Washer, friction plate, template, sheet, such as chip components, due to the poor rigidity and heat dissipation difficulties, heat treatment after bending, caused during clamping deformation and clamping when grinding easy warping, usually adopt magnetic chuck on surface grinding machine grinding, grinding is completed, remove the magnetic attraction, wafer workpiece restorable, difficult to guarantee the machining precision.If use the following the clamping way, guarantee chip positioning and clamping workpiece in free state, the use of double end face grinding, can achieve good effect, satisfies the requirement of precision parts processing.
A, with temporary measures to strengthen the rigid wafer workpiece
Using epoxy resin binder, stick wafer workpiece under free state on a tablet.Tablet along with chip on magnetic chuck.Smooth thin end plane, then will be removed from the tablet, wafer workpiece with smooth side on the magnetic chuck, grinding wafer workpiece on the other side of the plane again.Because before no hardening liquid epoxy resin, it can bridge chip clearance between the workpiece and tablet.When epoxy resin, the workpiece and the plate bonded together, as a whole, thus greatly enhance the rigidity of workpiece.Under the magnetic attraction, chip won't produce clamping deformation of workpiece, create conditions for grinding a flat plane.Also can use thick oil instead of epoxy resin filling wafer workpiece and clearance between magnetic chuck, enhance workpiece rigid, also can receive good effect.
Second, the mechanical clamping way
Used in surface grinding machine accessories parallel-jaw vice will borrow the small magnetic worktable parallel-jaw vice absorb wafer workpiece, because there are a certain height, flat pliers, therefore, jaw by the magnetic force is small.Based on feeding way to gradually reduce grinding flat wafer workpiece after a plane get off, then grinding has a good flat in a magnetic worktable, then another plane grinding chip parts, grinding repeatedly several times, two flat flatness is achieved.
Three, vacuum clamp mode
Use of atmospheric pressure clamping wafer workpiece for grinding.Its working principle is: the clip on the concrete with rubber seal, wafer workpiece on the rubber seal, so that the workpiece with sealed cavity formed between concrete.Use vacuum pump to the indoor air from the pumping hole, when the workpiece is clamped.Due to the clamping force is small, circular grinding method can be used for grinding.When after good wafer workpiece end plane grinding, grinding slice artifacts when the other end of the plane, can use the above way, also can get satisfactory results.
Fourth, cushion elastic gasket clamping way
The wafer workpiece in surface grinding machine grinding, use elastic clamping mechanism, make the wafer workpiece positioning and clamping under free state.Between workpiece and the magnetic table mat a 0.5 mm thick layer of rubber, when the workpiece by magnetic attraction, rubber is compressed, elastic deformation smaller, thus can be flat plane grinding work pieces.Grinding repeatedly several times, can meet the precision requirement.
