Showing papers on "Heat sink published in 1983"

Heat sink and method of attaching heat sink to a semiconductor integrated circuit and the like

Abstract: Two bodies such as an integrated circuit and a heat sink are maintained in a low stress and high thermal conductance abutment by pressure from capillary attraction. A surface of one of the bodies is provided with grooves preferably having reentrant surfaces. A surface of the other body is brought into abutment with the grooved surface with a liquid therebetween which partially fills the grooves. The grooves act as reservoirs for excess liquid so that a minimum thickness liquid interface is achieved, and the grooves enable trapped gas to escape out the open ends thereby preventing voids between the two bodies. Importantly, the groove geometry enforces a well-defined attractive force between the two surfaces due to the liquid surface tension.

Semiconductor chip carrier package with a heat sink

Abstract: A semiconductor chip carrier and contact array package having an apertured dielectric bottom layer (11), one or more chip connection layers such as wire bond layers (16, 17) insulated from one another, at least one chip-holding recess (24) in the wire bond layers and a heat conductive copper heat sink insert (26) extending across the aperture of the dielectric layer and forming a base adapted to be in heat-conductive contact with the bottom of an integrated circuit chip (27) to be attached thereon whereby heat flux generated by the chip is quickly and efficiently removed from the chip body. The wire bond layers (16, 17) contains metallization patterns (29) for bonding to the chip and a grid array of contacts or connection pins (20) connected to plated through-holes in the wire bond layer(s) for plugging the carrier to a circuit board or the like. The various layers of the carrier per se are manufactured by predrilling and aperturing, forming the metallization patterns, stacking and pressure laminating to form a reliable compact structure having high heat dissipation properties.

The generalized Carnot cycle: A working fluid operating in finite time between finite heat sources and sinks

Abstract: The production of work in finite time from a reservoir with finite heat capacity is studied. A model system, for which the only irreversibilities result from finite rates of heat conduction, is adopted. The maximum work obtainable in finite time from such a system is derived, and is found to be strongly dependent upon the reservoir heat capacity. The cycle producing the maximum work is derived for an arbitrary one‐component working fluid; no equation of state is assumed. In the optimum cycle, when the working substance is in contact with a finite reservoir, then the temperature of the working fluid is an exponential function of time and the entropy of the working substance is a linear function of time. While the maximum work obtainable in a single fixed‐time cycle is a strictly increasing function of the reservoir heat capacity, the efficiency (work produced/heat put in) is a strictly decreasing function of the reservoir heat capacity, for the model system with a finite hot reservoir and an infinite cold ...

Dimensionally stable semiconductor device

Abstract: A heat dissipating member including a heat sink is placed on a module base board with flip-chips mounted thereon, with metallic plates and first adhesive materials of a good thermal conductivity interposed between the heat dissipating member and the flip-chips in a close contact relation and with a second adhesive material interposed between the heat dissipating member and the base board, wherein the first adhesive material is selected to have a melting point lower than that of the second adhesive material, and then such an assembly is heated so that both the first and second adhesive materials are melted and the metallic plates are mounted onto the flip-chips and the heat dissipating member is mounted onto the base board. A gap is formed between the metallic plates and the heat dissipating member as a result of earlier solidification of the second adhesive material than that of the first adhesive material so as to be precisely controlled such that a heat transferring effect therebetween may not be degraded.

Natural convection cooling system for electronic components

Abstract: Natural convection cooling of power carrying electronic components mounted within an enclosure is achieved by mounting the power components at the base of the enclosure at the opening of an inner chimney which separates the enclosure interior into forward and rearward compartments. The inner chimney serves to duct the heated air rising from the components at the base of the enclosure forward compartment to the top of the enclosure. A heat exchanger is mounted on the inside face of the enclosure door to provide a cooled surface so that warm air at the top of the enclosure forward compartment is drawn downwardly along the heat exchanger surface to the base of the enclosure thereby creating natural air turbulence within the enclosure. Natural convection cooling is further improved by adding a plurality of heat sinks to the chassis base so that the heat sink fins extend into the rearward compartment which forms an outer chimney by virtue of air ducts being provided in the front and top walls of the enclosure in communication of the rearward compartment. The outer chimney creates an increased draft of cool air along the fins thereby reducing the average temperature of the air rising through the fins. In this way, convection cooling is achieved without the need for separate mechanical air handling equipment.

