Abstract: A two loop heat conversion system for high heat density planar devices in which high density heat in an area adjacent to a surface is transferred into a liquid cooling medium closed loop in a radiated heat to liquid heat transfer component positioned in contact with the surface that is connected, to a liquid to gas medium, heat exchanger in a first loop and a gas medium second loop is arranged to carry away all radiated heat from the assembly and all heat extracted from the liquid in the liquid to gas heat exchanger and exhaust it to the ambient. The radiated heat transfer component of the invention provides a transition in manufacturing that is practiced employing the planar type tools in fabrication which usually can neither be practiced manually or observed without substantial magnification.

Abstract: 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.

Abstract: A heat transfer device for a mobile computer system using a loop heat pipe, the evaporator of the loop heat pipe coupled to the processor die. The vapor space and liquid space are separated. The separation of the vapor space, and the wick structure of the liquid space, ensures that the vapor space will not be distorted or clogged by the wick structure. The heat transfer device can be bent to meet design criteria without distorting the width or radius of the vapor space. In one embodiment of the present invention the evaporator, condenser, and liquid space have different types of wick structure. Another embodiment of the present invention, the vapor space of the loop heat pipe has uniform thickness. The loop heat pipe device of the present invention provides reduced evaporator and condenser resistance and increased burn out flux, thereby increasing the power handling capacity of the device.

Abstract: The present invention of a heat sink modular structure inside an electronic product comprises of a heat sink fan mounted on one end of an air channel pipe body blowing the heat thereon outward from an outlet of an air channel disposed inside the said air channel pipe body, and blowing another draft of cold air from an outlet of another air channel disposed inside the said air channel pipe body to the said CPU and the electronic parts adjacent to its surrounding to enable the heat generated by the other electronic parts inside the said electronic product to have sufficient air convection.

Abstract: A heat absorbing and radiating device includes a driving unit having communicable first fluid outlets and fourth fluid inlets, a heat-exchange unit communicating at an end with third fluid outlets of the driving unit and at another end with an inlet end of a liquid-gas confluence unit, which communicates at an outlet end with an inlet end of a liquid-gas separation chamber, while the latter communicates at an outlet end with one of two second fluid inlets of the driving unit. The driving unit is provided therein with reciprocatingly movable magnets to alternately push first and second fluids into the heat-exchange unit before them enter the fluid-gas confluence unit, so that hot air is finally released from the liquid-gas separation chamber. Since radiating fins and cooling fan are omitted, the device has reduced volume for use with a heat source in a small space, such as a CPU of a portable computer.

Abstract: A computer microprocessor has a housing portion with a recess formed in a top side wall thereof, and a die portion inset within the recess. Operating heat from the die is removed by heat dissipation apparatus which automatically adapts to variations in the microprocessor bond line thickness and includes a sheet metal EMI shield wall overlying the microprocessor and having a condensing end portion of a thermosyphoning heat pipe secured to its bottom side, with an evaporating end portion of the heat pipe overlying the die recess and being resiliently deflectable toward a phase change thermal pad mounted on the top side of the die and inset into the housing die recess. A metal heat sink member is rotatably mounted on the heat pipe evaporating end portion and has a flat bottom side and an arcuate top side.

Abstract: A heat dissipating device includes a heat sink (50) for removing heat from an electronic device (90), and a plurality of adjusters (45) for adjusting distance and contact force between the electronic device and the heat sink. The heat sink defines a plurality of receiving holes (62) for receiving respective adjusters, and a plurality of communicating through holes (66) whose diameters are smaller than those of the receiving holes. A shoulder (64) of the heat sink is formed where each receiving hole communicates with each through hole. Each adjuster comprises a connecting shaft (42), a lock screw (46) with a head (464), and a spring (44). The lock screw threadedly engages with the connecting shaft, and the spring is secured between the shoulder of the heat sink and the head.

Abstract: The invention pertains to a new type of cooling system for cooling of heat sources, especially for cooling of electric components, with a cooler comprising, on a housing through which a coolant can flow, at least one first cooling surface that can be splashed with the coolant and at least one second cooling surface for flange-mounting of the heat source.

