scispace - formally typeset
Search or ask a question

Showing papers on "Heat sink published in 1988"


Patent
09 Mar 1988
TL;DR: A microchannel heat sink as discussed by the authors is used to cool a high power electronic device such as an integrated circuit comprising a plurality of channels in close thermal contact to the integrated circuit and through which a liquid is passed to create either a developing laminar flow or a turbulent flow.
Abstract: A microchannel heat sink used to cool a high power electronic device such as an integrated circuit comprising a plurality of channels in close thermal contact to the integrated circuit and through which a liquid is passed to create either a developing laminar flow or a turbulent flow. The turbulent flow may be either developing or fully developed. The heat sink features a compensation heater surrounding the integrated circuit and heated at the same rate as the integrated circuit to thereby provide a more uniform temperature at the perimeter of the integrated circuit.

269 citations


01 Jan 1988
TL;DR: In this paper, microchannel heat sinks useful in the cooling of diode laser arrays have been fabricated from InP and exhibit a thermal resistance as low as 0072 C/(W/sq cm).
Abstract: Microchannel heat sinks useful in the cooling of diode laser arrays have been fabricated from InP and exhibit a thermal resistance as low as 0072 C/(W/sq cm), corresponding to the dissipation of heat loads in excess of 1 kW/sq cm and representing a two-orders-of-magnitude reduction of levels achievable by current methods The pumping power required to force liquid coolants through microchannel heat sinks can be kept as low as as 10 W/sq cm Attention is presently given to a thermal- and fluid-performance model for these heat sinks, as well as to illustrative examples of microchannel fabrication for both InP and aluminum 19 references

202 citations


Patent
10 Feb 1988
TL;DR: In this article, a process for forming an integrated circuit pin grid array (268) comprising a flexible metal tape (20) and interconnect tape (18') adapted for use in tape automated bonding with a plurality of holes is described.
Abstract: A process for forming an integrated circuit pin grid array (268) comprising a flexible metal tape (20) and interconnect tape (18') adapted for use in tape automated bonding with a plurality of holes. Terminal pins (26a) are inserted into the holes and the tape and pins are disposed within a mold and firmly locked into the encapsulating resin (270). The heat sink (106) forms a portion of the exterior surface (272) of the package. The exterior base (247) of the heat sink is exposed to the external environment to facilitate heat removal. After the package (268) is removed from the mold a semiconductor chip (82) is attached to the interior base (245) of the heat sink by a die attach (272) and electrically connected to leads (21). A lid (276) seals the enclosure (278) using an adhesive or solder ring (280).

123 citations


Patent
18 Jul 1988
TL;DR: In this article, a CERDIP housing is provided with a heat pipe that passes through the closure seal lid whereby the heat pipe terminates within the housing cavity at the hot end thereof.
Abstract: A CERDIP housing is provided with a heat pipe that passes through the closure seal lid whereby the heat pipe terminates within the housing cavity at the hot end thereof. A quantity of working fluid, such as fluorinated octane, is contained within the package cavity. The heat pipe communicates with cooling fins that produce a cold end thereof. Heat from the semiconductor device inside the housing boils the working fluid and is cooled thereby. The fluid vapor passes along the heat pipe and is condensed at the cold end to be converted back to liquid. As a result the semiconductor device is in direct communication with the heat pipe working fluid.

113 citations


Patent
20 May 1988
TL;DR: In this article, a hot/cold therapy device includes a hot and cold pad assembly remotely connected to a control module, which includes a fan for drawing or blowing air through the shroud to maintain the temperature difference between the heat sink and attached plate of the thermoelectric heat pump element.
Abstract: A hot/cold therapy device includes a hot/cold pad assembly remotely connected to a control module. The hot/cold pad assembly includes a flexible pad filled with a convection (gel) or conduction (laminated metal, rubber impregnated with metal particles, etc.), or combination thereof (a conductive metal layer immersed in a gel). A thin plate of conductive material (copper) forms an extension of the cold plate of a thermoelectric heat pump, both of which are in thermal contact with the pad. An air cooled heat sink of the thermoelectric heat sink is mounted in a housing or shroud, the shroud is connected by a flexible umbilical line to the control module. The control module includes a fan for drawing or blowing air through the shroud to maintain the temperature difference between the heat sink and attached plate of the thermoelectric heat pump element. The control module includes temperature setting and adjust mechanisms together with a display for displaying the pad temperature detected by a temperature sensing transducer. Other embodiments include placement of the fan within the shroud to cool the heat sink, using a water cooled block heat sink connected to a water reservoir, radiator, and water pump contained in the control module together with a fan to cool the radiator. The pad is a conductive gel, laminated metal, metal filled rubber, or metal plate immersed in a gel filled flexible pad.

110 citations


Patent
23 May 1988
TL;DR: In this article, an enclosed mini-plenum is inserted between printed circuit boards to direct cooling air of various amounts into selected areas of the printed circuit board, providing orifices of varying sizes to direct amounts of cooling airflow to aligned heat sinks.
Abstract: An enclosed mini-plenum is inserted between printed circuit boards to direct cooling air of various amounts into selected areas of the printed circuit board. The mini-plenum provides orifices of varying sizes to direct amounts of cooling airflow to aligned heat sinks on the printed circuit board. Certain orifices may have raised foils or leaves which can further direct selected amounts of airflow through the orifices. This system provides specifically controlled amounts of cooling facilities to printed circuit board areas having different heat dissipation requirements.

