Anisotropic conductive film, production method thereof, and display apparatus using anisotropic film

• US 6,680,517 B2
• Filed: 08/23/2001
• Issued: 01/20/2004
• Est. Priority Date: 08/23/2000
• Status: Expired due to Fees

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Namba, Kenryo
• Primary Examiner(s): Pham, Long
• Assistant Examiner(s): Rao, Shrinivas H
• Application Number:
  US09/934,835
• Publication Number:
  US 20020071077A1
• Time in Patent Office: 880 Days
• Field of Search: 349/12, 345/173, 345/174, 298/30, 298/43, 298/46, 298/40, 298/52, 174/140.C, 174/141.C, 252/514, 252/499, 257/508, 257/501
• US Class Current: 257/499
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/133348 Charged particles addressed liquid crystal cells, e.g. controlled by an electron beam
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: Y10T 29/49126 Assembling bases
• CPC Class Codes: Y10T 29/49144 by metal fusion
• CPC Class Codes: Y10T 29/49149 by metal fusion bonding
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

An anisotropic conductive film which can be appropriately applied for the display apparatus by which the user can directly write characters•figures on the display, or erase characters and figures displayed on the display. The anisotropic conductive film according to the present invention is provided with the transparent insulating film 19 having a plurality of through holes 20 penetrating from one surface to the other surface, transparent conductive particle 21 buried in the through holes 20, and transparent stuffing material 22 stuffed in the void of the through holes 20 in which the conductive particle 21 is buried.

Claims

1. An anisotropic conductive film comprising:

an insulating film comprising two surfaces and having a plurality of through holes penetrating from one surface to the other surface; and

a conductive material which is in the through holes and which builds up the conductivity from the one surface to the other surface of the insulating film,

wherein both the insulating film and the conductive material are practically transparent;

the diameter of said through holes is about 30 μ

m-about 500 μ

m, and the interval between adjoining through holes is about 30 μ

m to about 100 μ

m.

2. An anisotropic conductive film according to claim 1, wherein the conductive material comprises conductive particles and a stuffing material stuffed in a void of the through hole in which the conductive particles are buried.

3. An anisotropic conductive film according to claim 2, wherein, for materials constituting the insulating film, conductive particles and stuffing material, the difference of the refractive indices between the material whose refractive index is the highest to visible light, and the material whose refractive index is the lowest, is within 0.5.

4. An anisotropic conductive film according to claim 2, wherein the refractive index to visible light of the material constituting the stuffing material is between the refractive index to visible light of the material constituting the insulating film and the refractive index to visible light of the material constituting the conductive particles.

5. An anisotropic conductive film according to claim 2, wherein the conductive particles are porous.

6. An anisotropic conductive film according to claim 2, wherein the conductive particles comprise at least one selected from the group consisting of:

indium oxide to which tin oxide is added (ITO);

indium oxide to which tungsten oxide is added (IMO);

tin oxide to which antimony oxide is added (ATO);

tin oxide to which fluorine is added (FTO);

tin oxide to which antimony oxide and fluorine are added AFTO);

tin oxide to which cadmium oxide is added (CTO);

zinc oxide (ZnO₂); and

zinc antimonic acid (ZnO.Sb₂O₅).

7. An anisotropic conductive film according to claim 1, wherein an opening area of one end of the through holes and an opening area of the other end thereof are different from each other.

11. A display apparatus comprising:

a common electrode;

a transparent anisotropic conductive film according to claim 1;

a display substance layer provided between the common electrode and the transparent anisotropic conductive film; and

a drawing means by which, by abrading the surface of the transparent anisotropic conductive film, an electric field is given between the common electrode and the transparent anisotropic conductive film, in the abraded portion.

12. A display apparatus according to claim 11, wherein the display substance layer is comprised of an electrophoresis layer in which at least an electrophoresis particle is filled.

13. A display apparatus according to claim 11, wherein the display substance layer is composed of a liquid crystal layer in which at least the liquid crystal is filled.

14. An anisotropic conductive film according to claim 3, wherein the conductive particles are porous.

15. An anisotropic conductive film according to claim 3, wherein the diameter of the particles is from 0.1 μ

m to 5 μ

m.

16. An anisotropic conductive film according to claim 2, wherein said stuffing material is a polymer.

17. An anisotropic conductive film according to claim 6, wherein said stuffing material is a polymer.

18. An anisotropic conductive film according to claim 17, wherein said polymer is selected from the group consisting of polyvinyl naphthalene, polymethacrylate α

-napthyl, polystyrene, styrene-maleic anhydride copolymer, styrene-acrylonitrile copolymer, polycyclohexyl methacrylate, and polymethyl methacrylate.

19. A display apparatus comprising:

a common electrode;

a transparent anisotropic conductive film according to claim 2;

a display substance layer provided between the common electrode and the transparent anisotropic conductive film; and

a drawing means by which, by abrading the surface of the transparent anisotropic conductive film, an electric field is given between the common electrode and the transparent anisotropic conductive film, in the abraded portion.

20. A display apparatus comprising:

a common electrode;

a transparent anisotropic conductive film according to claim 18;

a display substance layer provided between the common electrode and the transparent anisotropic conductive film; and

a drawing means by which, by abrading the surface of the transparent anisotropic conductive film, an electric field is given between the common electrode and the transparent anisotropic conductive film, in the abraded portion.

21. The anisotropic conductive film as claimed in claim 1, wherein the diameter of said through holes is about 50 μ

m-about 300 μ

m.

8. A method of producing an anisotropic conductive film comprising:

forming a plurality of through holes in an insulating film the diameter of which is about 30 μ

m-about 500 μ

m, the interval between adjoining through holes being about 30 μ

m to about 100 μ

m;

introducing a sol of conductive particles into the through holes;

further introducing a monomer into the through holes; and

stuffing the inside of the through hole by polymerizing the monomer.

9. A method according to claim 8, wherein both the insulating film and the conductive particles are practically transparent.

10. A method according to claim 8, wherein the conductive particles comprise a plurality of holes, and when the monomer is introduced into the through holes, the monomer is also introduced into the holes of the conductive particles.