JP2003096296A - Resin composition, prepreg and printed circuit board using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition, a prepreg and a printed circuit board having excellent heat resistance, low thermal expansion and a high level of flame-retardancy. SOLUTION: The resin composition comprises a cyanate resin and/or its prepolymer, a phenol resin and an inorganic filler. Additionally, the prepreg is prepared by impregnating a base material in the above resin composition. The printed circuit board of is prepared by laminating a metal foil on the above prepreg and molding the product under heating and pressure.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resin composition, a prepreg, and a printed wiring board using the same.

[0002]

2. Description of the Related Art In the field of semiconductors, a trend of shifting from conventional surface mounting to area mounting has progressed due to the progress of high-density mounting technology, and new packages such as BGA and CSP have appeared and are increasing. Therefore, a rigid substrate for an interposer has been receiving more attention than before, and a demand for a highly heat resistant and low thermal expansion substrate is increasing.

Further, in recent years, along with the demand for higher functionality of electronic equipment, high-density integration of electronic parts and further high-density mounting have been advanced. For this reason, the printed wiring boards and the like that are used for these and are compatible with high-density packaging are becoming smaller and more dense than ever before. Build-up multilayer wiring boards are often used as a measure for increasing the density of printed wiring boards and the like. However, in the build-up multilayer wiring board, since the interlayer connection is made by the fine vias, the connection strength is reduced, and it is difficult to maintain the mechanical and electrical connection reliability in a high temperature and high humidity atmosphere. there were.

Further, resin members used for these semiconductors are often required to have flame retardancy. In the past, in order to impart this flame retardancy, it has been common to use halogenated flame retardants such as brominated epoxy in epoxy resins.
However, since halogen-containing compounds may cause the generation of dioxins, the use of halogen-based flame retardants has come to be avoided as environmental problems have become more serious these days, and halogen-free compounds are widely used in industry. A flame retardant system has been demanded. Due to the demands of such times, phosphorus-based flame retardants have been in the limelight, and phosphoric acid ester and red phosphorus have been investigated.However, these conventional phosphorus-based flame retardants are easily hydrolyzed and have poor reaction with resin, and thus, they are resistant to hydrolysis. There was a problem such as a decrease in solder heat resistance.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a resin composition, a prepreg and a printed wiring board which are excellent in heat resistance, low thermal expansion and flame retardancy.

[0006]

These objects are achieved by the present invention described in (1) to (8) below. (1) Cyanate resin and / or its prepolymer,
A resin composition containing a phenol resin and an inorganic filler as essential components. (2) The resin composition according to (1), wherein the cyanate resin and / or its prepolymer is a novolac type cyanate resin and / or its prepolymer. (3) The cyanate resin is 5 to 6 of the entire resin composition.
The resin composition according to (1) or (2) above, which is 0% by weight. (4) The resin composition according to any one of (1) to (3), wherein the epoxy resin is an aryl alkylene type phenol resin. (5) The resin composition as described in (1) or (4) above, wherein the inorganic filler is spherical fused silica having an average particle size of 2 μm or less. (6) The inorganic filler is 30 to 80 of the entire resin composition.
The resin composition according to any one of (1) to (5) above, which is in a weight percentage. (7) A prepreg obtained by impregnating a substrate with the resin composition according to any one of (1) to (6). (8) A printed wiring board obtained by laminating a metal foil on the prepreg according to the above (7) and heat-pressing.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The resin composition, prepreg and printed wiring board using the same of the present invention will be described in detail below. The resin composition of the present invention is a resin composition containing a cyanate resin and / or its prepolymer, a phenol resin and an inorganic filler as essential components. Further, the prepreg of the present invention is obtained by impregnating a base material with the above resin composition. The printed wiring board of the present invention is obtained by laminating a metal foil on the prepreg and heat-pressing it.

