JP2006307227A - Heat-resistant resin composition, prepreg and laminate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition that has excellent heat resistance, dielectric property and water absorption by using a cyanate resin and a phenol aralkyl epoxy resin or a biphenyl aralkyl epoxy resin in combination and provide prepreg and laminated plate obtained from the prepreg. <P>SOLUTION: The heat-resistant resin composition comprises a cyanate resin bearing a benzene ring connected to an alkyl group, an aryl group or a divalent alkyl group or an aryl group or its prepolymer; and a biphenyl aralkyl epoxy resin that is composed of a phenylalkyl group with one or more repeating units or of a phenolaralkyl group having one or more repeating unit, or a phenol aralkyl epoxy resin as essential components. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a resin composition, a prepreg, and a laminate having excellent heat resistance and excellent dielectric properties. In particular, it is suitably used for high frequency circuit boards.

Information processing devices such as notebook personal computers and mobile phones are required to be downsized. There is an increasing demand for reduction in size and weight in printed wiring boards on which electronic components such as LSIs are mounted. In order to reduce the size and weight, it is necessary to reduce the wiring width, reduce the through-hole diameter, and reduce the plating thickness. If the plating thickness is reduced, plating cracks may occur during thermal shock, and heat resistance is required. At the same time, speeding up of these information processing crises is also demanded, and the CPU clock frequency is increasing. For this reason, it is required to increase the signal propagation speed, and it is necessary that the printed board has a low dielectric constant and low dielectric loss tangent, which is advantageous for increasing the speed.

Cyanate resin is used as a resin having excellent heat resistance and excellent dielectric properties (for example, Patent Document 1). Since the cyanate resin does not generate a highly polar reactive group such as a hydroxyl group by the curing reaction, it has excellent dielectric characteristics. However, since it contains a lot of nitrogen atoms, it has a drawback of high water absorption.
JP-A-8-8501

  The present invention has been made as a result of studies to solve such problems, and by using a cyanate resin and a phenol aralkyl epoxy resin or a biphenyl aralkyl epoxy resin in combination, a resin composition excellent in heat resistance, dielectric properties, and water absorption rate. An object, a prepreg, and a laminate obtained from the prepreg are provided.

（Ｂ１）下記一般式（ＩＩ）で表されるビフェニルアラルキルエポキシ樹脂、又は（Ｂ２）下記一般式（ＩＩＩ）で表されるフェノールアラルキルエポキシ樹脂

を必須成分として含有してなることを特徴とする耐熱性樹脂組成物、
（２）第（１）項記載の樹脂組成物を基材に含浸させてなることを特徴とするプリプレグ、
（３）第（２）項記載のプリプレグを１枚又は２枚以上重ね合わせ加熱加圧してなることを特徴とする難燃性積層板又は銅張積層板、
である。 The present invention provides (1) (A) a cyanate resin represented by the following general formula (I) or a prepolymer thereof, and

(B1) Biphenyl aralkyl epoxy resin represented by the following general formula (II), or (B2) Phenol aralkyl epoxy resin represented by the following general formula (III)

A heat-resistant resin composition characterized by comprising
(2) A prepreg obtained by impregnating a base material with the resin composition according to item (1),
(3) A flame retardant laminate or a copper clad laminate, wherein one or more prepregs according to (2) are superposed and heated and pressed,
It is.

  When applied to a printed wiring board material, the heat-resistant resin composition of the present invention has high heat resistance, low dielectric constant, and excellent water absorption. Therefore, in the future, it is an object to provide a resin composition optimal for a printed wiring board in a crisis for small information processing.

また、かかる一般式を有するシアネート樹脂をプレポリマー化したものも成形性、流動性を調整するために好ましく使用され、本発明の（Ａ）成分に含まれるものである。プレポリマー化は、通常加熱溶融して行われる。本発明でプレポリマーとは、３量化率２０〜５０％のものをいう。３量化率は赤外分光分析装置を用いて求めることができる。なお、シアネート樹脂とシアネート樹脂をプレポリ
マー化したものとを併用しても構わない。
シアネート樹脂は樹脂成分１００重量部中、５０〜８０重量部が好ましい。５０重量部未満では２６０℃の半田耐熱性が十分でなく、また８０重量部を越えると吸水率が悪化し好ましくない。
本発明におけるシアネート樹脂のＲ１のアルキル基は炭素数１〜６が好ましく、アリール基は炭素数は２〜６が好ましい。また、同様にＲ２のアルキル基は炭素数１〜４が好ましく、アリール基は炭素数１〜３が好ましい。 The (A) component cyanate resin used in the present invention is represented by the following general formula (I).

