Anisotropic conductive film, method for producing the same, and bonded structure
View Patent ↗Provided is an anisotropic conductive film, containing: an insulating layer formed of an insulating resin composition; and a conductive particle-contained layer containing a photo and thermal curing resin composition and conductive particles, the conductive particles being aligned into a monolayer in a portion adjacent to an interface with the insulating layer, in which the conductive particle-contained layer has a degree of cure which is gradually lowered in a thickness direction of the conductive particle-contained layer, from the side where the conductive particles are present to the side where the conductive particles are not present.
1. An anisotropic conductive film, comprising:
an insulating layer formed of an insulating resin composition; and
a conductive particle-contained layer comprising a photo and thermal curing resin composition and conductive particles, the conductive particles being aligned into a monolayer in a portion adjacent to an interface with the insulating layer,
wherein the conductive particle-contained layer has a degree of cure which is gradually lowered in a thickness direction of the conductive particle-contained layer, from the side where the conductive particles are present to the side where the conductive particles are not present.
2. The anisotropic conductive film according to claim 1 , wherein the conductive particle-contained layer is formed by being exposed to curing light from the side where the conductive particles are present.
3. The anisotropic conductive film according to claim 2 , wherein the exposure of the curing light is performed in at least one state of where a surface of the conductive particle-contained layer at which the conductive particles are not present is made into contact with oxygen, and where the conductive particle-contained layer is added with an absorbent for the curing light.
4. The anisotropic conductive film according to claim 1 , wherein the photo and thermal curing resin composition comprises a photopolymerization initiator.
5. The anisotropic conductive film according to claim 1 , wherein the photo and thermal curing resin composition comprises a thermoset initiator.
6. The anisotropic conductive film according to claim 1 , wherein the photo and thermal curing resin composition comprises a (meth)acryl monomer, and the insulating resin composition comprises epoxy resin.
7. The anisotropic conductive film according to claim 1 , wherein the insulating layer has a thickness of 5-20 μm, the conductive particle-contained layer has a thickness of 3-20 μm, the conductive particles have an average particle size of 2-10 μm, and the anisotropic conductive film has a total thickness of 10-50 μm.
8. The anisotropic conductive film according to claim 1 , wherein the conductive particle-contained layer has a thickness of 5-20 μm, and the conductive particles have an average particle size of 2-4 μm.
9. The anisotropic conductive film according to claim 1 , wherein the conductive particle-contained layer has a thickness of 10-20 μm, and the conductive particles have an average particle size of 2-5 μm.
10. A method for producing an anisotropic conductive film, comprising:
aligning conductive particles into a monolayer at one side of a layer comprising a photo and thermal curing resin composition, and exposing the one side of the layer to curing light so as to form a conductive particle-contained layer; and
laminating an insulating layer formed of an insulating resin composition on the one side of the conductive particle-contained layer,
wherein the conductive particle-contained layer has a degree of cure which is gradually lowered in a thickness direction of the conductive particle-contained layer, from the side where the conductive particles are present to the side where the conductive particles are not present.
11. The method according to claim 10 , wherein the insulating layer has a thickness of 5-20 μm, the conductive particle-contained layer has a thickness of 3-20 μm, the conductive particles have an average particle size of 2-10 μm, and the anisotropic conductive film has a total thickness of 10-50 μm.
12. The method according to claim 10 , wherein the conductive particle-contained layer has a thickness of 5-20 μm, and the conductive particles have an average particle size of 2-4 μm.
13. The method according to claim 10 , wherein the conductive particle-contained layer has a thickness of 10-20 μm, and the conductive particles have an average particle size of 2-5 μm.
14. A method for producing an anisotropic conductive film, comprising:
aligning conductive particles into a monolayer at one side of a layer comprising a photo and thermal curing resin composition, and exposing the one side of the layer to curing light so as to form a conductive particle-contained layer; and
laminating an insulating layer formed of an insulating resin composition on the one side of the conductive particle-contained layer,
wherein the exposure of the curing light is performed in a state of where a surface of the layer at which the conductive particles are not present is made into contact with oxygen.
15. The method according to claim 14 , wherein the insulating layer has a thickness of 5-20 μm, the conductive particle-contained layer has a thickness of 3-20 μm, the conductive particles have an average particle size of 2-10 μm, and the anisotropic conductive film has a total thickness of 10-50 μm.
16. A bonded structure, comprising:
at least two of electronic parts and substrates; and
an anisotropic conductive film,
wherein the at least two of electronic parts and substrates are electrically connected via the anisotropic conductive film, and the anisotropic conductive film comprises:
an insulating layer formed of an insulating resin composition; and
a conductive particle-contained layer comprising a photo and thermal curing resin composition and conductive particles, the conductive particles being aligned into a monolayer in a portion adjacent to an interface with the insulating layer,
wherein the conductive particle-contained layer has a degree of cure which is gradually lowered in a thickness direction of the conductive particle-contained layer, from the side where the conductive particles are present to the side where the conductive particles are not present.
17. The bonded structure according to claim 16 , wherein a particle capturing ratio of the conductive particles is 80% or more at a connecting portion of the at least two of electronic parts and substrates.
18. The bonded structure according to claim 16 , wherein the insulating layer has a thickness of 5-20μm, the conductive particle-contained layer has a thickness of 3-20 μm, the conductive particles have an average particle size of 2-10 μm, and the anisotropic conductive film has a total thickness of 10-50 μm.
19. The bonded structure according to claim 16 , wherein the conductive particle-contained layer has a thickness of 5-20 μm, and the conductive particles have an average particle size of 2-4 μm.
20. The bonded structure according to claim 16 , wherein the conductive particle-contained layer has a thickness of 10-20 μm, and the conductive particles have an average particle size of 2-5 μm.