The resin composition will be described below. In the present invention, a cyanate resin and / or its prepolymer is used. Accordingly, when the resin composition of the present invention is used for a printed wiring board, it can have high heat resistance and low thermal expansion. The cyanate resin and / or its prepolymer can be obtained, for example, by reacting a cyanogen halide compound with phenols and, if necessary, prepolymerizing by a method such as heating. Specific examples thereof include novolac type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, and bisphenol type cyanate resin such as tetramethylbisphenol F type cyanate resin. Among these, novolac type cyanate resin is preferable. Thereby, the heat resistance can be improved by increasing the crosslink density and the flame retardancy of the resin composition and the like can be improved. It is considered that the novolac type cyanate resin has a high proportion of benzene rings due to its structure and is easily carbonized. As the novolac type cyanate resin, for example, the one represented by the formula (I) can be used.

[Chemical 1] The n of the novolac type cyanate resin represented by the formula (I) is not particularly limited, but is preferably 1 to 10 and particularly preferably 1 to 7. If the amount is less than this, the novolac type cyanate resin is likely to be crystallized, and the solubility in a general-purpose solvent is relatively lowered, so that handling may be difficult. On the other hand, if it is more than the above range, the crosslinking density becomes too high, which may cause a phenomenon such as a decrease in water absorption and a cured product becoming brittle.

The weight average molecular weight of the cyanate resin and / or its prepolymer is not particularly limited, but a weight average molecular weight of 500 to 4500 is preferable, and 600 is particularly preferable.
~ 3000 is preferred. If it is smaller than this, tackiness may occur when the prepreg is manufactured, and when the prepregs come into contact with each other, they may adhere to each other or the resin may be transferred. Also, if it is larger than this, the reaction becomes too fast, and if a copper-clad laminate is used, molding defects may occur,
The interlayer peel strength may decrease. The content of the cyanate resin is not particularly limited, but is preferably 5 to 60% by weight, and particularly preferably 10 to 50% by weight based on the entire resin composition. If the cyanate resin and / or its prepolymer is less than the lower limit, the heat resistance and the effect of lowering the thermal expansion may decrease, and if it exceeds the upper limit, the crosslinking density increases and the free volume increases, so that the moisture resistance decreases. There is a case.

A phenol resin is used in the resin composition of the present invention. Examples of the phenol resin include novolac type phenol resin, resol type phenol resin and aryl alkylene type phenol resin. Among these, the aryl alkylene type phenol resin is preferable. Thereby, the heat resistance can be further improved. Examples of the aryl alkylene type phenol resin include xylylene type phenol resin and biphenyl dimethylene type phenol resin. The biphenyl dimethylene type phenol resin can be represented by, for example, the formula (II).

[Chemical 2] The n of the biphenyl dimethylene type phenol resin represented by the formula (II) is not particularly limited, but is preferably 1 to 12, and particularly preferably 2 to 8. If it is less than this range, the heat resistance may decrease. On the other hand, if the amount is larger than the above range, the compatibility with other resins is deteriorated and the workability may be deteriorated, which is not preferable. The combination of the above cyanate resin and / or its prepolymer (particularly novolac type cyanate resin) and the arylalkylene type phenol resin can control the crosslink density and improve the adhesion between the metal and the resin.

The content of the phenolic resin is not particularly limited, but is preferably 1 to 55% by weight, and particularly preferably 5 to 40% by weight based on the entire resin composition. If the phenol resin is less than the lower limit value, the heat resistance may decrease, and if it exceeds the upper limit value, the low thermal expansion property may be impaired. The weight average molecular weight of the phenol resin is not particularly limited, but a weight average molecular weight of 400 to 18,000 is preferable, and 500 to 15,000 is particularly preferable. If the weight average molecular weight is less than the above range, problems such as tackiness may occur in the prepreg, and if it is more than this range, impregnation into the base material during preparation of the prepreg is reduced, and a uniform product cannot be obtained. Problems may occur.

