Shock-resistive printed circuit board and electronic device including the same

• US 6,274,821 B1
• Filed: 09/15/1999
• Issued: 08/14/2001
• Est. Priority Date: 09/16/1998
• Status: Expired due to Term

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nomoto, Kaoru, Echigo, Masashi, Suzuki, Tadao, Aoyama, Masayuki
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): PATEL, ISHWARBHAI B
• Application Number:
  US09/396,426
• Time in Patent Office: 699 Days
• Field of Search: 174/255, 174/256, 174/258, 174/260, 174/262, 361/760, 361/762, 361/783, 257/702, 257/738, 257/778, 257/779, 428/209, 428/901, 428/416, 428/418
• US Class Current: 174/255
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/113 Via provided in pad; Pad over filled via
• CPC Class Codes: H05K 2201/0133 Elastomeric or compliant polymer
• 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 3/285 Permanent coating compositions
• CPC Class Codes: H05K 3/4644 by building the multilayer layer by layer, i.e. build-up multilayer circuits making via holes in the insulating layers H05K3/0011; special circuit boards as base or core whereon the multilayer is built H05K3/4602
• CPC Class Codes: H05K 3/465 by applying an insulating layer having channels for the next circuit layer
• CPC Class Codes: H05K 3/4676 Single layer compositions
• CPC Class Codes: H05K 3/4688 Composite multilayer circuits, i.e. comprising insulating layers having different properties having a special base or central core H05K3/4602
• CPC Class Codes: Y10S 428/901 Printed circuit

Abstract

A printed circuit board has a layer including a resin material, which has a tensile breaking strain of approximately 1% or more at a tensile strain rate of 40%/sec at 25° C., and an Izod impact strength of approximately 1 kgf·cm/cm or more at 25° C. Otherwise, the resin material has a peak value of dynamic loss tangent of 0.05 or more in a range of −100° C. to −50° C. by β relaxation, and a peak value of dynamic loss tangent of 0.02 or more in a range of 0° C. to 100° C. by β′ relaxation in a dynamic viscoelasticity spectral measurement. Accordingly, thermal shock resistance and drop shock resistance of the printed circuit board can be improved.

Claims

1. A printed circuit board comprising a layer including a resin material, a tensile breaking strain of which is approximately 1% or more at a tensile strain rate of 40%/sec at 25°

C.

2. The printed circuit board of claim 1, further comprising:

a plurality of insulation layers laminated with one another; and

a wiring pattern arranged in the plurality of insulation layers,

wherein the resin material is included in an uppermost layer of the plurality of insulation layers.

3. The printed circuit board of claim 1, wherein the layer is a soldering resist layer exposed on a surface of the printed circuit board.

4. The printed circuit board of claim 3, wherein:

the soldering resist layer is disposed on a structure composed of a plurality of laminated insulation layers; and

the resin material is included only in the soldering resist layer.

5. The printed circuit board of claim 1, wherein the resin material has an Izod impact strength of approximately 1 kgf·

cm/cm or more at 25°

C.

6. The printed circuit board of claim 1, wherein the layer includes fillers at a percentage content of approximately 10 wt % or less, the fillers having an elastic modulus of approximately 1 GPa or more.

7. A printed circuit board comprising a layer including a resin material at a percentage content of approximately 80 wt % or more, the resin material having a peak value of dynamic loss tangent of 0.05 or more in a range of −

100°

C. to −

50°

C. by β

relaxation, and a peak value of dynamic loss tangent of 0.02 or more in a range of 0°

C. to 100°

C. by β

′

relaxation in a dynamic viscoelasticity spectral measurement.

8. The printed circuit board of claim 7, wherein the percentage content of the resin material in the layer is approximately 90 wt % or more.

9. The printed circuit board of claim 7, further comprising:

a plurality of insulation layers laminated with one another; and

a wiring pattern arranged in the plurality of insulation layer,

wherein the resin material is included in an uppermost layer of the plurality of insulation layers.

10. The printed circuit board of claim 7, wherein the layer is a soldering resist layer exposed on a surface of the printed circuit board.

11. The printed circuit board of claim 7, wherein the layer incudes fillers at a percentage content of approximately 10 wt % or more, the fillers having an elastic modulus of approximately 1 GPa or more.

