Showing papers on "Heat sink published in 1985"

A Mid‐Ocean Ridge Thermal Model: Constraints on the volume of axial hydrothermal heat flux

Abstract: The depth to the axial magma chamber at three oceanic spreading centers, as indicated by seismic reflection surveys, is greater than that predicted by conductive cooling thermal models of ridge crests. The additional cooling at the ridge axis is owed to the circulation of seawater through the shallow crust. A theoretical model for the temperature distribution at spreading centers, which includes distributed heat sources and sinks, is presented. By representing the hydrothermal heat loss as a series of heat sinks, the depths to the axial magma chamber at the East Pacific Rise at latitude 9°N., the southern Juan de Fuca Ridge, and the Lau Basin spreading center are modeled. Heat sinks are added to the input model to increase the solidus depth until the computed magma chamber depth matches the magma chamber depth determined by seismic reflection surveys. The thermal modeling indicates that the axial hydrothermal heat flux is between 7.1×106 and 13.8×106 MJ/m2, or 10 to 20% of the total missing heat at the ridge axis, requiring extensive low-temperature circulation off axis. High-temperature vents that are spaced 1 km apart and are active between 4 and 10% of the time would account for the axial hydrothermal heat loss.

High density multi-chip interconnection and cooling package

Abstract: A package for mounting and cooling a high density array of integrated circuit chips includes an interconnection assembly for the IC chips which (1) provides base connections to a printed circuit board (PCB), which is adapted to connect to external signal circuits, and (2) separate peripheral power supply connections. The package also includes a cooling module containing fluid-cooled heat sinks that (a) collectively conform to the array of integrated circuit chips and (b) individually conform to the configuration and orientation of the individual chips. The heat sinks are conformed to the chip orientation independently of the coolant flow, which is established through the heat sinks immediately adjacent the interface. Among other aspects of the package, the interconnection assembly incorporates resilient connectors that provide essentially stress-impervious connections to the integrated circuit chips and to the signal PCB.

Cooling system for electronic circuit device

Abstract: 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.

Apparatus for cooling integrated circuit chips with forced coolant jet

Abstract: The capability of the microbellows cooling technique to remove heat from multi-chip modules is enhanced with a highly conductive, rigid, heat spreader. The heat spreader has a planar surface urged against a planar surface of the chip by the flexible microbellows. The surface area of the heat spreader is greater than the mating surface area of the chip. The heat spreader is attached to the bottom surface of the microbellows. The surface area of the heat spreader which mates with the surface of the chip is highly polished and coated with a highly conductive soft metal. A jet of coolant is forced into the inner surface of the microbellows.

Heat sink mounting arrangement for a semiconductor

Abstract: An arrangement for mounting a packaged semiconductor with a heat sink includes the heat sink having a channel formed therein with a pair of opposed side walls and utilizes one or more spring beams acting against one side wall of the channel to urge the semiconductor package into good heat transferring relation or engagement with the other side wall. The arrangement is especially suited for use with TO-220 transistor packages and uses an array of spring beam fingers joined by a spine in comb-like fashion to facilitate assembly.

Latent heat storage and transfer system and method

Abstract: Heat storage and transfer system and method in which a liquid-solid phase change material and a liquid-vapor phase change material selected for coaction with each other are disposed in a container with a body of the liquid phase of the liquid-vapor material in continuous contact with a body of the liquid phase of the liquid-solid material for superior heat transfer between the materials for giving up and transferring sensible heat and liquid to solid phase change latent heat to vaporize liquid-vapor phase change material and vapor to liquid phase change latent heat to a condenser/heat exchanger and also for superior heat transfer from a heat source such as a solar or electric heater by giving up the heat of condensation of a vapor phase to a solid-liquid material which accepts the heat as sensible heat and as heat of melting.

Integrated circuit package incorporating low-stress omnidirectional heat sink

Abstract: Disclosed is a heat sink for cooling an integrated circuit package. The heat sink comprises a single thin sheet of material having two oppositely facing major surfaces. These two major surfaces have a common perimeter defining a plurality of spaced-apart finger-shaped portions of the thin sheet of material that extend radially from a central portion of the sheet. The central portion is convex for attachment to the integrated circuit package; and the finger-shaped portions are formed to extend out of the plane of the central portion to become cooling fins for the central portion.

