Fujitsu Corporation

Yoshiaki Udagawa

Masahiro Suzuki

Haruhiko Yamamoto

Mitsuhiko Nakata

Junichi Ishimine

Shunichi Kikuchi

Koji Katsuyama

Izumi Ono

Hisashi Kawashima

Masahiro Mochizuki

Jie Wei

Keizo Takemura

Takeshi Nishiyama

Hideo Kubo

Akihiko Fujisaki

Masahiro Miyo

Osamu Ohshima

Kenichi Fujii

Masumi Suzuki

Masuo Ohnishi

Tadashi Katsui

Minoru Hirano

Masaaki Sakai

Kouji Katsuyama

Yoshinao Hirose

Jie Wie

A refrigeration system allows the refrigerant to circulate through a closed circulation channel. A dry evaporator is incorporated in the circulation channel. The dry evaporator is designed to keep a quality smaller than 1.0 in evaporating the refrigerant. The quantity of heat transfer per unit area, namely, a heat transfer coefficient depends on the quality. The heat transfer coefficient remarkably drops when the quality of the refrigerant exceeds a predetermined threshold level before the quality actually reaches 1.0. The quality of the refrigerant kept below the predetermined threshold level during vaporization of the refrigetant in the dry evaporator allows a reliable establishment of a higher performance of cooling. On the other hand, if a refrigerant completely evaporates in a dry evaporator in a conventional manner, the heat transfer coefficient of the refrigerant remarkably drops after the quality of the refrigerant exceeds the predetermined threshold level. Accordingly, the conventional dry evaporator is forced to absorb heat at a lower heat transfer coefficient, as compared with the present dry evaporator.

Refrigeration system utilizing incomplete evaporation of refrigerant in evaporator

A refrigeration system allows the refrigerant to circulate through a closed circulation channel. A dry evaporator is incorporated in the circulation channel. The dry evaporator is designed to keep a quality smaller than 1.0 in evaporating the refrigerant. The quantity of heat transfer per unit area, namely, a heat transfer coefficient depends on the quality. The heat transfer coefficient remarkably drops when the quality of the refrigerant exceeds a predetermined threshold level before the quality actually reaches 1.0. The quality of the refrigerant kept below the predetermined threshold level during vaporization of the refrigerant in the dry evaporator allows a reliable establishment of a higher performance of cooling. On the other hand, if a refrigerant completely evaporates in a dry evaporator in a conventional manner, the heat transfer coefficient of the refrigerant remarkably drops after the quality of the refrigerant exceeds the predetermined threshold level. Accordingly, the conventional dry evaporator is forced to absorb heat at a lower heat transfer coefficient, as compared with the present dry evaporator.

An electronic apparatus including a motherboard, a plurality of multi-chip modules mounted to the motherboard and cooling members for cooling the multi-chip modules. A refrigeration unit is arranged to deliver cooling water to the cooling members. A connection structure is provided for each multi-chip module for thermally and mechanically releasably coupling each multi-chip module to the refrigeration unit.

Liquid-cooled electronic apparatus

A cooling device for a portable electronic comprises a radiation plate and a fin for radiating the heat from the CPU. When the plug of an external power. supply is attached to the body of the portable electronic, the CPU may operate at a high clock frequency. The cooling device achieves a high cooling performance by operating a ventilation fan directed to the fin, for example. When the plug is removed from the body of the portable electronic, the CPU may operate at a low clock frequency. Power consumption can be reduced, so that the electric power stored in the built-in battery can be saved. The duration time of the operation can be extended. Calorific power generated at the CPU can also be reduced, so that the cooling device is adapted to suppress the rise in the temperature of the CPU without operation of the ventilation fan.

Method of controlling cooling device in portable electronic and cooling device therefor

A method and apparatus are provided for mounting circuit elements on a printed wiring board, wherein an integrated circuit having terminals with a first interterminal pitch are mounted onto a first surface of a terminal density. conversion board which converts the first interterminal pitch of the integrated circuit to terminals with a second interterminal pitch larger than the first interterminal pitch on a second surface of the terminal density conversion board; and the terminals on the second surface of the terminal density conversion board with the second interterminal pitch are mounted onto the printed wiring board.

Printed wiring board with mounted circuit elements using a terminal density conversion board

A method and apparatus are provided for mounting circuit elements on a printed wiring board, wherein an integrated circuit having terminals with a first interterminal pitch are mounted onto a first surface of a terminal density conversion board which converts the first interterminal pitch of the integrated circuit to terminals with a second interterminal pitch larger than the first interterminal pitch on a second surface of the terminal density conversion board; and the terminals on the second surface of the terminal density conversion board with the second interterminal pitch are mounted onto the printed wiring board.

Printed wiring board with mounted circuit element using a terminal

A cooling system used with a printed circuit board has at least a solid circuit component thereon. The cooling system comprises a cooling header and cooling modules connected to the cooling header. Each of the cooling modules engage to each of the components. The cooling module has a heat transfer plate connected to one end of a bellows which is connected to the cooling header at the other end. A layer of thermally conductive compound, such as a layer of thermal grease, is interposed between the heat transfer plate and the corresponding circuit component. The thermally conductive layer is initially pressed with a pressure higher than a critical pressure, and thereafter, the pressure is reduced to a working pressure exerted on the circuit component provided by the resilient force of the bellows and the hydraulic pressure of the coolant. The critical pressure is predetermined experimentally or practically. As the result, the thermal contact resistance between the heat transfer plate and the circuit component is favorably reduced and stabilized.

Cooling system used with an electronic circuit device for cooling

A cooling system includes a cooling module which has a heat transfer plate elastically biased and exposed to the flow of a coolant for transferring heat dissipated from a circuit component on a printed circuit board to the coolant, and a solder or low-melting-point metal for establishing thermal contact between the transfer plate and the circuit component.

Cooling system for an electronic circuit device

A cooling system including a cooling module which has a heat transfer plate that is exposed to a flow of coolant and is elastically biased toward a circuit component on a printed circuit board for transferring heat dissipated by the component to the coolant. A series of projections are provided on the heat transfer plate for producing turbulence in the flow of coolant. Alternatively, a cylindrical tubular plate is mounted on the heat transfer plate for increasing the surface area in contact with the flow of coolant.

A cooling system including a cooling module which has a heat transfer plate that is exposed to a flow of coolant and is elastically biased toward a circuit component on a printed circuit board for transferring heat dissipated by the component to the coolant, and means for guiding and preventing improper alignment of the transfer plate as the same is resiliently biased toward the circuit component. The coolant module may include a solder or low-melting-point metal for establishing thermal contact between the transfer plate and the circuit component.

A cooling module for an electronic circuit component on a printed circuit board includes a passage in which a coolant flows, a first heat transfer plate exposed to the flow of the coolant, a second heat transfer plate secured to the circuit component, a compliant member between the first and second heat transfer plates for establishing a compliant contact therebetween, and a bellows connected to the first heat transfer plate to elastically press the first heat transfer plate against the circuit component through the compliant member and the second heat transfer plate.

Cooling system for electronic circuit device

Disclosed is a printed circuit card construction comprising laminated conductor plates, a plurality of poles mounted on the laminated conductor plates, a plurality of mother boards fixed by two adjacent poles, a plurality of Input/Output connectors supported by the mother boards for holding each printed circuit card, and a plurality of power sources, wherein the poles and the power sources are directly connected to the corresponding conductor plates of the laminated conductor plates, which poles act as both mechanical means for supporting the mother boards and electrical means for supplying power to the printed circuit cards.

Growing community of inventors

Kawasaki, Japan

Yoshiaki Udagawa