Patent ID: 11894823
Assignee: DISCO CORPORATION
Field: Basic communication processes (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. A surface acoustic wave device manufacturing method comprising:
a piezoelectric ceramic substrate providing step of providing a piezoelectric ceramic substrate having a first surface and a second surface opposite to each other;
a support substrate providing step of providing a support substrate having a first surface and a second surface opposite to each other, the support substrate having a thermal expansion coefficient lower than that of the piezoelectric ceramic substrate;
a support substrate protective member applying step of applying a protective member to the second surface of the support substrate;
a piezoelectric ceramic substrate polishing step of polishing the first surface of the piezoelectric ceramic substrate to thereby planarize the first surface of the piezoelectric ceramic substrate;
a support substrate polishing step of polishing the first surface of the support substrate to thereby planarize the first surface of the support substrate by holding the second surface of the support substrate through the support substrate protective member on an upper surface of a chuck table and polishing the first surface of the support substrate;
a bonding step of bonding the first surface of the piezoelectric ceramic substrate to the first surface of the support substrate after performing the piezoelectric ceramic substrate polishing step and the support substrate polishing step, thereby forming a stacked substrate composed of the piezoelectric ceramic substrate and the support substrate;
a grinding step of grinding the second surface of the piezoelectric ceramic substrate of the stacked substrate after performing the bonding step while holding the second surface of the support substrate through the support substrate protective member on an upper surface of a chuck table, thereby reducing a thickness of the piezoelectric ceramic substrate to a predetermined thickness;
a vibration diffusion layer forming step of applying a laser beam to the stacked substrate in a condition where a focal point of the laser beam is positioned inside the piezoelectric ceramic substrate while holding the second surface of the support substrate through the support substrate protective member on an upper surface of a chuck table after performing the grinding step, the laser beam having a transmission wavelength to the piezoelectric ceramic substrate, thereby forming a modified layer as a vibration diffusion layer inside the piezoelectric ceramic substrate; and
an electrode forming step of forming an electrode pattern on the second surface of the piezoelectric ceramic substrate of the stacked substrate after performing the vibration diffusion layer forming step.