12. A printed circuit board comprising a layer formed from a resin main component, a molecule of which has a side chain including a functional group and branching from a main chain.

13. The printed circuit board of claim 12, wherein the layer is formed from a setting agent, a molecule of which has an acid anhydride structure at an end of a main chain thereof.

14. The printed circuit board of claim 12, wherein the layer is formed from a setting agent, a molecule of which has a side chain including a functional group and branching from a main chain.

15. The printed circuit board of claim 14, wherein:

the layer including a resin material formed from the resin main component and the setting agent is exposed on a surface of the printed circuit board; and

the resin material has a tensile breaking strain of approximately 1% or more at a tensile strain rate of 40%/sec at 25°

C.

16. The printed circuit board of claim 15, wherein the resin material has an Izod impact strength of approximately 1 kgf·

cm/cm or more at 25°

C.

17. The printed circuit board of claim 14, wherein the layer includes fillers at a percentage content of approximately 10 wt % or less, the fillers having an elastic modulus of approximately 1 GPa or more.

18. The printed circuit board of claim 14, wherein:

the layer includes a resin material formed from the resin main component and the setting agent at a parentage content of 80 wt % or more, and is exposed on a surface of the printed circui board; and

the resin material has a peak value of dynamic loss tangent of 0.05 or more in a range of −

100°

C. to −

50°

C. by β

relaxation, and a peak value of dynamic loss tangent of 0.02 or more in a range of 0°

C. to 100°

C. by β

′

relaxation in a dynamic viscoelasticity spectral measurement.

19. The printed circuit board of claim 12, wherein the layer has a network structure in which a side chain including a functional group branches from a main chain.

20. The printed circuit board of claim 19, wherein a bridging point of main chains has at least two side chains branching therefrom in the network structure.

21. The printed circuit board of claim 12, wherein the molecule of the resin main component includes two glycidyl groups connected to each other through at least 30 carbon atoms forming the main chain.

22. A printed circuit board comprising a layer formed from a setting agent, a molecule of which has a side chain branching from a main chain and including a functional group, the layer being exposed on a surface of the printed circuit board.

23. The printed circuit board of claim 22, wherein the layer is formed from the resin main component having a molecule including two glycidyl groups connected to each other.

24. The printed circuit board of claim 23, wherein the resin main component and the setting agent forms a network structure in the layer, the network structure including a plurality of bridging points of main chains, the plurality of bridging points each having at least two side chains branching therefrom.

25. An electronic device comprising:

a printed circuit board including;

a plurality of insulation layers laminated with each other;

a wiring pattern arranged in the plurality of insulation layers; and

a layer disposed on the plurality of insulation layers to be exposed on a surface of the printed circuit board and including a resin material, the resin material having one of first and second features, the first feature being that a tensile strain of the resin material is approximately 1% or more at a tensile strain rate of 40%/sec at 25°

C., the second feature being that the resin material has a peak value of dynamic loss tangent of 0.05 or more in a range of −

100°

C. to −

50°

C. by β

relaxation, and a peak value of dynamic loss tangent of 0.02 or more in a range of 0°

C. to 100°

C. by β

′

relaxation in a dynamic viscoelasticity spectral measurement; and

an electronic part disposed on the printed circuit board to be electrically connected to the wiring pattern.

26. The electronic device of claim 25, wherein:

the printed circuit board has a bump disposed on the plurality of insulation layers for electrically connecting the electronic part and the wiring pattern; and

the layer exposed on the surface of the printed circuit board is a soldering resist layer.

27. The electronic device of claim 25, wherein the layer exposed on the surface of the printed circuit board is an insulation layer laminated with the plurality of insulation layers.

28. The electronic device of claim 25, wherein the resin material of the layer has a network structure including a plurality of side chains branching from a plurality of main chains.

29. An electronic device comprising:

a printed circuit board including;

a plurality of insulation layers laminated with each other;

a wiring pattern arranged in the plurality of insulation layers; and

a layer disposed on the plurality of insulation layers to be exposed on a surface of the printed circuit board and including a resin material, the resin material having a network structure having a plurality of bridging points of main chains, the plurality of bridging points each having at least two side chains branching therefrom; and

an electronic part disposed on the printed circuit board to be electrically connected to the wiring pattern.