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US5664497A Expired / Lapsed US ⏱️ 0.0 years remaining

Laser symbolization on copper heat slugs

Assignee: Texas Instruments Inc
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Filing: 1995-12-20
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Granted: 1997-09-09
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Expires: 2015-12-20
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Abstract

Abstract The invention is to a method of placing symbolization on a heat spreader, used in conjunction with the semiconductor package, through the use of a low powered laser beam. The beam is scanned over the package surface at a preset intensity and for a desired time to change the surface texture of the heat spreader, and to change the reflectivity of the scanned area.

Inventors

  • 👤 Edgar R. Zuniga
  • 👤 Archie W. Sutton
  • 👤 Ray H. Purdom

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 17:08
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/06; H10P72/0614; B; B41; B41M; B41M5/00; B41M5/26; B41M5/267; G; G03; G03C; G03C1/00; G03C1/72; G03C1/725; B41M5/262

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 77 words
A method of placing symbolization on semiconductor devices, comprising the steps of: coating an area to be symbolized with an oxide material; exposing a portion of the oxide material in a desired pattern with a low power Laser beam in the range of 75 kilowatts; and exposing the portion of the oxide material for a period sufficient to change a reflectivity of the portion of the oxide material without burning through the portion of the oxide material.
Claim 2
Independent Claim 77 words
A method of placing symbolization on semiconductor devices, comprising the steps of: coating an area to be symbolized with an oxide material; exposing a portion of the oxide material in a desired pattern with a low power Laser beam in the range of 75 kilowatts; and exposing the portion of the oxide material for a period sufficient to change a reflectivity of the portion of the oxide material without burning through the portion of the oxide material.
Claim 3
Dependent Claim 20 words
The method according to claim 1, further comprising penetrating a plastic coating with the Laser beam to symbolize the area.
Claim 4
Dependent Claim 14 words
The method according to claim 1, wherein the area to be symbolized is metal.
Claim 5
Dependent Claim 11 words
The method according to claim 3, wherein the metal is copper.
Claim 6
Independent Claim 65 words
A method for placing symbolization on a semiconductor device package, comprising the steps of: oxide coating a surface of the package; tracing a desired pattern on the oxide coating with a laser beam in the range of 75 kilowatts; and maintaining the beam on the oxide coating for a time sufficient to change a reflectivity of the oxide coating without burning through the oxide coating.
Claim 7
Independent Claim 65 words
A method for placing symbolization on a semiconductor device package, comprising the steps of: oxide coating a surface of the package; tracing a desired pattern on the oxide coating with a laser beam in the range of 75 kilowatts; and maintaining the beam on the oxide coating for a time sufficient to change a reflectivity of the oxide coating without burning through the oxide coating.
Claim 8
Dependent Claim 21 words
The method according to claim 5, wherein the surface of the package is copper and the oxide coating is cupric oxide.
Claim 9
Dependent Claim 24 words
The method according to claim 5, further comprising the step of penetrating a plastic coating with the laser beam to expose the oxide coating.

References Cited (Backward Citations)

US4177372A Cited
US4592977A Cited
US4834834A Cited
US5196286A Cited
US5304357A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-09-08 2001-03-10 2001-09-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-09-08 2005-03-10 2005-09-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-09-08 2009-03-10 2009-09-09 $7700.00 Window Closed / Lapsed

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