Printed circuit board assembly having adhesive layer

• US 7,728,232 B2
• Filed: 12/26/2007
• Issued: 06/01/2010
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: Avary Holding (Shenzhen) Co., Limited., Garuda Technology Co., Ltd.
• Original Assignee: Foxconn Advanced Technology Inc., Fukui Precision Component Company Limited (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Huang, Feng-Yan, Liou, Shing-Tza
• Primary Examiner(s): LAM, CATHY FONG FONG
• Application Number:
  US11/964,578
• Publication Number:
  US 20090035566A1
• Time in Patent Office: 888 Days
• Field of Search: 428/40, 428343-356, 174/255, 174/254, 174/257, 174/258, 361/749, 361/750
• US Class Current: 174/254
• CPC Class Codes: C09J 2301/21 the adhesive layer being formed by alternating adhesive areas of different nature
• CPC Class Codes: C09J 2301/302 the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C
• CPC Class Codes: C09J 2433/00 Presence of (meth)acrylic polymer
• CPC Class Codes: C09J 7/10 without carriers
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 2201/0187 with regions of different dielectrics in the same layer, e.g. in a printed capacitor for locally changing the dielectric properties
• CPC Class Codes: H05K 2201/055 Folded back on itself
• CPC Class Codes: H05K 2201/056 Folded around rigid support or component
• CPC Class Codes: H05K 2201/10378 Interposers
• CPC Class Codes: H05K 2201/2009 Reinforced areas, e.g. for a specific part of a flexible printed circuit
• CPC Class Codes: H05K 3/0058 Laminating printed circuit boards onto other substrates, e.g. metallic substrates H05K1/0281 takes precedence
• CPC Class Codes: H05K 3/323 by applying an anisotropic conductive adhesive layer over an array of pads
• CPC Class Codes: H05K 3/386 by the use of an organic polymeric bonding layer, e.g. adhesive
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2848 Three or more layers
• CPC Class Codes: Y10T 428/2857 including metal or compound thereof or natural rubber

Abstract

An exemplary adhesive layer includes an adhesive main body having a first adhesive surface and a second adhesive surface on an opposite side of the adhesive main body to the first adhesive surface. The adhesive main body defines a number of through-holes between the first adhesive surface and the second adhesive surface therein. The through-holes are filled with an inner adhesive that has a higher adhesion than the adhesive main body. Adhesiveness of the first adhesive surface and the second adhesive surface of the adhesive main body can be improved, thereby preventing a printed circuit board having the adhesive layer from distortion.

Claims

1. A printed circuit board assembly, comprising:

a first portion, a second portion and an adhesive layer interposed between the first portion and the second portion, the adhesive layer comprising an adhesive main body having a first adhesive surface and a second adhesive surface on an opposite side of the adhesive main body to the first adhesive surface, the adhesive main body defining a plurality of through-holes between the first adhesive surface and the second adhesive surface, the through-holes being filled with an inner adhesive that has a higher adhesion than the adhesive main body, the inner adhesive being a fast drying, acrylic adhesive.

2. The printed circuit board assembly as claimed in claim 1, wherein the fast drying, acrylic adhesive comprises a plurality of electrically conductive particles.

3. The printed circuit board assembly as claimed in claim 1, wherein the adhesive main body is comprised of a pressure sensitive adhesive.

4. The printed circuit board assembly as claimed in claim 3, wherein the adhesive main body comprises a plurality of electrically conductive particles.

5. The printed circuit board assembly as claimed in claim 1, wherein each of the through-holes has a configuration of a dumbbell shaped cross-section taken normal to the first adhesive surface.

6. The printed circuit board assembly as claimed in claim 1, further comprising a bending portion interconnecting the first portion and the second portion, the bending portion, the first portion, and the second portion being respective portions of a flexible printed circuit board.

7. The printed circuit board assembly as claimed in claim 1, further comprising a stiffener interposed between the first portion and the second portion, wherein the stiffener is adhered to the first portion and the second portion via respective portions of the adhesive layer.

8. The printed circuit board assembly as claimed in claim 1, wherein the through-holes are exposed at the first and second adhesive surfaces, one end of the inner adhesive is exposed at the first adhesive surface and is in contact with the second portion, and another end of the inner adhesive is exposed at the second adhesive surface and is in contact with the first portion.

9. The printed circuit board assembly as claimed in claim 1, further comprising a stiffener and another adhesive layer, wherein said adhesive layer is interposed between and in contact with the first portion and the stiffener, said another adhesive layer is interposed between and in contact with the second portion and the stiffener, and the stiffener is interposed between and in contact with the two adhesive layers.

10. A printed circuit board assembly, comprising:

a first portion, a second portion and an adhesive layer interposed between the first portion and the second portion, the adhesive layer comprising an adhesive main body having a first adhesive surface and a second adhesive surface on an opposite side of the adhesive main body to the first adhesive surface, the adhesive main body defining a plurality of through-holes between the first adhesive surface and the second adhesive surface, the through-holes being filled with an inner adhesive that has a higher adhesion than the adhesive main body, the adhesive main body comprising a pressure sensitive adhesive comprising a plurality of electrically conductive particles.

11. The printed circuit board assembly as claimed in claim 10, further comprising a bending portion interconnecting the first portion and the second portion, the bending portion, the first portion, and the second portion being respective portions of a flexible printed circuit board.

12. The printed circuit board assembly as claimed in claim 10, further comprising a stiffener interposed between the first portion and the second portion, wherein the stiffener is adhered to the first portion and the second portion via respective portions of the adhesive layer.

13. A printed circuit board assembly, comprising:

a first portion, a second portion and an adhesive layer interposed between the first portion and the second portion, the adhesive layer comprising an adhesive main body having a first adhesive surface and a second adhesive surface on an opposite side of the adhesive main body to the first adhesive surface, the adhesive main body defining a plurality of through-holes between the first adhesive surface and the second adhesive surface, the through-holes being filled with an inner adhesive that has a higher adhesion than the adhesive main body; and

a stiffener and another adhesive layer, wherein said adhesive layer is interposed between the first portion and the stiffener, said another adhesive layer is interposed between the second portion and the stiffener, and the stiffener is interposed between the two adhesive layers.

14. The printed circuit board assembly as claimed in claim 13, wherein said adhesive layer is in contact with the first portion and the stiffener, said another adhesive layer is in contact with the second portion and the stiffener, and the stiffener is in contact with the two adhesive layers.

15. The printed circuit board assembly as claimed in claim 13, wherein the through-holes are exposed at the first and second adhesive surfaces, one end of the inner adhesive is exposed at the first adhesive surface and is in contact with the first portion, and another end of the inner adhesive is exposed at the second adhesive surface and is in contact with the stiffener.

16. The printed circuit board assembly as claimed in claim 13, further comprising a bending portion interconnecting the first portion and the second portion, the bending portion being in contact with a side surface of the stiffener and side surfaces of the two adhesive layers, each of the bending portion, the first portion, and the second portion being a portion of a flexible printed circuit board.

17. The printed circuit board assembly as claimed in claim 13, wherein the stiffener is one of a copper clad laminate sheet, a metal sheet, and a polyimide sheet.

18. The printed circuit board assembly as claimed in claim 13, wherein said another adhesive layer comprises another adhesive main body defining a second plurality of through-holes therein, and said second plurality of through-holes are filled with another inner adhesive that has a higher adhesion than said another adhesive main body.

19. The printed circuit board assembly as claimed in claim 18, wherein each adhesive main body is an electrically conductive pressure sensitive adhesive.

20. The printed circuit board assembly as claimed in claim 18, wherein each inner adhesive is an acrylic adhesive.