EP0484297A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for assembling and resin-encapsulating a semiconductor power device mounted on a heat sink
Assignee: STMicroelectronics SRL
•
Filing: 1991-10-30
•
Granted: —
•
Expires: 2011-10-30
Abstract
Abstract A die-stamped frame (2) is fastened to a heat sink metal baseplate (1) by wedging flexible tabs (3,4) into receiving indentations (5,6) of the baseplate (1) while keeping the frame (2) substantially in contact with the surface of the baseplate (1). The wire welding operations may then take place on the end of the fingers (2b) of the patterned metal frame (2) while the same are solidly resting on the surface of the baseplate (1) thus facilitating the welding. The backing-off of the metal frame (2) from the surface of the heat sink baseplate (1) takes place upon the closing of the mold (9,11) used for encapsulating in resin the device. The injection of the resin and its solidification "freezes" the pins (2b) in the backed-off position imposed by the mold (9,11) upon closing, thus ensuring the electrical isolation between the pins (2b) and the integral heat sink baseplate (1).
Inventors
- 👤 Paolo Casati
- 👤 Carlo Cognetti De Martiis
- 👤 Giuseppe Marchisi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 00:29
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/70; H10W40/77; H10W40/778; H10W74/00; H10W74/01; H10W74/016; Y; Y10; Y10S; Y10S425/00; Y10S425/228; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
398 words
A process for assembling and encapsulating in resin a die of a semiconductor wafer having metallized pads for wiring connections, which comprises fastening together a patterned metal frame and a flat metallic heat sink baseplate, disposed in respectively parallel planes, by wedging fastening tabs of said metal frame into indentations formed on opposite sides of said heat sink, and successively cementing said die on said heat sink, connecting said pads to the ends of coplanar fingers of said patterned frame by means of metal wires welded thereto, placing the mounted assembly in a mold capable of defining a cavity for containing said metal heat sink, said die, said connecting wires and an inner portion of said coplanar fingers, which extend beyond the perimeter of said cavity by passing between perimetral mating surfaces of said mold and of a counter-mold, and injecting resin into said cavity for encapsulating the assembly while leaving exposed a surface of said heat sink baseplate and ensuring the electric isolation of each of said coplanar fingers from said metallic heat sink, characterized by comprising the following steps fastening said metal frame to said heat sink while maintaining said coplanar fingers of the metal frame resting on the surface of the heat sink; welding said metal wires on the ends of said coplanar fingers resting on the surface of the heat sink; placing the mounted assembly on a substantially flat mold provided with raised portions for supporting the heat sink by said surface thereof, the supports being arranged along the sides of the perimeter of the heat sink on which said tabs of the metal frame are anchored thereto; closing the mold by means of a counter-mold having a substantially flat mating surface provided with a cavity capable of completely containing said heat sink, said-counter mold pushing said fingers while bending said fastening tabs against the surface of said flat mold thus spacing said coplanar fingers from the surface of the heat sink; injecting an encapsulation resin in the cavity defined between the surface of said mold and the opposed surface of the heat sink and laterally by said counter-mold and, partially, by the inner face of said raised supports of the mold; and solidifying the injected resin within the space comprised between said surface of the heat sink and said fingers of the metal frame before opening the mold and recovering the encapsulated device.
Claim 2
Dependent Claim
125 words
A process for assembling and encapsulating in resin a semiconductor power device incorporating a metallic heat sink baseplate which comprises fastening a patterned metal frame onto a face of said heat sink baseplate by wedging tabs of said patterned metal frame into indentations formed in the perimeter of said heat sink baseplate while maintaining the metal frame substantially in abutment with the surface of the baseplate; completing wire welding operations on the frame resting on the baseplate; placing the completed assembly into a mold and causing, upon closing the mold, the separation of the metal frame from said heat sink baseplate while yieldingly bending said fastening tabs; injecting and solidifying an encapsulation resin inside the mold before opening the mold and recovering the encapsulated device.
Claim 3
Dependent Claim
165 words
A mold for encapsulating in resin a semiconductor power device incorporating a metallic heat sink baseplate and a patterned metal frame fastened together by wedging at least two fastening tabs of said frame in indentations formed in two opposite sides of the perimeter of said heat sink baseplate, said frame having a plurality of coplanar patterned fingers onto which connecting wires to the semiconductor device are welded, characterized by comprising a first portion of mold substantially flat and provided with raised portions for supporting said metal frame and heat sink baseplate fastened together, projectively in correspondence of said wedging points on opposite sides of the perimeter of the heat sink baseplate, and a second part or counter-mold having a cavity capable of containing completely said heat sink baseplate and said raised portions and a surrounding substantially flat surface capable of flexing said coplanar patterned fingers of the metal frame and displacing them away from the face of the heat sink baseplate, upon closing the mold.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.