Method of manufacturing a composite substrate and a piezoelectric device using the substrate
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsAkihiko Namba, Tetsuyoshi Ogura, Yoshihiro Tomita, Kazuo Eda
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Abstract
A method of manufacturing a composite substrate and the composite substrate manufactured thereby wherein surfaces of first and second substrates having different thermal expansion coefficients are mirror finished and layered on each other. A first heat treatment is applied after which a part of the second substrate is removed to a depth sufficient to expose the first substrate. A final second heat treatment directly bonds the substrates.
Claims13
A method of manufacturing a composite substrate, comprising the steps of:
- mirror finishing at least one principal surface of a first substrate;
- mirror finishing at least one principal surface of a second substrate having a thermal expansion coefficient different from that of the first substrate;
- abutting the mirror finished principal surface of the first substrate against the mirror finished principal surface of the second substrate;
- applying a first heat treatment to the abutted substrates at a temperature lower than a temperature at which bonding of the first substrate and the second substrate would occur;
- cutting the substrates into at least two pieces, after said first heat treatment, while maintaining the first substrate abutted to the second substrate;
- and
- applying a second heat treatment to the at least two pieces at a temperature at which bonding occurs between the first substrate and the second substrate.
A method of manufacturing a composite substrate, comprising the steps of:
- mirror finishing at least one principal surface of a first substrate;
- mirror finishing at least one principal surface of a second substrate having a thermal expansion coefficient different from that of the first substrate;
- abutting the mirror finished principal surface of the first substrate against the mirror finished principal surface of the second substrate;
- applying a first heat treatment to the abutted substrates at a temperature lower than a temperature at which bonding of the first substrate and the second substrate would occur;
- removing a part of the second substrate to a depth sufficient to expose the first substrate after said first heat treatment;
- and
- applying a second heat treatment at temperature at which bonding occurs between the first substrate and the second substrate.
Dependencies are inferred from the claim text.