Ultratera Corporation

S & S Technology Corporation

Ming-Sung Tsai

Chong-Ren Maa

Wan-Kuo Chih

Chih-Horng Horng

Sung-Jin Kim

Chung-Ta Yang

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.

Method for fabricating window ball grid array semiconductor package

A solder mask manufacturing method adapted to apply a solder mask on a surface of a substrate of a circuit board, said surface is provided with a conductor pattern having an unsheltered portion and a sheltered portion which is covered by said solder mask. The method comprises the steps of: a) disposing a layer of semi-solid solder mask material having an expansion coefficient substantially the same as that of the substrate on the surface of said substrate to cover said copper conductor pattern, and a metal foil covering the material layer; b) applying pressure to the metal foil and applying baking treatment to cure the solder mask material in to solid; c) utilizing chemical solution and plasma etching to remove the metal foil and the solid solder mask material above the unsheltered portion of said copper conductor pattern respectively such that the unsheltered portion can be exposed; and d) using chemical solution to remove the residual metal foil.

Method of manufacturing solder mask of printed circuit board

A printed circuit board having a permanent solder mask includes a substrate made of a glassfiber reinforced epoxy resin material. The top and bottom surfaces of the substrate are disposed thereon a conductive pattern respectively. An epoxy resin solder mask is coated on each surface of the substrate in such a way that the conductive pattern is divided into a sheltered portion covered by the solder mask and an unsheltered portion exposed outside. The solder mask also has an even and smooth outer surface with a micro-roughness ranging between 0.5 &#x3bc;m&#x2dc;10 &#x3bc;m and an optimum thickness ranging between 2 &#x3bc;m&#x2dc;200 &#x3bc;m.

Printed circuit board having permanent solder mask

A printed circuit board having a permanent solder mask includes a substrate made of a glassfiber reinforced epoxy resin material. The top and bottom surfaces of the substrate are disposed thereon a conductive pattern respectively. An epoxy resin solder mask is coated on each surface of the substrate in such a way that the conductive pattern is divided into a sheltered portion covered by the solder mask and an unsheltered portion exposed outside. The solder mask also has an even and smooth outer surface with a micro-roughness ranging between 0.5 &mgr;m&tilde;10 &mgr;m and an optimum thickness ranging between 2 &mgr;m&tilde;200 &mgr;m.

Growing community of inventors

Keelung, Taiwan

Ming-Sung Tsai