06087198 is referenced by 89 patents and cites 5 patents.

An acoustic reflector (48) is applied over a thin-film piezoelectric resonator (41, 61) which is supported on a semiconductor or semiconductor-compatible substrate (42, 62) of a microelectronic device (40, 60), enabling an encapsulant (49) to be applied over the reflector-covered resonator without acoustically damping the resonator. In one embodiment, alternating high and low acoustic impedance layers (51, 53 . . . 55) of one-quarter wavelength thicknesses constructively reflect the resonating wavelength to make an encapsulant in the form of an inexpensive plastic molding compound appear as a "clamping" surface to a resonator (41) peripherally supported over an opening (43) on a silicon substrate (42). In another embodiment, an encapsulant- and reflector-covered resonator (61) is mechanically supported above a second reflector (68) which eliminates the need for peripheral support, making substrate (68) also appear as a clamping surface. The invention enables low cost plastic packaging of resonators and associated circuitry on a single monolithic structure. A radio frequency transceiver front-end application is given as an exemplary implementation.

Title
Low cost packaging for thin-film resonators and thin-film resonator-based filters
Application Number
9/22905
Publication Number
6087198
Application Date
February 12, 1998
Publication Date
July 11, 2000
Inventor
Carl M Panasik
Garland
TX, US
Agent
Frederick J Telecky Jr
Wade James Brady III
Warren L Franz
Assignee
Texas Instruments Incorporated
TX, US
IPC
H01L 21/00
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