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US4963307A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for producing a tablet for resin-molding semiconductor devices and resin-molding method making use of the tablet

Assignee: Mitsubishi Electric Corp
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Filing: 1988-11-16
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Granted: 1990-10-16
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Expires: 2008-11-16
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Abstract

Abstract A resin-molding tablet for use in resin-molding semiconductor devices has a tablet body formed of powdered or particulate resin. The particles of the resin are compacted such as to form voids between adjacent particles. At least the outer peripheral region of the tablet is fused such that the resin particles are welded together to form a continuous layer of fine and impervious structure substantially free of open pores. The internal air trapped in the voids of the tablet is drawn and removed before the tablet is fused so that the tablet is substantially free of air. The tablet is produced by placing a particulate or powdered resin material in a vacuum vessel so as to allow the internal air in the resin material to be drawn outside, and then applying pressure and heat to the resin material so that at least the peripheral region of the mass of the particulate resin is fused to weld together. The tablet thus formed is melted and forcibly fed into a vacuum die cavity in which a semiconductor device to be molded is accommodated, thereby to hermetically seal the semiconductor device. Thus, a semiconductor package having substantially no voids is produced.

Inventors

  • 👤 Kunito Sakai
  • 👤 Sueyosi Tanaka
  • 👤 Yasutugu Tutumi
  • 👤 Yutaka Morita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 13:57
CPC Classifications
B; B29; B29B; B29B11/00; B29B11/14; B29B11/06; B29B11/12; B29C; B29C37/00; B29C37/006; B29C43/00; B29C43/006; B29C43/32; B29C43/56; B29C49/00; B29C49/071; B29C2949/00; B29C2949/07; B29C2949/0715; Y; Y10; Y10T; Y10T428/00; Y10T428/8305

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 76 words
A method of producing a resin tablet comprising: placing a resin material having voids in a vacuum vessel and evacuating the vessel to remove air trapped in the voids of said resin material; and heating the resin material to a temperature below the softening point of the resin material and applying pressure to said resin material to fuse at least a shell of said resin material and form a resin tablet substantially free of open pores.
Claim 2
Independent Claim 76 words
A method of producing a resin tablet comprising: placing a resin material having voids in a vacuum vessel and evacuating the vessel to remove air trapped in the voids of said resin material; and heating the resin material to a temperature below the softening point of the resin material and applying pressure to said resin material to fuse at least a shell of said resin material and form a resin tablet substantially free of open pores.
Claim 3
Dependent Claim 24 words
A method of producing a resin tablet according to claim 1 wherein said resin material placed in the vacuum vessel is powdered or granular.
Claim 4
Dependent Claim 38 words
A method of producing a resin tablet according to claim 1 including applying heat and pressure simultaneously to the resin material in the vacuum vessel whereby the shell of resin material substantially free of open pores is formed.
Claim 5
Independent Claim 94 words
A method for resin-molding a semiconductor device comprising: placing particles of a resin in a vacuum vessel and evacuating the vessel to remove air trapped in voids between adjacent particles of said resin; heating the resin particles to a temperature below the softening point of the resin particles and compressing said particles of said resin to fuse at least a shell of said resin and form a resin tablet substantially free of open pores; and feeding said resin tablet into an evacuated die cavity in which a semiconductor device to be molded is disposed.
Claim 6
Independent Claim 94 words
A method for resin-molding a semiconductor device comprising: placing particles of a resin in a vacuum vessel and evacuating the vessel to remove air trapped in voids between adjacent particles of said resin; heating the resin particles to a temperature below the softening point of the resin particles and compressing said particles of said resin to fuse at least a shell of said resin and form a resin tablet substantially free of open pores; and feeding said resin tablet into an evacuated die cavity in which a semiconductor device to be molded is disposed.
Claim 7
Dependent Claim 31 words
A resin-molding method according to claim 4 including feeding said resin tablet into said die cavity only after the die cavity is evacuated to at least a predetermined degree of vacuum.
Claim 8
Dependent Claim 32 words
A resin-molding method according to claim 5 including feeding said resin tablet by forcibly charging the tablet with a piston after the predetermined degree of vacuum in said die cavity is reached.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-10-15 1994-04-16 1994-10-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-10-15 1998-04-16 1998-10-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-10-15 2002-04-16 2002-10-16 $7700.00 Window Closed / Lapsed

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