High thermal conductivity dielectric tape

• US 20080066942A1
• Filed: 09/19/2006
• Published: 03/20/2008
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Power Generation, Inc.
• Inventors: Miller, Mark L.
• Granted Patent: US 7,547,847 B2
• Time in Patent Office: Days
• US Class Current: 174/36
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: H01B 3/04 mica

Abstract

An electrical insulation tape that has a first and second carrier layer, and a dielectric thermally conductive, electrically insulative filler layer (24) that has mica particles/flakelets (6), filler particles (26) and a binder resin (28), disposed between the first and second carrier layers. The dielectric filler layer has mica flakelets (30), filler particles (32) and a binder resin. The ratio of mica flakelets to filler particles is at least 1:1 by volume, and the percentage of binder resin in the dielectric filler layer is 35-50% by volume. The first and second carrier layers are impregnated with a second resin.

Claims

1. An electrical insulation tape comprising:

a first and a second carrier layers; and

a dielectric filler layer disposed between said first and said second carrier layers;

wherein said dielectric filler layer comprises mica flakelets, filler particles and a binder resin;

wherein the ratio of said mica flakelets to said filler particles is at least 1;

1 by volume;

wherein the percentage of said binder resin in said dielectric filler layer is 25-50% by volume;

wherein said first and said second carrier layers are impregnated with a second resin.

2. The electrical insulation tape according to claim 1, wherein said second resin is a thermoset polymeric resin.

3. The electrical insulation tape according to claim 1, wherein said second resin is a b-stage resin.

4. The electrical insulation tape according to claim 1, wherein said carrier layers are glass fabric.

5. The electrical insulation tape according to claim 1, wherein said inorganic filler particles have a length of between 1-100,000 nm and an aspect ratio of approximately 5-50.

6. The electrical insulation tape according to claim 1, wherein said inorganic filler particles are selected from at least one of oxides, nitrides, and carbides.

7. The electrical insulation tape according to claim 6, wherein said dielectric filler layer is at least one of oxides, nitrides, and carbides comprising Al2O3, AlN, MgO, ZnO, BeO, BN, Si3N4, SiC and SiO2 with mixed stoichiometric and non-stoichiometric combinations.

8. The electrical insulation tape according to claim 1, wherein said filler particles are discoids and platelets.

9. The electrical insulation tape according to claim 1, wherein said inorganic filler particles have been surface treated to introduce surface functional groups that allow for the essentially complete co-reactivity with said binder resin.

10. The electrical insulation tape according to claim 9, wherein said functional groups comprise at least one of hydroxyl, carboxylic, amine, epoxide, silane and vinyl groups.

11. The electrical insulation tape according to claim 1, wherein said binder resin includes epoxy, polyimide epoxy, liquid crystal epoxy and cyanate-ester.

12. An electrical insulation tape comprising:

a first and a second glass fabric layer; and

a dielectric filler layer disposed between said first and said second glass fabric layers;

wherein said dielectric filler layer comprises mica flakelets, inorganic thermally conductive, electrically resistive filler particles and a binder resin;

wherein the ratio of said mica flakelets to said filler particles is at least 1;

1 by volume;

wherein the percentage of said binder resin in said filler layer is 25-50% by volume;

wherein said first and said second glass fabric layers are pre-impregnated with a second thermoset polymeric resin.

13. The electrical insulation tape according to claim 12, wherein said second thermoset polymeric resin is a b-stage resin.

14. A method for making an insulation tape comprising:

obtaining a first carrier layer and a second carrier layer;

impregnating a second resin into said first and second carrier layers;

coating said first carrier layer with a dielectric filler layer; and

adding said second carrier layer to said dielectric filler layer;

wherein said dielectric filler layer is comprised of mica flakelets, filler particles, and a binder resin;

wherein the percentage of said binder resin in said dielectric filler layer is 25-50% by volume;

wherein the ratio of said mica flakelets to said filler particles in said dielectric filler layer is at least 1;

1 by volume;

wherein said dielectric filler layer is at least one of oxides, nitrides, and carbides.

15. The method of claim 14, wherein said carrier layers are a glass fabric.

16. The method of claim 14, wherein said carrier layers are pre-impregnated with said second resin.

17. The method of claim 14, wherein the coating of said dielectric filler layer onto said first carrier layer is done by a sol-gel liquid ceramic/glass modified polymeric formulation binder with a high loading of the inorganic particle fillers.

18. The method of claim 14, wherein said insulation tape is fully cured after being applied to an electrical device.