Automatic wafer lapping apparatus

Claim 1

An automatic wafer lapping apparatus having: a lapping assembly consisting mainly of an upper lapping plate, a lower lapping plate, a sun gear provided horizontally at the center of the lower lapping plate, and an internal gear provided horizontally along the circumference of the lower lapping plate; a plurality of wafer carriers which are planetary gears adapted to mesh with said sun gear and said internal gear simultaneously; a pair of loader assemblies each consisting mainly of a wafer storage to store wafers, a wafer picker and setter means for picking the wafers from the wafer storage and setting them in said wafer carriers, and a wafer carrier setter means for setting the wafer carriers at proper positions in said lapping assembly; and an unloader assembly consisting mainly of a wafer recovery subassembly for recovering the wafers, and a wafer carrier picker means for picking wafer carriers from said lapping assembly and discarding them into said wafer recover subassembly; wherein each of said loader assemblies further comprises a turntable stage where said wafer carriers are piled up by said wafer carrier setter means and loaded with wafers by said wafer picker and setter means, said turntable stage having a vertical central shaft and a pin on which said wafer carriers are spitted; and the teeth of said sun gear and the internal gear of said lapping assembly are bevelled at their upper portions in a manner such that the upper end of each tooth is tapered and converges into a linear ridge.