Flexible printed wiring board and laminate for production of flexible printed wiring board
View Patent ↗The flexible printed wiring board according to the present invention includes a first flexible insulating layer, a first conductor wiring laminated on the first insulating layer, a second single-layered insulating layer laminated on the first insulating layer, as it covers the first conductor wiring, and a second conductor wiring laminated on the second insulating layer. The first conductor wiring has a thickness in the range of 10 to 30 μm, a line width in the range of 50 μm to 1 mm, and a line gap in the range of 50 μm to 1 mm. The thickness from the surface of the first conductor wiring to the surface of the second insulating layer is in the range of 5 to 30 μm. The surface waviness of the part of the second insulating layer covering the first conductor wiring is 10 μm or less.
1. A flexible printed wiring board, comprising
a first insulating layer that is flexible,
a first conductor wiring laminated on the first insulating layer,
a second insulating layer that is a single layer and laminated on the first insulating layer, as it covers the first conductor wiring, and
a second conductor wiring laminated on the second insulating layer, wherein:
the first conductor wiring has a thickness in the range of 10 to 30 μm, a line width in the range of 50 μm to 1 mm, and a line gap in the range of 50 μm to 1 mm;
a thickness from a surface of the first conductor wiring to a surface of the second insulating layer is in the range of 5 to 30 μm;
a surface waviness of part of the second insulating layer covering the first conductor wiring is 10 μm or less;
the second insulating layer is made of a hardened product of an epoxy resin composition containing an epoxy resin, a curing agent, and a carbodiimide-modified soluble polyamide; and
the epoxy resin contains a naphthalene skeleton-containing epoxy resin.
2. A flexible printed wiring board, comprising
a first insulating layer that is flexible,
a first conductor wiring laminated on the first insulating layer,
a second insulating layer that is laminated on the first insulating layer, as it covers the first conductor wiring, and
a second conductor wiring laminated on the second insulating layer, wherein:
the second insulating layer includes a third insulating layer directly laminated on the first insulating layer and a fourth insulating layer laminated on the third insulating layer;
the first conductor wiring has a thickness in the range of 10 to 30 μm, a line width in the range of 50 μm to 1 mm, and a line gap in the range of 50 μm to 1 mm;
a thickness from a surface of the first conductor wiring to a surface of the third insulating layer, among the multiple layers constituting the second insulating layer, is in the range of 5 to 30 μm;
a surface waviness of part of the second insulating layer covering the first conductor wiring is 10 μm or less;
the third insulating layer is made of a hardened product of an epoxy resin composition containing an epoxy resin, a curing agent, and a carbodiimide-modified soluble polyamide; and
the epoxy resin contains a naphthalene skeleton-containing epoxy resin.
3. The flexible printed wiring board as set forth in claim 1 , wherein a content of the carbodiimide-modified soluble polyamide in the epoxy resin composition is in the range of 40 to 70 mass %.
4. The flexible printed wiring board as set forth in claim 1 , wherein the naphthalene skeleton-containing epoxy resin contains at least one compound selected from compounds represented by the following formulae (1) to (3):
5. The flexible printed wiring board as set forth in claim 1 , wherein the curing agent contains at least one of dicyandiamide and aminotriazine novolac resins represented by the following formula (4):
6. The flexible printed wiring board as set forth in claim 1 , wherein the carbodiimide-modified soluble polyamide contains a reaction product of 100 parts by mass of a soluble polyamide and 0.5 to 20 parts by mass of a carbodiimide compound.
7. The flexible printed wiring board as set forth in claim 1 , wherein the epoxy resin composition contains a phenoxy resin.
8. The flexible printed wiring board as set forth in claim 1 , wherein the epoxy resin composition contains at least one compound selected from phosphorus-modified epoxy resins, phosphorus-modified phenoxy resins, and phosphorus-based flame retardants.
9. The flexible printed wiring board as set forth in claim 1 , wherein a through hole is formed in the first insulating layer and part of the second insulating layer fills the through hole.
10. A laminate for production of a flexible printed wiring board comprising:
a first insulating layer that is flexible,
a first conductor wiring laminated on the first insulating layer,
a second insulating layer that is a single layer and laminated on the first insulating layer, as it covers the first conductor wiring, and
a metal foil laminated on the second insulating layer, wherein
the first conductor wiring has a thickness in the range of 10 to 30 μm, a line width in the range of 50 μm to 1 mm, and a line gap in the range of 50 μm to 1 mm;
a thickness from a surface of the first conductor wiring to a surface of the second insulating layer is in the range of 5 to 30 μm;
a surface waviness of part of the second insulating layer covering the first conductor wiring is 10 μm or less;
the second insulating layer is made of a hardened product of an epoxy resin composition containing an epoxy resin, a curing agent, and a carbodiimide-modified soluble polyamide; and
the epoxy resin contains a naphthalene skeleton-containing epoxy resin.
11. A laminate for production of a flexible printed wiring board comprising
a first insulating layer that is flexible,
a first conductor wiring laminated on the first insulating layer,
a second insulating layer that is laminated on the first insulating layer, as it covers the first conductor wiring, and
a metal foil laminated on the second insulating layer, wherein
the second insulating layer includes a third insulating layer directly laminated on the first insulating layer and a fourth insulating layer laminated on the third insulating layer;
the first conductor wiring has a thickness in the range of 10 to 30 μm, a line width in the range of 50 μm to 1 mm, and a line gap in the range of 50 μm to 1 mm;
a thickness from a surface of the first conductor wiring to a surface of the third insulating layer, among the multiple layers constituting the second insulating layer, is in the range of 5 to 30 μM;
a surface waviness of part of the second insulating layer covering the first conductor wiring is 10 μm or less;
the third insulating layer is made of a hardened product of an epoxy resin composition containing an epoxy resin, a curing agent, and a carbodiimide-modified soluble polyamide; and
the epoxy resin contains a naphthalene skeleton-containing epoxy resin.
12. The flexible printed wiring board as set forth in claim 2 , wherein a content of the carbodiimide-modified soluble polyamide in the epoxy resin composition is in the range of 40 to 70 mass %.
13. The flexible printed wiring board as set forth in claim 2 , wherein the naphthalene skeleton-containing epoxy resin contains at least one compound selected from compounds represented by the following formulae (1) to (3):
14. The flexible printed wiring board as set forth in claim 2 , wherein the curing agent contains at least one of dicyandiamide and aminotriazine novolac resins represented by the following formula (4):
15. The flexible printed wiring board as set forth in claim 2 , wherein the carbodiimide-modified soluble polyamide contains a reaction product of 100 parts by mass of a soluble polyamide and 0.5 to 20 parts by mass of a carbodiimide compound.
16. The flexible printed wiring board as set forth in claim 2 , wherein the epoxy resin composition contains a phenoxy resin.
17. The flexible printed wiring board as set forth in claim 2 , wherein the epoxy resin composition contains at least one compound selected from phosphorus-modified epoxy resins, phosphorus-modified phenoxy resins, and phosphorus-based flame retardants.
18. The flexible printed wiring board as set forth in claim 2 , wherein a through hole is formed in the first insulating layer and part of the second insulating layer fills the through hole.