Lead frame including suspending leads having trenches formed therein
View Patent ↗In a lead frame, through holes are formed outside suspending leads and trenches are formed on a back surface along the suspending leads so as to communicate with the through holes. When sealing resin is injected into cavities of a resin molding die, air enters the through holes through air vents and flows out from the through holes by a resin injection pressure in the trenches, making it easier for the sealing resin to enter the through holes. Since the sealing resin leaking to the air vents can be injected into the through holes, it is possible to enhance the bonding force between the sealing resin after curing and the lead frame in the vicinity of the air vents and effect release of the resin molding die, while allowing the sealing resin leaking to the air vents to remain on the lead frame side without remaining within the air vents.
1. A lead frame in the shape of a thin plate used in a method of manufacturing a semiconductor device, comprising:
chip mounting portions capable of mounting semiconductor chips thereover;
suspending leads connected to the chip mounting portions;
a plurality of leads arranged around the chip mounting portions; and
frame portions connected to the suspending leads and the leads,
wherein the frame portions have through holes formed outside the suspending leads in extending directions of the suspending leads and also have trenches formed along the suspending leads on a back surface side opposite to the chip mounting portion side so as to communicate with the through holes.
2. The lead frame according to claim 1 , wherein said lead frame is plated with palladium.
3. A lead frame in the shape of a thin plate used in a method of manufacturing a semiconductor device, comprising:
chip mounting portions capable of mounting semiconductor chips thereover;
suspending leads connected to the chip mounting portions;
a plurality of leads arranged around the chip mounting portions; and
frame portions connected to the suspending leads and the leads,
wherein the frame portions have through holes formed outside the suspending leads in extending directions of the suspending leads and also have trenches formed along the suspending leads on the same side as the chip mounting portion side so as to communicate with the through holes.
4. The lead frame according to claim 3 , wherein said lead frame is plated with palladium.
5. A lead frame in the shape of a thin plate used in a method of manufacturing a semiconductor device, comprising:
chip mounting portions capable of mounting semiconductor chips thereover;
suspending leads connected to the chip mounting portions;
a plurality of leads arranged around the chip mounting portions; and
frame portions connected to the suspending leads and the leads,
wherein the frame portions have through holes formed outside the suspending leads in extending directions of the suspending leads and also have trenches formed in both surfaces and back surfaces of the frame portions along the suspending leads and at mutually deviated positions to avoid overlapping and so as to communicate with the through holes.
6. The lead frame according to claim 5 , wherein said lead frame is plated with palladium.