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US 2012/0079690 A1Published application
Method of piezoelectric vibrating piece, wafer, piezoelectric vibrator, oscillator, electronic apparatus, and radio-controlled timepiece
OwnerDaishi Arimatsuinventor
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Abstract
The present invention provides a novel method of producing piezoelectric vibration pieces in which a plurality of piezoelectric vibration pieces are formed at once from a wafer, using a plurality of photoresist processes. The wafer is marked with wafer marks each unique to a different one of photoresist masks to prevent a wrong use of the photoresist masks during the photoresist processes.
Claims8
A method of producing piezoelectric vibration pieces comprising:
- (a) forming in a wafer a plurality of piezoelectric pieces and wafer marks which comprise pairs of marks formed at predetermined locations in the wafer, wherein each mark has a predetermine shape which is asymmetrical in any directions, and each pair presents a unique mark pattern which is asymmetrical in any directions;
- (b) providing a plurality of masks each comprising a pair of marks identical in mark pattern to a different one of the pairs of marks formed in the wafer;
- (c) forming layers of electrode films on the wafer in which the plurality of piezoelectric pieces and the wafer marks are formed;
- (d) applying a resist film on the wafer on which the layers of electrode films are formed;
- (e) placing one of the masks on the wafer so as to coincide a pair of marks of the one mark with a corresponding pair of marks formed in the wafer;
- (f) partially removing the resist film according to a pattern of the mask;
- (g) partially removing at least one layer of electrode film using a remnant of the resist film;
- and
- (h) repeating steps (d), (e), (f) and (g) using a different mask.
6 more elements
Dependencies are inferred from the claim text.