WIRING BOARD AND WIRING BOARD MANUFACTURING METHOD

• US 20090314528A1
• Filed: 06/17/2009
• Published: 12/24/2009
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Gokan, Manabu, Hirose, Takayuki, Tsukahara, Norihito
• Granted Patent: US 8,237,057 B2
• Time in Patent Office: Days
• US Class Current: 174/256
• CPC Class Codes: H05K 1/0265 characterized by the lay-out of or details of the printed conductors, e.g. reinforced conductors, redundant conductors, conductors having different cross-sections
• 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 1/0272 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 2201/0116 Porous, e.g. foam
• 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 2201/0352 Differences between the conductors of different layers of a multilayer
• CPC Class Codes: H05K 2201/0391 Using different types of conductors
• CPC Class Codes: H05K 2201/068 wherein the coefficient of thermal expansion is important
• CPC Class Codes: H05K 2201/09036 Recesses or grooves in insulating substrate
• CPC Class Codes: H05K 2201/09136 Means for correcting warpage
• CPC Class Codes: H05K 2201/096 Vertically aligned vias, holes or stacked vias
• CPC Class Codes: H05K 2201/09727 Varying width along a single conductor; Conductors or pads having different widths
• CPC Class Codes: H05K 2203/013 Inkjet printing, e.g. for printing insulating material or resist
• CPC Class Codes: H05K 2203/0769 Dissolving insulating materials, e.g. coatings, not used for developing resist after exposure
• CPC Class Codes: H05K 3/1208 Pretreatment of the circuit board, e.g. modifying wetting properties; Patterning by using affinity patterns providing shape patterns H05K3/1258; adhesion treatments H05K3/38
• CPC Class Codes: H05K 3/125 by ink-jet printing
• CPC Class Codes: H05K 3/205 using a pattern electroplated or electroformed on a metallic carrier
• CPC Class Codes: H05K 3/386 by the use of an organic polymeric bonding layer, e.g. adhesive
• CPC Class Codes: H05K 3/4069 for via connections in organic insulating substrates
• CPC Class Codes: H05K 3/4602 : characterized by a special circuit board as base or central core whereon additional circuit layers are built or additional circuit boards are laminated
• CPC Class Codes: H05K 3/4664 : Adding a circuit layer by thick film methods, e.g. printing techniques or by other techniques for making conductive patterns by using pastes, inks or powders H05K3/4647 takes precedence
• CPC Class Codes: H05K 3/4697 : having cavities, e.g. for mounting components H05K3/4691 takes precedence
• CPC Class Codes: Y10S 977/773 : Nanoparticle, i.e. structure having three dimensions of 100 nm or less

Abstract

A wiring board is provided that suppresses spreading of liquid droplets when liquid droplets are discharged using an ink-jet method. The wiring board has a plurality of layers and includes an ink-jet wiring pattern that is formed in a soluble porous membrane member of any single layer and that includes electrically conductive nanoparticles as a principal material, and a transferred wiring pattern that does not include electrically conductive nanoparticles as a principal material. One layer among the plurality of layers is an electrically insulative substrate. Another layer among the plurality of layers is a porous membrane treated member layer including a porous membrane member at one part of a region of the other layer. The ink-jet wiring pattern is formed in the porous membrane treated member layer. The transferred wiring pattern is formed in the substrate.

Claims

1. A wiring board that has a single layer or a plurality of layers, comprising:

a first wiring pattern that includes electrically conductive nanoparticles as a principal material and is formed in a soluble porous membrane member of any single layer; and

a second wiring pattern that does not include the electrically conductive nanoparticles as a principal material.

2. The wiring board according to claim 1, wherein:

a single layer among the plurality of layers is an electrically insulative substrate;

an another single layer among the plurality of layers is a porous membrane member layer that includes the porous membrane member in all or one part of a region of the another single layer;

the first wiring pattern is formed in the porous membrane member layer; and

the second wiring pattern is formed on at least any one surface of the substrate.

3. The wiring board according to claim 2, wherein the porous membrane member layer is disposed on a surface of the substrate or on a surface of a different other single layer among the plurality of layers, on which the second wiring pattern is not formed.

4. The wiring board according to claim 2, wherein the porous membrane member layer is disposed on a surface of the substrate on which the second wiring pattern is formed.

5. The wiring board according to claim 3, wherein:

the porous membrane member layer is disposed on a surface of a different other single layer among the plurality of layers, on which the second wiring pattern is not formed;

a different other single layer among the plurality of layers is formed by a film substrate that is formed with an organic film;

the porous membrane member layer is disposed on one surface of the film substrate;

the substrate is disposed on another surface of the film substrate; and

the second wiring pattern is formed on a surface of the substrate on an opposite side to the film substrate.

6. The wiring board according to claim 4, wherein:

a different other single layer among the plurality of layers is an electrically insulative substrate that is provided adjoining the substrate or is provided in a condition in which one or a plurality of layers are sandwiched between the different other single layer and the substrate; and

a further different other single layer among the plurality of layers is a porous membrane member layer that includes a porous membrane member in all or a part of a region of the further different other single layer;

the wiring board further comprising;

a first wiring pattern formed in a porous membrane member layer that is the further different other single layer; and

a second wiring pattern that is formed in a substrate that is the different other single layer;

wherein the two porous membrane member layers are disposed so as to sandwich the two substrates.

7. The wiring board according to claim 6, wherein, to suppress warpage caused by temperature fluctuations, the two porous membrane member layers include porous membrane members for which coefficients of thermal expansion are different.