Abstract: An integrated circuit device package is integrated with a heat dissipation member to reduce the number of junctions in a packaged integrated circuit device. For example, the integrated circuit device package may include a substrate and a thermally conductive lid coupled to a first surface of the substrate, forming a closed cavity which encloses an integrated circuit die. The thermally conductive lid may be integrated with the heat dissipation member.

Abstract: A plate type heat pipe having a hermetically sealed container installed so as to face a printed board on which at least one part to be cooled is mounted, wherein a block which passes through at least one main surface portion of the container is arranged within the container in a corresponding portion to the part(s) to be cooled.

Abstract: A cold plate that provides air or liquid cooling for a computer circuit module and has at least one mounting plate with a board mounting surface on one side for carrying a printed circuit board assembly and a cooling surface located on the other side. A cover is disposed parallel to and spaced apart from the mounting plate with a cooling chamber defined between the two. The cooling chamber is divided into a liquid cooled section and an air cooled section. The liquid cooled section has a coolant inlet and outlet and flow channels for directing coolant through the liquid cooled section from inlet to outlet. The air cooled section has an air inlet and outlet and flow channels for directing air through the air cooled section from inlet to outlet. The cold plate is adapted so that it may be installed into a circuit module and provide either liquid cooling or air cooling for the module.

Abstract: A computer microprocessor has a housing portion with a recess formed in a top side wall thereof, and a die portion inset within the recess. Operating heat from the die is removed by heat dissipation apparatus which automatically adapts to variations in the microprocessor bond line thickness and includes a sheet metal EMI shield wall overlying the microprocessor and having a condensing end portion of a thermosyphoning heat pipe secured to its bottom side, with an evaporating end portion of the heat pipe overlying the die recess and being resiliently deflectable toward a phase change thermal pad mounted on the top side of the die and inset into the housing die recess. A laterally Enlarged heat sink section is integrally formed on the evaporating end portion and has a flat bottom side and an arcuate top side.

Abstract: The module has a metal substrate having one major face that is insulated and that carries electrical connection tracks, and at least one power component fixed to the substrate and having connection tabs (20) that are soldered to the tracks. The power component is fixed on the non-insulated face and it is placed in a housing constituting an inside wall of a cooling fluid circuit, or it is stuck thereto. The tabs of the component pass through the substrate via holes therein.

Abstract: A method (and structure) for cooling a portable computer includes attaching a portable computer to a holder, transferring heat of a heat-generating component disposed within the portable computer to the holder, and releasing the transferred heat to the atmosphere. The portable computer includes a fixture for detachably fixing the portable computer to the holder, a heat release device for releasing heat of a heat-generating component disposed within the portable computer to the outside, and a supporter which supports the fixture and the heat release device.

Abstract: In a computer system using an expanded unit for obtaining an expanded function, a heat sink of a computer main body and a heat sink of the expanded unit are connected to each other when the computer main body and the expanded unit are connected to each other. A surface area of the heat sink can be increased, and the radiation effect can be improved. Thereby, the computer main body can be operated under a full power mode in which sufficient radiation effect is assumed. Particularly, the performance of a small-sized computer whose setting space of the heat sink is limited can be improved.

Abstract: A component carrier (2) with electric components (4) mounted thereon, having at least one channel (14) for cooling liquid, characterized in that the component carrier (2) has an air cooling body (6), and a fan (8) is associated with the component carrier (2) for producing a forced air stream for air cooling at least part of the components (4) and for air recooling on the air cooling body (6).

Abstract: An amplifier having removable remote controls and the ability to easily couple with other amplifiers for easy mounting is disclosed. The amplifier includes removable remote controls and isocoupling systems that connect two or more amplifiers and that electrically insulate the mounting screws from the mounting surface. The amplifier may also be liquid cooled to dissipate heat generated by the amplifier.

Abstract: A cooling element (2) for power electronic devices comprises heat-exchange fluid inlet and outlet apparatus (29) and an interior volume in which said fluid circulates. The element (2) is made from an electrically insulative material and comprises at least one opening (28) connecting the internal volume (V) to the exterior of the element, a perimeter (24) of the at least one opening (28) forming a seat receiving at least one base (38A) of the power electronic device (36) to be cooled with sealing apparatus (43) between them. The element has a small volume compared to those of the prior art.

