摘要 |
A high-frequency BGA device (500) with the chip (501) assembled by metal bumps (503) on an insulating substrate (502) with conductive vias (505) and metal traces (504). Chip bumps which serve the high frequency signal terminals are attached directly to the lands (510) on the vias in order to minimize parasitic electrical parameters such as inductance, resistance, and IR drops, thus achieving the required 0.1 nH inductance for each chip terminal. Chip bumps which serve the remaining chip terminals are attached to pads on certain substrate traces. In both cases, the bumps can be attached reliably because the lands on the vias and the pads on the traces are plated with additional metal layers (511, 512), which provide extra thickness as well as a metallurgically suitable surface.
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