Electrochemically driven heat pump

Abstract: A refrigeration cycle or heat pump employing an electrochemical compressor. The cycle uses a working fluid at least one component of which is electrochemically active. Another component of the working fluid is condensable. In one embodiment, the electrochemically active component is hydrogen and the condensable component is water. The electrochemical compressor raises the pressure of the working fluid and delivers it to a condenser where the condensable component is precipitated by heat exchange with a sink fluid. The working fluid is then reduced in pressure in a thermal expansion valve. Subsequently, the low pressure working fluid is delivered to an evaporator where the condensed phase of the working fluid is boiled by heat exchange with a source fluid. The evaporator effluent working fluid may be partially in the gas phase and partially in the liquid phase when it is returned from the evaporator to the electrochemical compressor. In the process, heat energy is transported from the evaporator to the condenser and consequently, from the heat source at low temperature to the heat sink at high temperature.

An analysis of the thermal response of power chip packages

Abstract: Since power densities in integrated circuits and power semiconductor devices are continuously increasing due to miniaturization of circuitry, the design of optimum heat spreaders and heat sinks for these applications requires rather sophisticated calculational methods. The chips and spreaders are usually rectangular in shape and although the problem is three-dimensional in nature, it is usually approximated by two-dimensional configurations. Steady-state and transient analytic solutions are presented for the axisymmetric, two-dimensional, and three-dimensional spreader geometries, which can be used to calculate the thermal resistance of the base alone. To determine the thermal resistance of the chip-base combination, the one-dimensional chip thermal resistance should be added to that of the base. These analytic solutions provide calculational means which are easier than the numerical methods. The exact analytic steady-state and transient solutions developed for the axisymmetric, two-dimensional, and three-dimensional configurations are in excellent agreement with the numerical calculations. The parametric calculations provide information on the important guidelines that a packaging engineer should bear in mind while designing and optimizing heat spreaders for power semiconductor applications. These points can be summarized as follows: 1) for a given chip area there exists an optimal base area, 2) increasing the base thickness initially decreases the thermal resistance and beyond a certain limit the latter increases with base thickness, and 3) the convective heat transfer coefficient strongly affects the thermal resistance and the usual assumption of an isothermal base is not always appropriate.

Bulk heat or cold storage device for thermal energy storage compounds

Abstract: A bulk thermal energy storage device is provided comprising a bulk storage tank containing a latent energy storage material, preferably a phase change material which is subject to repeated melting and freezing during which latent thermal energy is absorbed or released by the phase change material. A plurality of heat exchange devices are generally vertically positioned within the phase change material and at a predetermined distance from each other and from the walls of the storage tank for flow of a heat exchange fluid serially through said passageways in the heat exchange devices. At least one screen is positioned in the storage tank in a generally horizontal position and extending between the walls of the tank and the heat exchange devices for supporting the phase change material when in a frozen condition during the melting cycle of the phase change material to prevent settling of the phase change material to the bottom of the tank. The predetermined positioning of the heat exchange devices and the screen in the storage tank provide for an optimum heat exchange between the heat exchange devices and the phase change material in the tank and prevent the loss of heat exchange efficiency due to a settling-out of frozen particles of the phase change material to the bottom of the tank.

Magnetic refrigeration apparatus with heat pipes

Abstract: A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe of pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

Integrated circuit packaging systems with double surface heat dissipation

Abstract: A mounting arrangement for a semiconductor integrated circuit chip having a first heat sink mounted to the bottom surface of the chip in good heat transfer relation and a second heat sink mounted to a region of the top surface of the chip interior to the bonding pads.

Combined Conduction and Radiation Heat Transfer in Porous Materials Heated by Intense Solar Radiation

Abstract: An analysis is presented to predict the heat transfer characteristics of a plane layer of a semitransparent, high-temperature, porous material which is irradiated by an intense solar flux. A transient, combined conduction and radiation heat transfer model, which is based on a two-flux approximation for the radiation, is used to predict the temperature distribution and heat transfer in the material. Numerical results have been obtained using thermophysical and radiative properties of zirconia as a typical material. The results show that radiation is an important mode of heat transfer, even when the opacity of the material is large (GAMMA /sub L/ greater than or equal to 100). Radiation is the dominant mode of heat transfer in the front third of the material and comparable to conduction toward the back. The semitransparency and high single scattering albedo of the zirconia combine to produce a maximum temperature in the interior of the material.

