# US 2019/0174622 A1 · Release material

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- Number: US 2019/0174622 A1
- Document ID: US20190174622A1
- Status: Published application
- Kind: A1
- Application number: 16/270,081
- Filed: 2019-02-07
- Published: 2019-06-06
- Earliest claimed: 2010-12-27
- Assignees: Kuraray Co., Ltd.
- Applicants: Kuraray Co., Ltd.
- Inventors: Kazuyuki OHMORI; Tatsuya SUNAMOTO
- Web page: https://patentgrep.com/patent/US20190174622A1

## CPC

- H05K 1/0245: {Lay-out of balanced signal pairs, e.g. differential lines or twisted lines}
- B29C 37/0075: {using release sheets}
- B29C 43/18: incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles {(B29C43/206 takes precedence)}
- H05K 1/0242: {Structural details of individual signal conductors, e.g. related to the skin effect}
- H05K 1/0296: {Conductive pattern lay-out details not covered by sub groups H05K1/02 - H05K1/0295 (H05K1/11 takes precedence; lay-out adapted to mounted component configuration H05K1/18)}
- H05K 1/0306: {Inorganic insulating substrates, e.g. ceramic, glass}
- H05K 1/09: Use of materials for the {conductive, e.g. } metallic pattern
- H05K 3/281: {by means of a preformed insulating foil (H05K3/284 takes precedence)}
- B29C 43/203: {Making multilayered articles}
- H05K 1/0237: {High frequency adaptations (H05K1/0216 takes precedence)}
- H05K 2201/0129: Thermoplastic polymer, e.g. auto-adhesive layer; Shaping of thermoplastic polymer
- H05K 2201/0141: Liquid crystal polymer [LCP]
- H05K 2203/068: Features of the lamination press or of the lamination process, e.g. using special separator sheets
- Y10T 156/10: Methods of surface bonding and/or assembly therefor
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Provided is a method of manufacturing a circuit board including preparing a board structural body (11) and covering a conductor circuit element (13) on an outermost layer of the board structural body (11) with a cover film (14), wherein a heat treatment is performed while having a release material (15) interposed between the cover film (14) and a heat-processing device. The release material (15) is a laminate at least including, sequentially from the cover film toward the heat-processing device, a low friction film (16) selected from an ultrahigh-molecular-weight polyethylene film and a polytetrafluoroethylene film, a first aluminum foil (17), a first high-density polyethylene film (18a), a second high-density polyethylene film (18b), and a second aluminum foil (19). The first high-density polyethylene film (18a) and the second high-density polyethylene film (18b) are positioned such that respective MD directions are perpendicular to each other.

## Claims

### Claim at position 1

1-4. (canceled)

### Claim at position 2

5: A release material comprising:
a low friction film having a coefficient of static friction, defined by JIS K 7125, of not larger than 0.30,
a first aluminum foil arranged on the low friction film,
a first high-density polyethylene film arranged on the first aluminum foil,
a second high-density polyethylene film arranged on the first high-density polyethylene film and positioned such that MD direction of the second high-density polyethylene film is perpendicular to MD direction of the first high-density polyethylene film, and
a second aluminum foil arranged on the second high-density polyethylene film.

### Claim at position 3

6-13. (canceled)

### Claim at position 4 (depends on 5)

14: The release material according to claim 5, wherein the low friction film is selected from the group consisting of an ultrahigh-molecular-weight polyethylene film and a polytetrafluoroethylene film.

### Claim at position 5 (depends on 5)

15: The release material according to claim 5, wherein each of the high-density polyethylene films has a viscosity average molecular weight of from 20,000 to 500,000.

### Claim at position 6 (depends on 5)

16: The release material according to claim 5, wherein each of the high-density polyethylene films has a melt flow index of 0.03 to 0.08.

### Claim at position 7 (depends on 14)

17: The release material according to claim 14, wherein the low friction film is the ultrahigh-molecular-weight polyethylene film, and the ultrahigh-molecular-weight polyethylene film has a viscosity average molecular weight of not lower than 1,000,000.

### Claim at position 8 (depends on 14)

18: The release material according to claim 14, wherein the low friction film is the polytetrafluoroethylene film, and the polytetrafluoroethylene film has an apparent melt viscosity at 380° C. of not lower than 101 poise.

### Claim at position 9 (depends on 5)

19: A method of using the release material of claim 5 for heat treatment of a thermoplastic liquid crystal polymer film, the method comprising interposing the release material between the thermoplastic liquid crystal polymer film and a heat-processing device.

### Claim at position 10 (depends on 19)

20: The method according to claim 19, wherein the thermoplastic liquid crystal polymer film is a cover film; and
a board structural body including a board and a conductor circuit element disposed on at least one surface of the board is covered with the cover film.