US5492866A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for correcting warped surface of plastic encapsulated semiconductor device
Assignee: NEC Electronics Corp
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Filing: 1993-08-02
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Granted: 1996-02-20
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Expires: 2013-08-02
Abstract
Abstract A process for correcting the warped surface of a plastic encapsulated semiconductor lead frame device. The semiconductor device is placed on a transporting plate and transported to a heating device. The semiconductor device and the transporting device are clamped between a pair of heating plates and heated. Then the semiconductor device and the transporting plate are removed from the device and clamped between a pair of cooling plates and cooled. The warp is corrected to a substantially flat surface.
Inventors
- 👤 Hideyuki Nishikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:12
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/04; H10W70/048; H10W74/00; H10W74/01; H10P; H10P72/00; H10P72/04; H10P72/0431; H10P72/0438; H10P72/30; H10P72/32; H10P72/3212; H10W74/10; H10W74/111; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49121
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
263 words
A method of manufacturing a plastic seal semiconductor device, comprising the steps of: mounting a plurality of semiconductor elements in spaced relation on a single lead frame, connecting connection regions of a plurality of leads of said lead frame to a plurality of connecting portions of said semiconductor elements by thin metal wires, and forming plastic seal portions each surrounding each of said semiconductor elements, said thin metal wires, said connection regions of said leads and peripheral areas thereof; correcting warpage of upper and lower main surfaces of said plastic seal portions by clamping said plastic seal portions within said single lead frame between upper and lower heating plates of a heating device while applying heat to said plastic seal portions through said heating plates, transporting said single lead frame from said heating device to a cooling device comprising upper and lower cooling plates, and clamping said plastic seal portions between said upper and lower cooling plates; separating an intermediate product of a plurality of plastic seal semiconductor devices from said lead frame, said intermediate product being prepared by cutting the plurality of leads to separate the plurality of said semiconductor elements from one another; and shaping the plurality of said leads of said intermediate products separated from said lead frame, wherein said lead frame is transported between said heating device and said cooling device on a transporting plate through which heat is applied to lower surfaces of said semiconductor elements in said heating device and through which heat is extracted from said lower surface of said semiconductor elements in said cooling device.
Claim 2
Independent Claim
263 words
A method of manufacturing a plastic seal semiconductor device, comprising the steps of: mounting a plurality of semiconductor elements in spaced relation on a single lead frame, connecting connection regions of a plurality of leads of said lead frame to a plurality of connecting portions of said semiconductor elements by thin metal wires, and forming plastic seal portions each surrounding each of said semiconductor elements, said thin metal wires, said connection regions of said leads and peripheral areas thereof; correcting warpage of upper and lower main surfaces of said plastic seal portions by clamping said plastic seal portions within said single lead frame between upper and lower heating plates of a heating device while applying heat to said plastic seal portions through said heating plates, transporting said single lead frame from said heating device to a cooling device comprising upper and lower cooling plates, and clamping said plastic seal portions between said upper and lower cooling plates; separating an intermediate product of a plurality of plastic seal semiconductor devices from said lead frame, said intermediate product being prepared by cutting the plurality of leads to separate the plurality of said semiconductor elements from one another; and shaping the plurality of said leads of said intermediate products separated from said lead frame, wherein said lead frame is transported between said heating device and said cooling device on a transporting plate through which heat is applied to lower surfaces of said semiconductor elements in said heating device and through which heat is extracted from said lower surface of said semiconductor elements in said cooling device.
Claim 3
Dependent Claim
14 words
The method according to claim 1, wherein said cooling device comprises a heat sink.
Claim 4
Dependent Claim
30 words
The method according to claim 1, wherein said heating device comprises a pair of heater blocks each formed integrally with a respective one of said upper and lower heating plates.
Claim 5
Dependent Claim
30 words
The method according to claim 1, wherein said cooling device comprises a pair of heat sinks each formed integrally with a respective one of said upper and lower cooling plates.
Claim 6
Dependent Claim
45 words
The method according to claim 1, wherein a series of said heating devices followed by a series of said cooling devices are provided, and wherein a corresponding plurality of said lead frames are acted on serially by each of said heating devices and cooling devices.
Claim 7
Dependent Claim
60 words
The method according to claim 1, wherein said shaping step comprises bending external leads, said external leads extending from side surfaces of said plastic seal portions at root portions thereof and further bending said external leads at outward portions thereof such that end portions of said external leads extend parallel to said lower main surface of said plastic seal portions.
Claim 8
Dependent Claim
20 words
The method according to claim 6, wherein said external leads extend from four side surfaces of said plastic seal portions.
Claim 9
Dependent Claim
17 words
The method according to claim 1, wherein said plastic seal portion is made of thermoplastic epoxy resin.
Claim 10
Independent Claim
239 words
A method of manufacturing a semiconductor device comprising the steps of: sealing each of a plurality of semiconductor elements mounted on a single lead frame with a resin and hardening said resin to form an intermediate device, said intermediate device thereby having a plurality of plastic seal portions each containing an associated one of said semiconductor elements therein, at least one of said plastic seal portions being warped to have a warped surface; placing said intermediate device on a transporting plate; moving said transporting plate having thereon said intermediate device into a heating device having a pair of heating plates; clamping and heating said plastic seal portions of said intermediate device in parallel to one another by said pair of heating plates with said transporting plate inserted between one of said pair of heating plates and each of said plastic seal portions; taking out said transporting plate having thereon said intermediate device from said heating device and then moving said transporting plate having thereon said intermediate device into a cooling device having a pair of cooling plates; and clamping and cooling said plastic seal portions of said intermediate device in parallel to one another by said pair of cooling plates with said transporting plate inserted between one of said cooling plates and each of said plastic seal portions; whereby said warped surface of said at least one of said plastic seal portions is corrected to a substantially flat surface.
Claim 11
Independent Claim
239 words
A method of manufacturing a semiconductor device comprising the steps of: sealing each of a plurality of semiconductor elements mounted on a single lead frame with a resin and hardening said resin to form an intermediate device, said intermediate device thereby having a plurality of plastic seal portions each containing an associated one of said semiconductor elements therein, at least one of said plastic seal portions being warped to have a warped surface; placing said intermediate device on a transporting plate; moving said transporting plate having thereon said intermediate device into a heating device having a pair of heating plates; clamping and heating said plastic seal portions of said intermediate device in parallel to one another by said pair of heating plates with said transporting plate inserted between one of said pair of heating plates and each of said plastic seal portions; taking out said transporting plate having thereon said intermediate device from said heating device and then moving said transporting plate having thereon said intermediate device into a cooling device having a pair of cooling plates; and clamping and cooling said plastic seal portions of said intermediate device in parallel to one another by said pair of cooling plates with said transporting plate inserted between one of said cooling plates and each of said plastic seal portions; whereby said warped surface of said at least one of said plastic seal portions is corrected to a substantially flat surface.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-02-19 | 1999-08-21 | 2000-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-02-19 | 2003-08-21 | 2004-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-02-19 | 2007-08-21 | 2008-02-20 | $7700.00 | Window Closed / Lapsed |