Efficient cooling of lasers, LEDs and photonics devices
The present invention provides an optoelectronic device comprising a heat source and a heat transfer fluid. The present invention also provides a method of preparing an optoelectronic device, which comprises (i) providing a heat source, and (ii) filling a space in the vicinity of the heat source with a heat transfer liquid. The optoelectronic device has gained technical merits such as improved heat removing efficiency, lower chip/junction temperature, increased lumen output, longer operational lifetime, and better reliability, among others.
1 . An optoelectronic device comprising a heat source and a heat transfer fluid.
2 . The optoelectronic device according to claim 1 , in which the heat transfer fluid is dielectric and does not cause any shorts in the optoelectronic device, wherein the fluid preferably has an optical absorption of less than about 2%/mm at any wavelength in the range of from about 300 nm to about 800 nm; the heat transfer fluid is a dielectric fluid with a volume resistivity (25° C.) of at least 1M (Ωcm), as measured with the method of ASTM D-257; the refractive index of the heat transfer fluid ranges from about 1.2 to about 2.5 at any wavelength in the range of from about 400 nm to about 800 nm; and the thermal expansion by volume of the heat transfer fluid at 25° C. ranges from about 0.000001 cc/cc/° C. to about 0.001 cc/cc/° C., as measured with the method of ASTM D-1903.
3 . The optoelectronic device according to claim 1 , in which the heat transfer fluid is selected from the group consisting of perfluorocarbon (PFC), polychlorinated biphenyl (PCB), dimethyl silicone, hydrocarbon oil, mineral oil, paraffinic oil, naphthenic oil, aromatic hydrocarbon, polyalphaolefin, polyol ester, vegetable oil, and the like, and the mixture thereof.
4 . The optoelectronic device according to claim 1 , in which the heat transfer fluid comprises Fluorinert liquid FC-72, Novec fluid such as HFE7100, Lightspan™ LS-5252, or any combination thereof.
5 . The optoelectronic device according to claim 3 , in which the aromatic hydrocarbon comprises triaryl methanes, triaryl ethanes, diaryl methanes, diaryl ethanes, alkylated biphenyls, monoaromatics with large alkyl groups, naphthalenes, and the mixture thereof.
6 . The optoelectronic device according to claim 3 , in which the polyalphaolefins are derived from the polymerization of hexene (C 6 ), octene (C 8 ), decene (C 10 ) or dodecene (C 12 ).
7 . The optoelectronic device according to claim 3 , in which the vegetable oil comprises a triglyceride molecule with the general formula:
wherein R 1 , R 2 , and R 3 are independently of each other selected from C 4 to C 22 hydrocarbon chains with 0 to 3 unsaturation levels.
8 . The optoelectronic device according to claim 1 , in which the heat transfer fluid further comprises dispersed phosphor particles with a size of from 1 nm to 5000 nm.
9 . The optoelectronic device according to claim 1 , in which the heat source is a light emitting diode (LED), a lamp, or a laser.
10 . The optoelectronic device according to claim 9 , in which the LED contains a Group III-V compound semiconductor layer such as GaAs, GaAlAs, GaN, InGaN, or GaP; a Group II-VI compound semiconductor layer such as ZnSe, ZnSSe, or CdTe; or a Group IV-IV semiconductor layer such as SiC.
11 . The optoelectronic device according to claim 1 , further comprising a solid cooling means and/or an air cooling means.
12 . The optoelectronic device according to claim 1 , further comprising a lens, a lead frame, a bond wire, a solder, an electrode, a pad, a contact layer, a phosphor layer, a dielectric layer and/or a housing.
13 . The optoelectronic device according to claim 1 , which is a LED package and the heat transfer liquid, locates in the vicinity of bulb/frontal surface area.
14 . The optoelectronic device according to claim 1 , further comprising a lens; and at least part of the gap between the heat source and the lens is filled with the heat transfer fluid.
15 . The optoelectronic device according to claim 1 , further comprising a lens and a housing; and at least part of the gap between the lens and the housing is filled with the heat transfer fluid.
16 . The optoelectronic device according to claim 1 , further comprising a lens and a housing; and at least part of the gap between the heat source and the lens and at least part of the gap between the lens and the housing are filled with the heat transfer fluid.
17 . The optoelectronic device according to claim 1 , which comprises a first body of heat transfer fluid located in the top-side of the heat source; and a second body of heat transfer fluid located in the back-side of the heat source.
18 . The optoelectronic device according to claim 17 , in which a synthetic jet actuator is operated with the second body of heat transfer fluid.
19 . The optoelectronic device according to claim 17 , in which the second body of heat transfer fluid is circulated to a heat exchanger located outside the body of fluid.
20 . The optoelectronic device according to claim 1 , which has a heat removing efficiency at least about 10% higher than that of the same optoelectronic device but without the heat transfer fluid.
21 . A method of preparing an optoelectronic device, which comprises (i) providing a heat source, and (ii) filling a space in the vicinity of the heat source with a heat transfer liquid which is hermetically sealed.
22 . The method according to claim 21 , in which the heat source comprises a light emitting diode (LED).
23 . The method according to claim 21 , in which the heat transfer fluid comprises Fluorinert liquid FC-72, Lightspan™ LS-5252, or combination thereof; and an external heat transfer mechanism is used to remove the heat from the enclosure such as heat sinks, conduction cooling or fluid circulation.