Quad leadframe packages and related methods
Implementations of power modules may include: a substrate having a first side and a second side. The power module may include a plurality of leads coupled to a second side of the substrate and a molding compound over a portion of five or more surfaces of the substrate. The power module may also include an opening extending from a first side of the substrate to an outer edge of the molding compound. The opening may be configured to receive a coupling device and the coupling device may be configured to couple with a heat sink or a package support.
1. A method of forming a semiconductor package, the method comprising:
coupling a lead frame to a substrate, wherein the lead frame has a plurality of leads extending from each of four sides of the lead frame;
selectively trimming a first set of the plurality of leads;
forming an encapsulant around at least five surfaces of the substrate and a portion of each of a second set of the plurality of leads; and
trimming the lead frame by trimming one or more of the plurality of leads to a predetermined length;
wherein the first set of the plurality of leads are completely removed from the semiconductor package during trimming of the lead frame.
2. The method of claim 1 , further comprising using a fixture to prevent a flow of encapsulant into one or more mounting holes in the substrate.
3. The method of claim 2 , the substrate further comprising a mounting hole extending from a first side to a second side of the substrate.
4. The method of claim 2 , wherein the substrate is one of a direct bonded copper substrate (DBC) with a ceramic core, a direct bonded aluminum (DBA) substrate, an active metal brazing (AMB) substrate, an insulated metal substrate (IMS), a plated ceramic substrate, a high-layer-count (HLC) printed wiring board (PWB), a low temperature co-fired ceramic (LTCC) substrate, a high temperature co-fired ceramic (HTCC) substrate, or a polymer coated conductive plate.
5. The method of claim 1 , wherein the lead frame is coupled to the substrate through one of soldering or sintering.
6. The method of claim 1 , wherein forming the encapsulant comprises using a transfer molding method.
7. The method of claim 1 , wherein each lead of the second set of leads extends further towards the substrate than each lead of the first set of leads.
8. The method of claim 1 , wherein the substrate is directly coupled to each lead of the second set of leads.
9. A method of forming a semiconductor package, the method comprising:
providing a substrate having a first side, a second side, and one or more mounting holes extending through an entire thickness of the substrate from the first side to the second side;
coupling a lead frame having a plurality of leads to the substrate;
selectively trimming a first set of the plurality of leads;
encapsulating at least five surfaces of the substrate and a portion of each of a second set of the plurality of leads in molding compound; and
trimming the lead frame from the remaining plurality of leads.
10. The method of claim 9 , wherein the substrate comprises two mounting holes extending from the first side to the second side of the substrate.
11. The method of claim 9 , wherein the first set of the plurality of leads does not extend into a cavity included in the transfer molding method.
12. The method of claim 9 , wherein the plurality of leads have a pitch of 3.2 mm.
13. The method of claim 9 , wherein the lead frame is coupled to the substrate through one of soldering or sintering.
14. The method of claim 9 , wherein forming the encapsulant comprises using a transfer molding method.
15. The method of claim 9 , wherein the encapsulant comprises one of epoxies, resins, polymers or any combination thereof.
16. The method of claim 9 , wherein the first set of the plurality of leads are completely removed from the semiconductor package during trimming of the lead frame.
17. A method of forming a semiconductor package, the method comprising:
coupling a lead frame to a substrate, wherein the lead frame has a plurality of leads extending from each of four sides of the lead frame;
selectively trimming a first set of the plurality of leads;
forming an encapsulant around at least five surfaces of the substrate and a portion of each of a second set of the plurality of leads; and
trimming the lead frame by trimming one or more of the plurality of leads to a predetermined length;
wherein each lead of the second set of leads extends further towards the substrate than each lead of the first set of leads;
wherein an entire length of each lead of the plurality of leads lies in the same plane.
18. The method of claim 17 , wherein the substrate is directly coupled to each lead of the second set of leads.