Flexible multilayer wiring board

• US 6,459,044 B2
• Filed: 07/16/2001
• Issued: 10/01/2002
• Est. Priority Date: 07/21/2000
• Status: Expired due to Fees

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Watanabe, Yasushi, Shinano, Kenichi
• Primary Examiner(s): LAM, CATHY FONG FONG
• Application Number:
  US09/907,004
• Publication Number:
  US 20020009578A1
• Time in Patent Office: 442 Days
• Field of Search: 174/254, 174/261, 174/262, 174/255, 428/209
• US Class Current: 174/254
• CPC Class Codes: B32B 3/00 Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
• CPC Class Codes: H05K 1/0272 Adaptations for fluid transport, e.g. channels, holes
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 2201/0195 Dielectric or adhesive layers comprising a plurality of layers, e.g. in a multilayer structure
• CPC Class Codes: H05K 2201/09063 Holes or slots in insulating substrate not used for electrical connections
• CPC Class Codes: H05K 2201/10477 Inverted
• CPC Class Codes: H05K 2203/1178 Means for venting or for letting gases escape
• CPC Class Codes: H05K 2203/1461 Applying or finishing the circuit pattern after another process, e.g. after filling of vias with conductive paste, after making printed resistors
• CPC Class Codes: H05K 2203/1572 Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
• CPC Class Codes: H05K 3/28 Applying non-metallic protective coatings H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673
• CPC Class Codes: H05K 3/321 by conductive adhesives
• CPC Class Codes: H05K 3/361 Assembling flexible printed circuits with other printed circuits
• CPC Class Codes: H05K 3/4069 for via connections in organic insulating substrates
• CPC Class Codes: H05K 3/4623 the circuit boards having internal via connections between two or more circuit layers before lamination, e.g. double-sided circuit boards H05K3/462 takes precedence
• CPC Class Codes: H05K 3/4626 characterised by the insulating layers or materials H05K3/4688 takes precedence
• CPC Class Codes: H05K 3/4635 laminating flexible circuit boards using additional insulating adhesive materials between the boards
• CPC Class Codes: Y10T 428/24917 including metal layer

Abstract

In a flexible multilayer wiring board, a first conductive pattern provided on a first flexible base material and a second conductive pattern provided on a second flexible base material are made to conduct via a first conductive body filled in a first through hole. Hereby, a flexible multilayer wiring board of which the productivity is satisfactory, which is low-priced and highly reliable in connection can be provided.

Claims

1. A flexible multilayer wiring board, comprising:

first and second flexible base materials, each having a bonded surface bonded with an adhesive and an unbonded surface; and

a first conductive body that electrically connects a first conductive pattern formed on the unbonded surface of the first flexible base material and a second conductive pattern formed on the second flexible base material, wherein;

the first flexible base material is provided with a first through hole and the first conductive body is provided in the first through hole;

space is provided between the bonded surface of the first flexible base material and the bonded surface of the second flexible base material in the periphery of the first through hole;

a conductive paste forming the first conductive body is filled in the space through the first through hole;

an air path via which air in the space can escape is provide between the first and second flexible base materials, wherein no adhesive is formed in said air path.

2. A flexible multilayer wiring board according to claim 1, wherein an air port of the air path is provided at the peripheral end of at least one of the first flexible base material and the second flexible base material.

3. A flexible multilayer wiring board according to claim 1, wherein an air port of the air path is provided to a mounting hole provided to mount the first and second flexible base materials.

4. A flexible multilayer wiring board according to claim 1, wherein:

the second conductive pattern is formed on the side of the bonded surface of the second flexible base material; and

the first conductive body is touched to at least a part of the second conductive pattern.

5. A flexible multilayer wiring board according to claim 1, wherein:

the second conductive pattern is formed on the side of the unbonded surface of the second flexible base material;

a second through hole is provided in a position opposite to the first through hole in the second flexible base material;

a second conductive body is filled in the second through hole; and

the first and second conductive patterns conduct via the second conductive body.

6. A flexible multilayer wiring board according to claim 1, wherein the first conductive body is formed by the screen printing of conductive paste.

7. A flexible multilayer wiring board according to claim 1, wherein:

insulating resist layers are respectively provided on the side of the bonded surface of the first and second flexible base materials; and

these resist layers are bonded via the adhesive.