Patent ID: 9592584
Date: 2017-03-14
CPC Classifications: B24B,H01L

Claim:
1. A wafer double-side grinding device for grinding a wafer, the device comprising: an upper surface plate disposed above the wafer; a lower surface plate disposed under the wafer facing the upper surface plate; a carrier disposed between the upper and lower surface plates and to which the wafer is attached; an internal gear disposed at an outer circumferential side of the lower surface plate; and a sun gear disposed at an inner circumferential side of the lower surface plate, wherein a plurality of first surface plate grooves are defined in a top surface of the lower surface plate in a first direction, and a plurality of second surface plate grooves are defined in the top surface of the lower surface plate in a second direction different from the first direction, and wherein, in the first and second surface plate grooves, first and second surface plate groove parts are defined, and each of the first and second surface plate grooves has a step difference toward a center or outer circumference of the lower surface plate.