Tie bar removal for semiconductor device packaging

Patent metadata

Field	Value
Publication number	US-2022093416-A1
Application number	US-202117457726-A
Country	US
Kind code	A1
Filing date	Dec 6, 2021
Priority date	Dec 26, 2019
Publication date	Mar 24, 2022
Grant date	—

Abstract

A method of tie bar removal is provided. The method includes forming a leadframe including a tie bar and a flag. The tie bar extends from a side rail of the leadframe and has a distal portion at an angle different from a plane of the flag. A semiconductor die is attached to the flag of the leadframe. A molding compound encapsulates the semiconductor die, a portion of the leadframe, and the distal portion of the tie bar. The tie bar is separated from the molding compound with an angled cavity remaining in the molding compound.

First claim

What is claimed is:

1 - 16 . (canceled)

17 . A semiconductor device comprising:
a leadframe having a plurality of conductive leads and a flag; a semiconductor die attached to the flag of the leadframe; and a molding compound encapsulating the semiconductor die and a portion of the leadframe, an angled cavity formed in the molding compound at an end of the semiconductor device, the angled cavity formed at an angle different from a plane of the flag.

18 . The semiconductor device of claim 17 , wherein the angle of the angled cavity is in a range of 15 to 75 degrees relative to the plane of the flag.

19 . The semiconductor device of claim 17 , wherein an innermost end of the angled cavity comprises a tetrahedron or pyramid shape.

20 . The semiconductor device of claim 17 , wherein an innermost end of the angled cavity comprises a semi-spherical or semi-cylindrical shape.

21 . The semiconductor device of claim 17 , wherein the angled cavity is formed by way of removing a tie bar.

22 . The semiconductor device of claim 17 , wherein an outermost end of the angled cavity is approximately coplanar with the flag of the leadframe.

23 . The semiconductor device of claim 17 , wherein an innermost end of the angled cavity is offset from a plane of the flag of the leadframe.

24 . A semiconductor device comprising:
a leadframe having a plurality of conductive leads and a flag; a semiconductor die attached to the flag of the leadframe; and a molding compound encapsulating the semiconductor die and a portion of the leadframe, an angled cavity formed in the molding compound at an end of the semiconductor device.

25 . The semiconductor device of claim 24 , wherein the angled cavity is formed having an angle different from a plane of the flag, the angle of the angled cavity having a range of 15 to 75 degrees relative to the plane of the flag

26 . The semiconductor device of claim 25 , wherein an outermost end of the angled cavity is approximately coplanar with the plane of the flag of the leadframe.

27 . The semiconductor device of claim 25 , wherein an innermost end of the angled cavity is offset from the plane of the flag of the leadframe.

28 . The semiconductor device of claim 24 , wherein an innermost end of the angled cavity comprises a tetrahedron or pyramid shape.

29 . The semiconductor device of claim 24 , wherein an innermost end of the angled cavity comprises a semi-spherical or semi-cylindrical shape.

30 . The semiconductor device of claim 24 , wherein the angled cavity is formed by way of removing a tie bar.

31 . A semiconductor device comprising:
a leadframe having a plurality of conductive leads and a flag; a semiconductor die attached to the flag of the leadframe; and a molding compound encapsulating the semiconductor die and a portion of the leadframe, an angled cavity formed in the molding compound at an end of the semiconductor device, an outermost end of the angled cavity approximately coplanar with a plane of the flag.

32 . The semiconductor device of claim 31 , wherein the angled cavity is formed having an angle different from the plane of the flag.

33 . The semiconductor device of claim 32 , wherein the angle of the angled cavity is in a range of 15 to 75 degrees relative to the plane of the flag.

34 . The semiconductor device of claim 31 , wherein an innermost end of the angled cavity is offset from the plane of the flag of the leadframe.

35 . The semiconductor device of claim 31 , wherein an innermost end of the angled cavity comprises a tetrahedron or pyramid shape.

36 . The semiconductor device of claim 31 , wherein an innermost end of the angled cavity comprises a semi-spherical or semi-cylindrical shape.

Assignees

• Nxp Usa Inc

Inventors

• Gan Richard Te
• Tank Rushik Prabhudas
• Gong Zhiwei
• Carpenter Burton Jesse
• Liu Jinmei

Classifications

• H10W74/129

  forming a chip-scale package [CSP] · CPC title

• H10W74/016

  using moulds · CPC title

• H10W70/424

  Cross-sectional shapes (H10W70/481 takes precedence) · CPC title

• H10W70/411

  Chip-supporting parts, e.g. die pads · CPC title

• H10W70/041

  Connecting or disconnecting interconnections to or from leadframes, e.g. connecting bond wires or bumps · CPC title