초록 ▼

A heat spreader having at least two adjoining strips of pyrolytic graphite material is made by cutting a strip from a sheet of pyrolytic graphite in the z direction. Thermal conductivity in the xy plane of the graphite sheet is greater than in the z direction. The z direction cut provides strips whi

A heat spreader having at least two adjoining strips of pyrolytic graphite material is made by cutting a strip from a sheet of pyrolytic graphite in the z direction. Thermal conductivity in the xy plane of the graphite sheet is greater than in the z direction. The z direction cut provides strips which are then each individually oriented 90 degrees such that the thickness direction of the original pyrolytic graphite sheet becomes the width or length of the cut strip. A face on the side of a first strip adjoins a face on the side of a second strip. Due to the greater thermal conductivity in the xy plane of the strips as compared to in the z direction heat transfers more rapidly in the length and thickness direction of the strips than across adjoining sides of the oriented strips.

대표청구항 ▼

What is claimed is: 1. A heat spreader comprising: a) a first planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a first plane of the first planar element and in a thickness direction of the first planar element and havi

What is claimed is: 1. A heat spreader comprising: a) a first planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a first plane of the first planar element and in a thickness direction of the first planar element and having a relatively low thermal conductivity in a direction of second lateral dimension of the first planar element, and b) a second planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a second plane of the second planar element and in a thickness direction of the second planar element and having a relatively low thermal conductivity in a direction of a second lateral dimension of the second planar element, wherein at least a portion of a first side of the first planar element which extends in a direction out of the first plane of the first planar element adjoins at least a portion of a second side of the second planar element which extends in a direction out of the second plane of the second planar element. 2. The heat spreader according to claim 1 wherein the portion of the first side of the first planar element which adjoins the portion of the second side of the second planar element extends substantially normal to the first plane of the first planar element, and the portion of the second side of the second planar element which adjoins the portion of the first side of the first planar element extends substantially normal to the second plane of the second planar element. 3. A heat spreader comprising: a) a first planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a first plane of the first planar element and in the thickness direction of the first planar element and having a relatively low thermal conductivity in a direction of second lateral dimension of the first planar element, wherein the direction of the first lateral dimension of the first plane of the first planar element and the thickness direction of the first planar element extend substantially in directions of orientation of a axes of the pyrolytic graphite of the first planar element and the direction of the second lateral dimension of the first planar element extends substantially in the direction of the c axis of the pyrolytic graphite of the first planar element, b) a second planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a second plane of the second planar element and in the thickness direction of the second planar element and having a relatively low thermal conductivity in a direction of a second lateral dimension of the second planar element, wherein the direction of the first lateral dimension of the second plane of the second planar element and the thickness direction of the second planar element extend substantially in directions of orientation of a axes of the pyrolytic graphite of the second planar element and the direction of the second lateral dimension of the second planar element extends substantially in the direction of the c axis of the pyrolytic graphite of the second planar element, wherein at least a portion of a first side of the first planar element which extends in a direction out of the first plane of the first planar element adjoins at least a portion of a second side of the second planar element which extends in a direction out of the second plane of the second planar element. 4. A heat spreader comprising: a) a first planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a first plane of the first planar element and in the thickness direction of the first planar element and having a relatively low thermal conductivity in a direction of second lateral dimension of the first planar element, wherein the direction of the first lateral dimension of the first plane of the first planar element and the thickness direction of the first planar element extend substantially in directions of orientation of a axes of the pyrolytic graphite of the first planar element and the direction of the second lateral dimension of the first planar element extends substantially in the direction of the c axis of the pyrolytic graphite of the first planar element, b) a second planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a second plane of the second planar element and in the thickness direction of the second planar element and having a relatively low thermal conductivity in a direction of a second lateral dimension of the second planar element, wherein the direction of the first lateral dimension of the second plane of the second planar element and the thickness direction of the second planar element extend substantially in directions of orientation of a axes of the pyrolytic graphite of the second planar element and the direction of the second lateral dimension of the second planar element extends substantially in the direction of the c axis of the pyrolytic graphite of the second planar element, wherein each of the first planar element and second planar element have a first side and a second side, the first side and second side of each of the first planar element and second planar element being substantially parallel and being spaced apart in the direction of the second lateral dimension at a first distance, the first side and second side of each of the first planar element and second planar element extending substantially normal to the direction of the second lateral dimension of the first planar element and the second planar element respectively wherein at least a portion of the first side of the first planar element adjoins at least a portion of the second side of the second planar element. 5. The heat spreader according to claim 4 wherein each of the first planar element and second planar element have a third side and fourth side, the third and fourth side of each of the first planar element and second planar element being substantially parallel and being spaced apart in the direction of the first lateral dimension at a second distance, the third side and fourth side of each of the first planar element and second planar element extending substantially normal to the direction of the first lateral dimension of the first planar element and the second planar element respectively. 6. The heat spreader according to claim 4 wherein the first distance at which the first side and the second side of the first planar element are spaced apart is at least about 1.5 millimeters. 7. The heat spreader according to claim 4 wherein the first distance at which the first side and the second side of the first planar element are spaced apart is from about 1.5 millimeters to about 1.3 centimeters. 8. The heat spreader according to claim 4 wherein the first distance at which the first side and the second side of the first planar element are spaced apart is from about 1.3 centimeters to about 2.5 centimeters. 9. The heat spreader according to claim 4 wherein the first distance at which the first side and the second side of the first planar element are spaced apart is at least about 1.3 centimeters. 10. The heat spreader according to claim 4 wherein the first distance at which the first side and the second side of the first planar element are spaced apart is at least about 4.0 centimeters. 11. The heat spreader according to claim 4 wherein the first distance at which the first side and the second side of the first planar element are spaced apart is from about 1.3 centimeters to about meters to about 5.0 centimeters. 12. The heat spreader according to claim 5 wherein the second distance at which the third side and the fourth side of the first planar element are spaced apart is at least about 1.0 centimeter. 13. The heat spreader according to claim 5 wherein the second distance at which the third side and the fourth side of the first planar element are spaced apart is from about 1.0 centimeters to about 40 centimeters. 14. The heat spreader according to claim 3 wherein the thermal conductivity along the a axis in the first planar element and in the second planar element is from about 450 to about 2000 Watts/meter° K. 15. The heat spreader according to claim 3 wherein the thermal conductivity, along the a axis in the first planar element and in the second planar element is from about 1000 to about 2000 Watts/meter° K. 16. The heat spreader according to claim 3 wherein the thermal conductivity along the a axis in the first planar element and in the second planar element is from about 1200 to about 2000 Watts/meter° K. 17. A method of making a heat spreader comprising the steps of: a) providing a first planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a first plane of the first planar element and in a thickness direction of the first planar element and having a relatively low thermal conductivity in a direction of second lateral dimension of the first planar element, and b) providing a second planar element of pyrolytic graphite having a relatively high thermal conductivity in a direction of a first lateral dimension of a second plane of the second planar element and in a thickness direction of the second planar element and having a relatively low thermal conductivity in a direction of a second lateral dimension of the second planar element, wherein at least a portion of a first side of the first planar element which extends in a direction out of the first plane of the first planar element adjoins at least a portion of a second side of the second planar element which extends in a direction out of the second plane of the second planar element.