Abstract: Embodiments of the present invention provide a system for distributing a thermal interface material. The system includes: an integrated circuit chip; a heat sink; and a compliant thermal interface material (TIM) between the integrated circuit chip and the heat sink. During assembly of the system, a mating surface of the heat sink and a mating surface of the integrated circuit chip are shaped to distribute the TIM in the predetermined pattern as the TIM is pressed between the mating surface of heat sink and a corresponding mating surface of the integrated circuit chip.

Abstract: A server heat dissipating assembly includes a server chassis, a heat dissipating unit, and at least one connecting unit. Several electronic components are mounted inside the server chassis, the server chassis defines a plurality of holes corresponding in location to each of the several electronic components. The heat dissipating unit includes several connecting ports and an exhaust fan. The connecting unit is connected to at least one hole of the server chassis and at least one connecting port of the heat dissipating unit, the exhaust fan exhausts the heat from the server chassis through the connecting unit.

Abstract: An electronic device includes a casing, a fan, and a heat sink. The casing defines a plurality of through holes therein. The fan defines air outlet at one side thereof facing the through holes of the casing. The air outlet includes a first portion and a second portion. Air pressure in the first portion is larger than air pressure of the second portion. The heat sink includes a first fin set arranged on the first portion and a second fin set arranged on the second portion. A first passage is defined between each two neighboring first fins. A second passage is defined between each two neighboring second fins. A width of the second passage is less than that of the first passage.

Abstract: Aspects of the disclosure relate generally to active cooling or removing heat generated by a processor in a computing device. More specifically, a cooling system in a computing device may include a heatpipe which moves heat along a fin pack. The fin pack may include top and bottom ends as well as a plurality of fins. The fins may extend only a portion of the way between the ends thus creating an air duct. The air duct may allow debris to move along an edge of the fin and out of the computing device. The fins may also be curved to promote the forcing of debris through the fin pack while still allowing the heat to be expelled through the fins.

Abstract: According to various aspects, exemplary embodiments are provided of thermal interface material assemblies. In one exemplary embodiment, a thermal interface material assembly generally includes a thermal interface material having a first side and a second side and a metallization layer having a layer thickness of about 0.0005 inches or less. The metallization layer is disposed along at least a portion of the first side of the thermal interface material.

Abstract: A modular processing module allowing in-situ maintenance is provided. The modular processing module comprises a set of processing module sides. Each processing module side comprises a circuit board, a plurality of connectors, and a plurality of processing nodes. Each processing module side couples to another processing module side using at least one connector in the plurality of connectors such that, when all of the set of processing module sides are coupled together, the modular processing module is formed. The modular processing module comprises an exterior connection to a power source and a communication system and at least one heatsink that couples to at least a portion of the plurality of processing nodes on one of the processing module sides and is designed such that, when a set of heatsinks in the modular processing module are installed, an empty space is left in a center of the modular processing module.

Abstract: A cooling apparatus is disclosed. The cooling apparatus comprising a printed circuit (PC) board with an integrated circuit (IC) socket mounted onto the top side of the PC board. A mounting frame generally in the shape of a plate, with a first opening passing through the center of the plate, is mounted on the top side of the PC board with the IC socket located inside the first opening. A cold plate is attached to the mounting frame, the cold plate has an opening that passes through the cold plate. The opening in the cold plate is sized to allow an IC to be inserted into the IC socket through the opening. A fluid passageway is formed inside the cold plate. A fluid inlet port and a fluid outlet port are mounted on the cold plate and coupled to a first end and a second end of the fluid passageway, respectively. A heat spreader is removably attached to the top side of the cold plate wherein the bottom side of the heat spreader is configured to contact the top side of an IC when the IC is mounted in the IC socket.

Abstract: A multi-hybrid module includes a plurality of hybrid assemblies that are perpendicularly mounted with respect to a plane of a circuit board. The hybrid assemblies are mounted on opposing sides of a heat sink. The heat sink has a first column disposed at a first end, a second column disposed at a second opposing end, and a generally flat center wall extending between the first column and the second column to which the hybrid assemblies are mounted. During operation the hybrid assemblies are mounted on edge perpendicular with respect to the circuit board to minimize an area profile of the multi-hybrid module on the circuit board.