Abstract: A portable computer includes a base having a heat producing electronic component mounted therein. A heat sink, also referred to as a remote heat exchanger, is positioned in the base adjacent to the heat producing component. A heat pipe has a first end permanently bonded to the heat sink and extends to a second end thermally engaged with the heat producing component. The heat sink and heat pipe assembly is rotatable about an axis of the heat sink so as to move the second end of the heat pipe into and out of thermal engagement with the heat producing component.

Abstract: Structure for housing and heat sinking active equipment pieces (3; 2) in a space vehicle, comprising a constraining external container (1; 46) containing a cooling gas or a mixture of gases, means for mechanically holding said boxes (3; 2) into the container (1; 46) and a plurality of channels (32) or empty volumes (18), provided between the external surfaces of the active equipment boxes (3; 2) and the means for mechanically holding said boxes, for the circulation of the cooling gas or mixture of gases. (FIG.

Abstract: An electronic package (10) designed to be mounted in a space vehicle includes active electronic components that produce heat energy during operation and has a shear plate (12) attached to a heat sink (13). A heat spreader (11) includes an L-shaped plate of thermal pyrolitic graphite encapsulated in aluminum, which has a long arm (20) attached to the shear plate (12) by a heat conductive adhesive and a short arm (21) attached to the heat sink (13) for transferring heat energy from the package (10) to the heat sink (13). Whereby the heat sink (13) and the package (10) produce a dynamic load and the heat sink (13) and the package (10) are designed to carry the dynamic load with the heat spreader (11) providing only thermal enhancement.

Abstract: An arrangement for enclosing a fluid includes a circuit board and an enclosure member. The circuit board includes an electronic component secured thereto. The enclosure member is secured to the circuit board such that the enclosure member and the circuit board cooperate so as to create a fluid tight barrier of a compartment defined by the circuit board and the enclosure member.

Abstract: A heating/cooling apparatus for electronic components of a wireless base station is described. The apparatus includes a heat exchanger having a material-filled chamber and a plurality of extrusions. The chamber is located adjacent to the electronic components. A heater is provided within the chamber. The material within the chamber, which is preferably a liquid, serves to conduct heat from the electronic components to the extrusions. The heater serves to heat the material within the chamber, which in turn conducts that heat to the electronic components, when heat is required to maintain operation of the components with prescribed parameters.

Abstract: An arrangement and method for enhancing the cooling capacity of portable personal computers. More particularly, there is provided to the provision of an arrangement for increasing the cooling capacity of portable personal computers, particularly such as laptop or notebook computers. The computer possesses a keyboard having the rear edge thereof hingedly connected with the bottom of an openable display unit or panel, and containing heat-generating computer electronics, from which heat is removed through a heat pipe terminating in a coupling arrangement possessing elements which connect to and disconnect from each other when, respectively, docking and undocking the portable personal computer in a docking station so as to facilitate the transference of heat from the portable personal computer through the coupling arrangement into the docking station from whence the heat is dissipated to the surroundings through the intermediary of a heat sink.

Abstract: A multi-layer circuit board includes several metallic layers. Each metallic layer includes a metallic ring surrounding a component pin hole formed through each layer of the board. The ring is isolated from its respective metallic layer by a concentric gap formed of non-metallic material. A plurality of metallic traces interconnect each ring with its respective metallic layer. The traces extend radially outwardly from the ring and segment the gap. Each trace has a width of about 0.010 mils and a length of about 0.050 mils.

Abstract: A heat absorber including a container providing an internal cavity, phase change material, such as microencapsulated phase change material, residing in the cavity, the container including at least one wall of thermally conductive material in thermal contact with the phase change material, such one wall provided with a plurality of spaced apart and inwardly extending members of thermally conductive material extending inwardly into the cavity and into and in thermal engagement with the phase change material, upon heat being transferred to the phase change material the phase change material changes phase and absorbs the heat. Such heat absorber in combination with electrical apparatus which produces heat when operating.

Abstract: An electronic apparatus having a heat pipe that is thermally bonded to plates to internal and external enclosures. The electronic apparatus is located in a heat dissipative external enclosure. The electronic apparatus having at least one unit contained in a thermally conductive internal housing providing RF isolation and mounted on a wall of the external enclosure in thermal contact therewith. The electronic apparatus also having a heat pipe having a first plate bonded to its evaporator and a second plate bonded to its condenser, both bonds being thermally conductive. The first plate being mounted by fixings in thermal contact with the internal housing, the second plate being mounted by fixings in thermal contact with the wall of the external enclosure at a position lower, in use, than the first plate. This allows the heat pipe to be easily removed. This also allows the inner housing to maintain RF isolation.

