SPECIAL NOTICE
A -- LAWRENCE LIVERMORE NATIONAL LABORATORY SEEKS TO LICENSE TECHNOLOGY TO BUILD SILICON MONOLITHIC MICROCHANNEL (SiMM) LASER DIODES PACKAGES
- Notice Date
- 9/2/2004
- Notice Type
- Special Notice
- NAICS
- 238990
— All Other Specialty Trade Contractors
- Contracting Office
- Department of Energy, Lawrence Livermore National Laboratory (DOE Contractor), Industrial Partnerships & Commercialization, 7000 East Avenue L-795, Livermore, CA, 94550
- ZIP Code
- 94550
- Solicitation Number
- Reference-Number-FBO81-04
- Response Due
- 10/8/2004
- Archive Date
- 10/11/2004
- Point of Contact
- Connie Pitcock, Administration, Phone 925-422-1072, Fax 925-423-8988,
- E-Mail Address
-
pitcock1@llnl.gov
- Description
- LAWRENCE LIVERMORE NATIONAL LABORATORY SEEKS TO LICENSE TECHNOLOGY TO BUILD SILICON MONOLITHIC MICROCHANNEL (SiMM) LASER DIODES PACKAGES Announcement: Lawrence Livermore National Laboratory (LLNL), operated by the University of California under contract with the U.S. Department of Energy (DOE), wants to license the technology to build Silicon Monolithic Microchannel (SiMM) high average power Laser Diode Packages. Researchers at LLNL have developed a water cooled, high average power laser diode packaging technology. The packages use microchannels etched in silicon in close proximity to the laser bars to provide aggressive cooling (LLNL has demonstrated over 500 W/cm2 thermal dissipation capability). The silicon platforms also permit efficient lens mounting over the laser diodes by using lens frames precisely mounted on the silicon platforms. LLNL has these SiMM laser diode packages in production and in use on several laser systems. The current SiMM laser diodes packages include 10 individual laser bars and are capable of handling 1.2 kilowatts of power (optical and heat). LLNL researchers use a novel combination of technologies to fabricate the microchannel packages. These technologies include anisotropic etching of silicon and silicon-to-glass anodic bonding. The net result is a simple and flexible fabrication technology used to build microchannel structures. The key to the aggressive cooling provided by the SiMM packages lies in the use of microchannels in extremely close proximity to the laser diode bar. In particular, the use of microchannels minimizes the thermal temperature rise across the stagnant boundry layer at the silicon wall-to-water interface. This stagnant boundary layer exists because of the ?no slip? boundary condition at the microchannel wall-to-water interface, which is the same physical phenomenon that allows dust to settle on rapidly turning fan blades without being blown off. The combination of the microchannel geometry combined with smooth laminar coolant flow (promoted by the silicon channel) minimizes the thermal rise across this stagnant boundary layer. LLNL has three patents which pertain directly to the SiMM laser diode packages. These patents are as follows: Patent #5,548,605, Patent #5,828,683, and Patent #5,828,683. These patents are available for non-exclusive licensing. Taking advantage of the large differential etch rates between the various crystallographic directions in silicon, it is straightforward to fabricate the very high aspect ratio channels that are the key to achieving aggressive heat removal with only moderated temperature rises. Because silicon can be conveniently bonded to glass using an anodic bonding technique, it is possible to fabricate feed plenums in one layer of silicon and microchannels in another and to join the two with a thin sheet of glass. The cooler in Fig 1 illustrates this feature, having silicon outer layers bonded to a glass central layer. This combination of technologies, anisotropic etching of silicon and silicon-to-glass anodic bonding, combine to give a very simple and flexible technology base from which microchannel based structures are simply fabricated. To understand in detail how microchannels function to give unsurpassed thermal performance, it is useful to use a very simplified picture of the heat flow in a liquid flow silicon based microchannel cooling circuit, and break down the temperature rise between the heat generating component and the cold inlet cooling fluid into three different components. The first component corresponds to the temperature rise associated with heat flowing through the solid silicon material, from the electronic component that generates heat down into the regions between the water flow channels. The next component corresponds to the temperature rise associated with heat flowing across the stagnant boundary layer of water and into the moving fluid. This stagnant boundary layer exists because of the ?no slip? boundary condition at the microchannel wall-to-water interface ? this is the same physical phenomenon that allows dust to settle on rapidly turning fan blades without being blown off. The last component corresponds to the temperature rise associated with the heat absorbed by the flowing water as it goes from the cold inlet side of the microchannels to the hot outlet side of the channels. It turns out that the temperature rise associated with the heat flowing across the stagnant water boundary layer at the solid-to-water interface is generally the largest temperature rise in flowing water heatsink structures. To understand this one need only consider that the thermal conductivity of a typical cooling fluid such as water at 0.0061 ?C/Wth-cm, which is approximately 250 times smaller than that of silicon at room temperature. Thus, in compact flowing water heatsink structures the biggest leverage in controlling the overall temperature rise is generally associated with minimizing the thickness of the stagnant boundary layer. Because boundary layer thickness scales with the channel width for laminar flow through microchannels, the solid material used to construct the cooler should be one that permits easy fabrication of narrow channels. This result explains the apparently paradoxical choice of silicon with its well developed anisotropic etching technologies as the preferred material for microchannel heatsinks over other more obvious materials with higher thermal conductivities such as copper. More thermal performance is to be had by using a material that permits tiny microchannel fabrication rather than materials having higher thermally conductivity but that are restricted to larger channel widths due to fabrication issues. Note: THIS IS NOT A PROCUREMENT. Companies interested in commercializing LLNL's SiMM Laser Diode Package technology should provide a written statement of interest, which includes the following: 1. Company Name and address. 2. The name, address, and telephone number of a point of contact. 3. A description of corporate expertise and facilities relevant to commercializing this technology. Written responses should be directed to: Lawrence Livermore National Laboratory Industrial Partnerships and Commercialization P.O. Box 808, L-795 Livermore, CA 94551-0808 Attention: FBO 81-04 Please provide your written statement within thirty (30) days from the date this announcement is published to ensure consideration of your interest in LLNL's SiMM Laser Diode Package technology.
- Record
- SN00664050-W 20040904/040902211747 (fbodaily.com)
- Source
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