Abstract: A computer apparatus comprising a computer chassis, a baseboard component disposed within the computer chassis and a computer module electronically coupled to the baseboard component is disclosed. A heat sink assembly is attached to the computer module to form a computer module heat sink assembly, wherein the heat sink assembly forms part of an integral exterior structure of the computer chassis. The chassis may comprise a compartment disposed through an exterior surface of the chassis for receiving the computer module heat sink assembly in mated fashion. The computer module heat sink assembly forms a water and air tight seal with the internal compartment of the chassis in mated fashion.

Abstract: A heat-dissipating casing for a communication apparatus accommodates a circuit board having a power element and includes an insulating case, a lid coupled to the insulating case, and a thermally conductive metal member. The insulating case has a receiving space, a first opening, and a second opening. The first and second openings communicate with the receiving space. The thermally conductive metal member is fixed to the inside of the insulating case, seals the second opening, and dissipates heat generated by the power element. The heat-dissipating casing is effective in dissipating heat, characterized by its low weight and low production costs, and conducive to protection and dust prevention.

Abstract: A portable air cooled data center can include interior fans, a heat sink integrally serving as part of a wall or ceiling, and an outer heat pipe assembly in thermal communication with the heat sink allowing for heat dissipation. External fans can pull external air over the outer heat pipe assembly. A first transducer can monitor inner air temperature within the data center, a second transducer can monitor the outer heat pipe assembly, and a third transducer can be secured proximate to a fin side of the heat sink. A controller can be connected to the transducers, fans, and a power supply. Computer instructions can be used to monitor temperatures from the transducers, compare the temperatures to preset limits, and individually or simultaneously actuate, regulate, or turn off the fans when monitored temperatures meet or exceed preset limits.

Abstract: According to one embodiment, a television apparatus includes an exothermic component, a heat transfer mechanism, a plurality of heat releasing fins, a fan, and a deflecting member. The exothermic component is housed in a housing. The heat transfer mechanism is at least partially housed in the housing. The heat transfer mechanism includes a heat receiving portion that receives heat from the exothermic component, a heat releasing portion that releases heat, and a heat transferring portion that houses a medium to transfer heat from the heat receiving portion to the heat releasing portion. The heat releasing fins are thermally connected to the heat releasing portion and arranged with gaps therebetween. The fan generates an air flow flowing through the gaps. The deflecting member is located at least downstream of the gaps to cover the gaps. The deflecting member deflects the air flow toward an exhaust outlet formed in the housing.

Abstract: Methods, apparatuses, and computer program products for modifying the spatial orientation of a thermal acoustic panel of a computing enclosure rack are provided. Embodiments include receiving, by a configuration controller, a configuration preference from a user; identifying, by the configuration controller, a spatial orientation configuration corresponding to the configuration preference received from the user; and coordinating, by the configuration controller, movement of the thermal acoustic panel relative to a body of the computing enclosure rack in accordance with the identified spatial orientation configuration.

Abstract: A laptop computer user thermal isolation apparatus is provided for inhibiting the transfer of waste heat from internal heat generating components to a user. The thermal isolation apparatus includes a casing substantially enclosing the heat generating components, the casing including at least one panel having a sealed enclosed cavity disposed between the heat generating components and an outer surface of the casing.

Abstract: An electronic assembly includes a workpiece, a through substrate via (TSV) die including a substrate and a plurality of TSVs, a topside and a bottomside having TSV connectors thereon. The TSV die is attached to the workpiece with its topside on the workpiece. A heat spreader having an inner open window is on the bottomside of the TSV die. Bonding features are coupled to the TSV connectors or include the TSV connectors themselves. The bonding features protrude from the inner open window to a height above a height of the top of the heat spreader that allows a top die to be bonded thereto.

Abstract: Heat dissipation apparatus for dissipating heat generated by a heat-generating component mounted to a circuit board. In one embodiment, the heat dissipation apparatus includes a thermally-conductive heat sink adapted to be placed in contact with the heat-generating component, a bracket adapted to hold the heat sink in place relative to the heat-generating component, and a single coil spring mounted to the bracket adapted to urge the heat sink into contact with the heat-generating component.

Abstract: An inverter (1) for supplying electric energy from a DC source to an AC grid includes a housing (2) in which electrical and electronic components (21, 22, 30) are accommodated. A cooling air channel (9) with cooling fins (37) arranged along its longitudinal axis runs across the back of the housing (2) in the middle. Sockets (13) for large electrical components (21, 22) that are closed in on at least three sides by the metal outer walls (14-19) of the housing (2) are provide on both sides of the cooling air channel (9) in the housing (2).