Radiative Heat Transfer in Fibrous Insulations—Part II: Experimental Study

Abstract: Two experiments have been conducted to study radiative heat transfer in light-weight fibrous insulations (LWFI). The spectral extinction coefficients for a commercial LWFI have been measured via transmission measurements, and a guarded hot plate apparatus has been used to measure the radiant heat flux as well as the total heat flux in the insulation. The experimental results are compared with the theoretial values calculated according to the analytical models are useful in Part I of this paper. The comparisons reveal that the analytical models are useful in giving representative values for the radiative properties of typical LWFI. However, only qualitative agreements have been obtained for the heat transfer results.

Heat management system for aircraft

Abstract: A novel heat management system for aircraft is provided which is based on the aircraft fuel as the heat exchange medium and comprises a dedicated thermal reserve fuel tank for containing refrigerated aircraft fuel (or other expendable liquid) which is cooled by heat exchange with the primary aircraft fuel flow to the engines, a fuel line loop for conducting fuel through a plurality of heat exchangers associated with cooling loops for heat generating aircraft systems, and a central microprocessor based controller for controlling fuel flow and temperature throughout the fuel loop system and into the aircraft engine.

Injection laser packages

Abstract: A hermetically sealed injection laser package is made by first forming a sub-assembly of a monitoring photodiode (50) on a metal support member (53) and welding it to a heat sink (30) on which the laser (31) is mounted. The heat sink is secured inside the package housing (10) and then a further sub-assembly, comprising a plastics packaged optical fiber (60) hermetically sealed in a fiber support tube (61), is introduced through an aperture in one wall of the housing. Anchorage means (70) is laser beam welded to this tube and to the heat sink to secure the inner end in position for optimum optical coupling between the laser and the fiber.

Heat sinks for integrated circuit modules

Abstract: In dissipating heat from miniature electronic devices, circuit modules, or the like, and particularly from dual-in-line package (DIP) type units having leads depending from opposite sides of a thin molded rectangular-parallelepiped body, an elongated sheet-metal strip of heat-radiating elements disposed above and in spaced relation to the top of the package has its opposite ends integrally connected with separate spaced heat-conducting clip members which are cantilevered from it in different directions to fit respectively about the top and bottom surfaces of the package and to flex so as to accommodate insertion of the package between them and yet adjust themselves into desirable broad-area abutments with those surfaces. Heat conducted away from the package by each of the cantilevered members first reaches a different end of the strip of heat-radiating elements, without coursing through the other member and without interfering with the heat-exchange taking place along the opposite surfaces of the package clipped between the members.

Apparatus for cooling integrated circuit chips

Abstract: Apparatus is provided for cooling a closely grouped plurality of integrated circuit chips by forced air convection A heat sink, having a plurality of fins and a narrow channel between each fin, is connected to a first side of a substrate and has one end protruding into an aperture in the substrate A chip is connected directly to the one end of the sink and is electrically connected to a second side of the substrate

Passive integral solar heat collector system

Abstract: The present invention relates to an improved apparatus for collecting, absorbing, transferring, and storing solar heat energy, economically and passively, without pumps or electric power. The apparatus comprises a solar collector with a flat finned heat pipe absorber and an attached integral insulated storage tank with a double wall heat exchanger. The absorber, made of one or more slightly tilted gravity assisted heat pipes with flat absorber fins, absorbs and transfers solar heat by evaporation, vapor transport, and condensation to the slightly elevated heat storage tank. The one or more heat pipes turn on when the sun is shining and turn off automatically when the sun is not shining.

Packaging arrangement for spacecraft computer

Abstract: The present invention relates to a packaging arrangement for a spacecraft computer designed to conduct experiments in a hostile environment of outer space. The computer has high density packaging of very large scale integration (VLSI) circuits. Heat is removed by direct contact with each heat producing item in the computer, which direct contact is provided for most integrated circuit chips by a heat conductive plane located between the chips and a printed circuit board. From the heat conductive plane, heat is further removed through direct contact with a housing adapted for physical connection to a cold plate for heat conduction thereto. All heat producing elements are in physical contact with heat transferring devices to transfer essentially all heat to the cold plate. The housing and heat transferring devices eliminate unwanted electromagnetic interference and help reduce galactical radiation especially of the x-ray frequency type. However, the subject invention still provides a lightweight, economical computer that has additional features of (1) ease of access for diagnostic checks of the computer, and (2) reprogrammability of the erasable programmable read only memory (EPROM).

