JP2005048036A - Prepreg and metal foil-clad laminate board using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prepreg having little characteristics differences in the lengthwise and transverse directions and a metal foil-clad laminate board using the prepreg. <P>SOLUTION: The prepreg is obtained by impregnating a resin varnish, which contains as the essential components (1) an epoxy resin and a phenolic resin, (2) an inorganic filler, and (3) a silicone oligomer composed of two or more siloxane repeating units and having on the terminal one or more functional groups that react with a hydroxy group, into a glass cloth which is 20-50 μm in thickness and has a ratio of the placing number of the transverse direction to that of the longitudinal direction, of 0.95-1.05. The metal foil-clad laminate board using the prepreg is also provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a prepreg and a metal foil-clad laminate using the prepreg.

  With the downsizing and high performance of electronic equipment, laminated boards used for printed wiring boards have been increasing in density due to thinning, through-hole diameter reduction, and hole spacing reduction. For this reason, the requirements for the heat resistance, drilling workability, insulation characteristics, etc. of the laminated board are becoming stricter.

  As a technique for improving heat resistance and insulation characteristics, conventionally, improvement of physical properties of a cured resin by increasing the Tg (glass transition temperature) of the resin has been widely performed. However, in order to sufficiently satisfy the above characteristics, it has been insufficient to improve the resin alone.

One solution is to use an inorganic filler in combination. Inorganic fillers are being studied not only as bulking agents but also for the purpose of improving dimensional stability, moisture and heat resistance, and the amount of fillers tends to increase.
Japanese Patent No. 2904311

  Laminate boards using these inorganic fillers are often used for package wiring boards among printed wiring boards, but they have characteristics such as longitudinal and lateral thermal expansion and elastic modulus from the viewpoint of behavioral compatibility with the chip. It is desirable that there is no difference. However, prepregs using conventional glass cloth have been found to be inferior in terms of warpage and reliability due to differences in vertical and horizontal characteristics.

  In view of the above, an object of the present invention is to provide a prepreg having a small vertical and horizontal characteristic difference, and a metal foil-clad laminate using the prepreg.

  The present invention includes 1) an epoxy resin and a phenol resin, 2) an inorganic filler, and 3) a resin comprising 2 or more siloxane repeating units and a silicone oligomer having at least one functional group that reacts with a hydroxyl group at the terminal as an essential component. Provided is a prepreg obtained by impregnating a glass cloth having a thickness of 20 to 50 μm and an implantation ratio of 0.95 to 1.05.

  In addition, the present invention provides a metal foil-clad laminate obtained by heating and pressing a predetermined number of the prepregs and further stacking metal foils on one or both sides thereof.

  ADVANTAGE OF THE INVENTION According to this invention, the prepreg with few vertical and horizontal characteristic differences and a metal foil tension laminated board using the same are provided.

  Hereinafter, the present invention will be described in detail.

  The resin varnish used for the prepreg of the present invention is 1) an epoxy resin and a phenol resin, 2) an inorganic filler, and 3) a silicone oligomer having two or more siloxane repeating units and one or more functional groups that react with hydroxyl groups at the terminals. As an essential component.

  The epoxy resin used in the present invention is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, phenol novolac type Epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin, diaminodiphenylmethane epoxy resin, diglycidyl etherified product of biphenol, diglycidyl etherified product of naphthalenediol, diglycidyl ether of phenols And diglycidyl etherified products of alcohols, and alkyl-substituted products, halides and hydrogenated products thereof. These epoxy resins may be used alone or in combination of two or more.

  The phenol resin used for this invention will not be specifically limited if it acts as a hardening | curing agent of the said epoxy resin. Examples of such a phenol resin include bisphenol A, bisphenol F, bisphenol S, a phenol novolac resin, a modified phenol novolac resin, a bisphenol novolac resin, and a cresol novolac resin.

  The compounding equivalent ratio of the epoxy resin and the phenol resin as described above is preferably epoxy group: phenolic hydroxyl group = 1: 0.9 to 1.1.

