US5094769A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compliant thermally conductive compound
Assignee: International Business Machines Corp
•
Filing: 1988-05-13
•
Granted: 1992-03-10
•
Expires: 2008-05-13
Abstract
Abstract A compliant thermally conductive, preferably dielectric, compound that enhances the power dissipation capability of high-powered electrical components such as bipolar VLSI semiconductor chips. The compound has chemically stable thermal conduction and viscosity properties; is not subject to phase separation during use and may be applied in small gaps to maximize thermal conduction. The compound preferably comprises a liquid carrier having thermal filler particles dispersed therein and a coupling agent having a functionality which is reactive with the calcined surface of the thermal filler particles, and a functionality having preferential wetting of the thermal filler particles over self-condensation. Additional additives such as fumed silica and polyisobutylene enhance the phase stability and resistance to thermo-mechanical shear force degradation of the thermally conductive compound encountered during functional usage, e.g., fluctuating power cycles.
Inventors
- 👤 Herbert R. Anderson, Jr.
- 👤 Richard B. Booth
- 👤 Lawrence D. David
- 👤 Mark O. Neisser
- 👤 Harbans S. Sachdev
- 👤 Mark A. Takacs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:41
CPC Classifications
C; C09; C09K; C09K5/00; C09K5/08; F; F28; F28F; F28F13/00; F28F2013/005; F28F2013/006; H; H10; H10W; H10W72/00; H10W72/851; H10W72/874; H10W72/877; H10W90/00; H10W90/701; H10W90/721; H10W90/724
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
154 words
A thermally conductive compound comprising: a liquid carrier, said liquid carrier comprising non-polar, low surface energy organic fluids having a viscosity of 30 to 500 centipoise at 100 degrees C., said liquid carrier selected from the group consisting of mineral and poly(alpha-olefin) oils; thermally conductive filler particles dispersed throughout said liquid carrier, said filler particles being present in a minimum amount of about 25 volume percent; said particles being higher in surface energy than said liquid carrier so that said liquid carrier wets said particles; and about 0.5 to 10 weight percent of a coupling agent having at least one functionality which is reactive with the surface of said thermally conductive filler particles and at least one functionality which is of similar polarity of said liquid carrier wherein said coupling agent is selected from the group consisting of organosilanes, organotitanates, organoaluminates and organozirconates; wherein said liquid carrier comprises the remaining amount of said compound.
Claim 2
Dependent Claim
154 words
A thermally conductive compound comprising: a liquid carrier, said liquid carrier comprising non-polar, low surface energy organic fluids having a viscosity of 30 to 500 centipoise at 100 degrees C., said liquid carrier selected from the group consisting of mineral and poly(alpha-olefin) oils; thermally conductive filler particles dispersed throughout said liquid carrier, said filler particles being present in a minimum amount of about 25 volume percent; said particles being higher in surface energy than said liquid carrier so that said liquid carrier wets said particles; and about 0.5 to 10 weight percent of a coupling agent having at least one functionality which is reactive with the surface of said thermally conductive filler particles and at least one functionality which is of similar polarity of said liquid carrier wherein said coupling agent is selected from the group consisting of organosilanes, organotitanates, organoaluminates and organozirconates; wherein said liquid carrier comprises the remaining amount of said compound.
Claim 3
Dependent Claim
19 words
The coupling agent of claim 1 wherein said coupling agent has a preferential wetting of said particles over self-condensation.
Claim 4
Dependent Claim
24 words
The thermally conductive compound of claim 1 wherein the viscosity of said compound is between approximately 2 and 20 million centipoise at 100° C.
Claim 5
Dependent Claim
27 words
The thermally conductive compound of claim 1 further comprising about 1 to 6 weight percent of high surface area inert particulate additives that absorb excess carrier liquid.
Claim 6
Dependent Claim
17 words
The thermally conductive compound of claim 4 wherein said high surface area inert additive comprises fumed silica.
Claim 7
Dependent Claim
30 words
The thermally conductive compound of claim 1 wherein said functionality which is reactive with the surface of said thermally conductive filler particles is (RO), wherein R=C n H 2n+1 .