Moreover, what prepolymerized cyanate resin which has this general formula is preferably used in order to adjust a moldability and fluidity | liquidity, and is contained in (A) component of this invention. The prepolymerization is usually performed by heating and melting. In the present invention, the prepolymer means a trimerization rate of 20 to 50%. The trimerization rate can be determined using an infrared spectroscopic analyzer. In addition, you may use together cyanate resin and what prepolymerized cyanate resin.
As for cyanate resin, 50-80 weight part is preferable in 100 weight part of resin components. If it is less than 50 parts by weight, the solder heat resistance at 260 ° C. is not sufficient, and if it exceeds 80 parts by weight, the water absorption rate is deteriorated.
The alkyl group of R1 of the cyanate resin in the present invention preferably has 1 to 6 carbon atoms, and the aryl group preferably has 2 to 6 carbon atoms. Similarly, the alkyl group of R2 preferably has 1 to 4 carbon atoms, and the aryl group preferably has 1 to 3 carbon atoms.

フェノールアラルキルエポキシ樹脂又はビフェニルアラルキルエポキシ樹脂は樹脂成分１００重量部中、２０〜５０重量部が好ましい。２０重量部未満では低吸水化が十分でなく、また５０重量部を越えると２６０℃の半田耐熱性が悪化し好ましくない。両者の中でもビフェニルアラルキルエポキシ樹脂が、エポキシ当量が大きく低吸水化の効果が大きい点で好ましい。
また、本発明でビフェニルアラルキル樹脂のｎは２〜７が２６０℃の半田耐熱性の点で好ましい。ｎが２未満であると架橋密度が低下する傾向があり２６０℃での半田耐熱性が悪化する場合があり、７を超えるとシアネート樹脂との相溶性が悪化する場合がある。また、フェノールアラルキルエポキシ樹脂のｍは２〜７が２６０℃の半田耐熱性の点で特に好ましい。ｍが２未満であると架橋密度が低
下する傾向があり２６０℃での半田耐熱性が悪化する場合があり、７を超えるとシアネート樹脂との相溶性が悪化する場合がある。 The biphenyl aralkyl resin of component (B1) used in the present invention is represented by the following general formula (II). The (B2) component phenol aralkyl epoxy resin is represented by the following general formula (III).

The phenol aralkyl epoxy resin or the biphenyl aralkyl epoxy resin is preferably 20 to 50 parts by weight per 100 parts by weight of the resin component. If it is less than 20 parts by weight, the water absorption is not sufficiently reduced, and if it exceeds 50 parts by weight, the solder heat resistance at 260 ° C. is deteriorated, which is not preferable. Among them, biphenyl aralkyl epoxy resin is preferable because it has a large epoxy equivalent and a large effect of reducing water absorption.
In the present invention, n in the biphenyl aralkyl resin is preferably 2 to 7 in view of solder heat resistance at 260 ° C. If n is less than 2, the crosslinking density tends to decrease, and solder heat resistance at 260 ° C. may be deteriorated. If n exceeds 7, compatibility with cyanate resin may be deteriorated. Further, m of the phenol aralkyl epoxy resin is particularly preferably 2 to 7 in view of solder heat resistance at 260 ° C. If m is less than 2, the crosslinking density tends to decrease, and solder heat resistance at 260 ° C. may be deteriorated, and if it exceeds 7, compatibility with cyanate resin may be deteriorated.

As described above, the cyanate resin generates a triazine ring by a curing reaction. However, since the triazine ring is excellent in symmetry, the polarization is small and the dielectric property is very excellent. Furthermore, since the triazine ring has a rigid structure containing nitrogen, it is characterized by excellent flame retardancy.
However, since cyanate resin has a high nitrogen content, it has a drawback of high water absorption. In order to reduce the water absorption rate, there is a method of adding a low water absorption resin such as an elastomer or a dicyclopentadiene resin. However, these resins have a drawback that they easily burn. In the present invention, in order to solve this problem, a phenol aralkyl epoxy resin or a biphenyl aralkyl epoxy resin is used in combination with a cyanate resin. The phenol aralkyl epoxy resin and the biphenyl aralkyl epoxy resin have a high epoxy equivalent and a low epoxy group concentration in the cured product, and thus have excellent dielectric characteristics. The benzene ring in the molecule has high hydrophobicity and low water absorption. In addition, the phenol aralkyl epoxy resin and the biphenyl aralkyl epoxy resin have a high benzene ring content and are easily carbonized. Furthermore, since the epoxy group reacts with the cyanate group, it can be incorporated into the resin skeleton, so that the excellent heat resistance of the cyanate resin is not lowered.

  Examples of the substrate used in the present invention include glass fabric, glass fabric, and fabric or fabric containing components other than glass. Among these base materials, a glass woven fabric is preferable in terms of strength and water absorption.

