US 12,224,232 B2
Semiconductor package having side wall plating
Barry Lin, Kaohsiung (TW)
Assigned to SILICONIX INCORPORATED
Appl. No. 17/436,454
Filed by SILICONIX INCORPORATED, San Jose, CA (US)
PCT Filed Mar. 8, 2019, PCT No. PCT/US2019/021272
§ 371(c)(1), (2) Date Sep. 3, 2021,
PCT Pub. No. WO2020/185192, PCT Pub. Date Sep. 17, 2020.
Prior Publication US 2022/0181239 A1, Jun. 9, 2022
Int. Cl. H01L 21/56 (2006.01); H01L 23/00 (2006.01); H01L 23/31 (2006.01); H01L 23/495 (2006.01)
CPC H01L 23/49582 (2013.01) [H01L 21/561 (2013.01); H01L 23/3114 (2013.01); H01L 23/49541 (2013.01); H01L 24/97 (2013.01); H01L 2224/48091 (2013.01); H01L 2224/48247 (2013.01); H01L 2224/73265 (2013.01); H01L 2224/97 (2013.01); H01L 2924/181 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method for fabricating a semiconductor package, the method comprising:
providing a lead frame assembly, the lead frame assembly comprising:
a plurality of plating bars, the plurality of plating bars comprising a first set of plating bars spaced apart from each other and extending in a first direction, and a second set of plating bars spaced apart from each other and extending in a second direction generally perpendicular to the first direction, and
a plurality of die packages organized in rows with each die package having an integrated circuit die, each die package of the plurality of die packages having a bottom surface, a first side and an opposite second side, a third side and an opposite fourth side,
each die package of the plurality of die packages positioned between, attached to and electrically coupled to a plating bar of the first set of plating bars adjacent the first side of the die package and an opposing plating bar of the first set of plating bars adjacent the second side of the die package, each die package of the plurality of die packages positioned between, attached to and electrically coupled to a plating bar of the second set of plating bars adjacent the third side and an opposing plating bar of the second set of plating bars adjacent the fourth side;
each die package of the plurality of die packages comprising:
a die paddle electrically coupled via a single first tie bar to a respective one of the plating bars of the first set of plating bars adjacent the first side of the die package, and electrically coupled via a single second tie bar to an opposing respective one of the plating bars of the first set of plating bars adjacent the second side of the die package;
a plurality of leads, each of the plurality of leads having a sidewall and a bottom surface, at least some of the plurality of leads extending from and electrically coupled to the die paddle, at least one lead of the plurality of leads being spaced apart from the die paddle and electrically coupled to the respective plating bar of the first set of plating bars adjacent the second side of the die package via a single third tie bar;
encapsulating at least portions of the lead frame assembly with a mold encapsulation while leaving exposed bottom surfaces of the plurality of leads and bottom surfaces of the die paddles, the lead frame assembly and mold encapsulation forming a package assembly;
making a first series of parallel cuts completely through the second set of plating bars of the package assembly and partially through the mold encapsulation of the package assembly to create exposed portions of surfaces of sidewalls of the plurality of leads;
electroplating at least portions of the exposed portions of the surfaces of the sidewalls of the plurality of leads;
making a second series of parallel cuts aligned with the first series of parallel cuts, fully through the mold encapsulation, a width of the second series of parallel cuts smaller than a width of the first series of parallel cuts, thereby forming step-cut wettable sides; and
making a third series of parallel cuts fully through the mold encapsulation and the first set of plating bars, perpendicular to the first series of parallel cuts and the second series of parallel cuts.