Radiation detector having temperature readout

Abstract: A hand held radiation detector may be used for scanning of a surface from a distance to obtain a gross indication of temperature variations in the surface. The radiation detector is provided with a nosepiece having a conical cup therein which can be placed directly against a surface. The radiation sensor views the surface through the cup to obtain an accurate indication of temperature substantially independent of the emissivity of the surface. The radiation sensor and a temperature sensor are potted with high conductivity material in an insulating sleeve within the nosepiece. The nosepiece is of high conductivity material and is thermally connected to a main housing which serves as a heat sink. Temperature indications are obtained from the sensed radiation indication by means of a piecewise linear gain analog circuit.

Cooler for automotive use

Abstract: A cooler for automotive use which uses neither the power of the engine nor that of the battery, but instead operates from power supplied by solar cells mounted on the roof of the vehicle. The cooler includes a liquid coolant filled evaporator, a radiator, a heat pipe connecting the evaporator and the radiator, a valve provided in series with the heat pipe for regulating the flow of coolant vapor through the heat pipe, the solar cells, a return pipe through which coolant liquefied in the heat sink is returned to the evaporator, a coolant circulating pump provided in the return pipe and operated by power generated by the solar cells, and fans provided near the evaporator and the radiator which are also operated by power generated by the solar cells. Preferably, the liquid coolant is one having a high saturated vapor pressure, boils at a temperature of about 40° to 70° C. at atmospheric pressure, and provides a large latent heat of evaporation.

Rotating rectifier assembly.

Abstract: A rotatable rectifier assembly for use in a brushless generator. A housing (40) receives a stack of heat sinks (56-68) which are both thermally and electrically conductive and which sandwich diode wafers (78) making up a multiple phase, full wave rectifier. The requisite electrical connections are made by electrical connectors (102, 110) slidably extending through the heat sinks and electrically connected to desired ones of the heat sinks and electrically isolated from other ones of the heat sinks.

Cryosystem for biological material

Abstract: A cryo-cell assembly for biological material including a space for receiving the material, the space being at least partly enclosed by means suitable for conducting heat from the space to a heat sink and including heat generating means in heat conducting relationship with the space. Power is applied to the heat generating means according to a desired temperature cycle stored in memory. The power supply unit senses actual temperature in said space and compares this with the desired temperature. Power is supplied to the heat generating means whenever the actual temperature falls below the desired temperature.

Heat sink structure

Abstract: There is disclosed a novel high heat flux liquid cooled semi-conductor heat sink structure suitable for mounting semi-conductor chips such as IC's, hybrids, lasers, and power semi-conductors, said heat sink being made of metals, such as tungsten or Molybdenum; ceramics such as alumina, Beryllia, aluminum nitride, silicon carbide or variants thereof or other suitable material such as crystalline carbon, said semi-conductor heat sink structure including at least one surface suitable for bonding one or more semi-conductor chips in intimate thermal relationship thereto, and including a heat exchange surface on the interior surface thereof, said structure providing means for enclosing said heat exchange surface in a liquid tight manner and including means for providing a flow of coolant liquid to remove heat from said heat exchange surface by formation of nucleate vapor bubbles on said heat exchange surface, the improvement wherein said heat exchange surface includes: means disposed on said heat exchange surface for forming pressure gradients in said liquid having a component perpendicular to said heat exchange surface without substantially impeding the relative velocity between the anode heat exchange surface and said liquid, said component having a magnitude directly proportional to the square of the relative velocity between said anode heat exchange surface and said liquid, to facilitate removal of said nucleate bubbles.

Dual mode heat exchanger

Abstract: A dual mode heat exchanger 10 for cooling airborne electronics 12 through a cold plate 14. The heat exchanger either radiates heat to air through radiator fins 18 or absorbs heat by evaporative cooling. A liquid coolant contained in grooves 16 of the cold plate 14 boils at a preselected temperature and thereby absorbs heat energy. Vapor released by the boiling liquid is exhausted through a hydrophobic filter membrane 24.

Microgravity beverage can cooler

Abstract: A refrigeration apparatus for cooling containers in the microgravity conditions of outer space comprising a cooler compartment having a cold plate therein which is contoured to the shape of sidewall portions of the cans to be cooled. The cold plate is coated with a complient heat transfer medium such as metal-filled silicone rubber. When the lid of the cooler is closed, the containers are firmly engaged by the complient material, forming a good conductive heat transfer relationship. A thermoelectric generator is disposed in a separate cabinet connected to one end of the cooler and includes thermoelectric elements and a heat sink operatively associated with the cold plate within the cooler. A fan is provided in combination with the thermoelectric generator for drawing air over the heat sink thereof to dissipate heat to the surrounding environment. Suitable temperature controls are provided for turning the fan and thermoelectric elements of the generator on and off, and a safety circuit is provided to protect the device against overcurrent and excessively high temperatures in the heat sink.

