| US 7,512,038 B2 | ||
| Ultrasonic transducer and manufacturing method | ||
| Shuntaro Machida, Kokubunji (Japan); Hiroyuki Enomoto, Musashino (Japan); and Yoshitaka Tadaki, Hanno (Japan) | ||
| Assigned to Hitachi, Ltd., Tokyo (Japan) | ||
| Filed on Feb. 05, 2007, as Appl. No. 11/671,040. | ||
| Claims priority of application No. 2006-096615 (JP), filed on Mar. 31, 2006. | ||
| Prior Publication US 2008/0042225 A1, Feb. 21, 2008 | ||
| Int. Cl. H04R 19/00 (2006.01) | ||
| U.S. Cl. 367—181 [600/459] | 2 Claims |
| 1. A method of manufacturing an ultrasonic transducer, comprising the steps of:
(a) patterning a conductive film to form a first electrode;
(b) forming a first insulation film covering said first electrode;
(c) flattening said first insulation film to expose the surface of said first electrode;
(d) forming a second insulation film covering said first electrode and said first insulation film;
(e) forming a sacrifice layer overlapping said first electrode on said second insulation film;
(f) forming a third insulation film covering said sacrifice layer and said second insulation film;
(g) forming a second electrode overlapping said sacrifice layer on said third insulation film;
(h) forming an interconnection joined to said second electrode;
(i) forming a fourth insulation film covering said second electrode, said interconnection and said third insulation film;
(j) forming an opening penetrating said third insulation film and said fourth insulation film to reach said sacrifice layer;
(k) forming a hollow part by removing said sacrifice layer using said opening; and
(l) filling said opening with a fifth insulation film to seal said hollow part.
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