Semiconductor device and method for fabricating same

A semiconductor device, comprising:

• a semiconductor chip;
• a lead frame which is provided with said semiconductor chip mounted thereon and electrically connected with said semiconductor chip;
• and
• a printed circuit board including conductive pads which are formed thereon and brought into direct contact with a bottom surface of said lead frame,
• wherein an uneven roughness exists on said bottom surface of said lead frame and a surface of said conductive pads, and
• wherein said uneven roughness comprises substantially even spaced protrusions.

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, said chip-mounting substrate including Cu wirings;
• solder balls formed on said first conductive pads;
• a printed circuit board on which second conductive pads connected with said solder balls are formed;
• and
• material injected into a clearance formed between said chip-mounting substrate and said printed circuit board,
• wherein a first uneven roughness is formed on a contact surface between said Cu wirings of said chip-mounting substrate and said solder balls,
• wherein said first uneven roughness exists on a bottom surface of said Cu wirings, and said Cu wirings are directly connected to said solder balls to form a joined surface,
• wherein said second conductive pads comprise a second uneven roughness in contact with said solder balls, and
• wherein said first uneven roughness and said second uneven roughness comprise substantially even spaced protrusions.