Abstract: A cooling system for a computer includes a chassis having a sidewall with an opening formed therein. A heat spreader plate is mounted in the chassis including a heat sink attached thereto adjacent the sidewall. The heat sink has a side mounted base and a plurality of fins extending laterally from the base toward the sidewall. One of the fins is attached to the heat spreader plate. A heat pipe is connected to the heat spreader plate and extends into engagement with the heat sink. Each of the fins has a terminal edge and opposed ends. The fins at one of the opposed ends are uniformly sloped at an angle toward the base and are exposed to the opening in the sidewall, thus providing the appearance of an inlet grill.

Abstract: A heat sink device for use in an electronic device for dissipating into the atmosphere outside a housing of the electronic device the heat generated by an electronic component disposed within the housing. The housing has a peripheral wall formed with a heat removal opening. A heat sink disposed within the housing comprises a metal body having a heat pipe portion, and a radiation fin attached to the body in the vicinity of the heat removal opening and opposed to the opening. The heat-generating electronic component, such as CPU, is held in contact with the metal body at a location away from the fin attached portion thereof.

Abstract: Electronic apparatus is contained in a heat dissipative external enclosure 2. The enclosure contains at least one unit contained in a thermally conductive internal housing 4,6 providing RF isolation and mounted on a wall 7 of the enclosure in thermal contact therewith. A wall 11 of the unit has a first recess 14 receiving the evaporator 13 of a heat pipe 12. The heat pipe is clamped between the external enclosure and the internal housing. The condenser 22 of the heat pipe is lower than the evaporator and is received by a recess 24 in the wall 7. The evaporator is clamped in the recess by a clamp member e.g. another unit 6.Because the heat pipe is clamped at its ends, it does not need to be an interference fit in either recess and may thus easily be removed. The inner housing can maintain RF isolation.

Abstract: A fluid control apparatus is adapted for use with a spray plate 100 having at least one atomizer 120 which cools an associated printed circuit board 200 carrying one or more heat-generating components such as integrated circuits 220. At least one spray plate and printed circuit board are carried within a coolant-tight enclosure such as a spray module 300. A preferred shroud 20 is supported by the spray plate. The shroud encloses a spray cavity 24 and provides control over the flow and direction of the spray coolant leaving the atomizers enclosed by the shroud. Control over the flow and direction of the coolant spray better cools the components carried on the printed circuit board and partially enclosed by the shroud.

Abstract: An EMI shielding fluid control shroud is adapted for use in spray cooling EMI producing or EMI sensitive components. The EMI shielding shroud, carried between a printed circuit board and a spray plate, defines an interior spray cavity which prevents interference with coolant spray directed at one or more heat-generating, EMI producing or sensitive components, such as integrated circuits. The size and shape of the shroud provide control over the flow and direction of the coolant spray and result in better cooling of the components carried on the printed circuit board and partially enclosed by the shroud. The shroud provides an EMI shield which prevents passage by EMI in either direction, while allowing coolant fluid to exit through the EMI shielding material.

Abstract: The power supply device for electrical discharge machining includes circuit component elements for converting a voltage from a power supply to a given pulse voltage which can be supplied to a minute gap between an electrode and a workpiece so that electrical discharge can be generated in the minute gap; a substrate on which the circuit component elements are mounted; a highly thermally conductive metal piece member disposed opposed to the substrate and including a cavity portion therein, the cavity portion being fittable with the circuit component elements or being capable of holding the circuit component therein; and, cooling appratus for cooling heat generated by the circuit component elements and conducted to the metal piece member by use of a machining liquid supplied to the minute gap as a cooling medium.

Abstract: A modular integrated apparatus and method that integrates mechanical, electrical, and thermal management, and that includes a computer processor (CPU), or VLSI module, connected to a circuit board and a thermal plate. The modular integrated apparatus includes a field replaceable apparatus and a receiving apparatus and attenuates EMI. By integrating mechanical, electrical, and thermal management features the modular integrated apparatus improves the process of repairing and upgrading the processor at a customer site by simplifying the modular integrated apparatus package. Additionally, by reducing the number of parts and the amount of circuit board space required to connect a processor to a thermal plate, the present embodiment improves ease of use and acts as a handle in its own installation and removal.

