# US 4,798,762 A · Laminate board containing uniformly distributed filler particles and method for producing the same

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- Number: US 4,798,762 A
- Document ID: US4798762A
- Status: Granted
- Kind: A
- Application number: 07/004,722
- Filed: 1987-01-20
- Granted: 1989-01-17
- Earliest claimed: 1985-08-14
- Assignees: Toray Industries, Inc.
- Inventors: Reisuke Okada; Hisami Fujino
- Web page: https://patentgrep.com/patent/US4798762A

## CPC

- B32B 27/12: next to a fibrous or filamentary layer
- H05K 1/036: {Multilayers with layers of different types}
- H05K 1/0373: {containing additives, e.g. fillers (H05K1/036 takes precedence)}
- H05K 1/0366: {reinforced, e.g. by fibres, fabrics (H05K1/036 takes precedence)}
- H05K 2201/0254: Microballoons or hollow filler particles
- Y10S 428/901: Printed circuit
- Y10T 428/24995: Two or more layers
- Y10T 428/249973: Mineral element
- Y10T 428/249974: Metal- or silicon-containing element
- Y10T 428/252: Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
- Y10T 428/265: 1 mil or less
- Y10T 428/2982: Particulate matter [e.g., sphere, flake, etc.]
- Y10T 428/31688: Next to aldehyde or ketone condensation product
- Y10T 428/31692: Next to addition polymer from unsaturated monomers
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A copper clad laminate board for a printed circuit has a center plate which is a thermosetting resin containing hollow glass microspheres uniformly distributed in the resin. The center plate has sheets provided on both sides thereof, which sheets are a thermosetting resin having a reinforcing fabric. The board has a high electrical resistance and resists bending during subsequent processing.

## Claims

### Claim 1

A copper clad laminate board for a printed circuit, having a thickness from 0.5 to 1.6 mm, comprising a center plate which consists of a thermosetting resin and hollow glass microspheres, uniformly distributed in said resin, the volume fraction of which ranges from 0.5 to 0.7, based upon the volume of the center plate, and sheets, provided on both sides of said center plate, which comprise a thermosetting resin and a reinforcing fabric, the specific gravity of the laminate board being from 0.8 to 1.3.

### Claim 2 (depends on 1)

The laminate board of claim 1, wherein the center plate has a thickness of at least 0.3 mm.

### Claim 3 (depends on 1)

The laminate board of claim 1, wherein the reinforcing fabric is made of glass.