  Examples of the inorganic filler used in the present invention include aluminum hydroxide, magnesium hydroxide, calcium carbonate, aluminum borate whisker, crystalline silica, amorphous silica, alumina, clay, talc, antimony trioxide, and pentoxide. Examples thereof include antimony, zinc oxide, fused silica, glass powder, quartz powder, shirasu balloon, low dielectric glass filler, glass fiber, pulp fiber, synthetic fiber, and ceramic fiber. As a compounding quantity of an inorganic filler, it is preferable to mix | blend 50-150 weight part with respect to a total of 100 weight part of 1) an epoxy resin and a phenol resin. When the blending amount is less than 50 parts, the reduction of the thermal expansion coefficient, the improvement of the elastic modulus, and the improvement of the moisture and heat resistance are not remarkably observed, and when it exceeds 150 parts by weight, the coating workability is lowered. Moreover, since the uniformity of a property with a glass cloth can be obtained by using 50 weight% or more of silica as an inorganic filler, drill workability and laser workability become favorable. The maximum particle size of the silica is preferably 20 μm or less.

  The silicone oligomer used in the present invention has two or more siloxane repeating units and has one or more functional groups that react with a hydroxyl group at the terminal. By blending such a silicone oligomer into the resin varnish, the coating workability and fluidity can be improved. As a compounding quantity of a silicone oligomer, it is preferable that it is 0.1-10 weight part with respect to 100 weight part of inorganic fillers, and it is more preferable that it is 0.5-5 weight part.

  Moreover, you may mix | blend a hardening accelerator other than the said essential component. Examples of the curing accelerator include imidazole compounds, organic phosphorus compounds, tertiary amines, quaternary ammonium salts, and the like, and two or more kinds may be used in combination.

  In addition, various additives and fillers such as thermoplastic particles, flame retardants, fluorescent agents, dyes, pigments, antifoaming agents, UV opaque agents, antioxidants, reducing agents, etc. are appropriately blended in the resin varnish. Also good.

  The resin varnish used in the present invention comprises the above essential components and other components appropriately blended, such as benzene, toluene, xylene, trimethylbenzene, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, isopropanol, butanol, 2-methoxy. It can be obtained by dissolving in an organic solvent such as ethanol, 2-butoxyethanol, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide. The amount of solvent in the resin varnish is preferably in the range of 20 to 80% by weight, and more preferably in the range of 30 to 60% by weight. The viscosity of the resin varnish is preferably in the range of 20 to 100 cP at 25 ° C.

  The prepreg of the present invention is obtained by impregnating a glass cloth having the above resin varnish with a thickness of 20 to 50 μm and an implantation ratio of 0.95 to 1.05 (the number of horizontal / the number of vertical). Can be obtained.

  The method for producing the prepreg of the present invention by impregnating the above-mentioned resin varnish into the above glass cloth is not particularly limited, and may be a general method. For example, after impregnating or applying an insulating resin composition to a glass cloth so that the resin content of the prepreg after drying is 20 to 90% by weight, the temperature is usually 100 to 200 ° C. for 1 to 30 minutes. A prepreg in a semi-cured state (B stage state) can be obtained by heat drying.

  The metal foil-clad laminate of the present invention can be obtained by heating and pressing a predetermined number of the prepregs of the present invention, and further stacking metal foils on one or both sides.

  As the metal foil used here, copper, aluminum, brass, nickel or the like alone, an alloy, or a composite metal foil can be used, and is not particularly limited. The thickness of the metal foil is not particularly limited, but is generally 3 to 70 μm.

  The heating and pressurization may be performed by a general method, for example, using a multistage press, a multistage vacuum press, continuous molding, an autoclave molding machine, and the like, at about 150 to 200 ° C. and about 1.0 to 8.0 MPa. Heat and press for 0.1 to 5 hours under conditions. Similarly, a predetermined number of prepregs may be disposed between the inner layer base material and the metal foil, and heated and pressed to produce a printed wiring board.

  Examples of the present invention will be described below.

Example 1
In a glass flask equipped with a stirrer, a condenser and a thermometer, 40 g of tetramethoxysilane, 50 g of dimethoxydimethylsilane, and 100 g of methanol were mixed with 1.2 g of acetic acid and 35 g of distilled water. The mixture was stirred for 8 hours to synthesize a silicone oligomer.

