CORE LAYER STRUCTURE HAVING VOLTAGE SWITCHABLE DIELECTRIC MATERIAL

• US 20100047535A1
• Filed: 08/16/2009
• Published: 02/25/2010
• Est. Priority Date: 08/22/2008
• Status: Abandoned Application

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Littelfuse Incorporated
• Inventors: Kosowsky, Lex, Fleming, Robert
• Application Number:
  US12/541,963
• Publication Number:
  US 20100047535A1
• Time in Patent Office: Days
• US Class Current: 428/195.100
• CPC Class Codes: H05K 1/0257 Overvoltage protection
• CPC Class Codes: H05K 1/0259 Electrostatic discharge [ESD] protection
• CPC Class Codes: H05K 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence
• CPC Class Codes: H05K 1/167 incorporating printed resistors
• CPC Class Codes: H05K 2201/0738 Use of voltage responsive materials, e.g. voltage switchable dielectric or varistor materials
• CPC Class Codes: H05K 2201/09318 Core having one signal plane and one power plane
• CPC Class Codes: H05K 3/4688 Composite multilayer circuits, i.e. comprising insulating layers having different properties having a special base or central core H05K3/4602
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]

Abstract

A core layer structure is provided for substrate and packed devices. The core layer structure includes a first layer, a second layer combined with the first layer. A layer of voltage switchable dielectric (VSD) material provided in between the first layer and second layer

Claims

1. A core layer structure for substrate and packed devices, the core layer structure comprising:

a first layer;

a second layer combined with the first layer;

wherein at least one of the first layer or second layer comprises conductive material;

a layer of voltage switchable dielectric (VSD) material provided in between the first layer and second layer.

2. The core layer structure of claim 1, wherein each of the first layer and second layer is formed from a same conductive material.

3. The core layer structure of claim 1, wherein the layer of VSD material is provided to be in contact with the at least one of the first layer or second layer that comprises conductive material.

4. The core layer structure of claim 1, wherein the first layer comprises conductive material, and the second layer comprises insulative material.

5. The core layer structure of claim 1, wherein the first layer comprises conductive material, and the second layer comprises resistive material.

6. The core layer structure of claim 1, wherein each of the first layer and second layer comprises conductive material, wherein the VSD material is provided to be in contact with one of the first layer and second layer, and wherein the core layer structure comprises one or more additional layers comprised of conductive material, insulative material, or resistive material.

7. The core layer structure of claim 1, wherein the VSD material comprises a combination of conductive and/or semi-conductive particles dispersed in a binder.

8. The core layer structure of claim 1, wherein the VSD material comprises varistor particles.

9. The core layer structure of claim 1, wherein the VSD material comprises varistor particles without a binder.

12. The core layer structure of claim 9, wherein at least one of the second layer or third layer is patterned.

10. A core layer structure for substrate and packed devices, the core layer structure comprising:

a plurality of layers, the plurality of layers comprising;

a first layer comprising conductive material;

a layer of voltage switchable dielectric (VSD) material formed on the first layer;

a second layer formed on the layer of VSD material, the second layer comprising one of conductive material, insulative material, or resistive material.

11. The core layer structure of claim 10, further comprising a third layer formed on the second layer, the third layer comprising one of conductive material, insulative material, or resistive material.

13. A method for forming a core layer structure, the method comprising the steps of:

creating an intermediate structure comprising (i) a first layer, and (ii) a layer of voltage switchable dielectric (VSD) material formed on the first layer; and

forming a second layer on the intermediate structure.

14. The method of claim 13, wherein at least one of the first layer or the second layer is comprised of conductive material.

15. The method of claim 13, wherein at least the first layer is comprised of conductive material, and wherein creating the intermediate structure includes B-staging the layer of VSD material onto the first layer.

16. The method of claim 13, wherein creating the intermediate structure includes coating the layer of VSD material onto the first layer.

17. The method of claim 13, wherein forming the second layer includes forming a thickness of conductive material corresponding to the second layer by subjecting the intermediate structure to an electrolytic plating process.

18. The method of claim 17, wherein forming the thickness includes applying sufficient voltage to the intermediate structure to switch the layer of VSD material into a conductive state, wherein the voltage is applied when the intermediate structure is submerged in an electrolytic solution.

19. The method of claim 17, wherein forming a thickness of conductive material includes using a seed layer to form the thickness when subjecting the intermediate structure to the electrolytic plating process.

20. A core layer structure for substrate and packed devices, the core layer structure comprising:

a surface layer comprising conductive material, the conductive material being patterned to provide a plurality of discrete elements;

a layer of voltage switchable dielectric (VSD) material that underlies the surface layer;

a conductive element that electrically connects the layer of VSD material to ground;

wherein the surface layer includes resistive material that occupies a space between two or more of the discrete elements.

21. The core layer structure of claim 20, wherein the conductive element corresponds to a via that extends, by way of a vertical path through a thickness of the core layer structure, from at least the layer of VSD material to ground.

22. The core layer structure of claim 21, further comprising a layer of insulative material that is provided over and/or under the layer of VSD material.