Patent ID: 7485029

Claim:
A double face polishing apparatus, comprising: a lower polishing plate having an upper face, which acts as a polishing face; an upper polishing plate having a lower face, which acts as a polishing face, said upper polishing plate being provided above said lower polishing plate and capable of moving in the vertical direction; a carrier being provided between said lower polishing plate and said upper polishing plate, said carrier having a through-hole for holding a workpiece; a plate driving unit for rotating said lower polishing plate and said upper polishing plate about their axes; a carrier driving unit for rotating said carrier; a plurality of ring-shaped ducts being coaxially provided relative to said upper polishing plate; a slurry supply source supplying slurry to said ring-shaped ducts; and a plurality of supply pipes communicating slurry supply holes of said ring-shaped ducts to slurry supply holes of said upper polishing plate so as to supply the slurry to the polishing face of said lower polishing plate via the slurry supply holes, wherein said lower polishing plate, said upper polishing plate and said carrier are rotated, while supplying the slurry to said lower polishing plate, so as to polish both faces of the workpiece, and the slurry is supplied to each of coaxial polishing zones of said lower polishing plate via said corresponding ring-shaped ducts and said supply pipes.