A method for preparing a surface acoustic wave device single-sided polished substrate

Abstract

The invention discloses a preparation method of a single-side polishing substrate sheet for a surface acoustic wave device. The preparation method sequentially comprises the following steps: corroding workblank wafers; roughening the workblank wafers; corroding the roughened wafers again; performing adhesion on non-processing surfaces of the wafers; performing fine grinding and accurate grinding on polishing surfaces; separating and corroding the wafers; chamfering; performing adhesion on non-polishing surfaces of the two wafers; performing rough polishing on the polishing surfaces; performing CMP fine polishing; and separating and cleaning workpieces, wherein adhesion of the wafers adopts a water-soluble adhesive which consists of Arabic gum, pure water, aluminium alums and glycerinum. Double sides are ground and polished simultaneously in grinding and polishing links. Through process improvement, the yield of products reaches above 95 percent, the characteristics that the product index consistency is high, the technical index is high, the processing efficiency is high, the production cost is low and the process is easy to realize and monitor are achieved, and the requirement of industrialized large-scale production can be met.

Description

technical field [0001] The invention relates to a surface acoustic wave device, in particular to a method for preparing a single-side polished substrate sheet for a surface acoustic wave device, and belongs to the field of crystal material processing. Background technique [0002] Surface acoustic wave (SAW) filter has flexible design, excellent passband selectivity, extremely small in-band distortion, small group delay time deviation and excellent frequency-phase linearity, easy input and output impedance conversion, and good anti-electromagnetic interference performance , high reliability, real-time signal processing capability, miniaturization and chip manufacturing, and other characteristics, it has become the core device of mobile communication. Quartz (SiO 2 ), lithium niobate (LT), lithium tantalate (LT), gallium lanthanum silicate (LGS), gallium lanthanum tantalate (LGT) and other piezoelectric single crystals, which need to be processed into single-sided polished w...

AI Technical Summary

Problems solved by technology

[0004] (1) Since the processing surface of the wafer needs to be processed separately in sequence, the efficiency is relatively low;

[0005] (2) The non-processed surface of the substrate is bonded together by paraffin wax and ceramic disc, and the cleaning cost of paraffin wax is high. There are two common cleaning agents for cleaning paraffin wax, but gasoline cleaning paraffin wax will cause lead residues, sulfuric acid and potassium dichromate will also seriously pollute the environment

If a special wax remover is used, the production cost will increase; at the same time, the residual paraffin will easily pollute the cavity of the coating equipment;

[0006] (3) The paraffin wax needs to be heated and melted to be bonded to the wafer. When the two wafers are separated, the paraffin wax needs to be heated. Due to the difference in thermal expansion coefficient, the wafer will be deformed after being removed from the fixture, resulting in a large warpage of the wafer. For 4-inch wafers If no chemical corrosion method is used to control, the value will exceed 100μm;

[0007] (4) After the wafer is removed from the fixture, the surface shape changes greatly and is uncontrollable;

[0008] (5) In order to obtain better surface shape and thickness consistency, manual intervention in multiple processes is required, which is highly dependent on the experience of skilled workers, and product accuracy is more controlled by people rather than equipment;

[0009] (6) The loss of crystal material caused by the large amount of wafer processing and removal is large

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