Substantially continuous layer of embedded transient protection for printed circuit boards

• US 20060181826A1
• Filed: 02/16/2006
• Published: 08/17/2006
• 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.
• Granted Patent: US 7,688,598 B2
• Time in Patent Office: Days
• US Class Current: 361/58
• 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 layers having a length, a width and a cross-sectional area, said plurality of layers including at least one signal area, and at least one reference plane wherein said at least one reference plane includes transient protection material.

2. The printed circuit board with integrated transient protection as recited in claim 1, wherein said transient protection material bridges a region between a conductive material and a section of a conductive via barrel wherein said conductive material and said section of said conductive via barrel are on said at least one reference plane.

3. The printed circuit board with integrated transient protection as recited in claim 1, wherein said transient protection material bridges a nonconductive region between a conductive material and at least one via pad wherein said conductive material and said via pad is on said at least one reference plane.

4. The printed circuit board with integrated transient protection as recited in claim 3 wherein said nonconductive region comprises any one of:

a square, circle, oblong and polygon.

5. The printed circuit board with integrated transient protection as recited in claim 1, further comprising at least one layer of conductive material that are coated with transient protection material.

6. The printed circuit board with integrated transient protection as recited in claim 5, wherein said at least one layer conductive material coated with transient protection material is bonded to at least one surface of at least one layer of dielectric material.

7. The printed circuit board with integrated transient protection as recited in claim 6, wherein a thickness of said at least one layer of dielectric material is in the range of 0.3 mils to 80 mils.

8. The printed circuit board with integrated transient protection as recited in claim 6, wherein a thickness of said at least one layer of dielectric material is in the range of 0.1 mils to 4 mils.

9. The printed circuit board with integrated transient protection as recited in claim 5, wherein said conductive material comprises copper.

10. The printed circuit board with integrated transient protection as recited in claim 5, wherein a thickness of said at least one layer of conductive material is in the range of 0.1 mils to 10 mils.

11. The printed circuit board with integrated transient protection as recited in claim 1, wherein said transient protection material comprises at least one of:

a voltage switchable dielectric material and resettable non-linear polymers having properties that protect against at least one of over-current and over-voltage.

12. 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.

13. The printed circuit board with integrated transient protection as recited in claim 1, wherein said at least one reference plane further includes a conductive material in contact with said transient protection material.

14. A method for making a core layer structure for use in PCB manufacturing, the method comprising:

using a first layer of conductive foil;

coating a layer of transient protection material on one surface of the conductive foil;

using one or more layers of B-stage dielectric material to bond said coated first layer of conductive foil on one surface of said one or more layers of B-stage dielectric material with a second layer of conductive foil on the opposing surface.

15. A method for making a core layer structure for use in PCB manufacturing, the method comprising:

using a layer of conductive material, said layer of conductive material having a top surface and a bottom surface; and

coating a layer of transient protection material on one of said top surface and said bottom surface.

16. The method as recited in claim 15, further comprising bonding said coated conductive material to at least one surface of a layer of dielectric material to form said core layer structure.

17. The method as recited in claim 16, wherein said layer of dielectric material is any one of:

epoxy, polyimide, teflon and any nonconducting polymer.

18. The method as recited in claim 16, wherein said layer of dielectric material is un-reinforced film.

19. The method as recited in claim 16, wherein said layer of dielectric material is reinforced with fiberglass material of varying composition.

20. The method as recited in claim 16, wherein said layer of dielectric material is reinforced with random fibers of various compositions.

21. The method as recited in claim 16, further comprising laminating said core layer structure to a PCB stackup.

22. The method as recited in claim 15, wherein said layer of conductive material is coated with a resin.

23. The method as recited in claim 22, wherein said resin is any one of a polyimide and an epoxy polymer.

24. The method as recited in claim 15, wherein exposed areas of said layer of transient protection material is removed by mechanical methods.

25. A system with integrated transient protection, the system comprising:

a multi-layered printed circuit board having a length, a width and a cross-sectional area;

a plurality of electrical components on one or more layers of said multi-layered printed circuit board; and

wherein said multi-layered printed circuit board comprises at least one signal area, and at least one reference plane wherein said at least one reference plane includes a transient protection material.

26. A method for making a printed circuit board with integrated transient protection, the method comprising:

making said printed circuit board using multiple layers including at least one signal area, and at least one reference plane; and

making said at least one reference plane using transient protection material and at least one layer of conductive material.

27. The method as recited in claim 26, wherein said transient protection material behaves in a bidirectional manner for clamping both positive and negative transients of at least one of current and voltage.

28. A planar distributed capacitance structure with integrated transient protection, the planar distributed capacitance structure comprising:

multiple layers having a length, a width and a cross-sectional area, said multiple layers including at least one sub-composite structure, wherein said sub-composite structure includes transient protection material and at least two layers of conductive material, and having a capacitance of at least 100 picofarads per square inch.

29. The planar distributed capacitance structure as recited in claim 28, further comprising at least one layer of dielectric material with a thickness in the range of 0.1 mils to 4 mils.

30. A system with integrated transient protection, the system comprising:

a multi-layered planar distributed capacitance structure having a length, a width and a cross-sectional area;

a plurality of electrical components on one or more layers of said multi-layered planar distributed capacitance structure; and

wherein said multi-layered planar distributed capacitance structure comprises at least one sub-composite structure, wherein said sub-composite structure includes transient protection material and at least two layers of conductive material, and having a capacitance of at least 100 picofarads per square inch.

31. The system as recited in claim 30, further comprising at least one layer of dielectric material with a thickness in the range of 0.1 mils to 4 mils.