METHOD OF MACHINING OF THE MONOCRYSTALLINE LANTHANUM-GALLIUM SILICATE SUBSTRATES Russian patent published in 2007 - IPC B24B1/00 C30B33/00 C30B29/34 

FIELD: chemical industry; other industries; methods of machining of the piezoelectric substrates.

SUBSTANCE: the invention is pertaining to the machining of the piezoelectric substrates, in particular, it is dealt with the precision machining of the slices of the lanthanum-gallium silicate of the orientation (0, 138.5, 26.7) by the method of the lanthanum-gallium silicate lapping and polishing. The invention may be used at manufacture of the piezoelectric devices using the surface acoustic waves. The method provides for the double-side a double-side lapping with usage of the aqueous suspension of the micropowder of the green silicon carbide at the specific pressure on the substrate of 20-60 g/cm² and the chemical-mechanical polishing of the substrates preliminary pasted in-pairs by their non-working sides with the help of the solution containing (in mass %): suspension of silicon dioxide - 8-11.5, orthophosphoric acid - 0.8-1.5, the distilled water - 87-91.2 at the specific pressure on the substrate of 50-90 g/cm². The method allows to improve the frequency characteristics of the devices operating in the range of the surface acoustic waves ensuring production of the plain parallel substrates at the speed of removal of the substrate material within the range of 5-10 microns/hour at achievement of the roughness of the lapped surface the value of R_a ≤ 0.7 nanometers.

EFFECT: the invention ensures the improved frequency characteristics of the devices operating in the surface acoustic waves range, provision of production of the plain parallel substrates at the speed of removal of the substrate material within the range of 5-10 microns/hour at achievement of the roughness of the lapped surface below 1 nanometer.

5 cl, 1 ex