Abstract: A computer system includes a computer case and an air guiding duct. The motherboard is attached to the computer case, and a heat sink is attached to the motherboard. The air guiding duct includes a top panel. A mounting member is slidably attached to the top panel and is clipped to the heat sink. A limiting device is located on the top panel and engaged with the mounting member to prevent the mounting member from sliding relative the top panel.

Abstract: An exemplary embodiment of the present invention includes an add-on module. The add-on module is in contact with a base cooling plate that is connected to a thermal energy transport element and at least one thermal energy generating device when the cooling capacity of the base cooling plate is exceeded by the rating of the thermal energy generating device.

Abstract: Systems and methods are provided for controlling output energy levels in wireless communications devices, such as wireless USB modems, while optimizing performance of the wireless communications devices. Controlling output energy levels includes controlling specific absorption rate (SAR) levels and heat levels generated by one or more radiating elements in a wireless communications device. Controlling output energy levels is achieved by integrating one or more radiating elements in a movable device, such a fan and/or by incorporating a moving reflector element, such as a fan, proximate to one or more radiating elements. Integrating the one or more radiating elements in, e.g., a fan, or by using a fan near the one or more radiating elements, the radiation pattern resulting from the output energy may be spatially averaged and/or dithered, reducing SAR levels and allowing for excessive output heat energy to be vented and/or one or more radiating elements to be cooled.

Abstract: A mounting assembly includes a circuit board, a securing member and a heat dissipating device. A retainer is located on the circuit board. The securing member includes a positioning portion and a claw connected to the positioning portion. The heat dissipating device includes a base attached to the circuit board and a number of fins perpendicularly located on the base. The number of fins defines a number of first air paths and a number of second air paths substantially perpendicular to the number of first air paths. The positioning portion is received in at least one of the number of first air paths and at least one of the number of second air paths, and the claw is engaged with the retainer.

Abstract: The invention relates to a heat sink for an interchangeable expansion module that can be connected to a computer board, said heat sink having at least one cooling module in which a coolant flows, and at least one first electrical connector, wherein said expansion module (4) has at least one second electrical connector configured to be connected to said first electrical connector of said board, and has at least one heat-exchange surface (18, 19), said heat sink (20) comprising at least one heat-transfer device (21) configured to be removably placed against said exchange surface (18, 19), and said device (21) further being configured such that it is in thermal contact with said cooling module and is mechanically attached, in a removable manner, to said cooling module of said board when said extension module (4) is connected to said board.

Abstract: Provided is a heat sink clip for fastening a heat sink on a printed circuit board (PCB). The heat sink clip includes two hooks and a wire clip. The two hooks are inversely fixed to the PCB at two opposite sides of the heat sink. The wire clip includes a pressing wire pressing the heat sink, two pairs of deforming wires extending from the lateral of the pressing wire along two radial directions of the pressing wire and away from the PCB, and two engaging wires engaging with the respective hooks such that the deforming wires are bent towards the PCB.

Abstract: A printed circuit board assembly is provided. The assembly includes a chassis, a heatframe coupled to the chassis, a printed circuit board (PCB), a thermal interface material (TIM) coupled between the PCB and the heatframe, and at least one thermal via extending through the PCB and coupled to the TIM, wherein the assembly is configured to transfer heat from the PCB to the chassis through the TIM and the at least one thermal via.

Abstract: An electronic device includes a bottom plate, a circuit board having an electronic component, a fan, and an airflow guide member. The circuit board is fixed to the bottom plate. The fan is arranged at the front of the circuit board. The airflow guide member is arranged between the fan and the circuit board. The airflow guide member includes an airflow guide wall defining a number of spaced slots, and a number of stop plates selectively inserted into the corresponding slots of the airflow guide wall, to leave some of the slots directly in front of the bottom of the electronic component open.

Abstract: A power module includes a first heat sink, first and second power chips, a thermo-conductive insulating layer, a lead frame and a molding compound. The first heat sink has a first area and a second area. The first power chip is disposed in the first area. The thermo-conductive insulating layer is disposed in the second area. The second power chip is disposed on the heat sink through the thermo-conductive insulating layer. The lead frame is electrically connected to at least one of the first and second power chips. The molding compound covers the first and second power chips, the thermo-conductive insulating layer and a portion of the lead frame. The first heat sink is electrically connected to at least one of the first and second power chips. Because the first power chip is not disposed on the first heat sink through the thermo-conductive insulating layer, the cost can be reduced.