Claim 8
Dependent Claim
27 words
The thermally conductive compound of claim 1 wherein said functionality which is of similar polarity of said liquid carrier is R', wherein R'=C n H 2n+1 .
Claim 9
Dependent Claim
27 words
The thermally conductive compound of claim 1 wherein said functionality which is of similar polarity of said liquid carrier is: ##STR7## wherein R'=C n H 2n+1 .
Claim 10
Dependent Claim
21 words
The thermally conductive compound of claim 6 wherein the surface area of said fumed silica corresponds to 100-300 m 2 /gram.
Claim 11
Dependent Claim
32 words
The thermally conductive compound of claim 1 further comprising about 2 to 6 weight percent of a nonpolar polymer that readily dissolves in said liquid carrier, wherein said nonpolar polymer is polyisobutylene.
Claim 12
Dependent Claim
13 words
The thermally conductive compound of claim 6 wherein said fumed silica is hydrophobic.
Claim 13
Dependent Claim
24 words
The thermally conductive compound of claim 1 having high particle packing density and being capable of maintaining particle dispersion in a low viscosity compound.
Claim 14
Dependent Claim
32 words
The thermally conductive compound of claim 1 further comprising about 2 to 6 weight percent of a nonpolar polymer that readily dissolves in said liquid carrier, wherein said nonpolar polymer is polyisobutylene.
Claim 15
Dependent Claim
14 words
The thermally conductive compound of claim 1 wherein said liquid carrier is chemically saturated.
Claim 16
Dependent Claim
14 words
The thermally conductive compound of claim 14 wherein said liquid carrier is a dielectric.
Claim 17
Dependent Claim
13 words
The thermally conductive compound of claim 14 wherein said liquid carrier is poly(alpha-olefin).
Claim 18
Dependent Claim
11 words
The thermally conductive compound of claim 1 further comprising an antioxidant.
Claim 19
Dependent Claim
11 words
The thermally conductive compound of claim 12 further comprising an antioxidant.
Claim 20
Dependent Claim
20 words
The thermally conductive compound of claim 1 wherein said thermally conductive filler particles are platelet, spherical, or cubic in shape.
Claim 21
Dependent Claim
13 words
The thermally conductive compound of claim 1 wherein said particles are boron nitride.
Claim 22
Dependent Claim
20 words
The thermally conductive compound of claim 1 wherein said particles are aluminum spheres coated with Al 2 O 3 .
Claim 23
Dependent Claim
13 words
The thermally conductive compound of claim 1 wherein said particles are vanadium boride.
Claim 24
Dependent Claim
22 words
The thermally conductive compound of claim 1 wherein the volume percent of thermally conductive filler particles is between 25 and 65 percent.
Claim 25
Dependent Claim
20 words
The thermally conductive compound of claim 12 wherein the polarity of said polymer matches the polarity of said liquid carrier.
Claim 26
Dependent Claim
16 words
The thermally conductive compound of claim 1 wherein said thermally conductive filler particles are electrical insulators.
Claim 27
Dependent Claim
25 words
The thermally conductive compound of claim 1 wherein said liquid carrier is easily removable by organic solvents from solders, molybdenum, gold, copper, chromium, or titanium.
Claim 28
Dependent Claim
22 words
The thermally conductive compound of claim 1 wherein said liquid carrier is noncorrosive to solders, molybdenum, ceramic, gold, copper, chromium, or titanium.
Claim 29
Dependent Claim
21 words
The thermally conductive compound of claim 1 wherein the surfaces of said thermally conductive filler particles are free of organic contaminants.
Claim 30
Dependent Claim
20 words
The thermally conductive compound of claim 1 wherein said coupling agent is of the same polarity of said liquid carrier.
