Electronic coatings

• US 6,144,106 A
• Filed: 09/29/1997
• Issued: 11/07/2000
• Est. Priority Date: 10/04/1996
• Status: Expired due to Fees

• Current Assignee: Dow, Inc.
• Original Assignee: Dow, Inc.
• Inventors: Camilletti, Robert Charles, Michael, Keith Winton, Bearinger, Clayton R., Haluska, Loren Andrew
• Primary Examiner(s): GUAY, JOHN FRANCIS
• Application Number:
  US08/939,241
• Time in Patent Office: 1,135 Days
• Field of Search: 257/789, 257/790, 257/703, 257/705, 257/922, 428/447
• US Class Current: 257/789
• CPC Class Codes: H01L 23/296 Organo-silicon compounds
• CPC Class Codes: H01L 23/3192 Multilayer coating
• CPC Class Codes: H01L 23/573 using passive means
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10S 257/922 with means to prevent inspection of or tampering with an integrated circuit, e.g. "smart card", anti-tamper

Abstract

The instant invention pertains to a multi-layer tamper proof electronic coating wherein the first layer is a protecting layer produced from a preceramic silicon containing material and at least one filler. The second layer is a resin sealer coat produced from a sealer resin selected from the group consisting of colloidal inorganic-based siloxane resins, benzocyclobutene based resins, polyimide polymers, siloxane polyimides and parylenes. An optional third layer is a cap coating layer selected from SiO₂ coating, SiO₂ /ceramic oxide coating, silicon containing coatings, silicon carbon containing coatings, silicon nitrogen containing coatings, silicon oxygen nitrogen coatings, silicon nitrogen carbon containing coatings and/or diamond like coatings. An optional fourth layer is a resin overcoat produced from an overcoat resin selected from the group consisting of colloidal inorganic-based siloxane resins, benzocyclobutene based resins, polyimide polymers, siloxane polyimides, parylenes, photoresist polymers, siloxane room temperature vulcanizable compositions, or other organic polymer. The use of the multi-layer coating on the electronic device results in an electronic device that is resistant to analytical techniques such as ozone, UV-ozone, gaseous free radicals and ions, vapor or liquid borne reactive species, plasma, abrasion, radiation, light, wet etching and others; moisture; chemicals and other environmental contaminants; shock and erosion, delamination and/or separation.

Claims

1. An electronic device produced by a method comprising

(A) forming a protection layer on an electronic device by applying on the electronic device a composition comprising a preceramic silicon-containing material and a filler to a surface of the electronic device and thereafter heating the composition to a temperature sufficient to convert the preceramic silicon-containing material into a silica-containing ceramic having filler dispersed therein;

and

(B) forming a resin sealer coat over the protection layer by applying a sealer resin selected from the group consisting of colloidal inorganic-based siloxane resins, benzocyclobutene based resins, a polyimide polymers, a siloxane polyimides and parylenes and thereafter curing the sealer resin to produce the resin sealer coat.

2. The electronic device as claimed in claim 1 wherein a cap coating layer is formed over the resin sealer coat by depositing onto the resin sealer coat a material selected from the group consisting of an amorphous SiC:

H, diamond, silicon nitride and parylene.

3. The electronic device as claimed in claim 2 wherein a resin overcoat layer is formed over the cap coating layer by applying an overcoat resin selected from the group consisting of colloidal inorganic-based siloxane resins, benzocyclobutene based resins, polyimide polymers, siloxane polyimides, parylenes, photoresist polymers, siloxane room temperature vulcanizable compositions, and organic polymers and thereafter curing the overcoat resin to produce the resin overcoat layer.

6. The electronic device as claimed in claim 1 wherein the filler is selected from the group consisting of optically opaque fillers, radiopaque fillers, luminescent fillers, oxidation resistant filler, abrasion resistant fillers, magnetic fillers, conductive fillers, flux materials and mixtures thereof.

7. The electronic device as claimed in claim 1 wherein the composition comprising the preceramic silicon-containing material and filler is heated to a temperature of 50°

C. to 450°

C.

8. The electronic device as claimed in claim 1 wherein the protection layer has a thickness of 0.5 to 500 micrometers.

9. The electronic device as claimed in claim 1 wherein the sealer resin of (B) is a colloidal inorganic-based siloxane resin.

10. The electronic device as claimed in claim 9 wherein the sealer resin is cured by heating the resin at a temperature 60°

C. to 400°

C.

11. The electronic device as claimed in claim 1 wherein the resin sealer coat has a thickness of 0.1 to 8 micrometers.

12. The electronic device as claimed in claim 2 wherein the cap coating layer is formed by the plasma enhanced chemical vapor deposition of amorphous SiC:

H.

13. The electronic device as claimed in claim 2 wherein the cap coating layer is formed by the plasma enhanced chemical vapor deposition of silicon nitride.

14. The electronic device as claimed in claim 2 wherein the cap coating layer has a thickness of from 0.1 to 100 micrometers.

15. The electronic device as claimed in claim 3 wherein the overcoat resin is a colloidal inorganic-based siloxane resin.

16. The electronic device as claimed in claim 15 wherein the overcoat resin is cured by heating the resin at a temperature 60°

C. to 400°

C.

17. The method as claimed in claim 3 wherein the resin overcoat layer has a thickness of 0.1 to 8 micrometers.

4. The electronic device as claimed in 1 wherein the preceramic silicon-containing material is selected from the group consisting of hydrogen silsesquioxane resin, hydrolyzed or partially hydrolyzed compounds or mixtures of compounds having the formula R¹_n Si(OR¹)_4-n wherein each R¹ is independently selected from the group consisting of aliphatic, alicyclic and aromatic substituents having from 1 to 20 carbon atoms and n has a value of 0, 1, 2 or 3.

5. The electronic device as claimed in claim 4 wherein the silicon oxide precursor is a hydrogen silsesquioxane resin.