High K dielectric composition for thermoformable capacitive circuits

Patent metadata

Field	Value
Publication number	US-9685270-B2
Application number	US-201414324760-A
Country	US
Kind code	B2
Filing date	Jul 7, 2014
Priority date	Jul 7, 2014
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

This invention is directed to a polymer thick film thermoformable dielectric composition with a high dielectric constant. Dielectrics made from the composition can be used in various electronic applications to enhance the performance of thermoformable capacitive circuits.

First claim

What is claimed is:

1. A polymer thick film thermoformable dielectric composition consisting of:
(a) 15-50 wt % of a first organic medium consisting of 10-50 wt % urethane resin dissolved in 50-90 wt % first organic solvent, wherein the weight percent of the urethane resin and the first organic solvent are based on the total weight of the first organic medium; and
(b) 15-50 wt % of a second organic medium consisting of 10-50 wt % thermoplastic phenoxy resin in 50-90 wt % second organic solvent wherein the weight percent of the thermoplastic phenoxy resin and the second organic solvent are based on the total weight of the second organic medium; and
(c) 1-70 wt % of a powder of a high-K material with a K of at least 40;

wherein the wt % of the first organic medium, the second organic medium and the powder of the high-K material are based on the total weight of the dielectric composition.

2. The polymer thick film thermoformable dielectric composition of claim 1 , wherein said urethane resin is a urethane elastomer or a polyester-based copolymer.

3. The polymer thick film thermoformable dielectric composition of claim 2 , wherein said urethane resin is an elastomer.

4. The polymer thick film thermoformable dielectric composition of claim 1 , consisting of:
(a) 20-45 wt % of said first organic medium consisting of 15-35 wt % urethane resin dissolved in 65-85 wt % first organic solvent, wherein the weight percent of the urethane resin and the first organic solvent are based on the total weight of the first organic medium; and
(b) 20-45 wt % of the second organic medium consisting of 15-45 wt % thermoplastic phenoxy resin in 55-85 wt % second organic solvent wherein the weight percent of the thermoplastic phenoxy resin and the second organic solvent are based on the total weight of the second organic medium; and
(c) 20-60 wt % of the powder of a high-K material with a K of at least 40;

wherein the wt % of the first organic medium, the second organic medium and the powder of the high-K material are based on the total weight of the dielectric composition.

5. The polymer thick film thermoformable dielectric composition of claim 1 , wherein the high-K material has a K of at least 100.

6. The polymer thick film thermoformable dielectric composition of claim 5 , wherein the high-K material has a K of at least 500.

7. The polymer thick film thermoformable dielectric composition of claim 4 , wherein the high-K material has a K of at least 100.

8. The polymer thick film thermoformable dielectric composition of claim 7 , wherein the high-K material has a K of at least 500.

9. The polymer thick film thermoformable dielectric composition of claim 1 , wherein the high-K material is selected from the group consisting of barium titanate, lead zirconium titanate, barium strontium titanate and lead lanthanum zirconium titanate.

10. A capacitive switch circuit comprising a dielectric layer formed from the polymer thick film thermoformable dielectric composition of claim 1 , wherein the capacitive switch circuit has been thermoformed.

11. The capacitive switch circuit of claim 10 , wherein the capacitive switch circuitry has been subsequently subjected to an injection molding process.

12. The capacitive switch circuit of claim 10 , further comprising;
(a) a substrate;
(b) a first electrical conductor deposited on the substrate; and
(c) a second electrical conductor;

wherein the dielectric layer is deposited between the first electrical conductor and the second electrical conductor thereby forming a capacitor.

13. The capacitive switch circuit of claim 12 , wherein the first electrical conductor and the second electrical conductor are silver.

14. The capacitive switch circuit of claim 12 , wherein the high-K material used in the polymer thick film thermoformable dielectric composition of claim 1 has a K of at least 500.

15. The capacitive switch circuit of claim 12 , wherein the high-K material used in the polymer thick film thermoformable dielectric composition of claim 1 is selected from the group consisting of barium titanate, lead zirconium titanate, barium strontium titanate and lead lanthanum zirconium titanate.

16. The capacitive switch circuit of claim 12 , wherein the capacitive switch circuit has subsequently been subjected to an injection molding process.

17. A capacitor comprising two electrical conductors separated by a dielectric layer formed from the polymer thick film thermoformable dielectric composition of claim 1 , wherein the capacitor has been thermoformed.

18. The capacitor of claim 17 , wherein the high-K material used in the polymer thick film thermoformable dielectric composition of claim 1 has a K of at least 500.

19. The capacitor of claim 17 , wherein the high-K material used in the polymer thick film thermoformable dielectric composition of claim 1 is selected from the group consisting of barium titanate, lead zirconium titanate, barium strontium titanate and lead lanthanum zirconium titanate.

Assignees

• Du Pont

Inventors

• Dorfman Jay Robert

Classifications

• H01B3/302 Primary

  Polyurethanes or polythiourethanes; Polyurea or polythiourea · CPC title

• H01G4/008

  Selection of materials · CPC title

• C08K3/0075

  Chemistry & Metallurgy · mapped topic

• C08L63/00

  Compositions of epoxy resins; Compositions of derivatives of epoxy resins · CPC title

• C08G2650/56

  Polyhydroxyethers, e.g. phenoxy resins · CPC title