In the present invention, an inorganic filler is used. As a result, low thermal expansion and improvement of flame retardancy can be achieved. Further, the elastic modulus can be improved by combining the above-mentioned cyanate resin and / or its prepolymer (particularly novolac type cyanate resin) with an inorganic filler. Examples of the inorganic filler include talc, alumina, glass, silica, mica and the like.
Among these, silica is preferable, and fused silica is preferable because it has excellent low expansion properties. There are crushed and spherical shapes, but spherical silica is used to lower the melt viscosity of the resin composition in order to ensure impregnation into the glass substrate, and a method of use adapted to the purpose is adopted. .

The average particle diameter of the inorganic filler is not particularly limited, but is preferably 0.01 to 5 μm, particularly 0.2 to
2 μm is preferable. If the particle size of the inorganic filler is smaller than the lower limit value, the viscosity of the varnish increases, which may affect workability during prepreg production. On the other hand, if the amount exceeds the upper limit, phenomena such as sedimentation of the inorganic filler occur in the varnish, which is not desirable. Further, spherical fused silica having an average particle diameter of 5 μm or less is preferable, and spherical fused silica having an average particle diameter of 2 μm or less is particularly preferable. Thereby, the filling property of the inorganic filler can be improved. The content of the inorganic filler is preferably 30 to 80% by weight of the entire resin composition,
Particularly, 40 to 70% by weight is preferable. When the inorganic filler is within the above range, low thermal expansion and low water absorption can be achieved.

In the resin composition of the present invention, although not particularly limited, it is preferable to further use an epoxy resin as a resin component. This makes it possible to improve the reactivity of the cyanate resin and / or its prepolymer. Examples of the epoxy resin include a phenol novolac type epoxy resin, a bisphenol type epoxy resin, a naphthalene type epoxy resin, and an aryl alkylene type epoxy resin. Of these, aryl alkylene type epoxy resins are preferable. Thereby, the moisture resistance can be improved. The aryl alkylene type epoxy resin refers to an epoxy resin having one or more aryl alkylene groups in a repeating unit. Examples thereof include xylylene type epoxy resin and biphenyl dimethylene type epoxy resin. Among these, biphenyl dimethylene type epoxy resin is preferable. The biphenyl dimethylene type epoxy resin can be represented by, for example, the formula (III).

[Chemical 3] The n of the biphenyl dimethylene type epoxy resin represented by the formula (III) is not particularly limited, but is preferably 1 to 10 and particularly preferably 2 to 5. If the amount is less than the above range, the biphenyl dimethylene type epoxy resin is likely to be crystallized, and the solubility in a general-purpose solvent is relatively lowered, which may make the handling difficult. On the other hand, if the amount is larger than the above range, the fluidity of the resin is lowered, which may cause defective molding or the like. Furthermore, when a copper-clad laminate is prepared using a combination of the above-mentioned cyanate resin and / or its prepolymer (especially novolac type cyanate resin) and aryl alkylene type epoxy resin (especially biphenyl dimethylene type epoxy resin), it is excellent. Dimensional stability can be obtained.

The weight average molecular weight of the epoxy resin is not particularly limited, but the weight average molecular weight is 500 to 20,000.
Is preferred, and 800 to 15000 is particularly preferred. If the weight average molecular weight is less than the above range, problems such as tackiness may occur in the prepreg, and if it is more than this range, impregnation into the base material during preparation of the prepreg is reduced, and a uniform product cannot be obtained. Problems may occur. The content of the epoxy resin is not particularly limited, but is preferably 1 to 55% by weight, and particularly 2 to 40% by weight of the entire resin composition.
Weight percent is preferred. If the amount of the resin is less than the lower limit, the reactivity of the cyanate resin may decrease, or the moisture resistance of the obtained product may decrease, and if the amount of the resin exceeds the upper limit, the heat resistance may decrease.

In the resin composition of the present invention, a part of the above cyanate resin and / or its prepolymer, phenol resin and epoxy resin is used as another thermosetting resin such as vinyl ester resin and melamine resin, phenoxy resin and polyimide resin. , A polyamideimide resin, a polyphenylene oxide resin, a polyether sulfone resin, or the like may be used in combination.

