Resin composition, and protective film, dry film, circuit board, and multilayer circuit board containing same

Patent metadata

Field	Value
Publication number	US-9408296-B2
Application number	US-201113976630-A
Country	US
Kind code	B2
Filing date	Dec 26, 2011
Priority date	Dec 28, 2010
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A resin composition which is capable of forming a film that has excellent heat resistance and slidability/bendability; a protective film for circuits, which uses the resin composition; and a dry film or the like which comprises the protective film are provided. Other aspects are a circuit board and a multilayer circuit board, each of which has excellent heat resistance and slidability/bendability. Furthermore, a protective film for circuit boards is provided, which is arranged in contact with a circuit of a printed wiring board, and contains a polyoxazolidone resin that has a weight average molecular weight of 3×10 4 or more.

First claim

The invention claimed is:

1. A protective film for circuit board to be disposed in contact with a circuit of a printed circuit board, the protective film comprising:
a polyoxazolidone resin (A) having a weight-average molecular weight of 3×10 4 or more, the polyoxazolidone resin (A) being obtained by a reaction of a dicarbamate compound represented by the following general formula (2):
R 5 OOCHN—R 2 —NHCOOR 5   (2)

wherein:
R 2 is C 1-60 divalent organic group, and
each R 5 is independently a C 1-12 alkyl group, a C 1-12 alkoxyalkyl group,
or a C 1-12 monovalent organic group represented by R a —(OR b )m- (wherein R a is an alkyl group, R b is an alkylene group, and m is an integer of 1-11)

with a diepoxy compound represented by the following general formula (3):

wherein:
R 1 is C 1-60 divalent organic group, and
each R 3 is independently hydrogen or C 1-6 hydrocarbon group; and

a thermosetting resin (C) having three or more reactive functional groups in one molecule thereof which is at least one member selected from the group consisting of an epoxy resin, a thermosetting polyimide and an acrylate compound, the content of thermosetting resin (C) in the resin composition being 10-50 mass %, based on the total mass of the polyoxazolidone resin (A) and the thermosetting resin (C).

2. The protective film according to claim 1 , wherein the resin composition contains a flame retardant (B).

3. The protective film according to claim 1 , wherein the polyoxazolidone resin (A) has a repeat unit represented by the following general formula (1):

where R 1 and R 2 are independently C 1-60 divalent organic group, and each R 3 is independently hydrogen or C 1-6 hydrocarbon group.

4. A dry film comprising:
a flexible support; and
the protective film according to claim 1 disposed on the flexible support.

5. A circuit protective layer in a printed circuit board, wherein the circuit protective layer is made of a cured product of the protective layer according to claim 1 .

6. A circuit board comprising:
a printed circuit board including a substrate and a circuit formed on the substrate; and
a cured product of the protective film according to claim 1 , the cured product being laminated onto the printed circuit board so as to be in contact with the circuit.

7. The circuit board according to claim 6 , wherein the circuit board is a flexible circuit board.

8. A multilayer circuit board comprising:
two or more printed circuit boards laminated together, each including a substrate and a circuit formed on the substrate; and
a cured product of the protective film according to claim 1 disposed between a pair of the printed circuit boards.

9. The multilayer circuit board according to claim 8 , wherein the multilayer circuit board is a flexible multilayer circuit board.

10. A resin composition comprising:
a polyoxazolidone resin (A) having a weight-average molecular weight of 3×10 4 or more, the polyoxazolidone resin (A) being obtained by a reaction of a dicarbamate compound represented by the following general formula (2):
R 5 OOCHN—R 2 —NHCOOR 5   (2)

wherein:
R 2 is C 1-60 divalent organic group, and
each R 5 is independently a C 1-12 alkyl group, a C 1-12 alkoxyalkyl group,
or a C 1-12 monovalent organic group represented by R a —(OR b )m- (wherein R a is an alkyl group, R b is an alkylene group, and m is an integer of 1-11)

with a diepoxy compound represented by the following general formula (3):

wherein:
R 1 is C 1-60 divalent organic group, and
each R 3 is independently hydrogen or C 1-6 hydrocarbon group; and

a thermosetting resin (C) having three or more reactive functional groups in one molecule thereof which is at least one member selected from the group consisting of an epoxy resin, a thermosetting polyimide and an acrylate compound, the content of thermosetting resin (C) in the resin composition being 10-50 mass %, based on the total mass of the polyoxazolidone resin (A) and the thermosetting resin (C).

11. The resin composition according to claim 10 , further comprising a flame retardant (B).

12. The resin composition according to claim 10 , wherein the polyoxazolidone resin (A) has a repeat unit represented by the following general formula (1):

where R 1 and R 2 are independently C 1-60 divalent organic group, and each R 3 is independently hydrogen or C 1-6 hydrocarbon group.

13. A method of manufacturing a circuit board, the circuit including: a printed circuit board that includes a substrate and a circuit disposed on the substrate; and a circuit protective layer laminated to the printed circuit board so as to be in contact with the circuit, the method comprising:
providing the printed circuit board;
disposing the protective film according to claim 1 on the circuit of the printed circuit board followed by vacuum lamination; and
thermally curing the protective film to form the circuit protective layer.

Assignees

• Tahara Shuji
• Yasuda Kiyomi
• Mitsui Chemicals Tohcello Inc

Inventors

• Tahara Shuji
• Yasuda Kiyomi

Classifications

• B32B2457/08

  PCBs, i.e. printed circuit boards · CPC title

• H05K3/4617

  characterized by laminating only or mainly similar single-sided circuit boards · CPC title

• H05K1/0346

  containing N · CPC title

• H05K1/0213 Primary

  Electrical arrangements not otherwise provided for · CPC title

• C08G18/7671

  containing only one alkylene bisphenyl group · CPC title