Claim 31
Dependent Claim
154 words
A thermally conducting compound comprising: a liquid carrier, said liquid carrier comprising non-polar, low surface energy organic fluids having a viscosity of 30 to 500 centipoise at 100 degrees C., said liquid carrier selected from the group consisting of mineral and poly(alpha-olefin) oils; thermally conductive filler particles dispersed throughout said liquid carrier, said filler particles being present in a minimum amount of about 25 volume percent; said particles being higher in surface energy than said liquid carrier so that said liquid carrier wets said particles; and about 0.5 to 10 weight percent of a coupling agent having at least one functionality which is reactive with the surface of said thermally conductive filler particles and at least one functionality which is of similar polarity of said liquid carrier wherein said coupling agent is selected from the group consisting of organosilanes, organotitanates, organoaluminates and organozirconates; wherein said liquid carrier comprises the remaining amount of said compound.
Claim 32
Dependent Claim
154 words
A thermally conducting compound comprising: a liquid carrier, said liquid carrier comprising non-polar, low surface energy organic fluids having a viscosity of 30 to 500 centipoise at 100 degrees C., said liquid carrier selected from the group consisting of mineral and poly(alpha-olefin) oils; thermally conductive filler particles dispersed throughout said liquid carrier, said filler particles being present in a minimum amount of about 25 volume percent; said particles being higher in surface energy than said liquid carrier so that said liquid carrier wets said particles; and about 0.5 to 10 weight percent of a coupling agent having at least one functionality which is reactive with the surface of said thermally conductive filler particles and at least one functionality which is of similar polarity of said liquid carrier wherein said coupling agent is selected from the group consisting of organosilanes, organotitanates, organoaluminates and organozirconates; wherein said liquid carrier comprises the remaining amount of said compound.
Claim 33
Dependent Claim
14 words
The thermally conducting compound of claim 30 wherein said electronic components are semiconductor chips.
Claim 34
Dependent Claim
19 words
The thermally conducting compound of claim 31 wherein said heat dissipating means is the cap of a semiconductor module.
Claim 35
Dependent Claim
21 words
The thermally conducting compound of claim 31 wherein said heat dissipating means is an internal thermal enhancement of a semiconductor module.
Claim 36
Dependent Claim
19 words
The thermally conducting compound of claim 32 being in the range of approximately 1 to 10 mils in thickness.
Claim 37
Dependent Claim
19 words
The thermally conducting compound of claim 33 being in the range of approximately 1 to 10 mils in thickness.
Claim 38
Dependent Claim
27 words
The thermally conductive compound of claim 30 further comprising about 1 to 6 weight percent of high surface area inert particulate additives that absorb excess carrier liquid.
Claim 39
Dependent Claim
22 words
The thermally conductive compound of claim 30 wherein said liquid carrier is noncorrosive to solders, molybdenum, ceramic, gold, copper, chromium, or titanium.
Claim 40
Dependent Claim
13 words
The thermally conductive compound of claim 30 wherein said liquid carrier is poly(alpha-olefin).
Claim 41
Dependent Claim
11 words
The thermally conductive compound of claim 30 further comprising an antioxidant.
Claim 42
Dependent Claim
30 words
The thermally conductive compound of claim 30 wherein said functionality which is reactive with the surface of said thermally conductive filler particles is (RO), wherein R=C n H 2n+1 .
Claim 43
Dependent Claim
27 words
The thermally conductive compound of claim 30 wherein said functionality which is of similar polarity of said liquid carrier is R', wherein R'=C n H 2n+1 .
Claim 44
Dependent Claim
27 words
The thermally conductive compound of claim 30 wherein said functionality which is of similar polarity of said liquid carrier is: ##STR8## wherein R'=C n H 2n+1 .
Claim 45
Dependent Claim
20 words
The thermally conductive compound of claim 30 wherein said thermally conductive filler particles are platelet, spherical, or cubic in shape.
Claim 46
Dependent Claim
22 words
The thermally conductive compound of claim 30 wherein the volume percent of thermally conductive filler particles is between 25 and 65 percent.
Claim 47
Dependent Claim
25 words
The thermally conductive compound of claim 30 wherein said liquid carrier is easily removable by organic solvents from solders, molybdenum, gold, copper, chromium, or titanium.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-10 | 1995-09-09 | 1996-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-10 | 1999-09-09 | 2000-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-10 | 2003-09-09 | 2004-03-10 | $7700.00 | Window Closed / Lapsed |