For integrated circuits, the thickness of the 4-inch wafer is 0.520mm, and the thickness of the 6-inch wafer is about 0.670mm. The wafer must be thinned, otherwise the loss of the scribing knife is great, and it must be scratched twice.
We do DIP package, 4 inch wafer should be reduced to 0.300mm; The 6-inch wafer should be thinned to about 0.320mm, with an error of 0.020mm. Measuring the thickness of the instrument with a micrometer on the line, the film thickness is generally measured with a thermal wave instrument, by measuring the thickness of different distribution of multiple points, to obtain the average film thickness, generally reflect the uniformity of the film, and can be seen analog contour lines.