The resin composition of the present invention is not particularly limited, but it is preferable to use a coupling agent. The coupling agent improves the wettability of the interface between the resin and the inorganic filler, so that the resin and the filler are uniformly fixed to the substrate, and the heat resistance, especially the solder heat resistance after moisture absorption, is improved. Compound. As the coupling agent, any commonly used one can be used, and among them, one or more selected from epoxysilane coupling agents, titanate coupling agents, aminosilane coupling agents and silicone oil type coupling agents can be used. It is preferable to use a coupling agent in terms of high wettability with the interface of the inorganic filler and improvement in heat resistance. In the present invention, the coupling agent content is preferably 0.05% by weight or more and 3% by weight or less with respect to the inorganic filler. If it is less than this, the filler may not be sufficiently covered and sufficient heat resistance may not be obtained, and if it is more than this, the reaction is affected and the bending strength etc. decreases, so use within this range desirable.

In the resin composition of the present invention, a curing accelerator may be used if necessary. A well-known thing can be used as a hardening accelerator. For example, organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonatocobalt (II) and trisacetylacetonatocobalt (III), triethylamine, tributylamine, diazabicyclo [2,2]. 2,2] octane and other tertiary amines, 2-phenyl-4-methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxy Examples include imidazoles, imidazoles such as 2-phenyl-4,5-dihydroxyimidazole, phenol compounds such as phenol, bisphenol A, and nonylpheno, organic acids such as acetic acid, benzoic acid, salicylic acid, and paratoluenesulfonic acid, or a mixture thereof. To be

In the resin composition of the present invention, if necessary,
Additives other than the above components can be added within a range that does not impair the characteristics.

Next, the prepreg of the present invention will be described. The prepreg of the present invention is obtained by impregnating a base material with the above resin composition. This makes it possible to obtain a prepreg excellent in heat resistance, low expansion and flame retardancy. Examples of the base material include glass woven cloth, glass non-woven cloth, glass fiber base material such as glass paper, paper, aramid, polyester, aromatic polyester, woven cloth and synthetic fiber such as fluororesin, and metal fiber. , Carbon fiber,
Examples thereof include woven fabrics, non-woven fabrics, mats and the like made of mineral fibers and the like. You may use these base materials individually or in mixture. Of these, a glass fiber base material is preferable. This can improve the rigidity and dimensional stability of the prepreg.

The method of impregnating the base material with the resin composition includes, for example, a method of immersing the base material in a resin varnish, a method of coating with a variety of coaters, and a method of spraying. Among these, the method of immersing the base material in the resin varnish is preferable. Thereby, the impregnation property of the resin composition on the substrate can be improved. In addition,
When dipping the base material in the resin varnish, ordinary impregnation coating equipment can be used.

The solvent used for the resin varnish preferably has good solubility in the resin composition, but a poor solvent may be used within a range that does not have an adverse effect. Examples of the solvent exhibiting good solubility include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like. The solid content of the resin varnish is not particularly limited, but the solid content of the resin composition is preferably 30 to 80% by weight, and particularly preferably 40 to 70% by weight. This can improve the impregnation property of the resin varnish into the base material. The base material is impregnated with the resin composition at a predetermined temperature, for example 90
A prepreg can be obtained by drying at ~ 180 ° C.

Next, the printed wiring board will be described.
The printed wiring board of the present invention is obtained by laminating a metal foil on the above prepreg and heat-pressing it. This makes it possible to obtain a printed wiring board excellent in heat resistance, low expansion and flame retardancy. When using one prepreg, overlay metal foil on both upper and lower surfaces or on one side. Also, two or more prepregs can be laminated. Prepreg 2
When laminating one or more sheets, a metal foil or film is laminated on the outermost upper and lower surfaces or one side of the laminated prepreg. Next, a printed wiring board can be obtained by heat-press molding a prepreg and a metal foil that are stacked. The heating temperature is not particularly limited, but is 120
-220 degreeC is preferable and 150-200 degreeC is especially preferable. The pressure to be applied is not particularly limited, but is 1.5
-5 MPa is preferable, and 2-4 MPa is particularly preferable.
Further, if necessary, post-curing may be performed in a high temperature bath or the like at a temperature of 150 to 300 ° C.

