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US6175162B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Semiconductor wafer having a bottom surface protective coating

Assignee: National Semiconductor Corp
•
Filing: 1999-09-08
•
Granted: 2001-01-16
•
Expires: 2019-09-08
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Abstract

Abstract Disclosed is a packaged integrated circuit device. The device includes a die having a plurality of electrical contacts on a first surface of the die and a protective film adhered directly to a back surface of the die, the protective film being thick enough to allow laser marking of the protective film without the laser penetrating to the die. In one preferred embodiment, the protective film of the device is a thick film formed by screen printing. In a preferred embodiment, the protective film has a thickness of between about 1.5 and 5 mils. Also, disclosed is a method of fabricating a semiconductor wafer having a wafer substrate with a top surface and a bottom surface and a plurality of dies. In this embodiment, the method includes providing a plurality of dies on the top surface of the wafer substrate, applying a thick film over the bottom surface of the wafer substrate, adhering the thick film to a mounting tape that is not ultraviolet curable, and dicing the wafer to separate the dies. The thick film reduces chipping along edges of the separated dies.

Inventors

  • 👤 Pai-Hsiang Kao
  • 👤 William Jeffrey Schaefer
  • 👤 Nikhil Vishwanath Kelkar

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 21:40
CPC Classifications
H; H10; H10W; H10W42/00; H10W42/121; H10W46/00; H10W74/00; H10W74/01; H10W74/10; H10W74/131; H10W46/601; H10W46/603; H10W72/00; H10W72/01; H10W72/013; H10W72/01331; H10W72/071; H10W72/072; H10W72/07251; H10W72/20

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 72 words
A packaged integrated circuit device comprising: a die having a plurality of electrical contacts on a first surface of the die; a protective film adhered directly to a back surface of the die, the protective film having a thickness that is selected to decrease damage to the die when the die is placed on an external substrate, the protective film being substantially the same size as the back surface of the die.
Claim 2
Dependent Claim 72 words
A packaged integrated circuit device comprising: a die having a plurality of electrical contacts on a first surface of the die; a protective film adhered directly to a back surface of the die, the protective film having a thickness that is selected to decrease damage to the die when the die is placed on an external substrate, the protective film being substantially the same size as the back surface of the die.
Claim 3
Dependent Claim 21 words
The packaged integrated circuit device recited in claim 1 wherein the protective film is a thick film formed by screen printing.
Claim 4
Dependent Claim 39 words
The packaged integrated circuit device recited in claim 1 wherein the packaged integrated circuit device is one selected from the group consisting of a flip chip device, a grid array device, a flash memory device, and a CSP device.
Claim 5
Dependent Claim 27 words
The packaged integrated circuit device recited in claim 1 wherein the protective film is a thick film formed from a material that adheres to a mounting tape.
Claim 6
Dependent Claim 34 words
The packaged integrated circuit device recited in claim 1 wherein the protective film is a thick film formed from a material that adheres to a mounting tape that is not a UV type tape.
Claim 7
Dependent Claim 91 words
A semiconductor wafer comprising: a multiplicity of semiconductor dies, each die having a plurality of electrical contacts that are exposed on a first surface of the wafer; a protective thick film adhered directly to a second surface of the wafer, the protective film having a thickness that is selected to reduce chipping along an associated edge of each die while the each die is being separated from the dies, the protective film being substantially the same size as the surfaces of the dies when the chips are separated from the wafer.
Claim 8
Dependent Claim 91 words
A semiconductor wafer comprising: a multiplicity of semiconductor dies, each die having a plurality of electrical contacts that are exposed on a first surface of the wafer; a protective thick film adhered directly to a second surface of the wafer, the protective film having a thickness that is selected to reduce chipping along an associated edge of each die while the each die is being separated from the dies, the protective film being substantially the same size as the surfaces of the dies when the chips are separated from the wafer.
Claim 9
Dependent Claim 16 words
The semiconductor wafer recited in claim 6 wherein the protective film is formed by screen printing.

References Cited (Backward Citations)

JPS6184824A Cited
JPS63285955A Cited
US5083191A Cited
JPH04116955A Cited
US5294812A Cited
US5536970A Cited
US5504374A Cited
US5925936A Cited
US5892288A Cited
US6034437A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2004-01-16 2004-07-17 2005-01-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2008-01-16 2008-07-17 2009-01-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2012-01-16 2012-07-17 2013-01-16 $7700.00 Window Closed / Lapsed

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