Abstract: A grinding device, comprising a body configured as a hollow barrel having an opening and a first fixing element positioned close to the opening; an inner cap configured to mount to an inner wall of an end close to the opening of the body having a second fixing element corresponding to the first fixing element; wherein an aperture is provided on the inner cap, and a first leak-proof seal is configured to surround the aperture; an outer cover having a second leak-proof seal, wherein the second leak-proof seal engages the first leak-proof seal for leak-proofing; and a grinding element positioned inside the body and capable of moving therein freely; wherein an area of any cross section of the grinding element is bigger than the aperture of the inner cap.

Abstract: The present invention is related to a grinding device, comprising a body configured as a hollow barrel having an open and a first fixing element positioned close to said open; an inner cap configured to mount to an inner wall of an end close to said open of said body having a second fixing element corresponding to said first fixing element; wherein an aperture is provided on said inner cap, and a first leak-proof seal is configured to surround said aperture; an outer cover having a second leak-proof seal, wherein said second leak-proof seal is made joint said first leak-proof seal for leak-proofing; and a grinding element positioned inside said body and capable of moving therein freely; wherein an area of any cross section of said grinding element is bigger than said aperture of said inner cap.

Abstract: A method mending the erosion of bonding pad. A passivation layer and a polyimide layer are sequentially formed on a wafer to cover a bonding pad, where the polyimide layer is patterned to expose a portion of the passivation layer. The polyimide layer is used as a mask for etching the passivation layer, so as to expose the bonding pad. The bonding pad is eroded by the etchant residue remaining after etching the passivation layer on the bonding pad. After removing the eroded part of the bonding pad, an oxide layer is formed subsequently to prevent a further erosion.