Abstract: An image displaying apparatus, which is excellent in heat radiation efficiency and has an excellent back design, includes a display panel for displaying an image; a heat generating member provided on a back side of the display panel; and a cabinet for covering the display panel and the heat generating member at least from the back side of the display panel. In the cabinet, an aperture is provided at a position facing the heat generating member, and an opening/closing unit enables switching between closing and opening of the aperture. In a state that the aperture is opened by the opening/closing unit and one part of a heat-transfer member is positioned on a side of the cabinet opposite to the display panel, the other part of the heat-transfer member extends through the aperture so that the heat-transfer member can thermally be connected to the heat generating member.

Abstract: An assembly includes an article, and a computer housing including left and right sidewalls cooperatively defining an accommodating space and an opening for communicating the accommodating space with an external environment, and a positioning member provided on one of the sidewalls. Each sidewall includes a slide rail. A package is mounted removably in the accommodating space via the opening, is connected slidably to the slide rails of the sidewalls, and is positioned within the accommodating space through the positioning member. The package includes two interconnected cover parts cooperatively defining a receiving space for receiving the article and a communicating hole for communicating the receiving space with the external environment, and a handgrip to mount removably the package in the accommodating space. Each cover part includes a stop member abutting against the article to prevent escape of the article from the receiving space via the communicating hole.

Abstract: A dust-free and anti-vibration industrial computer. The industrial computer has a case sealed from the outside, a heat diffusion fin assembly mounted on the outer surface of the case, and a circulation pipe for allowing a heat generating component and at least a heat diffusion fin to be communicated with each other, or a heat pipe for transferring heat between the heat generating component and the heat diffusion fin. The heat generating component can be cooled in a state in which dust is prevented from being produced within the case.

Abstract: An electronic device includes an electronic component mounted on a substrate; a cooling system for cooling the electronic component; and a fastening structure for fastening the cooling system to the substrate. The fastening structure includes a first magnet provided to one of the substrate and the cooling system, a second magnetic material fixed to the other of the substrate and the cooling system and magnetically coupled with the first magnet, and a magnetic shield that covers a part or all of the first magnet except for a coupling face to be coupled with the second magnetic material.

Abstract: A modular heat-dissipating device includes an electronic device, a cold plate and a heat-dissipating base. The electronic device includes a casing, a covering plate and a circuit board. The circuit board is disposed within the casing. Plural electronic components are disposed on the circuit board. The cold plate, the casing and the covering plate are combined together to define a sealed space. The cold plate includes plural first fixing structures. The heat-dissipating base is selected from an air-cooling member or a liquid-cooling member. Each of the air-cooling member and the liquid-cooling member includes a first slab under the cold plate and plural second fixing structures corresponding to the first fixing structures. The air-cooling member and the liquid-cooling member are normalized. The heat generated by the electronic device is transmitted to the first slab through the cold plate, and then dissipated away by the air-cooling member or the liquid-cooling member.

Abstract: Systems and methods for balanced cooling of electrical systems, including electrical systems containing transceivers used in electrical and optical communication. An electrical system includes a cage, where the cage has a top, front and bottom. The cage contains a plurality of upper bays disposed in the front of the cage. Each of the plurality of upper bays is configured to receive a transceiver. The cage also contains a plurality of lower bays disposed in the front of the cage. Each of the lower bays is configured to receive a transceiver. Additionally, each of the plurality of upper bays is stacked on one of the plurality of lower bays. An upper heat sink extends from the outer surface of the top of the cage and a lower heat sink extends from the outer surface of the bottom of the cage.

Abstract: A system to remove heat from a heat-generating electronic component within a computer chassis and to contain electromagnetic radiation from traversing high-throughput vents in a bezel that forms a portion of the chassis containment structure comprises a heat sink having a fin structure with an inlet face, an outlet face and interconnected air channels therethrough, a base to engage the component and to transfer heat from the component to the fin structure, wherein the inlet face of the fin structure is disposed proximate the vents to block electromagnetic radiation from traversing the vents. In one embodiment, a heat pipe or a spreader bar moves heat from a base engaging a component distal from the bezel to the fin structure having an air inlet face proximal to the vents.

