THERMALLY CONDUCTIVE POLYMER BASED PRINTED CIRCUIT BOARD

• US 20100012354A1
• Filed: 07/13/2009
• Published: 01/21/2010
• Est. Priority Date: 07/14/2008
• Status: Abandoned Application

• Current Assignee: David Miller, Logan Brook Hedin
• Original Assignee: David Miller, Logan Brook Hedin
• Inventors: Miller, David Michael, Hedin, Logan Brook
• Application Number:
  US12/501,989
• Publication Number:
  US 20100012354A1
• Time in Patent Office: Days
• US Class Current: 174/252
• CPC Class Codes: H05K 1/0203 Cooling of mounted components H05K1/0272 takes precedence
• CPC Class Codes: H05K 1/0313 Organic insulating material
• CPC Class Codes: H05K 1/0326 containing O
• CPC Class Codes: H05K 2201/0141 Liquid crystal polymer [LCP]
• CPC Class Codes: H05K 2201/0145 Polyester, e.g. polyethylene terephthalate [PET], polyethylene naphthalate [PEN]
• CPC Class Codes: H05K 3/181 by electroless plating adhesives therefor H05K3/387
• CPC Class Codes: H05K 3/388 by the use of a metallic or inorganic thin film adhesion layer

Abstract

A printed circuit board has a liquid crystalline polymer layer that is bonded to an electrically conductive layer that includes traces that electrically connect components mounted on the printed circuit board. The liquid crystalline polymer material is thermally conductive and dielectric. When the components produce heat, the liquid crystalline polymer layer absorbs and dissipates the heat produced by the electrical components mounted on the printed circuit board. The thermal equilibrium of the printed circuit board is lower than the maximum operating temperature of the components.

Claims

1. A printed circuit board comprising:

a thermally conductive dielectric polymer layer; and

a first electrically conductive layer having a first set of traces bonded to the thermally conductive dielectric polymer layer.

2. The printed circuit board of claim 1 further comprising:

a bonding agent layer between the electrically conductive layer and the polymer layer for bonding the electrically conductive metal layer to the polymer layer.

3. The printed circuit board of claim 1 further comprising:

a plurality of vias in the printed circuit board that are electrically coupled to the traces and further extend at least partially through the thermally conductive dielectric polymer layer.

4. The printed circuit board of claim 1 wherein the thermally conductive dielectric polymer layer comprises partially crystalline aromatic polyesters.

5. The printed circuit board of claim 1 wherein the thermally conductive dielectric polymer layer has a thermal conductivity greater than 4 W/mK.

6. The printed circuit board of claim 1 wherein the thermally conductive dielectric polymer layer has a coefficient of thermal expansion less than 18 ppm/degree Celsius in the X and Y axis directions.

7. The printed circuit board of claim 1 wherein the thermally conductive dielectric polymer layer has a dielectric constant is less than 4.7 at a frequency of 1 megahertz.

8. The printed circuit board of claim 1 wherein the thermally conductive dielectric polymer layer has a volume resistivity greater than 1×

10⁶ megaohms per centimeter.

9. The printed circuit board of claim 1 wherein the thermally conductive dielectric polymer layer has a surface resistivity greater than 1×

10³ megaohms.

10. A thermally conductive printed circuit board comprising:

a thermally conductive liquid crystalline polymer layer; and

an electrically conductive layer having a first set of patterned electrical traces bonded to the liquid crystalline polymer layer.

11. The printed circuit board of claim 10 further comprising:

a bonding agent layer between the electrically conductive layer and the polymer layer for bonding the electrically conductive metal layer to the polymer layer.

12. The printed circuit board of claim 10 further comprising:

a plurality of vias that are electrically coupled to the traces and extend at least partially through the thermally conductive dielectric polymer layer.

13. The printed circuit board of claim 10 wherein the thermally conductive liquid crystalline polymer layer comprises partially crystalline aromatic polyesters based on a p-hydroxybenzoic acid and related monomers.

14. The printed circuit board of claim 10 wherein the liquid crystalline polymer layer has a thermal conductivity greater than 4 W/mK.

15. The printed circuit board of claim 10 wherein the liquid crystalline polymer layer has a coefficient of thermal expansion range less than 18 ppm/degree Celsius in the X and Y axis directions.

16. The printed circuit board of claim 10 wherein the liquid crystalline polymer layer has a dielectric constant less than 4.7 at a frequency of 1 Megahertz.

17. The printed circuit board of claim 10 wherein the liquid crystalline polymer layer has a volume resistivity greater than 1×

10⁶ megaohms centimeter.

18. The printed circuit board of claim 10 wherein the liquid crystalline polymer layer has a surface resistivity is greater than 1×

10³ megaohms.

19. A printed circuit board comprising:

a first dielectric thermally conductive liquid crystalline polymer layer;

a first electrically conductive layer having a first pattern of electrical traces bonded to a first side of the first dielectric thermally conductive liquid crystalline polymer layer; and

a second electrically conductive layer having a second pattern of electrical traces bonded to a second side of the first dielectric thermally conductive liquid crystalline polymer layer.

20. The printed circuit board of claim 19 further comprising:

a second dielectric thermally conductive liquid crystalline polymer layer; and

a third electrically conductive layer having a third pattern of electrical traces bonded to a second side of the second dielectric thermally conductive liquid crystalline polymer layer;

wherein the second electrically conductive layer is bonded to a first side of the second dielectric thermally conductive liquid crystalline polymer layer.