摘要 |
The method mainly contains the following steps. First, an UBM is formed on a top side of a semiconductor's I/O pad. An isolative layer and a metallic foil are sequentially arranged in this order on the UBM. Then, a via is formed to expose the top surface of the UBM. Subsequently, a thin metallic layer is formed in the via and a resist is formed on the metallic foil. Then, by using the metallic foil and the thin metallic layer as an electrode to conduct electrical current, a metallic bump is formed using electroplating in the via on the top side of the UBM. Finally, the resist and the metallic foil are removed and the formation of the metallic bump is completed. Optionally coating on bump may be needed for certain chosen bump materials.
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