US 12,224,734 B2
Surface acoustic wave device and method of manufacturing the same
Cheng-Hung Shih, Changhua County (TW); and Cheng-Fan Lin, Hsinchu County (TW)
Assigned to CHIPBOND TECHNOLOGY CORPORATION, Hsinchu (TW)
Filed by CHIPBOND TECHNOLOGY CORPORATION, Hsinchu (TW)
Filed on Jul. 1, 2022, as Appl. No. 17/856,036.
Application 17/856,036 is a division of application No. 16/581,901, filed on Sep. 25, 2019, granted, now 11,522,517.
Claims priority of application No. 108124391 (TW), filed on Jul. 10, 2019.
Prior Publication US 2022/0337216 A1, Oct. 20, 2022
Int. Cl. H03H 3/08 (2006.01); H03H 9/02 (2006.01); H03H 9/05 (2006.01); H03H 9/145 (2006.01); H10N 30/87 (2023.01)
CPC H03H 9/02952 (2013.01) [H03H 3/08 (2013.01); H03H 9/02834 (2013.01); H03H 9/059 (2013.01); H03H 9/145 (2013.01); H10N 30/877 (2023.02)] 8 Claims
OG exemplary drawing
 
1. A method of manufacturing a surface acoustic wave device comprising:
providing a piezoelectric substrate including a base, a conductive pad and a transducer, the conductive pad and the transducer are disposed on the base and electrically connected with each other;
forming a supportive layer on the piezoelectric substrate;
patterning the supportive layer to form a lower via hole and an opening hole, the lower via hole is located outside the opening hole and exposes the conductive pad, the opening hole is located above the transducer,
wherein the patterned supportive layer surrounds the transducer;
forming a cover layer on the supportive layer, the cover layer covers the opening hole;
patterning the cover layer to form an upper via hole, the upper via hole is located above the lower via hole and communicated to the lower via hole,
wherein the upper via hole has a first top opening, a first bottom opening and a first lateral opening, the first top opening is located on a top surface of the cover layer, the first bottom opening is located on a bottom surface of the cover layer, the first lateral opening is located on a lateral surface of the cover layer, and both ends of the first lateral opening are connected to the first top opening and the first bottom opening, respectively;
forming a photoresist layer on the cover layer;
patterning the photoresist layer to form an opening, the opening is communicated to the upper via hole;
forming a pillar bump in the lower via hole and the upper via hole, the pillar bump is connected to the conductive pad; and
removing the photoresist layer;
wherein the pillar bump in the cover layer includes a first part and a second part, the first part is located in the upper via hole and the second part is protruded from the lateral surface of the cover layer via the first lateral opening of the upper via hole.