US 12,033,665 B2
Thin substrate built-in hard disk drive and base plate member for thin substrate built-in hard disk drive
Kotaro Kitawaki, Tokyo (JP); Hideyuki Hatakeyama, Tokyo (JP); Wataru Kumagai, Tokyo (JP); and Ryo Sakamoto, Tokyo (JP)
Assigned to UACJ Corporation, Tokyo (JP); and Furukawa Electric Co., Ltd., Tokyo (JP)
Filed by UACJ Corporation, Tokyo (JP); and Furukawa Electric Co., Ltd., Tokyo (JP)
Filed on Apr. 20, 2023, as Appl. No. 18/303,899.
Application 18/303,899 is a continuation of application No. PCT/JP2021/037203, filed on Oct. 7, 2021.
Claims priority of application No. 2020-177486 (JP), filed on Oct. 22, 2020.
Prior Publication US 2024/0119967 A1, Apr. 11, 2024
Int. Cl. G11B 25/04 (2006.01); C22C 21/00 (2006.01); G11B 33/02 (2006.01); C22C 21/02 (2006.01)
CPC G11B 25/043 (2013.01) [C22C 21/00 (2013.01); G11B 33/02 (2013.01); G11B 33/022 (2013.01); C22C 21/02 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A base plate member made of an aluminum alloy, for a thin substrate built-in hard disk drive comprising a metallographic structure in which a perimeter of a second phase particle having a longest diameter of 10 μm or more is 3 mm/mm2 or more, and a number of second phase particles having a longest diameter of 500 μm or more is 0 particles/mm2.