Ultratera Corporation

Sung-Jin Kim

Chih-Horng Horng

Ming-Sung Tsai

Chung-Ta Yang

A substrate for solder joint is provided, including: a core layer; at least one conductive trace formed on the core layer and having a circular terminal as a pad through which a plurality of hollow portions are formed and expose predetermined portions of the core layer underneath the pad, wherein the hollow portions are arranged at equal intervals and spaced from a periphery of the circular pad; and a solder mask for covering the conductive trace and having at least one opening bordered across each of the hollow portions of the pad, such that part of the pad and part of each of the predetermined portions of the core layer are exposed via the opening, to allow a conductive element to be bonded to the exposed part of the pad and the exposed part of the predetermined portions of the core layer in the opening of the solder mask.

Substrate for solder joint

A method for fabricating a window ball grid array (WBGA) semiconductor package is provided. A substrate is prepared having a through opening and ball pads on a lower surface thereof. A chip is mounted over the opening of the substrate via an adhesive, with gaps not applied with the adhesive left between the chip and substrate. The chip is electrically connected to the substrate via bonding wires through the opening. A spacer is attached to the lower surface of the substrate and has a through hole and a recessed portion around the through hole. During molding, the spacer is clamped between the substrate and a mold, and the recessed portion is located between the ball pads and the opening, such that a resin material for forming an encapsulation body encapsulates the chip and flows through the gaps to encapsulate the bonding wires. The recessed portion holds resin flash therein.

Growing community of inventors

Hsin-Chu, Taiwan

Sung-Jin Kim