| 摘要 |
An improved method of flip-chip mounting a semiconductor device, such as a transistor, on a pattern of electrical conductors carried on an insulating substrate, comprising providing the device chip with a glass protective layer and on the glass layer metallized bonding pads adjacent to the corners of the chip. Each of the bonding pads includes a relatively wide portion adapted to contain a relatively high mound of solder, and a second portion of a relatively narrow width capable of holding only a thin layer of solder. The thin solder layers overlie heat-generating P-N junction portions of the device. The conductors on the substrate have solder-wettable portions of larger areas than the bonding pads on the chip. Solder balls are placed on the wide portions of the bonding pads and melted to reflow the solder. The chip is then placed face down over the conductors on the substrate and the solder is again reflowed so that the relatively high mounds collapse to the thickness of the thin solder layer portions and the relatively thin solder layer portions are joined directly to the substrate conductors. |
