US5031017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite optical shielding
Assignee: Avago Technologies International Sales Pte Ltd
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Filing: 1988-01-29
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Granted: 1991-07-09
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Expires: 2008-01-29
Abstract
Abstract An opaque shield is provided for integrated circuits and comprises reflective particles of titanium dioxide and light-absorbing particles of carbon black suspended in polyimide. The reflective particles increase the effective path length of light traversing the carrier so that a much lower concentration of carbon black is required to render the shield opaque. The concentration of carbon black can be low enough so that its conductivity does not impair operation of the integrated circuit. In addition to shielding the integrated circuit from light, the shield also protects the integrated circuit from contamination. A fluid precursor material is formed by mixing titanium dioxide and carbon black particles into a polyamic acid solution. This solution is diluted, filtered and vacuum distilled to yield a suspension free of over-sized particles. The resulting suspension can be applied and patterned using conventional semiconductor processing techniques. As a result, an integrated circuit can be completely or selectively shielded as desired.
Inventors
- 👤 Joseph Pernyeszi
- 👤 Michael D. Walters
- 👤 Kevin Venor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:50
CPC Classifications
H; H10; H10F; H10F39/00; H10F39/10; H10F39/103
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
57 words
An integrated circuit structure comprising: an integrated circuit including a semiconductor substrate and plural circuit elements fabricated thereon; an insulating material disposed over at least one of said circuit elements, said material including nonconductive reflective particles and light-absorbing particles suspended in a carrier, said material being selected to absorb light over at least a predetermined frequency range.
Claim 2
Dependent Claim
57 words
An integrated circuit structure comprising: an integrated circuit including a semiconductor substrate and plural circuit elements fabricated thereon; an insulating material disposed over at least one of said circuit elements, said material including nonconductive reflective particles and light-absorbing particles suspended in a carrier, said material being selected to absorb light over at least a predetermined frequency range.
Claim 3
Dependent Claim
28 words
The integrated circuit structure of claim 1 wherein said integrated circuit includes at least one photo-responsive element, said material being patterned to permit light access to photo-responsive element.
Claim 4
Dependent Claim
108 words
An integrated circuit structure comprising: an integrated circuit including a semiconductor substrate and plural circuit elements fabricated thereon, including at least one photo-responsive element; material disposed over at least one of said circuit elements, said material including reflective particles and light-absorbing carbon black particles suspended in a carrier and patterned to permit light access to said photo-responsive element, said material being selected to absorb light over at least a predetermined frequency range; and wherein at most a negligible proportion of particles suspended in said carrier having diameters greater than 3 μm, and said reflective particles are of titanium dioxide and have diameters between 0.1 μm and 2.0 μm.
Claim 5
Dependent Claim
108 words
An integrated circuit structure comprising: an integrated circuit including a semiconductor substrate and plural circuit elements fabricated thereon, including at least one photo-responsive element; material disposed over at least one of said circuit elements, said material including reflective particles and light-absorbing carbon black particles suspended in a carrier and patterned to permit light access to said photo-responsive element, said material being selected to absorb light over at least a predetermined frequency range; and wherein at most a negligible proportion of particles suspended in said carrier having diameters greater than 3 μm, and said reflective particles are of titanium dioxide and have diameters between 0.1 μm and 2.0 μm.
Claim 6
Dependent Claim
34 words
The integrated circuit structure of claim 3 wherein the range of concentrations by weight of polyimide to titanium dioxide to carbon black is at least 50% polyimide, 20%-50% titanium dioxide and 2%-10% carbon black.
Claim 7
Dependent Claim
34 words
The integrated circuit structure of claim 2 wherein said material is formed by spinning a prepolymer-based suspension on said integrated circuit using thick-film techniques, photo-lithographically patterning said prepolymer suspension, and curing said prepolymer carrier.
Claim 8
Dependent Claim
14 words
The integrated circuit structure of claim 2 wherein said light-absorbing particles are electrically conductive.
Claim 9
Dependent Claim
14 words
The integrated circuit structure of claim 2 wherein said light-absorbing particles are carbon black.
Claim 10
Dependent Claim
23 words
The integrated circuit structure of claim 2 wherein a negligible proportion of particles suspended in said carrier have diameters greater than 3 μm.
Claim 11
Dependent Claim
19 words
The integrated circuit structure of claim 8 wherein said reflective particles have diameters between 0.1 μm and 2.0 μm.
Claim 12
Dependent Claim
102 words
An integrated circuit structure comprising: an integrated circuit including a semiconductor substrate and plural circuit elements fabricated thereon including at least one photo-responsive element; and material disposed over at least one of said circuit elements, said material including reflective titanium dioxide particles and light-absorbing particles suspended in a carrier and patterned to permit light access to said photo-responsive element, said material being selected to absorb light over at least a predetermined frequency range, and wherein a negligible proportion of particles suspended in said carrier having diameters greater than 3 μm, and said reflective particles have diameters between 0.1 μm and 2.0 μm.
Claim 13
Dependent Claim
102 words
An integrated circuit structure comprising: an integrated circuit including a semiconductor substrate and plural circuit elements fabricated thereon including at least one photo-responsive element; and material disposed over at least one of said circuit elements, said material including reflective titanium dioxide particles and light-absorbing particles suspended in a carrier and patterned to permit light access to said photo-responsive element, said material being selected to absorb light over at least a predetermined frequency range, and wherein a negligible proportion of particles suspended in said carrier having diameters greater than 3 μm, and said reflective particles have diameters between 0.1 μm and 2.0 μm.
Claim 14
Dependent Claim
45 words
A material comprising: a carrier; light-absorbing carbon black particles suspended in said carrier, at most a negligible proportion of said carbon black particles having diameters greater than 3.0 μm; and nonconductive reflective particles having diameters between 0.1 μm and 2.0 μm suspended in said carrier.
Claim 15
Dependent Claim
45 words
A material comprising: a carrier; light-absorbing carbon black particles suspended in said carrier, at most a negligible proportion of said carbon black particles having diameters greater than 3.0 μm; and nonconductive reflective particles having diameters between 0.1 μm and 2.0 μm suspended in said carrier.
Claim 16
Dependent Claim
11 words
The material of claim 11 wherein said carrier is a prepolymer.
Claim 17
Dependent Claim
10 words
The material of claim 11 wherein said carrier is polyimide.
Claim 18
Dependent Claim
48 words
A material comprising: a polyimide carrier; particles suspended in said carrier, at most a negligible proportion of said particles having diameters greater than 3.0 μm, said particles including reflective titanium dioxide particles and light-absorbing carbon black particles, said reflective particles having diameters between 0.1 μm and 2.0 μm.
Claim 19
Dependent Claim
48 words
A material comprising: a polyimide carrier; particles suspended in said carrier, at most a negligible proportion of said particles having diameters greater than 3.0 μm, said particles including reflective titanium dioxide particles and light-absorbing carbon black particles, said reflective particles having diameters between 0.1 μm and 2.0 μm.
Claim 20
Dependent Claim
32 words
The material of claim 14 wherein the range of concentrations by weight of polyimide to titanium dioxide to carbon black is at least 50% polyimide, 20%-50% titanium dioxide and 2%-10% carbon black.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-07-08 | 1995-01-07 | 1995-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-08 | 1999-01-07 | 1999-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-08 | 2003-01-07 | 2003-07-09 | $7700.00 | Window Closed / Lapsed |