Substantially continuous layer of embedded transient protection for printed circuit boards

• US 7,688,598 B2
• Filed: 02/16/2006
• Issued: 03/30/2010
• Est. Priority Date: 02/16/2005
• Status: Active Grant

• Current Assignee: Sanmina-SCI Corporation
• Original Assignee: Sanmina-SCI Corporation
• Inventors: Schroeder, Gregory J., Gisin, Franz, Dudnikov, George Jr.
• Primary Examiner(s): Lee; Jinhee J
• Assistant Examiner(s): Getachew; Abiy
• Application Number:
  US11/356,562
• Publication Number:
  US 20060181826A1
• Time in Patent Office: 1,503 Days
• Field of Search: 361/760, 174/261
• US Class Current: 361/760
• CPC Class Codes: H01L 23/62 Protection against overvoltage, e.g. fuses, shunts
• 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: H05K 1/0257 Overvoltage protection
• CPC Class Codes: H05K 1/0259 Electrostatic discharge [ESD] protection
• CPC Class Codes: H05K 1/0298 Multilayer circuits
• 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 2201/09309 Core having two or more power planes; Capacitive laminate of two power planes

Abstract

The protection of sensitive components on printed circuit boards by using planar transient protection material in one or more layers of a printed circuit board stackup is disclosed.

Claims

1. A printed circuit board with integrated transient protection, the printed circuit board comprising:

a plurality of stacked layers including at least one reference plane, wherein said at least one reference plane includes a layer of conductive material coated with a layer of transient protection material, wherein said layer transient protection material bridges a region between a part of the layer of conductive material and a section of a conductive via barrel, wherein said part of the layer of conductive material and said section of said conductive via barrel are co-planar.

2. The printed circuit board with integrated transient protection as recited in claim 1, wherein said transient protection material comprises resettable non-linear polymers having properties that protect against at least one of over-current and over-voltage.

3. The printed circuit board with integrated transient protection as recited in claim 1, wherein said transient protection material behaves in a bi-directional manner for clamping both positive and negative transients of voltage.

4. The printed circuit board with integrated transient protection of claim 1, wherein the layer of transient protection material is parallel with the layer of conductive material.

5. The printed circuit board with integrated transient protection of claim 1, wherein the layer of transient protection material is on a different plane to the layer of conductive material.

6. The printed circuit board with integrated transient protection of claim 1, wherein the conductive via barrel extends across a plurality of the stacked layers to another conductive layer.

7. The printed circuit board with integrated transient protection of claim 1, wherein the at least one reference plane further includes a dielectric layer coupled to the layer of transient protection material, the dielectric layer coupled to a first side of the layer of transient protection material while the layer of conductive material is coupled to an opposite second side of the layer of transient protection material.

8. The printed circuit board with integrated transient protection of claim 7, wherein the at least one reference plane further includes a second layer of conductive material coupled to the dielectric layer, the second layer of conductive material coupled to a first side of the dielectric layer while the layer of transient protection material is coupled to an opposite second side of the dielectric layer.

9. The printed circuit board with integrated transient protection of claim 7, wherein the at least one reference plane further includes a second layer of transient protection material coupled to the dielectric layer, the layer of transient protection material coupled to a first side of the dielectric layer while the second layer of transient protection material is coupled to an opposite second side of the dielectric layer.

10. The printed circuit board with integrated transient protection of claim 8, wherein the layer of conductive material is a ground plane and the second layer of conductive material is a power plane.

11. A printed circuit board with integrated transient protection, the printed circuit board comprising:

a plurality of stacked layers including at least one reference plane, wherein said at least one reference plane includes a layer of conductive material coated with a layer of transient protection material, wherein said transient protection material bridges a nonconductive region between a part of the layer of conductive material and at least one via pad, wherein said part of the layer of conductive material and said via pad are co-planar.

12. The printed circuit board with integrated transient protection as recited in claim 11 wherein said nonconductive region comprises any one of a square, circle, oblong and polygon.

13. A printed circuit board with integrated transient protection, the printed circuit board comprising:

a plurality of stacked layers including at least one reference plane, wherein said at least one reference plane includes a layer of conductive material, the layer of conductive material is coated with a layer of transient protection material, the layer of transient protection material is bonded to at least one surface of at least one layer of dielectric material.

14. The printed circuit board with integrated transient protection as recited in claim 13, wherein a thickness of said at least one layer of dielectric material is in the range of 0.3 mils to 80 mils.

15. The printed circuit board with integrated transient protection as recited in claim 13, wherein a thickness of said at least one layer of dielectric material is in the range of 0.1 mils to 4 mils.

16. The printed circuit board with integrated transient protection as recited in claim 13, wherein a thickness of the layer of conductive material is in the range of 0.1 mils to 10 mils.

17. A circuit board structure with integrated transient protection, the circuit board structure comprising:

multiple stacked layers including at least one sub-composite structure, wherein said sub-composite structure includes at least one layer of transient protection material and at least two layers of conductive material, and wherein the sub-composite structure has a capacitance of at least 100 picofarads per square inch.

18. The planar distributed capacitance structure as recited in claim 17, further comprising at least one layer of dielectric material with a thickness in the range of 0.1 mils to 4 mils.

19. A printed circuit board with integrated transient protection, the printed circuit board comprising:

a plurality of stacked layers including a conductive layer, and an area of transient protection material disposed in a plane parallel to and in contact with the conductive layer, wherein the area of transient protection material bridges a gap in the conductive layer, the area of transient protection material is formed by a coating on the layer of conductive material, the area of transient protection material is bonded to at least one surface of at least one layer of dielectric material.

20. The printed circuit board of claim 19, wherein the conductive layer forms at least part of a reference plane.

21. The printed circuit board of claim 19, wherein the gap in the conductive layer is bounded in part by a conductive via barrel.

22. The printed circuit board of claim 19, wherein the gap in the conductive layer is bounded in part by a via pad.

23. The printed circuit board of claim 22, wherein the gap in the conductive layer is shaped as any one of:

a square, circle, oblong and polygon.

24. The printed circuit board of claim 19, wherein a thickness of said at least one layer of dielectric material is in the range of 0.3 mils to 80 mils.

25. The printed circuit board of claim 19, wherein a thickness of said at least one layer of dielectric material is in the range of 0.1 mils to 4 mils.

26. The printed circuit board of claim 19, wherein a thickness of the layer of conductive material is in the range of 0.1 mils to 10 mils.

27. The printed circuit board of claim 19, wherein said transient protection material comprises resettable non-linear polymers having properties that protect against at least one of over-current and over-voltage.

28. A printed circuit board core, comprising:

a first conductive layer;

a transient protection layer coupled to the first conductive layer; and

a dielectric layer coupled to the transient protection layer, wherein the first conductive layer and the dielectric layer are on opposite sides of the transient protection layer.

29. The printed circuit board core of claim 28, further comprising:

an electrically conductive via extending through the first conductive layer to the transient protection layer but electrically isolated from the first conductive layer.

30. The printed circuit board core of claim 28, further comprising:

a second conductive layer coupled to the dielectric layer, wherein the second conductive layer and the transient protection layer are on opposite sides of the dielectric layer.

31. The printed circuit board core of claim 28, further comprising:

a second dielectric layer coupled to the transient protection layer, wherein the dielectric layer and the second dielectric layer are on opposite sides of the transient protection layer.