包含全氟烷基表面活性剂的焊料凸点用锡合金电镀液

本发明涉及包含全氟烷基表面活性剂的焊料凸点用锡合金电镀液。本发明的锡合金电镀液是用于形成倒装芯片封装的焊料凸点的锡类电镀液，所述锡类电镀液包含甲磺酸锡、甲磺酸银、甲磺酸、氟化表面活性剂、芳香族聚氧亚烷基醚和水。本发明还公开了使用所述电镀液形成焊料凸点的方法。该方法包括：(1)用铜或铜/镍电镀液电镀硅晶片，所述硅晶片具有露出电极焊盘的保护层和凸点下金属(UBM)层，从而在所述凸点下金属层上形成铜或铜/镍柱；和(2)用所述锡类电镀液电镀所述柱，从而形成焊料凸点。 Disclosed is a tin-based electroplating solution for forming solder bumps of a flip chip package. The tin-based electroplating solution includes tin methanesulfonate, silver methanesulfonate, methanesulfonic acid, a fluorinated surfactant, an aromatic polyoxyalkylene ether, and water. Also disclosed is a method for forming solder bumps by using the electroplating solution. The method includes (1) electroplating a silicon wafer having a protective layer through which an electrode pad is exposed and an under bump metallurgy (UBM) layer with a copper or copper/nickel plating solution to form copper or copper/nickel pillars on the under bump metallurgy layer and (2) electroplating the pillars with the tin-based electroplating solution to form solder bumps.