Abstract: A cooling element for an electronic apparatus can include an inlet for receiving fluid, an outlet for forwarding fluid from the cooling element, and multiple pipes providing parallel fluid paths for passing the fluid from the inlet to the outlet. To obtain a simple and efficient cooling element, multiple base plates for receiving electronic components can be attached to the pipes for conducting heat generated by the electronic components to the fluid in the pipes.

Abstract: Various computing devices and methods of thermally managing the same are disclosed. In one aspect, a method of thermally managing a computing device is provided where the computing device includes a housing that has a wall adapted to contact a body part of a user, a circuit board in the housing, and a semiconductor chip coupled to the circuit board. The method includes placing a first heat spreader in thermal contact with the semiconductor chip and the circuit board but separated from the wall by a gap.

Abstract: An exemplary heat dissipation device includes a fin assembly, a heat pipe, and a protective member. The fin assembly includes stacked fins and air passages between fins. Each fin includes a main body, an extending hole defined in the main body, and a flange extending from the main body around the extending hole. The heat pipe is received in the extending holes of the fins and abuts the flanges of the fins. The protective member includes a plurality pairs of elastic arms. Each pair of elastic arms is sandwiched between a free end of the flange of a corresponding fin and the main body of a corresponding adjacent fin to prevent solder associated with the heat pipe from flowing into the corresponding air passage.

Abstract: A heat sink comprises a plurality of fins that may be positioned in a plurality of orientations relative to a heat-generating electronic component to which the heat sink is thermally coupled. A controller may be used to detect an elevated processor temperature and to activate a drive member to automatically adjust the orientation of fins on the heat sink. The fins may be moved and aligned with an air flow made over the heat sink. The adjustable-fin heat sink affords added flexibility in arranging a processor or other heat-generating electronic component on a circuit board. The orientation or position of the heat sink fins may also be automatically changed in response to a change in the air flow direction as manifested by a rise in the temperature of the heat sink or the heat-generating member.

Abstract: A computer system includes a circuit board assembly and a chassis. The circuit board assembly includes a circuit board and one or more heat producing components coupled to the circuit board. At least one of the heat producing components includes an exposed surface. The chassis includes one or more mounting portions that are coupled to the circuit board and support the circuit board. The chassis also includes one or more heat spreading portions. The heat spreading portions couple to exposed surfaces of one or more heat producing components on the circuit board.

Abstract: An object is to achieve a compact design by using a dead space in an inverter box effectively, to improve cooling properties of heat-generating electrical components disposed on a control circuit board of an inverter, and to increase flexibility of wiring layout. In an inverter box provided at a periphery of a housing, a heat-dissipating flat portion that is parallel to a control circuit board of an inverter is formed, and electrical components are disposed in a space between the heat-dissipating flat portion and the control circuit board. Preferably, the electrical components are installed so that the back faces thereof abut against the heat-dissipating flat portion either directly or via a heat-conducting member. More preferably, faces of the electrical components on the board side abut against the control circuit board.

Abstract: A circuit board assembly including a heating device operated during cold boot startup includes a circuit board having a computer component. A thermal transfer device connected to the circuit board assembly acts when the computer component is operating to remove heat generated by the computer component. A heating device operates to heat the thermal transfer device. A field programmable gate array acts to energize the heating device when a temperature defining a cold startup condition at the computer component or the thermal transfer device is sensed. The thermal transfer device when heated by the heating device heats the computer component to greater than the temperature of the cold startup condition. A control device connected to the heating device provides an operational mode of the heating device.

Abstract: According to one embodiment, an information processing apparatus, includes a heat generator on the printed-circuit board in the housing, a heat radiator in the housing configured to radiate heat of the heat generator to the outside of the housing, a first thermometer configure to sense a first temperature at a first position on the board, a second thermometer on the board configured to sense a second temperature at a second position away from the heat generator than the first position, a cooling performance determination module configured to monitor whether a temperature difference between the first temperature and the second temperature is above a threshold, and to determine whether performance of the heat radiator is deteriorated based on a result of the monitoring.

Abstract: A motherboard includes a heat sink, a circuit board forming an electronic element and two latches at opposite sides of the electronic element, and two fixing members. The heat sink includes a base board and a number of rows of spaced fins. Two lows of protrusions are formed on the base board and are respectively located at opposite sides of a row of fins. Each protrusion defines a through hole. Each fixing member includes a clamping portion engaging with one of the latching members, and two engaging portions engaging in the corresponding through holes.

