Patent ID: 7829384
Filing Date: 2010-11-09
Classification: H01L

Abstract:
1. A method of laser-marking a semiconductor device, comprising: providing a first carrier; providing a semiconductor wafer having a plurality of bumps formed on contact pads disposed on an active surface of the semiconductor wafer, the bumps having a height of 250-280 micrometers; mounting a back surface of the semiconductor wafer, opposite the active surface, to the first carrier for structural support; applying a tape over the bumps of the semiconductor wafer, the tape having optically translucent properties and a thickness substantially equal to the height of the bumps; providing a second carrier; leading with the tape, mounting the semiconductor wafer to the second carrier for structural support; removing the first carrier; removing a portion of the backside of the semiconductor wafer while mounted to the second carrier to reduce wafer thickness by backgrinding using a mechanical grinder followed by wet etching; removing the second carrier after reducing the wafer thickness; laser-marking the backside of the semiconductor wafer while the tape remains applied to the bumps, wherein the tape reduces wafer warpage during laser-marking to about 0.3-0.5 millimeters; and removing the tape from the bumps after laser-marking the backside of the semiconductor wafer.