[0024]

Examples Example 1 20 parts by weight of novolac type cyanate resin (Lonza Japan KK, Primaset PT-60) (hereinafter abbreviated as "part"), biphenyl dimethylene type epoxy resin (Nippon Kayaku Co., NC) -3000P) 11 parts by weight, biphenyl dimethylene type phenol resin (manufactured by Meiwa Kasei Co., Ltd., MEH-7851-S) 9 parts by weight, and epoxysilane type coupling agent (manufactured by Nippon Unicar Co., Ltd., A-
187) 0.3 part by weight is dissolved in methyl ethyl ketone at room temperature, 10 parts of spherical fused silica SFP-10X (manufactured by Denki Kagaku Kogyo Co., Ltd.) and SO-32R (manufactured by Admatechs Co., Ltd.) are added, and a high-speed stirrer is used. It was stirred for 10 minutes. The prepared varnish is woven with glass (thickness 200μ
m, manufactured by Nitto Boseki Co., Ltd., WEA-7628), and impregnated with 120
It was dried for 2 minutes in a heating furnace at 0 ° C. to obtain a prepreg having a varnish solid content (components of resin and silica in the prepreg) of about 50%. A predetermined number of these prepregs are stacked, and 18μ on both sides.
A double-sided copper-clad laminate was obtained by stacking m copper foils and heating and pressing at a pressure of 4 MPa and a temperature of 200 ° C. for 2 hours.

The evaluation method of the obtained double-sided copper-clad laminate is described below.
Shown in. The entire surface of a double-sided copper-clad laminate with a glass transition temperature of 0.6 mm is etched,
A test piece of 10 mm × 60 mm was cut out from the obtained laminated plate, heated at 3 ° C./min using a dynamic viscoelasticity measuring device DMA983 manufactured by TA Instruments, and tan δ
Was taken as the glass transition temperature.

A double-sided copper clad laminate having a linear expansion coefficient of 1.2 mm in thickness is entirely etched,
A test piece of 2 mm × 2 mm was cut out from the obtained laminated plate, and the linear expansion coefficient in the thickness direction (Z direction) was measured at 5 ° C./minute using TMA.

According to the flame retardant UL-94 standard, a 1 mm thick test piece was measured by the vertical method.

A double-sided copper-clad laminate having a water absorption of 0.6 mm was completely etched, and a test piece of 50 mm × 50 mm was cut out from the obtained laminate and measured according to JIS6481.

Moisture absorption solder heat resistance 50 mm x 50 m from a double-sided copper clad laminate having a thickness of 0.6 mm
A test piece was prepared by cutting out to m and performing half-face etching according to JIS6481. After treating with a pressure cooker at 125 ° C., the copper foil surface was floated down in a soldering bath at 260 ° C., and the treatment time for generating blisters after 180 seconds was measured.

Examples 2 to 7 and Comparative Examples 1 to 4 With the formulations shown in Table 1, double-sided copper-clad laminates were obtained in the same manner as in Example 1. The evaluation method is also as described above.

The evaluation results of these copper clad laminates are shown in Table 1. The copper-clad laminates obtained in each example have excellent flame retardancy despite not using a halogen-based flame retardant and a phosphorus compound, have a high glass transition temperature, and have a small linear expansion coefficient, It can be seen that it has excellent heat resistance to moisture-absorbing solder.

