Alpha Omega Semiconductor Inc.

Guo Feng Lian

Jun Lu

Yan Xun Xue

Zhiqiang Niu

Hamza Yilmaz

Yueh-Se Ho

Ming-Chen Lu

Hua Pan

Yan Huo

Yu Gong

Hong Fu

A wafer process for molded chip scale package (MCSP) comprises: depositing metal bumps on bonding pads of chips on a wafer; forming a first packaging layer at a front surface of the wafer to cover the metal bumps; forming an un-covered ring at an edge of the wafer to expose two ends of each scribe line of a plurality of scribe lines; thinning the first packaging layer to expose metal bumps; forming cutting grooves; grinding a back surface of the wafer to form a recessed space and a support ring at the edge of the wafer; depositing a metal seed layer at a bottom surface of the wafer in the recessed space; cutting off an edge portion of the wafer; flipping and mounting the wafer on a substrate; depositing a metal layer covering the metal seed layer; removing the substrate from the wafer; and separating individual chips from the wafer by cutting through the first packaging layer, the wafer, the metal seed layers and the metal layers along the scribe lines.

Wafer process for molded chip scale package (MCSP) with thick backside metallization

A wafer process for MCSP comprises: depositing a metal bump on bonding pads of chips; forming a first packaging layer at front surface of wafer covering metal bumps while forming an un-covered ring at the edge of wafer to expose the ends of each scribe line located between two adjacent chips; thinning first packaging layer to expose metal bumps; grinding back surface of wafer to form a recessed space and a support ring at the edge of the wafer; depositing a metal seed layer and a thick metal layer at bottom surface of wafer in recessed space in a sequence; cutting off the edge portion of wafer; and separating individual chips from wafer by cutting through first packaging layer, the wafer and the metal seed and metal layers along the scribe line.

A semiconductor package is provided with an Aluminum alloy lead-frame without noble metal plated on the Aluminum base lead-frame. Aluminum alloy material with proper alloy composition and ratio for making an aluminum alloy lead-frame is provided. The aluminum alloy lead-frame is electroplated with a first metal electroplating layer, a second electroplating layer and a third electroplating layer in a sequence. The lead-frame electroplated with the first, second and third metal electroplating layers is then used in the fabrication process of a power semiconductor package including chip connecting, wire bonding, and plastic molding. After the molding process, the area of the lead-frame not covered by the molding compound is electroplated with a fourth metal electroplating layer that is not easy to be oxidized when exposing to air.

Aluminum alloy lead-frame and its use in fabrication of power semiconductor package

Growing community of inventors

Shanghai, China

Guo Feng Lian