22.6 g of the silicone oligomer prepared above and 67.4 g of methyl ethyl ketone were added to a glass flask equipped with a stirrer, a condenser and a thermometer to prepare a treatment liquid having a solid content of 10% by weight. 50 parts by weight of methyl ethyl ketone and 100 parts by weight of aluminum hydroxide as an inorganic filler were mixed with 3 parts by weight of this treatment liquid, and stirred at room temperature for 1 hour to prepare a solution with a treatment filler. This solution was heated to 50 ° C., and 65 parts by weight of a bisphenol A type epoxy resin (epoxy equivalent: 200, manufactured by Yuka Shell Epoxy Co., Ltd., Epicoat 828) was added to 1 part by weight of the silicone oligomer in the solvent. Blended to a ratio of 35 parts by weight of resin (Dainippon Ink & Chemicals, Phenolite LF2882) and 0.5 parts by weight of curing accelerator 2PN-CZ (made by Shikoku Chemicals Co., Ltd.), added methyl ethyl ketone Thus, a resin varnish having a resin content including the filler of 70% by weight was produced. The resin varnish was impregnated into a glass cloth having a thickness of 45 μm, a weight per unit area of 48 g / m ² , and a vertical and horizontal driving number of 54 × 54 (aspect ratio: 1), and then dried by heating at 140 ° C. for 5 minutes. A 60 wt% prepreg was obtained.

Example 2
A prepreg was obtained in the same manner as in Example 1 except that 60 parts by weight of silica and 40 parts by weight of talc were used as the inorganic filler.

Example 3
Using a glass cloth having a thickness of 20 μm, a weight per unit area of 23 g / m ² , and a vertical and horizontal driving number of 70 × 73 (aspect ratio: 0.95 <70/73 <1.05), the resin content of the prepreg A prepreg was obtained in the same manner as in Example 1 except that the amount was 65% by weight.

Comparative Example 1
Example 1 except that a glass cloth having a thickness of 45 μm, a weight per unit area of 48 g / m ² , and a vertical / horizontal driving number of 60 × 47 (aspect ratio: 47/60 <0.95) was used. A prepreg was obtained.

Comparative Example 2
A prepreg was obtained in the same manner as in Example 1 except that the silicone oligomer prepared in Example 1 was not added to the resin varnish.

  A predetermined number of prepregs prepared as described above are stacked, 12 μm copper foil is arranged on both sides, and heating and pressurization are performed at a temperature rising rate of 6 ° C./min, 200 ° C. for 120 minutes, and a pressure of 6.0 MPa. After producing a laminated board, the sample for evaluation was produced by etching the copper foil whole surface. About this sample, the thermal expansion coefficient, elastic modulus, laser workability, and moldability were evaluated as follows. The results are shown in Table 1.

(Evaluation methods)
Thermal expansion coefficient: TMA 2940 (manufactured by Dupont, TMA (Thermal Material Analyzer)) was used to measure the thermal expansion coefficient.

  Elastic modulus: The storage elastic modulus was measured at a heating rate of 5 ° C./min using Rheogel-E4000 (manufactured by UBM, DVE (Dynamic Visco Elastic Analyzer)).

  Laser workability: A carbon dioxide laser was used to machine a 100 μm laser hole, and the ratio between the maximum diameter and the minimum diameter in one hole was determined, and this was used as an index of processability. It can be said that the closer this ratio is to 1, the closer to a perfect circle and the better the workability.

Formability: The presence or absence of voids is confirmed visually.

Claims (5)

  1) Epoxy resin and phenol resin, 2) inorganic filler, and 3) resin varnish containing, as an essential component, a silicone oligomer having two or more siloxane repeating units and one or more functional groups that react with hydroxyl groups at the terminals. Is impregnated into a glass cloth having an aspect ratio of 0.95 to 1.05.   The prepreg according to claim 1, wherein 50 to 150 parts by weight of the 2) inorganic filler is blended with 100 parts by weight of the total of 1) the epoxy resin and the phenol resin.   The prepreg according to claim 1 or 2, wherein 50% by weight or more of the 2) inorganic filler is silica.   The prepreg according to claim 3, wherein the maximum particle size of the silica is 20 μm or less.   A metal foil-clad laminate obtained by heating and pressing a predetermined number of prepregs according to any one of claims 1 to 4 and further stacking metal foils on one or both sides thereof.