US4649637A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing resin-molded semiconductor device having heat radiating plate embedded in the resin
Assignee: NEC Electronics Corp
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Filing: 1984-01-17
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Granted: 1987-03-17
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Expires: 2004-01-17
Abstract
Abstract A lead frame has a plurality of metallic heat radiating plates, leads connected to each metallic heat radiating plate, other leads separated from the metallic heat radiating plates and a common insulator web attached to the metallic heat radiating plates. When the lead frame is placed in the cavity of a mold, the metallic heat radiating plates are correctly positioned in the mold cavity by means of the insulating web and the connected leads. By effecting a resin molding under this condition, the metallic heat radiating plates are molded in resin such that a layer of resin with a uniform thickness cover the back surface of the respective metallic heat radiating plates.
Inventors
- 👤 Mikio Hatakeyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 01:31
CPC Classifications
H; H10; H10W; H10W40/00; H10W40/70; H10W40/77; H10W40/778; H10W70/00; H10W70/40; H10W70/481; H10H; H10H20/00; H10H20/80; H10H20/85; H10H20/858; H10H20/8585; H10W72/00; H10W72/01; H10W72/0198; H10W72/50; H10W72/541; H10W72/5449; H10W72/551; H10W72/552; H10W74/00; H10W74/10; H10W74/111; H10W90/00; H10W90/701; H10W90/751; H10W90/756; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
181 words
A method for producing a semiconductor device comprising the steps of: preparing a lead frame in which united are a plurality of units each having a plurality of leads for external connection and a metallic heat radiating plate secured to one of said leads; securing a common insulator web to one end of said metallic heat radiating plates of said lead frame; securing a semiconductor pellet to each of said metallic heat radiating plate of said lead frame; electrically connecting the electrodes of said semiconductor pellet to said leads of said lead frame; placing said lead frame having said semiconductor pellets secured thereto and having said leads connected to said electrodes of said semiconductor pellets in a cavity of a mold; positioning said metallic heat radiating plates in said mold cavity by clamping said leads and said insulator web by said mold; charging a resin into said mold cavity; taking out said lead frame from said mold after the solidification of said resin; and cutting said lead frame and said insulator web to severe said lead frame into individual semiconductor devices.
Claim 2
Independent Claim
181 words
A method for producing a semiconductor device comprising the steps of: preparing a lead frame in which united are a plurality of units each having a plurality of leads for external connection and a metallic heat radiating plate secured to one of said leads; securing a common insulator web to one end of said metallic heat radiating plates of said lead frame; securing a semiconductor pellet to each of said metallic heat radiating plate of said lead frame; electrically connecting the electrodes of said semiconductor pellet to said leads of said lead frame; placing said lead frame having said semiconductor pellets secured thereto and having said leads connected to said electrodes of said semiconductor pellets in a cavity of a mold; positioning said metallic heat radiating plates in said mold cavity by clamping said leads and said insulator web by said mold; charging a resin into said mold cavity; taking out said lead frame from said mold after the solidification of said resin; and cutting said lead frame and said insulator web to severe said lead frame into individual semiconductor devices.
Claim 3
Dependent Claim
47 words
A method for producing a semiconductor device as claimed in claim 1, wherein said insulator web is cut along the surface of the solidified resin so that the surface of said insulator web exposed through said solidified resin is flush with the surface of said solidified resin.
Claim 4
Dependent Claim
47 words
A method for producing a semiconductor device as claimed in claim 1, wherein said metallic heat radiating plate is positioned in said mold cavity such that the bottom of said metallic heat radiating plate is spaced 0.35 to 0.65 mm from the bottom of said mold cavity.
Claim 5
Dependent Claim
40 words
A method for producing a semiconductor device as claimed in claim 1, wherein said insulator web is made from an insulating material having a softening point higher than the temperature at which said resin is charged into said mold cavity.
Claim 6
Dependent Claim
38 words
A method for producing a semiconductor device as claimed in claim 1, wherein said metallic heat radiating plate is provided at said one end thereof with a metallic projection, said insulator web being attached to said metallic projection.
References Cited (Backward Citations)
US4451973A
Cited
JPS63736A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-16 | 1990-09-15 | 1991-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-16 | 1994-09-15 | 1995-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-16 | 1998-09-15 | 1999-03-17 | $7700.00 | Window Closed / Lapsed |