Means for periodic desorption of a cryopump

Abstract: A cryopump comprising a primary cryopanel (67) associated with a low temperature heat sink (60) having means for adsorbing a first low boiling point gas and a secondary cryopanel (80) associated with heat sink (60) and a higher temperature heat sink (48) having means for condensing a higher boiling point gas. There are means (90) for selectively conducting heat to the primary cryopanel to raise the temperature of the cryopanel above that which is necessary to cause said first gas to become desorbed from said cryopanel while having minimal effect on the capacity of the higher temperature heat sink.

Circuit package with membrane, containing thermoconductive material, ruptured against a heat sink

Abstract: An electronic circuit package mountable to a heat sink is provided with burstable membrane means adhesively stuck to the circuit package and containing thermoconductive material. Upon mounting of the circuit package to the heat sink, the membrane means ruptures, and the thermoconductive material, such as silicon grease, is automatically spread along the interface of the circuit package and the heat sink to enhance heat transfer. There is no need for a manual separate step to spread the grease at the time of installation.

Techniques for Obtaining Detailed Heat Transfer Coefficient Measurements Within Gas Turbine Blade and Vane Cooling Passages

Abstract: This paper reviews the techniques developed jointly by Rolls-Royce Bristol and Oxford University for determining detailed heat transfer coefficient distributions inside turbine blade and vane cooling passages.These techniques make use of a low temperature phase change paint to map the heat flux distributions within models of the cooling passages. The paints change from an opaque coating to a clear liquid at a well defined melting point.Thus, the surface temperature history of a model subjected to transient convective heating is recorded. From this history the heat transfer coefficient distribution is deduced using a transient conduction analysis within the model. The general method may be applied to a range of model thicknesses and geometries. The Rolls-Royce data are usually obtained from the inner surface of thick walled models whereas the Oxford measurements are performed on the outside of thin walls.Results are presented for the detailed heat transfer coefficient distributions within a variety of cooling passages. Firstly, smooth ducts of circular cross section are considered and serve the purpose of validating the experimental techniques. Secondly, results for complex passages with varying cross-sectional area are presented, and the effect of introducing discrete roughness elements and film cooling exhausts into these ducts assessed. Finally, data obtained from a comprehensive examination of a typical engine multi-pass cooling geometry are presented.Copyright © 1983 by ASME

Apparatus and method for heat flow measurement

Abstract: A method for accurate, on site heat flow measurement through a substrate surface using surface mounted heat flow sensors and an apparatus for on site calibration of surface mounted heat flow sensors are presented. The method comprises mounting on the substrate surface a heat flow sensor which is calibrated to establish the relationship between heat flow through the surface and the resultant induced voltage in the sensor under the convective and radiative heat transfer environmental conditions of the surface, measuring the voltage output induced in the sensor by heat flow through the surface, and converting the voltage output to a quantitative heat flow on the basis of the calibration of the sensor. The apparatus of the invention permits the calibration of the sensors under convective and radiative heat transfer environmental conditions which substantially duplicate those of the experimental substrate.

Heater assembly for thermal processing of a semiconductor wafer in a vacuum chamber

Abstract: A heater assembly for annealing a semiconductor wafer in a vacuum chamber includes a blackbody source having a constant planar energy flux charactertistic and a wafer support for supporting the wafer adjacent to, but not spaced apart from, the source in planar parallel alignment therewith. The heater assembly further includes radiation shields and a housing providing support for the source, the wafer support and the radiation shields in fixed relationship. The housing includes a heat sink for removal of thermal energy and a slot for insertion and removal of the wafer. The heater assembly confines thermal energy and reduces input energy requirements. In addition, the requirement for a movable shutter is eliminated.