Abstract: A system and method for measuring integrated circuit (IC) temperature. An integrated circuit (IC) includes a thermal sensor and data processing circuitry. The thermal sensor utilizes switched currents provided to a reference diode and a thermal diode. The ratios of the currents provided to each of these diodes may be chosen to provide a given delta value between the resulting sampled diode voltages. At a later time, a different ratio of currents may be provided to each of these diodes to provide a second given delta value between the resulting sampled diode voltages. A differential amplifier within the data processing circuitry may receive the analog sampled voltages and determine the delta values. Other components within the data processing circuitry may at least digitize and store one or both of the delta values. A difference between the digitized delta values may calculated and used to determine an IC temperature digitized code.

Abstract: The subject of the invention is an electric power switchgear, an insulating radiator, and a method for installing the radiator in an electric power switchgear, and in particular in a medium or high voltage switchgear. The electric power switchgear comprising working elements placed in the housing and connected with busbars and branches, and cooled with air, is characterized in that it contains at least one insulating radiator made of thermoplastic material of increased thermal conductivity ??2 W/mK, which is placed in the electric field of the switchgear and which is connected by a non-permanent fastening to at least one busbar or/and at least one branch. The insulating radiator designed for the switchgear is an injection molding including a base plate to whose top face a system of heat evacuating elements of identical or diverse shape is attached, and to its side surfaces elastic assembly catches are fixed.

Abstract: An exemplary electronic device includes a cover, a circuit board and a driving module both mounted on the bottom cover, an electronic component fixed on the circuit board, a heat dissipating plate mounted on the circuit board and thermally contacting the electronic component, and a top cover covering the bottom cover. The driving module has a rotating shaft adapted for supportively driving an optical disk to rotate. The electronic component generates heat during operation. Through holes are defined in the top cover and located at a periphery of the rotating shaft. Two opposing elongated extending portions extend downwardly from the heat dissipating plate towards the circuit board. An airflow channel is formed between the two extending portions under the heat dissipating plate and aligned with the electronic component.

Abstract: A computer enclosure includes an enclosure, an air conduction member mounted in the enclosure to guide airflow, and a data storage device mounted to a top of the air conduction member.

Abstract: An exemplary heat dissipation device is adapted for dissipating heat generated by an electronic component mounted on a printed circuit board. The printed circuit board is secured on a casing of an electronic system. The heat dissipation device includes a heat sink disposed on the electronic component; and a plurality of fasteners extending through the heat sink, respectively, to assemble the heat sink to the printed circuit board. Each of the fasteners includes a supporting member fixed in the printed circuit board, an engaging member fixed in the board, and a screwing post engaging with the heat sink. A bottom portion of the screwing post extends through the printed circuit board via the supporting member, and is screwed into the engaging member.

Abstract: The exemplary embodiments of the present invention provide a method and system for aligning graphite nanofibers in a thermal interface material to enhance the thermal interface material performance. The method includes preparing the graphite nanofibers in a herringbone configuration, and dispersing the graphite nanofibers in the herringbone configuration into the thermal interface material. The method further includes applying a magnetic field of sufficient intensity to align the graphite nanofibers in the thermal interface material. The system includes the graphite nanofibers configured in a herringbone configuration and a means for dispersing the graphite nanofibers in the herringbone configuration into the thermal interface material. The system further includes a means for applying a magnetic field of sufficient intensity to align the graphite nanofibers in the thermal interface material.

Abstract: The disclosed embodiments relate to techniques for facilitating thermal transfer in a portable electronic device. This portable electronic device may include a battery pack, which includes a battery cell and enclosure material for enclosing the battery cell. This enclosure material extends beyond the enclosure for the battery cell to facilitate thermal transfer within the portable electronic device.

Abstract: A computer system includes an enclosure, a printed circuit board, and an airflow guiding duct. The enclosure includes a bottom plate. The printed circuit board is mounted on the bottom plate. The printed circuit board includes a first heat generating element and a second heat generating element. The airflow guiding duct includes a top wall, a first sidewall, a second sidewall, a first mounting wall, and a second mounting wall. An input opening is surrounded by the top wall and the first and second sidewalls. A first output opening corresponds to the first heat generating element, and is surrounded by the top wall and the first and second mounting walls. A second output opening is defined in the second sidewall corresponding to the second heat generating element. An obtuse angle is defined between the second sidewall and the second mounting wall.