Abstract: A thermal management controller to regulate the operating temperature of high speed, high circuit density semiconductor dice in an electronic product. The thermal management controller monitors the temperature of a heat sink in thermal contact with the high speed, high circuit density semiconductor dice and also monitors the operational status of one or more specified devices which may increase the heat load within the electronic product. As the temperature of the heat sink increases and/or as specified devices increase the heat load in the electronic product, the thermal management controller will start cooling fans and/or increases the speed of the cooling fans to increase heat removal from the electronic product by forced convection.

Abstract: A cooler-equipped printed circuit board, in which electronic devices arranged in a matrix form on the printed circuit board are covered with a sealed case held in liquidtight contact with the board and having a coolant channel from an inlet port and an outlet port made in the case. Barriers are provided in the coolant channel to change the direction of flow of the coolant to stir it and make its temperature uniform throughout it.

Abstract: An electronic apparatus having a heat dissipative external enclosure is disclosed. The external enclosure having a containment wall from which depend extended surfaces or fins having a length extending vertically and defining channels therebetween. The thickness of the enclosure between external surfaces of opposed containment walls varying between a relatively thin portion and a relatively thick portion to provide an interior space having a relatively narrow portion and a relatively wide portion to accommodate components or units of corresponding different extent. The fins having outer edges, spaced from the containment wall, and having plain first opposed surfaces adjacent their outer edges, the first surfaces including a first angle therebetween. The fins or parts of fins adjacent the relatively thin portion of the enclosure also having plain second opposed surfaces inwards of the first surfaces, the second surfaces including therebetween a second angle greater than the first angle.

Abstract: An electronic system that may include an electronic card sub-module that is electrically connected to, and in fluid communication with, an electronic card module. The electronic card module can be mated with a motherboard and coupled to a manifold of a cooling system that provides a cooling fluid to the modules. The cooling fluid can flow directly onto integrated circuits or integrated circuit packages located within the modules. Each module may have an electrical connector and a fluid connector that allows the sub-module to be plugged into the module, and the module to be plugged into the motherboard and manifold without using any tools or hardware.

Abstract: An apparatus, such as a computer, comprises a housing having an interior portion into which a printed circuit board may be inserted. The printed circuit board, when inserted, is supported by a support structure. A spring mechanism resiliently supports a heat sink structure in contact with a major side portion of the inserted printed circuit board. During operation, fluid flows in thermal transfer relationship with the heat sink structure. In this manner, heat is transferred from the heat sink structure to the fluid.

Abstract: A combination support and heat sink structure is mounted within a computer housing for pivotal movement between connected and disconnected positions and includes a pair of cooling plates, one air cooled and the other liquid cooled, carried in a spaced apart, parallel opposing relationship. The two cooling plates are movable toward and away from one another and a pair of manually operable spring clip members permit a processor card to be removably sandwiched and clamped between the cooling plates without the use of tools.

Abstract: A cooling device for a machine, especially, but not limited to, a device for cooling the central processing unit (CPU) of a desktop computer, thereby increasing the speed at which it can operate. In the preferred embodiment, the cooling device includes a copper evaporation chamber and a conduit made of copper pipe having a condensation coil, which are connected in a single closed loop, and contain water. As heat is absorbed by the evaporation chamber from the CPU or other heat generating component, the water changes from liquid to gas, and gravity and pressure differences cause the water to circulate through the conduit. As heat is transferred from the conduit to its surroundings, the water changes from gas to liquid, and returns to the evaporation chamber. The high heat of vaporization and condensation of water allows heat to be efficiently transferred with a small difference in temperature between its liquid and gaseous states.

Abstract: A combination support and heat sink structure is mounted within a computer housing for pivotal movement between connected and disconnected positions and includes a pair of cooling plates, one air cooled and the other liquid cooled, carried in a spaced apart, parallel opposing relationship. The two cooling plates are movable toward and away from one another and a pair of manually operable spring clip members permit a processor card to be removably sandwiched and clamped between the cooling plates without the use of tools.