Geothermal energy conversion system

Abstract: Apparatus and a method for using terrestrial heat to increase the temperature of a liquid, such as water. A circulation pipe buried in the earth in a region of high subterranean heat allows the liquid to move in heat exchange relationship to the subterranean heat. The liquid is pumped from a tank adjacent to the surface of the earth and through the pipe back to the tank. The heated water in the tank can be removed from the tank and caused to flow through a heat exchanger also adjacent to the surface of the earth. Then, the water is returned to the tank for re-use and reheating.

Development of thermal energy storage technology using metal hydrides

Abstract: The rate of heat transfer is important in heat storage technology using metal hydrides because the rate of hydrogen transfer depends on the rate of heat transfer. A new metal hydride container with heat pipes which were able to transfer heat rapidly was constructed and was used to operate the heat storage system with a hydrogen flow of 1.51 min−1 between 3.5 kg beds of CaNi5 and LaNi5. The metal hydride beds were located inside cylindrical heat pipes 66 cm long with an inside diameter of 4 cm.

Surface mounted integrated circuit chip package and method for making same

Abstract: A surface mountable integrated circuit chip package is taught. Briefly stated, a flexible laminate having conductive strips thereon is wrapped around a heat sink. Plastic is molded around the laminate-heat sink piece, with a window left in the center thereof, which coincides with a window in the laminate. An integrated circuit chip is then bonded to the heat sink with wire leads then run from the chip to the conductive strips on the laminate. A potting material is then placed in the window thereby completely encapsulating the integrated circuit chip so as to prevent exposure to environmental or physical damage. This thereby forms a package which is surface mountable to a circuit board through attachment techniques such as the vapor phase soldering.

Optimization of a heat engine based on a dissipative system

Abstract: A new class of heat engine is analyzed in which the working fluid operates in a dissipative process, never in equilibrium. The conditions are found for stability and for the generation of work. Then the optimal path is found for operating the general dissipative engine by means of optimal control theory. The optimal cycle consists of arcs of constant power and of approximately instantaneous adiabats. If the heat flow is a function of temperature only, then the constant power arcs become isotherms. An upper bound is found to the power output. Two examples are worked out in detail: a light‐driven dissipative engine whose absorption is a step function of temperature, and a light‐driven dissipative engine whose working fluid undergoes a chemical reaction (isomerization), absorbing light in the isomeric form favored at high temperatures.

A Method of making injection laser packages and packages made by using the method

Abstract: A hermetically seaied injection laser package is made by first forming a sub-assembly of a monitoring photodiode (50) on a metal support member (53) and welding it to a heat sink (30) on which the laser (31) is mounted. The heat sink is secured inside the package housing (10) and then a further sub- assembly, comprising a plastics packaged optical fibre (60) hermetically sealed in a fibre support tube (61), is introduced through an aperture in one wall of the housing. Anchorage means (70) is laser beam welded to this tube and to the heat sink to secure the inner end in position for optimum optical coupling between the laser and the fibre.

Heat sink arrangement with clip-on portion

Abstract: The present invention includes a heat sink device which, in a preferred embodiment, has a number of fins extending from a flat base section. In addition, there are matching grooves formed in a pair of said fins and snapped into said grooves, there is located a plastic clip-on member. The clip-on member is designed to be spread, or temporarily deformed at its ends, in order to be clipped onto a holder which is holding an active element (a heat generating element), such as an integrated circuit. When the clip-on member is so clipped onto the holder, it applies force to hold said flat base section of said heat sink means against the section of the holder which overlies the active element to thereby conduct heat from the active element. The clip-on member can be readily removed if, for instance, the integrated circuit fails and in this way the heat sink is not wasted.

Thermal storage heat exchanger systems of heat pumps

Abstract: In a heat pump having a heat source, a heat sink and a thermal storage heat exchanger in which heat energy is cyclically accumulated and discharged by circulation of a secondary refrigerant therethrough, the improvement wherein: the secondary refrigerant is a aqueous solution having a concentration which is below its Eutetic concentration, the heat sink is adapted to super cool the aqueous solution to partially freeze it to generate a partially frozen solution in which fine ice particles are retained in suspension, the thermal storage heat exchanger has a storage chamber adapted to receive said partially frozen solution from the heat sink and to separate the ice particles from the liquid phase refrigerant to form a porous ice bed and a substantially ice free liquid bath, and wherein the thermal storage heat exchanger is adapted to receive heated refrigerant and to discharge the heated refrigerant into said chamber such that it is placed in intimate contact with the ice bed in a manner such that it may pass through the pores of the porous ice bed prior to its return to the bath.

