JPH0251294A - Multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To enable it to be miniaturized making use of high permittivity of ceramics with no problem in processability, and to enable it to be adopted suitably as a printed wiring board for high frequency equipment by forming a circuit pattern in a laminate where sheets of prepreg which were made by impregnating ceramic fiber fabric base material, whose inside layer material is mainly composed of Si2N4, with resin varnish and drying it are laminated and then a metallic foil is laminated on and united with the outermost layer. CONSTITUTION:The inside layer material is ceramic fibers mainly composed of Si2N4, and ceramic fiber fabric base material whose permittivity is 9 or more is impregnated with resin varnish and these are dried so as to make prepreg. These sheets of prepregs are piled up and a metallic foil is arranged at the outermost layer, and with these things as one set sets are arranged between heat discs through formation plates and are heated and pressed so as to laminate and unite themselves, thus a laminate is made.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a multilayer printed wiring board using a ceramic fiber cloth base material mainly made of 5i1N as a base material for an inner layer material.

[Conventional technology]

With the advent of the information society, there is a desire for a significant expansion of the communication customer base, and the use of high-frequency fiber is becoming more concrete for wired systems and high frequency for wireless systems. In the non-#I high frequency band, for example, a car phone that used to have a 400 MHz band has a 900 MHz band.
8) A shift to the Iz band or 1.3 GHz band is planned. The high-frequency printed circuit board material used for this purpose has not only the performance traditionally required, but also has particular dielectric properties, i.e., l
Ti! Trains require the ability to be immersed in one electric dissipation tangent. By the way, since upstream electrical circuits have conventionally been designed using lumped constant circuits, insulation, dimensional stability, workability, etc., have been considered important for printed circuit board materials. On the other hand, for high-frequency circuits, the design concept of distributed constant circuits is essential in addition to lumped constant circuits, and the dielectric constant of printed circuit board materials is an important physical constant that determines essential parameters of distributed constant circuits such as characteristic impedance and wavelength shortening rate. The need to handle it is increasing. For example, as the dielectric constant increases, the advantage that the base material can be made smaller in terms of the equivalent circuit of distributed constants, that is,
〃If you design a circuit with the same performance using a lath epoxy laminate and an alumina ceramic board using distributed constants, the latter will be about 1/1 of the former.
This is possible with an area of 2.

[Problem to be solved by the invention]

Ceramic substrates were not suitable for use as printed wiring boards due to difficulty in processability and α. The present invention has been made to solve the above problems, and its purpose is to provide a multilayer printed wiring board that uses ceramic fiber cloth with excellent workability and can be suitably used as a printed wiring board for high-frequency equipment. Our goal is to provide the following.

[Means to solve the problem]

The multilayer printed wiring board of the present invention consists of laminating a plurality of prepregs formed by impregnating and drying a resin varnish on a ceramic fiber cloth base material mainly composed of 513N as an inner layer material, and laminating a metal foil on the outermost layer. This structure is characterized by having a circuit pattern formed on a laminate plate, and this structure solves the above-mentioned problems. [Action J: Is the base material of the inner layer a ceramic based mainly on 5iJ-? Since it is a fiber cloth, there is no problem in processability even when ceramic is used, and it is possible to downsize by utilizing the quotient dielectric constant of ceramic, making it suitable for use as a printed wiring board for high frequency #FI equipment. be. The present invention will be explained in detail below. The base material of the inner layer material is ceramic γ-ri A mainly composed of 513N4.
The ceramic fiber cloth is preferably a cloth bag with a dielectric constant of 9 or more. For example, a ceramic fiber cloth manufactured by Sango Pan Co., Ltd. can be used. This base material is impregnated with resin varnish and dried to produce prepreg a. As the resin, Evokin resin, polyimide resin, polyester resin, fluorine θ1 resin, polybutadiene resin, PPO resin, etc. can be used, but a resin with a small dielectric loss tangent is preferable. A plurality of sheets of this prepreg are stacked and a metal foil is placed on the outermost layer, and the prepregs are placed between heating platens via forming plates, and heated at 100°C or higher for 20-150°C.
A laminate is manufactured by heating and pressing with kg7cm2.40-1009 to form a laminated image. This M-layer plate is sequentially subjected to hole drilling, electroless plating, pattern formation, pattern plating, resist plating, lenost removal,
For example, through-hole plating printed wiring boards are processed through processes such as etching, external finishing, and symbol mark printing.
1 remains and is used as the inner layer material of the present invention. A multilayer printed wiring board is manufactured by attaching metal foil as an outer layer material to one or both sides of the inner layer material via a prepreg, or laminating laminates.9 Next, specific examples of the present invention will be described. Explain. (Example 1) Ceramic fiber cloth with a dielectric constant of 18 (Sangopan sl[
Impregnate cloth #18J) with epoxy resin varnish and dry 9.
& Let it contain resin f! L (1?il type) 50% by weight prepreg is ill! L. Four sheets of this prepreg were stacked, copper foil was placed on both sides, and heated and pressed at 170℃ and 30 kg/cm''.
A laminate of &/'70.8vm was produced by imaging. A circuit pattern was formed on this laminate to produce an inner layer material. A multilayer printed wiring board was manufactured by laminating and forming a copper foil onto this inner layer material via a prepreg. Measure i% train,
The required size as a printed wiring board was compared with a comparative example, and the comparative example was quantified as 100. The results are shown in Table 1. (') Ground side 2) A multilayer printed wiring board was manufactured in the same manner as in Example 1 except that polyimide resin varnish was used instead of epoxy resin varnish. Measurements similar to those in Example 1 were performed. The results are shown in Table 1. (Comparative example) Glass cloth impregnated with resin varnish and dried? jf fat content 1
A multilayer printed wiring board was produced in the same manner as in Example 1, except that R14 prepreg was used with 50% by weight of t (m type). It can be used. Required size for dielectric constant printed wiring board

Claims (2)

[Claims] (1) A circuit pattern is formed on a laminate made by laminating multiple sheets of prepreg formed by impregnating and drying a ceramic fiber cloth base material whose inner layer material is Si_3N_4 with a resin varnish, and integrating a metal foil into the outermost layer. A multilayer printed wiring board characterized by being formed of. (2) The multilayer printed wiring board according to claim 1, wherein the ceramic fiber cloth has a dielectric constant of 9 or more.