(19)
(11) EP 4 287 507 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
Note: Bibliography reflects the latest situation

(15) Correction information:
Corrected version no 1 (W1 A1)

(48) Corrigendum issued on:
16.10.2024 Bulletin 2024/42

(43) Date of publication:
06.12.2023 Bulletin 2023/49

(21) Application number: 23172124.2

(22) Date of filing: 08.05.2023
(51) International Patent Classification (IPC): 
H03H 9/19(2006.01)
H03H 9/02(2006.01)
 H03H 3/02(2006.01)
H03H 9/13(2006.01)
(52) Cooperative Patent Classification (CPC):
H03H 9/19; H03H 3/02; H03H 2003/022; H03H 9/02055; H03H 9/132
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC ME MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA
Designated Validation States:
KH MA MD TN

(30) Priority: 31.05.2022 TW 111120274

(71) Applicant: Aker Technology Co., Ltd.
Taichung City 42760 (TW)

(72) Inventors:
  • HORNG, Ray-Hua
    40253 Taichung City (TW)
  • LIN, Yi-Lun
    42760 Taichung City (TW)

(74) Representative: V.O. 
P.O. Box 87930
2508 DH Den Haag
2508 DH Den Haag (NL)

   


(54) CRYSTAL OSCILLATOR AND METHOD OF MAKING THE SAME


(57) A crystal oscillator (100) includes a piezoelectric substrate (2) having a thinned portion (21) with opposite upper and lower surfaces (211, 212) respectively defining upper and lower surface work portions, and at least one side portion (22) having at least one recessed portion (221) with a bottom surface flush with the upper surface (211) of the thinned portion (21). A top electrode layer (3) has a top work portion (31) disposed on the upper surface work portion, and a top extension (32) extending from the top work portion (31) onto the bottom surface of the recessed portion (221). A bottom electrode layer (4) has a bottom work portion (41) disposed on the lower surface work portion, and a bottom extension (42) extending from the bottom work portion (41) toward the one end of the thinned portion (21) and then bending upward (422) and inward (423) onto the bottom surface of the recessed portion (221). A method of making the crystal oscillator (100) is also disclosed; the method uses a temporary handle substrate attached to the lower surface (212) and the bottom electrode layer (4) for thinning / etching the quartz to the upper surface (211) and forming the side (22) and recessed portion (221).