Selective deposition of embedded transient protection for printed circuit boards

• US 20060181827A1
• 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 7,593,203 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

Protection for sensitive components on a printed circuit board by selectively depositing transient protection material on one or more layers of the printed circuit board is disclosed.

Claims

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

a transient protection material selectively deposited on portions of one or more planes selected from a signal plane, a power plane and a ground plane, and wherein said selectively deposited transient protection material is in contact with a conductive material in any of said one or more planes.

2. The printed circuit board with integrated transient protection as recited in claim 1, wherein said transient protection material is deposited in one or more of an annular shape, closed curve, and polygon.

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

4. 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 in current or voltage.

5. 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 via pad wherein said conductive material and said via pad are on any of said one or more planes.

6. 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 any of said one or more planes.

7. The printed circuit board with integrated transient protection as recited in claim 1, wherein said conductive material comprises copper with a thickness in a range of 3 microns to 10 mils.

8. The printed circuit board with integrated transient protection as recited in claim 1, wherein said transient protection material possesses variable characteristics depending on proximity to sensitive components on said printed circuit board.

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

printing and etching a copper clad core material comprising any one of resin impregnated fiberglass cloth, random fiber and film material;

selectively depositing a transient protection material on portions of one or more planes selected from a signal plane, a power plane and a ground plane, and wherein said selectively deposited transient protection material is in contact with a conductive material on any of said one or more planes; and

laminating said copper clad core into a multilayer PCB structure and completing a fabrication process of said PCB comprising;

drilling holes, depositing conductive seed, imaging, plating, etching outer layer copper to form component mounting pads connected to elements of selectively deposited transient protection material.

10. The method as recited in claim 9, wherein said transient protection material is deposited in one or more of an annular shape, closed curve, and polygon.

11. The method as recited in claim 9, wherein said transient protection material comprises at least one of resettable non-linear polymers and VSDM having properties that protect against over voltage, and over-current.

12. The method as recited in claim 9, wherein said transient protection material behaves in a bi-directional manner for clamping both positive and negative transients in current or voltage.

13. The method as recited in claim 9, wherein said transient protection material bridges a region between a conductive material and a via pad wherein said conductive material and said via pad are on any of said one or more planes.

14. The method as recited in claim 9, 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 any of said one or more planes.

15. The method as recited in claim 9, wherein said conductive material comprises copper, and wherein an area where said transient protection material contacts said copper is coated with a precious metal to reduce or control contact resistance.

16. 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, wherein said multi-layered printed circuit board comprises at least one signal region, at least one power region, and at least one ground region; and

a transient protection material selectively deposited on portions of said one or more layers or regions, wherein said selectively deposited transient protection material is in contact with a conductive material in any of said one or more layers or regions.

17. 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.

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

19. The planar distributed capacitance structure as recited in claim 17, wherein said transient protection material is selectively deposited in portions of said sub-composite structure and is in contact with at least one of said two layers of conductive material.

20. 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.

21. The system as recited in claim 20, further comprising at least one layer of dielectric material with a thickness in a range of 0.1 mils to 4 mils.

22. The system as recited in claim 20, wherein said transient protection material is selectively deposited in portions of said sub-composite structure and is in contact with at least one of said two layers of conductive material.