Connecting film, and joined structure and method for producing the same

1. A connecting film which electrically connects a first circuit member with a second circuit member having a nitrogen atom-containing film on a surface thereof facing the first circuit member, the connecting film comprising:

a first layer which is to be located at the first circuit member side; and

a second layer which is to be located at the second circuit member side,

wherein the first layer comprises a cationic curing agent, an epoxy resin and hydrophobic silica fine particles, and the second layer comprises a radical curing agent, an acrylic resin and an epoxy compound,

wherein the epoxy compound has a molecular weight of 5,000 to 50,000, and an epoxy equivalent of 1,000 to 5,000,

wherein only the first layer is a conductive particle-containing organic resin layer, and the second layer is an insulating organic resin layer containing no conductive particles,

wherein the minimum melt viscosity of the conductive particle-containing organic resin layer is ten times or more greater than the minimum melt viscosity of the insulating organic resin layer at a rate of temperature rise of 10° C./min,

wherein pH of the hydrophobic silica fine particles is 4.0 to 7.0 and a carbon content of the hydrophobic silica fine particles is 3.5-5.5 wt %,

wherein an amount of the hydrophobic silica fine particles is 10 parts out of 100 parts of the composition of the first layer,

wherein a BET surface area of the hydrophobic silica fine particles is 100±20 m 2 /g,

wherein a particle diameter of the hydrophobic silica fine particles is about 12 nm,

wherein an apparent specific gravity of the hydrophobic silica fine particles is about 50 g/l, and

wherein the hydrophobic silica fine particles are treated with dimethyl silicon oil.

2. The connecting film according to claim 1 , wherein the second layer further contains hydroxyl group-containing acrylate.

3. The connecting film according to claim 1 , wherein the minimum melt viscosity of the conductive particle-containing organic resin layer is 10 times to 1,000 times greater than the minimum melt viscosity of the insulating organic resin layer at a rate of temperature rise of 10° C./min.

4. The connecting film according to claim 1 , wherein the first circuit member is one of a LCD panel, a PDP panel and an organic EL panel, and the second circuit member has a nitrogen atom-containing film on a surface facing the first circuit member.

5. The connecting film according to claim 1 , wherein the cationic curing agent comprises a sulfonium salt or an onium salt.

6. The connecting film according to claim 1 , wherein the epoxy resin comprises a thermosetting epoxy resin.

7. The connecting film according to claim 1 , wherein the epoxy resin comprises one selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, novolac epoxy resins and modified epoxy resins thereof.

8. The connecting film according to claim 1 , wherein the radical curing agent comprises an organic peroxide.

9. The connecting film according to claim 1 , wherein the acrylic resin comprises one selected from the group consisting of methyl(meth)acrylate, ethyl(meth)acrylate, isopropyl(meth)acrylate, isobutyl(meth)acrylate, epoxy(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, tetramethyleneglycol tetra(meth)acrylate, 2-hydroxy-1,3-di(meth)acryloxypropane, 2,2-bis[4-((meth)acrloxymethoxy)phenyl]propane, 2,2-bis[4-((meth)acryloxyethoxy)phenyl]propane, dicyclopentenyl(meth)acrylate, tricyclodecanyl(meth)acrylate, tris((meth)acryloxyethyl)isocyanurate and urethane(meth)acrylate.

10. The connecting film according to claim 1 , wherein a surface of the hydrophobic silica fine particles have been treated with dimethyl silicone oil.

11. A joined structure comprising:

a first circuit member; and

a second circuit member having a nitrogen atom-containing film on a surface thereof facing the first circuit member; and

a connecting film, which electrically connects the first circuit member with the second circuit member, and comprises:

a first layer which is to be located at the first circuit member side, and

a second layer which is to be located at the second circuit member side,

wherein the first layer comprises a cationic curing agent, an epoxy resin and hydrophobic silica fine particles, and the second layer comprises a radical curing agent, an acrylic resin and an epoxy compound, wherein the epoxy compound has a molecular weight of 5,000 to 50,000, and an epoxy equivalent of 1,000 to 5,000,

wherein only the first layer is a conductive particle-containing organic resin layer, and the second layer is an insulating organic resin layer containing no conductive particles,

wherein the minimum melt viscosity of the conductive particle-containing organic resin layer is ten times or more greater than the minimum melt viscosity of the insulating organic resin layer at a rate of temperature rise of 10° C./min,

wherein pH of the hydrophobic silica fine particles is 4.0 to 7.0 and a carbon content of the hydrophobic silica fine particles is 3.5-5.5 wt %,

wherein an amount of the hydrophobic silica fine particles is 10 parts out of 100 parts of the composition of the first layer,

wherein the BET surface area of the hydrophobic silica fine particles is 100±20 m 2 /g,

wherein a particle diameter of the hydrophobic silica fine particles is about 12 nm,

wherein an apparent specific gravity of the hydrophobic silica fine particles is about 50 g/l, and

wherein the hydrophobic silica fine particles are treated with dimethyl silicon oil.

12. The connecting film according to claim 11 , wherein a surface of the hydrophobic silica fine particles have been treated with dimethyl silicone oil.