Abstract: A spray cooled circuit card cage includes opposed card guides separated by opposed card cage side panels. Each card guide carries a top rail and lower manifold. The manifold provides coolant fluid to a plurality of spray plate assemblies, which direct a spray of coolant over the top surface of the electronic cards carried between the card guides. A VME or other type of electronic back plane is typically attached to the manifolds and a back plane support, and is in electronic communication with the circuit cards.

Abstract: Disclosed is an electronic packaging substrate which includes a sintered ceramic body having at least one internal layer of wiring and at least one cooling channel internal to and integral with the sintered ceramic body for cooling a heat-generating electronic device placed on the sintered body. Also disclosed is a method of making the electronic packaging substrate.

Abstract: Colloidal fluids having improved insulating and/or cooling properties. Embodiments of the invention involve colloidal fluids which comprise a carrier liquid and a dispersed phase of non-metallic particles, wherein the colloidal fluid has a saturation magnetization of less than about 50 Gauss. The compositions may be employed to insulate and/or cool electromagnetic devices, including high power devices, such as power transformers.

Abstract: A liquid-cooled heat-sink including a cooling housing defining a cooling chamber where the chamber is positioned adjacent to a semi-conductor device or devices to be cooled. An inlet port introduces a liquid coolant into the chamber and an exit port removes the liquid coolant from the chamber. A single unit plastic baffle is positioned within the chamber. The baffle includes strategically configured plenums, jet ports and transfer ports that direct the liquid coolant in both a series and parallel manner for increased cooling efficiency. The jet ports direct the liquid coolant onto the semiconductor devices in a parallel manner, and liquid coolant is transferred from one set of jets to another set of jets in a series manner.

Abstract: In an electronic component cooling unit, parts of the outer surfaces of a plurality of passageways in which refrigerant flows are coupled to one surface of a cold plate on the other surface of which an electronic component is mounted, and a header tank is provided in the plurality of passageways so that a plurality of looped passageways are formed. The plurality of passageways are provided by a multi-flow-path container which is formed by extrusion molding and has a flattened cross section.

Abstract: The apparatus of the present invention comprises a housing defining a closed interior volume of a size sufficient to accommodate the appliance, a first heat sink located within the housing, a second heat sink located outside the housing, a reversible heat pump disposed between and in heat conductive engagement with each of the first and second heat sinks, a temperature sensor located within the housing, and electronic circuitry to actuate the heat pump in either of a first cooling mode or a second heating mode in response to predetermined temperature set points sensed by the temperature sensor within the housing. The apparatus also includes an appliance support tray and a holding bracket that engages and maintains the tray in spaced relation within the housing. A pressure equalizing diaphragm is also employed to accommodate pressure changes within the housing.

Abstract: A cooling method that involves circulating a liquid coolant through the motor housings and mounting surfaces for electrical/electronic components, such as the electric motors and associated electronic drives, in electric plastic processing machines. Specifically, the motors are provided with a housing having an integral heat exchanger, such as stainless steel tubing cast into a cylindrical aluminum stator housing. The various electrical/electronic components are mounted to the surface of a plate type heat exchanger (chill plate) that is contained within the electrical cabinet for the primary electrical circuitry. In addition, the air within the electrical cabinet is continually circulated over the chill plate to provide a more uniform temperature distribution within the enclosure and minimize condensation on the surface of the plate. The heat generated by the motors and electronics is absorbed from the motor housings and chill plate by the circulating liquid and released through a heat exchanger.

Abstract: Apparatus for cooling charge-coupled device (CCD) imaging systems. The apparatus comprises a thermoelectric cooler thermally coupled to the imaging system for transferring heat away from and cooling the imaging system portion of the imaging system. The thermoelectric cooler has a cold side and an opposing hot side, with the cold side thermally coupled to the imaging sensor to enable the transfer of heat from the sensor in response to a supply of power. A power supply is coupled to the cooler for supplying required power. The hot side of the cooler is thermally coupled to a heat pipe, which is composed of a heat-conducting material having a hollow portion containing a wicking material and a working fluid. A heat sink is thermally coupled to the heat pipe enabling heat dissipation. The working fluid cyclically evaporates into vapor and condenses into liquid to effect the heat transfer from the heat pipe to the heat sink.