Anisotropic conductive film and production method of the same

Abstract

An anisotropic conductive film has first and second connection layers formed on a first layer surface. The first connection layer is a photopolymerized resin layer, and the second is thermo- or photo-cationically, anionically, or radically polymerizable resin layer. On the surface of the first connection layer on a second connection layer side, conductive particles for anisotropic conductive connection are in a single layer. The first connection layer has fine projections and recesses in a surface. An anisotropic conductive film of another aspect has first, second, and third connection layers layered in sequence. The first layer formed of photo-radically polymerized resin. The second and third layers are formed of thermo-cationically or thermo-anionically polymerizable resin, photo-cationically or photo-anionically polymerizable resin, thermo-radically polymerizable resin, or photo-radically polymerizable resin. On a surface of the first connection layer on a second connection layer side, conductive particles for anisotropic conductive connection are in a single layer.

1 . An anisotropic conductive film having a first connection layer and a second connection layer formed on a surface of the first connection layer, wherein
 the first connection layer is a photopolymerized resin layer,   the second connection layer is a thermo- or photo-cationically, anionically, or radically polymerizable resin layer, and   the first connection layer has conductive particles for anisotropic conductive connection that are arranged in a single layer on a surface on a side of the second connection layer, and fine projections and recesses are provided to a surface of the first connection layer opposite to the side of the second connection layer.   
     
     
         2 . An anisotropic conductive film having a second connection layer layered on a surface of a first connection layer and a third connection layer layered on another surface of the first connection layer, wherein
 the first connection layer is formed of a photopolymerized resin,   the second and third connection layers are each formed of a thermo-cationically or thermo-anionically polymerizable resin, a photo-cationically or photo-anionically polymerizable resin, a thermo-radically polymerizable resin, or a photo-radically polymerizable resin,   the third connection layer has a tack force larger than 3 kPa that is measured by a probe method (stainless cylindrical probe, diameter: 5 mm, pressing load: 196 kgf, pressing rate: 30 mm/min, separation rate: 5 mm/min), and   the first connection layer has conductive particles for anisotropic conductive connection arranged in a single layer on a surface thereof on a side of the second connection layer.   
     
     
         3 . A production method of the anisotropic conductive film according to  claim 1 , comprising the following steps (A) to (D):
 Step (A)
 a step of forming a photopolymerizable resin layer having fine projections and recesses in a surface thereof using an original plate having fine projections and recesses; 
   Step (B)
 a step of arranging conductive particles in a single layer on another surface of the photopolymerizable resin layer having the fine projections and recesses in the surface; 
   Step (C)
 a step of irradiating the photopolymerizable resin layer having the arranged conductive particles with ultraviolet light to cause a photo-radical polymerization reaction to form the first connection layer in which the fine projections and recesses are formed in the one surface and the conductive particles are fixed in the other surface; and 
   Step (D)
 a step of forming the second connection layer that includes a thermo- or photo-cationically, anionically, or radically polymerizable resin layer on the other surface of the first connection layer on a side of the fixed conductive particles. 
   
     
     
         4 . A production method of the anisotropic conductive film according to  claim 1 , comprising the following steps (AA) to (EE):
 Step (AA)
 a step of forming a photopolymerizable resin layer having fine projections and recesses in a surface thereof using an original plate having fine projections and recesses; 
   Step (BB)
 a step of arranging conductive particles in a single layer on another surface of the photopolymerizable resin layer having the fine projections and recesses on the surface; 
   Step (CC)
 a step of irradiating the photopolymerizable resin layer having the arranged conductive particles with ultraviolet light to cause a photopolymerization reaction to form a first temporary connection layer in which the fine projections and recesses are formed in the one surface and the conductive particles are temporarily fixed in the other surface; 
   Step (DD)
 a step of forming the second connection layer that includes a thermo-cationically, anionically, or radically polymerizable resin layer on a surface of the first temporary connection layer on a side of the conductive particles; and 
   Step (EE)
 a step of irradiating the first temporary connection layer with ultraviolet light from a side opposite to the second connection layer to cause a photopolymerization reaction, thereby fully curing the first temporary connection layer to form the first connection layer. 
   
     
     
         5 . A production method of the anisotropic conductive film according to  claim 2 , comprising the following steps (A) to (D):
 Step (A)
 a step of disposing conductive particles in a single layer on a surface of a photopolymerizable resin layer; 
   Step (B)
 a step of irradiating the photopolymerizable resin layer having the disposed conductive particles with ultraviolet light to cause a photopolymerization reaction, thereby forming the first connection layer in which the conductive particles are fixed in the surface thereof; 
   Step (C)
 a step of layering the second connection layer that is formed of a thermo-cationically or thermo-anionically polymerizable resin, a photo-cationically or photo-anionically polymerizable resin, a thermo-radically polymerizable resin, or a photo-radically polymerizable resin on a surface of the first connection layer on a side of the conductive particles; and 
   Step (D)
 a step of layering the third connection layer that is formed of a thermo-cationically or thermo-anionically polymerizable resin, a photo-cationically or photo-anionically polymerizable resin, a thermo-radically polymerizable resin, or a photo-radically polymerizable resin, and has a tack force larger than 3 kPa that is measured by a probe method (stainless cylindrical probe, diameter: 5 mm, pressing load: 196 kgf, pressing rate: 30 mm/min, separation rate: 5 mm/min), wherein 
 the step (D) is performed by layering the third connection layer on the photopolymerizable resin layer before the step (A) or by layering the third connection layer on a surface of the first connection layer opposite to the second connection layer after the step (C).