For the method of impregnating the substrate with the resin composition obtained in the present invention, an impregnation coating facility or the like is used.
In the present invention, when impregnating the base material, it is usually preferable from the viewpoint of impregnation to use it in the form of a varnish dissolved in a solvent. The solvent used preferably has good solubility in the composition, but a poor solvent may be used as long as it does not adversely affect the composition. Examples of the solvent exhibiting good solubility include methyl ethyl ketone and cyclohexanone.
A prepreg can be obtained by impregnating a base material with a varnish obtained by dissolving the resin composition of the present invention in a solvent and drying at 80 to 200 ° C.

  One or two or more prepregs obtained in the present invention are overlapped and heated and pressed at 150 to 200 ° C. to obtain a laminate or a copper-clad laminate.

The resin composition of the present invention contains the above-described cyanate resin and a phenol aralkyl epoxy resin or a biphenyl aralkyl epoxy resin as essential components. However, other resins, curing accelerators, couplings may be used as long as they do not contradict the purpose of the present invention. Additives, flame retardants, and other ingredients may be added. When a brominated epoxy resin is used as the flame retardant, the epoxy group and the cyanate group react with each other and the flame retardant can be incorporated into the resin skeleton, which is preferable without deteriorating the properties of the resin. As the curing accelerator, cobalt-containing compounds such as cobalt acetylacetonate and cobalt naphthenate, zinc-containing compounds such as zinc chloride and zinc naphthenate, and copper-containing compounds such as copper chloride are preferable.

Example 1
70 parts by weight of bisphenol A cyanate resin (prepolymerized, trimerization rate 40%, C-40 Geigy B-40), biphenyl aralkyl epoxy resin (epoxy equivalent 280, Nippon Kayaku NC-3000S) 30 parts by weight, Dimethyl cellosolve was added to 0.10 parts by weight of the cobalt acetylacetone complex, and the varnish was adjusted so as to have a nonvolatile content concentration of 55% by weight.
Using this varnish, 100 parts by weight of glass fiber cloth (thickness 0.18 mm, manufactured by Nitto Boseki Co., Ltd.) was impregnated with 80 parts by weight of varnish solids, and dried in a dryer oven at 150 ° C. for 5 minutes to obtain a resin. A prepreg having a content of 44.4% was prepared.
6 sheets of the above prepreg are stacked, and 35 μm thick electrolytic copper foils are stacked on the top and bottom. The pressure is 40 kgf / cm ² , the temperature is 200 ° C. for 120 minutes, and the temperature is 220 ° C. for 60 minutes, and the thickness is 1.2 mm. A double-sided copper clad laminate was obtained.

(Examples 2 to 5 and Comparative Examples 1 to 3)
A double-sided copper-clad laminate was prepared in the same manner as in Example 1 except for the formulation shown in Table 1.

  The obtained copper-clad laminate was measured for flame retardancy, solder heat resistance, peel strength and water absorption. Solder heat resistance, peel strength, and water absorption are measured according to JIS C 6481. Solder heat resistance is an abnormal appearance after being immersed in a solder bath at 260 ° C. for 120 seconds after performing a moisture absorption treatment for 2 hours at boiling. The presence or absence of was investigated. Flame retardancy was evaluated by a vertical method using a 1 mm thick sample in accordance with UL-94 standards. The glass transition point was measured using RDS-7700 manufactured by Rheometrics at a heating rate of 3 ° C./min and a frequency of 1 Hz. The dielectric constant and dielectric loss tangent were measured according to JIS C 6481 and measured by measuring the capacitance at a frequency of 1 MHz. The evaluation results are shown in Table 1. It can be seen that the copper-clad laminates shown in the examples all have low dielectric constant and dielectric loss tangent, and are excellent in heat resistance, solder heat resistance, and water absorption.

Notes to the table (1) Bisphenol A cyanate (prepolymerization: trimerization rate 40%, trade name: B-40 manufactured by Ciba Geigy)
(2) Biphenyl aralkyl epoxy resin (epoxy equivalent 280, trade name: NC-3000S manufactured by Nippon Kayaku Co., Ltd.)
(3) Phenol aralkyl epoxy resin (epoxy equivalent 235, trade name: E-XL-3L manufactured by Mitsui Chemicals)
(4) Brominated epoxy resin (epoxy equivalent 400, bromination ratio 48%, Epicron 153 manufactured by Dainippon Ink & Chemicals, Inc.)
(5) Cobalt acetylacetonate (6) Phenol novolac epoxy resin (epoxy equivalent 190, Epiklon N-770 manufactured by Dainippon Ink & Chemicals, Inc.)

Claims (3)

(A) a cyanate resin represented by the following general formula (I) or a prepolymer thereof, and

(B1) biphenyl aralkyl epoxy resin represented by the following general formula (II), or (B2) phenol aralkyl epoxy resin represented by the following general formula (III),

Is contained as an essential component. A prepreg obtained by impregnating a base material with the resin composition according to claim 1. A flame-retardant laminate or a copper-clad laminate, wherein one or more prepregs according to claim 2 are superposed and heated and pressed.