Patent ID: 6806560
Filing Date: 2004-10-19
Classification: H01L,H05K,Y02P

Abstract:
A semiconductor device, comprising:a semiconductor chip; a chip-mounting substrate which is provided with said semiconductor chip mounted on a top surface thereof and first conductive pads formed on a bottom surface thereof and connected with said semiconductor chip electrically; solder balls formed on said first conductive pads; a printed circuit board on which second conductive pads connected with said solder balls are formed; a solder mask formed on a bottom surface of said chip-mounting substrate, said solder mask comprising a first uneven roughness; and underfill material injected into a clearance formed between said chip-mounting substrate and said printed circuit board, wherein said first uneven roughness is formed on a surface which is brought into contact with said underfill material, wherein said first uneven roughness increases an area of a contact surface between said chip-mounting substrate and the underfill material, wherein at least one of said first conductive pads and said second conductive pads comprises a second uneven roughness; and wherein said first uneven roughness and said second uneven roughness comprise substantially even spaced protrusions.