A base material is peeled from the multilayer printed wiring board 1 obtained above, and it is 10 minutes in 70 degreeC swelling liquid (Atotech Japan company make "Swelling dip securigant P500"). It was immersed and further immersed in an aqueous potassium permanganate solution (manufactured by Atotech Japan, “Concentrate Compact CP”) at 80 ° C. for 20 minutes, followed by neutralization and roughening treatment.
After passing through the steps of degreasing, applying a catalyst, and activating this, an electroless copper plating film is formed to about 1 μm and electroplated copper is formed to 30 μm, and annealed at 200 ° C. for 60 minutes in a hot air drying device, and a multilayer printed wiring board Got.

<Example 2>
15 parts by weight of cyanate resin A, 10 parts by weight of cyanate resin B, 25 parts by weight of epoxy resin, 10 parts by weight of phenoxy resin A, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 3>
Cyanate resin A 40 parts by weight, epoxy resin 10 parts by weight, phenoxy resin A 10 parts by weight, and curing catalyst A 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 4>
20 parts by weight of cyanate resin A, 30 parts by weight of epoxy resin, 10 parts by weight of phenoxy resin A, and 0.1 parts by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 5>
30 parts by weight of cyanate resin A, 15 parts by weight of epoxy resin, 15 parts by weight of phenoxy resin A, and 0.1 parts by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 6>
17 parts by weight of cyanate resin A, 17 parts by weight of epoxy resin, 6 parts by weight of phenoxy resin A, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 60 parts by weight of an inorganic filler and 0.3 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 7>
30 parts by weight of cyanate resin A, 10 parts by weight of cyanate resin B, 20 parts by weight of epoxy resin, 10 parts by weight of phenoxy resin A, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 30 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative Example 1>
Cyanate resin A 25 parts by weight, epoxy resin 25 parts by weight, phenoxy resin A 10 parts by weight, and curing catalyst B 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative example 2>
15 parts by weight of cyanate resin A, 10 parts by weight of cyanate resin B, 25 parts by weight of epoxy resin, 10 parts by weight of phenoxy resin A, and 0.1 part by weight of curing catalyst B were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative Example 3>
50 parts by weight of cyanate resin A, 10 parts by weight of phenoxy resin A, and 0.1 parts by weight of curing catalyst B were dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative example 4>
50 parts by weight of epoxy resin, 10 parts by weight of phenoxy resin A, and 0.1 parts by weight of curing catalyst B were dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative Example 5>
30 parts by weight of cyanate resin A, 10 parts by weight of cyanate resin B, 50 parts by weight of epoxy resin, 10 parts by weight of phenoxy resin A, and 0.1 part by weight of curing catalyst B were dispersed in methyl ethyl ketone to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 11>
Cyanate resin A 25 parts by weight, epoxy resin 25 parts by weight, phenoxy resin A 5 parts by weight, phenoxy resin B 5 parts by weight, and curing catalyst A 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 12>
15 parts by weight of cyanate resin A, 10 parts by weight of cyanate resin B, 25 parts by weight of epoxy resin, 5 parts by weight of phenoxy resin A, 5 parts by weight of phenoxy resin B, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 13>
Cyanate resin A 40 parts by weight, epoxy resin 10 parts by weight, phenoxy resin A 5 parts by weight, phenoxy resin B 5 parts by weight, and curing catalyst A 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 14>
20 parts by weight of cyanate resin A, 30 parts by weight of epoxy resin, 5 parts by weight of phenoxy resin A, 5 parts by weight of phenoxy resin B, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 15>
30 parts by weight of cyanate resin A, 15 parts by weight of epoxy resin, 10 parts by weight of phenoxy resin A, 5 parts by weight of phenoxy resin B, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 16>
17 parts by weight of cyanate resin A, 17 parts by weight of epoxy resin, 3 parts by weight of phenoxy resin A,
3 parts by weight of phenoxy resin B and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 60 parts by weight of an inorganic filler and 0.3 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Example 17>
30 parts by weight of cyanate resin A, 10 parts by weight of cyanate resin B, 20 parts by weight of epoxy resin, 5 parts by weight of phenoxy resin A, 5 parts by weight of phenoxy resin B, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 30 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative Example 11>
Cyanate resin A 25 parts by weight, epoxy resin 25 parts by weight, phenoxy resin A 5 parts by weight, phenoxy resin B 5 parts by weight, and curing catalyst B 0.1 part by weight were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative Example 12>
15 parts by weight of cyanate resin A, 10 parts by weight of cyanate resin B, 25 parts by weight of epoxy resin, 5 parts by weight of phenoxy resin B, 5 parts by weight of phenoxy resin B, and 0.1 part by weight of curing catalyst A were dissolved and dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative Example 13>
50 parts by weight of cyanate resin A, 5 parts by weight of phenoxy resin A, 5 parts by weight of phenoxy resin B, and 0.1 part by weight of curing catalyst B were dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative example 14>
50 parts by weight of epoxy resin, 7 parts by weight of phenoxy resin A, 3 parts by weight of phenoxy resin B, and 0.1 part by weight of curing catalyst B were dispersed in methyl ethyl ketone. Furthermore, 40 parts by weight of an inorganic filler and 0.2 part by weight of a coupling agent were added, and the mixture was stirred for 10 minutes using a high-speed stirrer to prepare a resin varnish having a solid content of 50% by weight.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

<Comparative Example 15>
30 parts by weight of cyanate resin A, 10 parts by weight of cyanate resin B, 50 parts by weight of epoxy resin, 3 parts by weight of phenoxy resin A, 7 parts by weight of phenoxy resin B and 0.1 part by weight of curing catalyst B were dispersed in methyl ethyl ketone to give a solid content of 50% by weight. A resin varnish was prepared.
Using this resin varnish, an insulating sheet with a base material and multilayer printed wiring boards 1 and 2 were obtained in the same manner as in Example 1.

