摘要 |
The present invention discloses a vacuum evaporation apparatus comprising a vacuum pump, an evaporation chamber and a power supply. The evaporation chamber comprises a substrate, an evaporation source and an evaporation mask. The evaporation mask exhibits a coefficient of thermal expansion substantially equal to the substrate, and the evaporation mask has a pattern of metal tracks. Thus, the apparatus of the present invention also can be applied to form solder bumps on a large sized silicon wafer. Moreover, the position pattern of the mask is formed by an anisotropic etching process; the diameter of the pattern will not be influenced by the thickness of the mask. Therefore, the tendency of the solder bumps with the smaller size and the pitch are met.
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