Secondly, temporary measures are used to strengthen the rigidity of thin plate workpieces.
Using epoxy resin adhesive, the sheet workpiece is bonded to the flat plate in a free state. The flat plate is placed on the magnetic chuck together with the thin plate. After grinding one end face of the wafer, the wafer workpiece is removed from the flat plate, the ground face is placed on the magnetic chuck, and then the other end face of the wafer workpiece is ground. Because epoxy resin has fluidity before hardening, it can fill the gap between thin workpiece and flat plate. When the epoxy resin hardens, the workpiece and the flat plate are bonded together and become a whole, which greatly enhances the rigidity of the workpiece.
Third, the mechanical clamping mode
The flat-faced pliers in the accessories of the surface grinder are used for the magnetic workbench to absorb thin-plate workpieces. Because the flat-nose pliers have a certain height, the jaws are less subject to magnetic force. The feed speed is gradually reduced to smooth one plane of the film workpiece, and then it is removed. At this time, the ground plane is placed on the magnetic workbench, and then the other plane of the film workpiece is polished several times, and the flatness of the two planes meets the requirements.
Fourth, the vacuum clamping mode
The wafer workpiece is held by atmospheric pressure for grinding. Its working principle is that a rubber sealing ring is arranged on the clamp body, and a thin workpiece is placed on the rubber sealing ring, so that a sealed cavity is formed between the workpiece and the clamp body. Indoor air is pumped from the suction hole by vacuum pump, and the workpiece is clamped at this time. Because of the small clamping force, circumferential grinding can be used for grinding. After grinding one end face of the film workpiece, grinding the other end face of the film workpiece can be carried out in the above manner, and satisfactory results can also be obtained.