US5458912A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tamper-proof electronic coatings
Assignee: Dow Silicones Corp
•
Filing: 1993-08-09
•
Granted: 1995-10-17
•
Expires: 2013-08-09
Abstract
Abstract Disclosed is a method of forming tamper-proof coatings on electronic devices. The method comprises applying a coating of a silica precursor resin and a filler onto the electronic device, wherein the filler is one which reacts in an oxidizing atmosphere to liberate enough heat to damage the electronic device. The coated electronic device is then heated at a temperature sufficient to convert the silica precursor resin to a silica containing ceramic matrix.
Inventors
- 👤 Robert C. Camilletti
- 👤 Loren A. Haluska
- 👤 Keith W. Michael
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:33
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C03; C03C; C03C17/00; C03C17/006; C03C17/007; C03C17/008; C03C17/009; C03C17/34; C03C17/3411; C03C17/3417; C03C17/3429; C03C17/3435; C03C17/3441; C04B41/009; C04B41/45; C04B41/50; C04B41/5025; C04B41/5035; C09; C09D; C09D183/00; C09D183/04; C09K; C09K11/00; C09K11/02; C09K11/08; C14; C14C; C14C11/00; C23; C23C; C23C18/00; C23C18/02; C23C18/12; C23C18/1204; C23C18/1208; C23C18/1212; C23C18/122; C23C18/1225; C23C18/125; C23C18/1262; C23C18/127; C23C18/1279; H; H10; H10D; H10D89/00; H10W; H10W42/00; H10W42/40; C03C2217/00; C03C2217/40; C03C2217/43; C03C2217/44; C03C2217/45; C03C2217/46; C03C2217/465; C03C2217/47; C03C2217/475; C03C2217/479; C04B2111/00; C04B2111/00474; C04B2111/00844; C04B2111/80; C04B2111/90; C04B2111/94
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
70 words
A method of forming a tamper-proof coating on an electronic device comprising: applying a coating composition comprising a silica precursor resin and a filler onto an electronic device, wherein the filler is one which reacts in an oxidizing atmosphere to liberate enough heat to damage the electronic device; and heating the coated substrate in a non-oxidizing atmosphere at a temperature sufficient to convert the coating composition into a ceramic coating.
Claim 2
Independent Claim
70 words
A method of forming a tamper-proof coating on an electronic device comprising: applying a coating composition comprising a silica precursor resin and a filler onto an electronic device, wherein the filler is one which reacts in an oxidizing atmosphere to liberate enough heat to damage the electronic device; and heating the coated substrate in a non-oxidizing atmosphere at a temperature sufficient to convert the coating composition into a ceramic coating.
Claim 3
Dependent Claim
41 words
The method of claim 1 wherein the coating composition is applied to the substrate by a process which comprises coating the substrate with a liquid mixture comprising a solvent, the silica precursor resin and the filler and then evaporating the solvent.
Claim 4
Dependent Claim
47 words
The method of claim 1 wherein the silica precursor resin is selected from the group consisting of hydrogen silsesquioxane resin and hydrolyzed or partially hydrolyzed R n Si(OR) 4-n , wherein R is an aliphatic, alicyclic or aromatic substituent of 1-20 carbon atoms and n is 0-3.
Claim 5
Dependent Claim
32 words
The method of claim 1 wherein the coated substrate is heated at a temperature in the range of between about 50° C. and about 450° C. for less than about 3 hours.
Claim 6
Dependent Claim
31 words
The method of claim 3 wherein the hydrogen silsesquioxane resin is fractionated such that at least 75% of the polymeric species have a molecular weight between about 1200 and about 100,000.
Claim 7
Dependent Claim
76 words
The method of claim 1 wherein the coating composition also contains modifying ceramic oxide precursors comprising a compound containing an element selected from the group consisting of titanium, zirconium, aluminum, tantalum, vanadium, niobium, boron and phosphorous wherein the compound contains at least one hydrolyzable substituent selected from the group consisting of alkoxy or acyloxy and the compound is present in an amount such that the coating contains 0.1 to 30 percent by weight modifying ceramic oxide.
Claim 8
Dependent Claim
40 words
The method of claim 3 wherein the coating composition also contains a platinum, rhodium or copper catalyst in an amount of between about 5 and about 500 ppm platinum, rhodium or copper based on the weight of hydrogen silsesquioxane resin.
Claim 9
Dependent Claim
20 words
The method of claim 1 wherein the coating composition also contains a material which modifies the surface of the filler.
Claim 10
Dependent Claim
14 words
The method of claim 1 wherein the coating composition also contains a suspending agent.
Claim 11
Dependent Claim
22 words
The method of claim 1 wherein the filler is in a form selected from the group consisting of powders, particles, and flakes.
Claim 12
Dependent Claim
11 words
The method of claim 1 wherein the filler is a metal.
Claim 13
Dependent Claim
21 words
The method of claim 11 wherein the metal is selected from the group consisting of magnesium, iron, silicon, tin and zinc.
Claim 14
Dependent Claim
28 words
The method of claim 1 wherein the filler is present in the coating composition in an amount in the range of about 10 to about 80 weight percent.
References Cited (Backward Citations)
US3725671A
Cited
US3882323A
Cited
US3882324A
Cited
US3986997A
Cited
US5042386A
Cited
US4898907A
Cited
US4756977A
Cited
US4749631A
Cited
US4808653A
Cited
US5008320A
Cited
US4753855A
Cited
US4749631B1
Cited
US4999397A
Cited
US5045592A
Cited
JPH0410339A
Cited
US5100503A
Cited
US5063267A
Cited
US5258334A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-16 | 1999-04-17 | 1999-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-16 | 2003-04-17 | 2003-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-16 | 2007-04-17 | 2007-10-17 | $7700.00 | Window Closed / Lapsed |