Manufacturing method of piezoelectric vibrating piece, piezoelectric vibrating piece, piezoelectric vibrator, oscillator, electronic equipment and radio-controlled timepiece
There are provided a piezoelectric vibrating piece, which has been more miniaturized and whose efficiency has been more increased, by easily and certainly electrode-dividing an exciting electrode, and a manufacturing method of the same. There is provided a manufacturing method of a piezoelectric vibrating piece, characterized by having an exposure process in which a mask having an opening part is disposed such that the opening part is located on at least either edge of a 1st edge, in two places, formed by a main face and a side face of a vibrating arm part or a 2nd edge, in two places, formed by the main face and a side face of a groove part, and a parallel light is slantingly irradiated through the opening part toward at least either of a bottom face or an outside of the groove part while following a face intersecting perpendicularly to a longitudinal direction of the vibrating arm part to thereby expose a photosensitive film.
1. A method of manufacturing a piezoelectric vibrating piece having one pair of vibrating arm parts having been disposed parallel by using a photolithography technique to a piezoelectric plate consisting of a piezoelectric material, a base part integrally fixing base end sides of the one pair of vibrating arm parts, groove parts having been formed respectively in both main faces of the one pair of vibrating arm parts along a longitudinal direction of the vibrating arm part, and an exciting electrode which is formed on outer surfaces of the one pair of vibrating arm parts and which vibrates the one pair of vibrating arm parts, characterized in that an electrode formation process for forming the exciting electrode has:
a coating process for coating an electrically conductive film to whole outer surfaces of the one pair of vibrating arm parts,
an application process for applying a photosensitive film consisting of positive type photosensitive material onto the electrically conductive film,
an exposure process in which a mask having an opening part having been previously patterned is disposed such that the opening part is located on at least either edge of a 1st edge, in two places, formed by the main face and a side face of the vibrating arm part or a 2nd edge, in two places, formed by the main face and a side face of the groove part, and a parallel light is slantingly irradiated through the opening part toward at least either of a bottom face or an outside of the groove part while following a face intersecting perpendicularly to a longitudinal direction of the vibrating arm part to thereby expose the photosensitive film,
a development process for developing the photosensitive film to thereby remove an exposed region, and
an etching process for etching-working the electrically conductive film with the residual photosensitive film being made a mask, thereby forming the exciting electrode.
2. A method of manufacturing a piezoelectric vibrating piece according to claim 1 , characterized in that, on an occasion of the exposure process, the mask is disposed such that the opening parts are located respectively on the 1st edge in one place and on the 2nd edge, in one place, which is in a positional relation nipping the groove part between it and the 1st edge, and the photosensitive film is exposed in two places at the same time through the opening parts.
3. A method of manufacturing a piezoelectric vibrating piece according to claim 1 , characterized in that when the parallel light is irradiated toward a bottom face of the groove part in the exposure process, an incident angle of the parallel light and a position of the opening part are adjusted such that a plane region or a deepest part of the photosensitive film having been formed on the bottom face of the groove part is irradiated.
4. A method of manufacturing a piezoelectric vibrating piece according to claim 1 , characterized in that, on an occasion of the exposure process, by relatively changing a direction of the one pair of vibrating arm parts with respect to an irradiation direction of the parallel light, the parallel light is irradiated under a state that a predetermined angle has been formed with respect to the face intersecting perpendicularly to the longitudinal direction.