US 11,715,929 B2
System and apparatus for sequential transient liquid phase bonding
Zhizhong Tang, San Carlos, CA (US); Pradeep Srinivasan, Fremont, CA (US); Kevin Masuda, Alhambra, CA (US); and Wenjing Liang, San Jose, CA (US)
Assigned to Aeva, Inc., Mountain View, CA (US)
Filed by Aeva, Inc., Mountain View, CA (US)
Filed on May 2, 2022, as Appl. No. 17/734,506.
Application 17/734,506 is a continuation of application No. 17/502,941, filed on Oct. 15, 2021, granted, now 11,362,485.
Prior Publication US 2023/0123042 A1, Apr. 20, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01S 5/0237 (2021.01); H01S 5/40 (2006.01); B23K 101/40 (2006.01); B23K 1/005 (2006.01)
CPC H01S 5/0237 (2021.01) [B23K 1/0056 (2013.01); H01S 5/4025 (2013.01); B23K 2101/40 (2018.08)] 14 Claims
OG exemplary drawing
 
1. An apparatus for sequential bonding comprising:
a stage to receive a substrate having a plurality of receiving pads, wherein a first and a second receiving pads of said plurality of receiving pads each comprise a first metal alloy;
a first pickup head configured to attach a first semiconductor chip comprising a first metal layer to said first receiving pad;
a first heating unit coupled to said first pickup head to raise a temperature of said first semiconductor chip according to a first temperature profile to cause intermixing of said first metal layer on said first semiconductor chip and said first metal alloy of said first receiving pad to form a second metal alloy having a higher melting point than said first metal alloy;
a second pickup head configured to attach a second semiconductor chip comprising a second metal layer to said second receiving pad; and
a second heating unit coupled to said second pickup head to raise a temperature of said second semiconductor chip according to a second temperature profile to cause intermixing of said second metal layer on said second semiconductor chip and said first metal alloy of said second receiving pad to form a third metal alloy having a higher melting point than said first metal alloy;
wherein said first temperature and said second temperature profiles are based on a common set of temperature set points and time durations and wherein said second temperature profile is executed after a completion of said first temperature profile.