Improvement of Adhesion Strength Between Epoxy Resin and Copper Alloy Lead-frame with Silver Layer Electrodeposited from Acid Aqueous Solution

Adhesion strength between epoxy resin and copper alloy lead-frame was improved using silver layer electrodeposited from acid aqueous solution. Surface roughness of silver layer electrodeposited on copper alloy lead-frame was controlled by the electrodeposition current density. The surface roughness of silver layer electrodeposited from acid aqueous solution was increased up to 2.11 μm, while that electrodeposited from cyanide aqueous solution was around 0.9 μm. The adhesion strength between epoxy resin and copper alloy lead-frame with silver layer was increased to 5.86 MPa with increasing the surface roughness of silver layer up to 1.69 μm. Copper alloy lead-frame with silver layer, which has the surface roughness more than 1.15 μm, showed a conventional level of die bonding and wire bonding properties