[0032]

[Table 1]

Note 1 in the table) Primaset PT-30 (novolak type cyanate resin, weight average molecular weight about 700): Lonza Japan Co., Ltd. 2) Primaset PT-60 (novolak type cyanate resin, weight average molecular weight about 2600): Lonza Japan Co., Ltd. 3) AroCy B-30 (bisphenol A type cyanate resin): Asahi Kasei Epoxy Co., Ltd. 4) NC-3000P (biphenylalkylene type epoxy resin, epoxy equivalent 275): Nippon Kayaku Co., Ltd. 5) Epicron N -775 (Novolak type epoxy resin, epoxy equivalent 190): Dainippon Ink and Chemicals, Inc. 6) PR-51714 (Novolak resin, hydroxyl equivalent 1)
03): Sumitomo Bakelite Co., Ltd. 7) MEH-7851-S (biphenylalkylene novolac resin, hydroxyl equivalent 203): Meiwa Kasei Co., Ltd. 8) SFP-10X (spherical fused silica, average particle size 0.3)
μm): manufactured by Denki Kagaku Kogyo Co., Ltd. 9) SO-32R (spherical fused silica, average particle size 1.5 μm)
m): 10) FB-5SDX manufactured by Admatechs Co., Ltd. (spherical fused silica, average particle size 4.
4 μm): Denki Kagaku Kogyo KK 11) AO-802 (spherical alumina, average particle size 0.7 μm)
m): manufactured by Admatex Co., Ltd. 12) A-187 (epoxysilane type coupling agent): manufactured by Nippon Unicar Co., Ltd. 13) 2MZ (2-methylimidazole): manufactured by Shikoku Chemicals Co., Ltd.

[0034]

The first effect of the present invention is to provide a resin composition and a prepreg which have excellent flame retardancy without using a halogen compound and a phosphorus compound and can exhibit high heat resistance and low thermal expansion characteristics. , And a copper clad laminate can be obtained. Further, the second effect of the present invention is to be able to control the coefficient of thermal expansion in the thickness direction of the prepreg and the like, thereby improving the connection strength between the layers, mechanical and electrical in a high temperature and high humidity atmosphere. It is possible to improve reliable connection reliability.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 1/03 610 H05K 1/03 610K 610R 3/00 3/00 R (72) Inventor Takayuki Takahashi Tokyo 2-5-8 Higashi-Shinagawa, Shinagawa-ku, Sumitomo Bakelite Co., Ltd. (72) Inventor, Takeshi August August 2--5-8, Higashi-Shinagawa, Shinagawa-ku, Tokyo Sumitomo Bakelite Co., Ltd. F-term (reference) 4F072 AA01 AA05 AA07 AB04 AB05 AB06 AB09 AB10 AB28 AB29 AD13 AD23 AD27 AD42 AD45 AE01 AE04 AE23 AF06 AF21 AG03 AG17 AG19 AH02 AH31 AH52 AK05 AK14 AL12 AL13 4F100 AA01A AA20A AB01B AB03B02 BA07B02BA02 BA07CA02A02BA07 CA02A02 BA07 CA23A DE04A01B02BA02 BA07CA01A02BA07 CA23A DE04A02 CM02W DE146 DJ016 DJ046 DJ056 DL006 EE047 EF037 EF097 EG017 EJ027 EJ037 EJ067 EU117 EV237 FD016 FD157 GF00 GH0 0 GQ00 GQ01 HA01

Claims (8)

[Claims] 1. A resin composition containing a cyanate resin and / or a prepolymer thereof, a phenol resin and an inorganic filler as essential components. 2. The resin composition according to claim 1, wherein the cyanate resin and / or its prepolymer is a novolac type cyanate resin and / or its prepolymer. 3. The resin composition according to claim 1, wherein the cyanate resin accounts for 5 to 60% by weight of the entire resin composition. 4. The resin composition according to claim 1, wherein the phenol resin is an aryl alkylene type phenol resin. 5. The resin composition according to claim 1, wherein the inorganic filler is spherical fused silica having an average particle size of 2 μm or less. 6. The inorganic filler comprises 3 parts of the total resin composition.
The resin composition according to any one of claims 1 to 5, which is 0 to 80% by weight. 7. A prepreg obtained by impregnating a substrate with the resin composition according to any one of claims 1 to 6. 8. A printed wiring board obtained by laminating a metal foil on the prepreg according to claim 7 and heat-pressing.