| US 7,459,094 B2 | ||
| Method for making a surface acoustic wave device package | ||
| Chi-Yen Shen, Kaohsiung (Taiwan) | ||
| Assigned to I Shou University, (Taiwan) | ||
| Filed on Feb. 16, 2007, as Appl. No. 11/675,751. | ||
| Application 11/675751 is a division of application No. 10/982204, filed on Nov. 05, 2004, granted, now 7,198,725. | ||
| Prior Publication US 2007/0187360 A1, Aug. 16, 2007 | ||
| Int. Cl. B44C 1/22 (2006.01); C23F 1/00 (2006.01); H01L 21/00 (2006.01) | ||
| U.S. Cl. 216—2 [216/41; 216/83; 438/689; 438/745] | 4 Claims |
| 1. A method for making a surface acoustic wave (SAW) device package that includes a SAW die having a piezoelectric substrate,
and transmitting and receiving transducers and a cap formed on the substrate, the cap having a peripheral wall and a cover
wall which cooperate with the substrate to define an embedded air cavity thereamong, said method comprising the steps of:
forming a pattern of lift-off layer on a wafer surface of a wafer through lithography techniques;
forming a metal layer on the wafer surface of the wafer and the lift-off layer through metallization techniques;
removing the lift-off layer and the metal layer on the lift-off layer by dissolving the lift-off layer in a solution so as
to form a pattern of the metal layer, that defines the transmitting and receiving transducers of the SAW die, on the wafer
surface of the wafer;
forming a pattern of a first photo sensitive layer, which defines the peripheral wall of the cap of the SAW die, on the metal
layer and the wafer surface of the wafer through lithography techniques;
forming a pattern of a second photo sensitive layer, which defines the cover wall of the cap of the SAW die, on the first
photo sensitive layer through lithography techniques;
curing the first and second photo sensitive layers;
dicing the wafer into SAW dies; and
encapsulating the SAW dies with a molding compound.
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