Air temperature control system

Abstract: An air temperature control system which is highly energy efficient and virtually maintenance free. The system includes an intake conduit for receiving air at a non-selected temperature, an exit conduit for delivering the air at a controlled temperature to a preselected location, a heat exchanger located below the surface of the ground, and a heat sink preferably of limestone which surrounds the heat exchanger and which adjusts the temperature of the air flowing through the heat exchanger to a controlled temperature. A fan effects the flow of air through the system.

Car air conditioner with heat storage tank for cooling energy

Abstract: An air conditioner for vehicle includes a cooler cooled in a cooling circuit which includes a compressor, a heat exchanger located in the vicinity of the cooler, a thermal storage tank connected with the heat exchanger via a heat transfer passage, a pump provided in said heat transfer passage, a first temperature sensor for detecting the temperature TO in close proximity to of the cooler, a second temperature sensor for detecting the temperature TC of the storage tank, and a third sensor for detecting the temperature TR in the car interior, and a heat transfer type partition wall can be integrally provided between a cooling flowing passage of the cooler and a fluid passage of the heat exchanger. The air conditioner for the vehicle serves to cause said pump to be operated to permit cooling energy to be stored when TC is greater then TO and TR is lower than a set value, and to cause said pump to be operated to permit said cooling energy to be radiated when TR is higher than the set value. Cooling energy can be effectively transferred to the heat exchanger via the heat transfer type partition wall. When the temperature in a car is raised to that higher than a set value, the heat stored in storage tank can be radiated to lower the temperature in the car interior.

Unitary slotted heat sink for semiconductor packages

Abstract: A unitary heat sink for a semiconductor package having a plurality of cooling fin elements, each element having upwardly extending openings that divide the base into a plurality of leg portions, the heat sink having a plurality of flat base portions individually bonded to a surface of the package, each of the leg portions of an individual fin element being integral with different but adjacent flat base portions, in operation the heat sink preventing a build-up of stresses at the bonded interface of the base portions and package due to differential coefficient of expansions of the heat sink and package.

Multichip thin film module

Abstract: A package for thermal dissipation of heat from multiple integrated circuit chips is described. The package includes a silicon substrate for electrical connection to silicon integrated-circuit chips. The silicon substrate provides a high degree of thermal dissipation of heat generated by the chips. In addition, the invention comprehends that the silicon substrate is attached to a heat dissipating means. In the preferred embodiment, the heat dissipating means includes a metal heat sink. The package is capable of dissipating up to six watts per square centimeter of heat from the chips.

A device for detecting the presence of noncondensable gas in steam sterilizers

Abstract: A device for indicating the presence of unacceptable levels of noncondensable gas, such as air, in a steam sterilization chamber. The device (10) includes an insulated heat sink (12) having an upper end (14) and a lower end (16). The upper end of the heat sink is in such open communication with the sterilization chamber that the steam enters the heat sink. The device also includes a chamber (34) proximate the lower end of the heat sink. The heat sink defines a path (18) through which the steam travels from the upper end toward the chamber. The path is adapted to provide sufficient exposure of the steam to the heat sink so that the steam condenses within the path, releasing any noncondensable gas associated with the steam and forcing it toward the chamber. The chamber includes means (40) for indicating the presence of noncondensable gas accumulated therein. The device also includes means such as the air in the chamber for preventing the condensate from affecting the indicating means.

Method and apparatus for measure of heat flux through a heat exchange tube

Abstract: The present invention relates to a method and apparatus used to determine the heat flux through a portion of a surface of a heat exchanger tube, using heat flux sensor means that is installed on the inner wall of the heat exchanger tube and send a signal to a connected heat flux meter.

Heat dissipating retainer for electronic package

Abstract: A heat dissipating retainer for a flat, rectangular solid state package of electronic components is made from a single piece of pliable, springy electrically conductive sheet material bent to form a generally W-shaped structure. This structure has an inner inverted U-shaped channel section open at its front, back, and bottom ends to receive the package in frictional engagement under spring tension by contact with sides of the channel section. This structure serves as a heat sink by effectively dissipating by conduction, convection and radiation, heat generated in the solid state package of electronic components.