Mounting of a compact circuit package to a heat sink or the like

Abstract: A compact circuit package includes a housing providing a cavity for containing heat generating electrical components. A ceramic substrate is mounted to close the cavity. The package is adapted to be mounted in heat transferring relationship with a heat sink. The bottom surface of the compact circuit package is provided with a self-contained chamber containing a supply of grease. The chamber is defined by the package bottom surface and a bubble of plastic film which overlies the substrate and which is removable sealed to the package around the periphery of the substrate. In this form, the compact circuit package can be transported and stored until ready for use. When the package is ready to be mounted to a heat sink, pressure such as by a finger is applied to the top surface of the bubble film to thereby spreadingly apply the grease to the surface of the substrate. The film is then removed from the bottom of the compact circuit package and the greasey underside of the film placed into engagement with the heat sink surface and rubbed, as by a finger, to thereby spread the remaining residue grease onto the heat sink. The film is then removed and discarded and the compact circuit package mounted to the heat sink.

Heat sink for electronic package

Abstract: A cooling fin assembly for mounting on a semiconductor package that includes a plurality of pins adapted to be affixed to a surface on the package, and a cooling fin means having a thin walled cellular configuration with the cells defining elongated openings in side-by-side relation that extend through the fin means, the pins being seated in the cells of the fin means.

Heat conduction mechanism for semiconductor devices

Abstract: The present invention provides a mechanism for conducting heat away from a semiconductor device, and has particular application for use with VLSI technology. The present invention comprises an elongated, resilient and deformable central body having a thermally conductive outer surface which is disposed in contact with a surface of the semiconductor device. In the preferred embodiment, the semiconductor devices comprising an electronic circuit configuration are disposed on a circuit board in rows. The present invention is formed into strips such that one strip of the central body portion of the present invention is disposed over each row of semiconductor devices. A heat sink is placed over the central body portion of the present invention such that the central body with its thermally conductive outer surface is sandwiched between an upper surface of the semiconductor device and the heat sink. Heat generated by the semiconductor device is conducted through the thermally conductive outer surface of the resilient central body to the heat sink where it is radiated and conducted away from the semiconductor device.

Vertical concentric-tube ground-coupled heat exchangers

Abstract: An experimental and analytical project to study the design of vertical, concentric-tube ground-coupled heat exchangers for use in heat pump applications is described. The experimental apparatus consists of a concentric configuration of two 155-ft (47.2-m) polyvinylchloride (PVC) pipes (sealed at both ends with connections so that hot or cold water could be pumped through the system) with instrumentation to measure heat transfer. This heat exchanger was placed in a well with an 8-in (0.20-m) inside diameter (ID), which was backfilled with sand to establish good thermal contact. Heat transfer was measured for heat exchanger operation under several sets of operating conditions. A mathematical model was developed and converted into a computer program to simulate the operation of the ground-coupled heat exchanger. Data collected using the experimental apparatus was used to validate the computer program, and the computer model was then used to study the effects of variations in heat exchanger length, diameter, flow rate, and thermal conductivity and the thermal conductivity of the ground on the heat exchanger performance. Results are presented.

Heat pipe assembly

Abstract: Means for accurately controlling the transfer of heat to or from a device includes a heat pipe having a condenser end and an evaporator end. A helical screw thread is provided on the exterior surface of the heat pipe so that a portion of the heat pipe may be removably insertable via the threading into a threaded aperture in a desired section of the device. Alternatively, a connecting member, in which a portion of the heat pipe is fixed, may be selectively secured to the desired section of the device. At least one heat sink fin which is selectively securable on the heat pipe via the threading may also be provided.

Electrically insulated heat sink assemblies and insulators used therein

Abstract: An insulator used in connecting heat generating electrical components to heat sinks. Fasteners which include insulators of the present invention include flexible engaging means for preassembling an insulating washer portion to a conductive fastener element. The insulators may be made of high performance plastic material or of a coated metal. The fasteners used with the insulators preferably have integral spring washers to maintain thermal conductivity between the components and the associated heat sinks. The insulator preferably have integral bosses which prevent arcing between the conductive fasteners and the heat sinks.