  The characteristics of the insulating sheets with base materials and multilayer printed wiring boards obtained in the examples and comparative examples were evaluated. The results are shown in Tables 1 and 2.

The evaluation method is as follows.
1. Evaluation of Insulating Sheet with Base Material (1) Glass Transition Temperature Two insulating sheets with a base material are laminated with the insulating sheet sides inside, and this is overlapped for 2 hours at a pressure of 2 MPa and a temperature of 200 ° C. using a vacuum press apparatus. After performing heat and pressure molding, the substrate was peeled and removed to obtain a cured resin. From the obtained insulating sheet cured product, 10 mm × 30 m
A sample for evaluation of m was cut out and heated at 5 ° C./min using DMA (TA Instruments), and the peak position of tan δ was defined as the glass transition temperature.

(2) Linear expansion coefficient Two insulating sheets with a base material were laminated with the insulating sheet sides facing each other, and this was heat-pressed for 2 hours at a pressure of 2 MPa and a temperature of 200 ° C. using a vacuum press apparatus. Thereafter, the substrate was peeled and removed to obtain a cured resin. A sample for evaluation of 4 mm × 20 mm was collected from the obtained cured resin, and measured by raising the temperature at 10 ° C./min using a TMA apparatus (manufactured by TA Instruments).

2. Evaluation of multilayer printed wiring board 1 (1) Flame retardance The substrate of the multilayer printed wiring board 1 was peeled off and measured according to the UL-94 standard and the vertical method.

(2) Formability The base material of the multilayer printed wiring board 1 was peeled and removed, and the presence or absence of molding voids was visually observed. The thing without a molding void was set as (circle).

2. Evaluation of Multilayer Printed Wiring Board 2 (1) Moisture Absorbing Solder Heat Resistance A 50 mm × 50 mm sample was taken from the multilayer printed wiring board 2 and the entire surface of one side and 1/2 copper foil on the other side were removed by etching. This was treated with a 125 ° C. pressure cooker for 2 hours and then floated in a solder bath at 260 ° C. for 180 seconds with the copper foil face down to check for blistering and peeling. Those without blistering and peeling were marked with ◯, and those with blistering and peeling were marked with x.

(2) Plating peel strength From the multilayer printed wiring board 2, the peel strength of the plated copper was measured based on JIS C-6481.
(3) Surface roughness (Ra)
The surface roughness (Ra) of the substrate after the roughening treatment of the multilayer printed wiring board 2 was measured with a laser microscope.

Examples 1-7, 11-17 are the resin composition of this invention containing cyanate resin and / or its prepolymer, an epoxy resin, a phenoxy resin, an imidazole compound having compatibility with the above resin components, and an inorganic filler. And a metal foil with resin and a multilayer printed wiring board using the same.
Examples 1 to 7 and 11 to 17 all had high glass transition temperatures, low linear expansion, and good flame retardancy, moldability, and heat resistance. And since many fine unevenness | corrugations were able to be formed by the roughening process, the peeling strength of the plating metal was also favorable.
Since each of Comparative Examples 1-4 and Comparative Examples 11-14 used an imidazole compound having low compatibility with the components (A) to (C), the surface roughness after the roughening treatment due to non-uniformity of curing. However, the peel strength of the plated metal was not improved and the heat resistance was poor.
Furthermore, since the comparative examples 3 and 13 used cyanate resin, the glass transition temperature became high, but since epoxy resin was not used, heat resistance fell. Since Comparative Examples 4 and 14 did not use cyanate resin, the glass transition temperature was lowered and the flame retardancy was inferior.
Since Comparative Examples 5 and 15 did not use an inorganic filler, sufficient unevenness could not be formed by the roughening treatment, and the peel strength of the plated metal was lowered. Moreover, the linear expansion coefficient became large and the flame retardance became inferior.

The present invention is a resin composition used for forming an insulating layer of a multilayer printed wiring board,
(A) cyanate resin and / or prepolymer thereof,
(B) epoxy resin,
(C) phenoxy resin,
(D) an imidazole compound, and
(E) inorganic filler,
And the (D) imidazole compound has compatibility with the components (A) to (C), an insulating sheet with a substrate using the resin composition, and a multilayer It is a printed wiring board.
By using the resin composition of the present invention for an insulating layer of a multilayer printed wiring board, in addition to high heat resistance and low thermal expansion that do not cause peeling or cracking of the conductor circuit layer in a thermal shock test such as a thermal cycle, it has flame resistance. It is possible to manufacture a multilayer printed wiring board having a high density and fine circuit formation.

Claims (7)

A resin composition used for forming an insulating layer of a multilayer printed wiring board,
(A) cyanate resin and / or prepolymer thereof,
(B) epoxy resin,
(C) phenoxy resin,
(D) an imidazole compound, and
(E) inorganic filler,
And the (D) imidazole compound is compatible with the components (A) to (C). The resin composition according to claim 1, wherein the (A) cyanate resin is a novolac-type cyanate resin. The resin composition according to claim 1, wherein the (B) epoxy resin is an aryl alkylene type epoxy resin. The (D) imidazole compound is selected from 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, and 2-ethyl-4-methylimidazole. The resin composition described in 1. 5. The resin composition according to claim 1, wherein the (B) epoxy resin and the (C) phenoxy resin are substantially free of halogen atoms. An insulating sheet with a base material, wherein the resin composition according to any one of claims 1 to 5 is supported on the base material. A multilayer printed wiring board, wherein the insulating sheet with a base material according to claim 6 is overlaid on one or both sides of an inner layer circuit board and heated and pressed.