8. The wiring board according to claim 2, wherein:

the wiring board is bent around a bending section; and

the porous membrane member layer is formed using the porous membrane member that is provided at parts excluding a vicinity of the bending section.

9. The wiring board according to claim 1, wherein:

the second wiring pattern is formed in an identical layer to the first wiring pattern; and

the identical layer is formed by the porous membrane member.

10. The wiring board according to claim 1, wherein:

the second wiring pattern is formed in an identical layer to the first wiring pattern;

the identical layer is formed by an electrically insulative substrate;

the second wiring pattern is provided in the substrate so that a surface thereof and a surface of the substrate are positioned on a substantially same plane; and

the first wiring pattern is formed in the porous membrane member that is disposed in a concave section provided in a surface of the substrate.

11. The wiring board according to claim 2, wherein a different other single layer among the plurality of layers is formed by an ultraviolet-curing resin.

12. The wiring board according to claim 2, wherein all or a part of the first wiring pattern is used as an interlayer connection via that electrically connects wiring patterns formed in two layers that sandwich the porous membrane member layer.

13. The wiring board according to claim 2, wherein a predetermined number of layers that are adjacently disposed among the plurality of layers are the porous membrane member layer.

14. The wiring board according to claim 13, wherein at least one part of wiring portions of first wiring patterns in the predetermined number of porous membrane member layers that are adjacently disposed are formed so that centers in a width direction of the wiring portions are positioned on a substantially same straight line.

15. The wiring board according to claim 14, wherein widths of the wiring portions that are formed in the respective porous membrane member layers are substantially the same.

16. The wiring board according to claim 14, wherein:

widths of the wiring portions between the porous membrane member layers that are adjacent are formed so as to be substantially the same or to become larger in a direction from a first predetermined porous membrane member layer towards a second predetermined porous membrane member layer among the predetermined number of porous membrane member layers;

a width of the wiring portion that is formed in a third predetermined porous membrane member layer that is disposed adjoining a surface opposite the first predetermined porous membrane member layer side of the second predetermined porous membrane member layer is not more than a width of the wiring portion formed in the first predetermined porous membrane member layer; and

widths of the wiring portions between the porous membrane member layers that are adjoining are formed so as to be substantially the same or to become larger in a direction from the third predetermined porous membrane member layer towards a fourth predetermined porous membrane member layer that is disposed on an opposite side to the second predetermined porous membrane member layer.

17. The wiring board according to claim 13, wherein a cavity is formed in at least any one porous membrane member layer among the predetermined number of porous membrane members.

18. The wiring board according to claim 17, wherein the cavity is formed adjacent to one part of wiring portions of the first wiring pattern.

19. The wiring board according to claim 18, wherein:

at least one part of wiring portions of a first wiring pattern in the predetermined number of porous membrane member layers that are adjacently disposed are formed so that centers in a width direction of the wiring portions are positioned on a substantially same straight line;

the one part of wiring portions of the first wiring pattern to which the cavity is adjacent is the one part of wiring portions of a first wiring pattern that are formed so that centers in the width direction are positioned on a substantially same straight line;

a width of the wiring portions to which the cavity is adjacent is smaller than a width of the wiring portion formed in at least one porous membrane member layer that is adjacent to a porous membrane member layer in which the cavity is formed; and

the cavity is also adjacent to the wiring portion formed in the at least one porous membrane member layer that is adjacent.

20. The wiring board according to claim 1, wherein the second wiring pattern is formed in a layer such that a surface thereof and a surface of the layer in which the second wiring pattern is formed are positioned on a substantially same plane.

21. The wiring board according to claim 1, wherein the second wiring pattern is formed so that a surface thereof protrudes from a surface of a layer in which the second wiring pattern is formed.

22. The wiring board according to claim 1, wherein the porous membrane member includes polyamide-imide or polyetherimide as a principal component.

23. The wiring board according to claim 1, wherein the electrically conductive nanoparticles are nanoparticles of a material selected from the group consisting of gold, silver, and copper.

24. The wiring board according to claim 1, wherein:

the first wiring pattern has at least a first electrically conductive nanoparticle layer and a second electrically conductive nanoparticle layer;

the first electrically conductive nanoparticle layer occupies all or a part of a thickness direction of the porous membrane member; and

the second electrically conductive nanoparticle layer is positioned on the porous membrane member.

25. A method of manufacturing a wiring board that has a single layer or a plurality of layers, comprising:

a first wiring pattern formation step which discharges a material including electrically conductive nanoparticles as a principal material onto a soluble porous membrane member using an ink-jet method to form a first wiring pattern on any one layer; and

a second wiring pattern formation step which forms a second wiring pattern using a material that does not include the electrically conductive nanoparticles as a principal material.

26. The method of manufacturing a wiring board according to claim 25, wherein:

a single layer among the plurality of layers is an electrically insulative substrate;

the second wiring pattern formation step is a transfer step which transfers the second wiring pattern onto the substrate using a transfer material that has the second wiring pattern; and

a surface of the second wiring pattern becomes positioned on a substantially same plane as a surface of the substrate.

27. The method of manufacturing a wiring board according to claim 25, further comprising:

a treatment step of treating the porous membrane member with a predetermined solution after forming the first wiring pattern, to thereby reduce a thickness of the porous membrane member.

28. The method of manufacturing a wiring board according to claim 27, wherein:

the porous membrane member includes polyamide-imide or polyetherimide as a principal component; and

the predetermined solution is N-methyl-2-pyrrolidinone.