Prodn. of clockwork mechanism used in mfr. of micro-step motors

摘要

Prodn. of a clockwork mechanism comprises (a) thermally oxidising both sides of a double sided polished monocrystalline Si wafer; (b) providing one side of the wafer with a Si2N4 layer of 1500-2000 A thickness; (c) defining circular windows as a concentric rings in the SiO2 layer formed in (a) with a photolithographic mask, etching with HF, and removing the photolacquer; (d) anisotropically etching to produce recesses having trapezoidal cross-section (e) providing annular recesses with a 100 A thick SiO2 layer in a thermal re-oxidn. step; (f) liberating the base of the recess from the SiO2 layer by ionic sputtering etching leaving a residual layer on the walls; (g) vaporising the wafter via a mask with 20 microns Al, and diffusing the Al into the SiO2-free surfaces in the direction of the Si3N4; (h) etching the P<+> doped regions; (i) vaporising a Cr/Au layer using a mask; (j) using the Si3N4 layer as mask to anisotropically etch pyramid structures to produce electrical magnetic and induction coils; (k) producing induction coil by vaporising non-magnetic and rectangular conductors; (l) applying magnetic material to the outer periphery of the holes in the wafer and the inside of the wafer by vaporising; (m) vaporising pads of solder material, e.g. Pb-Sn alloy, on the holes in the wafter was well as on the inside of the wafer using a mask; (n) defining circular windows as concentric rings of lower dia. than (c) using a photolithographic masks; (o) positioning supporting device with the pads on the outer pads of the wafer and heat treating; (p) sawing the finished clockwork mechanism for the Si wafer using the conventional methods, used in semiconductor chip mfr.