105 citations


Patent
26 Oct 1988
TL;DR: In this paper, a heat sink body is formed by extrusion and parallel fins are gang sawed at right angles across and through the parallel grooves to provide a predetermined number of pins extending outwardly from the body.
Abstract: Unitary heat sink apparatus for use in removal of heat from a heat generating component is disclosed which includes a heat sink body formed by extrusion. Parallel fins extend outwardly a first predetermined distance for the heat sink body and are separated by a first predetermined number of grooves of a first predetermined depth and width. The ratio of the height of the fins to the width of the grooves is approximately four to one. The first predetermined number of parallel grooves are gang sawed to a second predetermined depth to provide a second and greater predetermined height to the parallel fins such that the new ratio of the second predetermined height of the fins to the width of the parallel grooves is increased to at least six to one. In another embodiment, the heat sink is then rotated ninety degrees and a second predetermined number of grooves are gang sawed at right angles across and through the parallel fins to provide a predetermined number of pins extending outwardly from the heat sink body.

99 citations


Patent
26 Aug 1988
TL;DR: In this article, the authors improved on the indirect evaporative cooling method and apparatus by making use of a working fluid that is pre-cooled with and without desiccants before it is passed through a Wet Channel where evaporative fluid is on the walls to take heat and store it in the working fluid as increased latent heat.
Abstract: The within invention improves on the indirect evaporative cooling method and apparatus by making use of a working fluid that is pre-cooled with and without desiccants before it is passed through a Wet Channel where evaporative fluid is on the walls to take heat and store it in the working fluid as increased latent heat. The heat transfer across the membrane between the Dry Channel and the Wet Channel may have dry, solid desiccant or liquid desiccant and may have perforations, pores or capillary pathways. The evaporative fluid may be water, fuel, or any substance that has the capacity to take heat as latent heat. The Wet Channel or excess cooled fluid is in heat transfer contact with a Product Channel where Product Fluid is cooled without adding any humidity. An alternative embodiment for heat transfer between adjacent channels is with heat pipes.

96 citations


Patent
26 Aug 1988
TL;DR: In this paper, a two-dimensional surface-emitting diode laser arrays are described that take advantage of both the advanced state of development of linear laser arrays with conventional cleaved end faces and the rapid development of Si heat sink technology.
Abstract: Two-dimensional surface-emitting diode laser arrays are described that take advantage of both the advanced state of development of linear laser arrays with conventional cleaved end faces and the rapid development of Si heat sink technology. A hybrid array consists of linear arrays of edge-emitting lasers that are mounted in grooves with flat bottoms and 45° sidewalls etched in the top of a Si substrate containing microchannels for fluid flow on the backside. The 45° sidewalls of the top Si grooves are coated with a highly reflecting metallic layer. These 45° mirrors deflect the laser emission from the cleaved end faces of the linear laser arrays by 90° so the emission is normal to the array surface. Use of the integral microchannel heat sink in the bottom of the Si substrate provides excellent heat removal capabilities for high power density operation.

92 citations


Journal ArticleDOI
01 Sep 1988-Energy
TL;DR: In this paper, the power output of a simple, finite-time Carnot heat engine was studied and the model adopted is a reversible Carnot cycle coupled to a heat source and a heat sink by heat transfer.

77 citations


Patent
13 Jul 1988
TL;DR: In this article, a fluid passageway along which are a pumping device, a vaporizing device, and a flowing device, all in fluid communication with the passagway, is used to deliver precisely controlled, substantially continuous and monitored vapor flows for uses such as in plasma enhanced vapor deposition.
Abstract: A vaporizing apparatus delivers precisely controlled, substantially continuous and monitored vapor flows for uses such as in plasma enhanced vapor deposition The vaporizing apparatus includes a fluid passageway along which are a pumping device, a vaporizing device, and a flowing device, all in fluid communication with the passageway The vaporizing device vaporizes liquid pumped from the pumping device and includes a heat sink layer, a heated layer, and a portion of the passageway sandwiched therebetween The vaporizing apparatus can sustain a flow of organosilicon vapor at a flow rate of about 1 to about 100 SCCM for as long as desired

Patent
27 Jun 1988
TL;DR: In this paper, a sealed bellows type container with an evaporator section at one end and a condenser section at an opposite end is used to conduct heat away from an electronic device to a heat sink.
Abstract: A bellows type heat pipe which conducts heat away from an electronic device to a heat sink. The heat pipe is a sealed bellows type container which has an evaporator section at one end and a condenser section at an opposite end. The evaporator section contains a saturated radial wick while the condenser section is lined with a radial wick and a circumferential wick. A corrugated slab wick is longitudinally disposed within the heat pipe interconnecting the evaporator and the condenser sections. The evaporator section is placed on the electronic device and the condenser section is enclosed in a housing which is connected to a heat sink. In operation, the electronic device generates heat energy which causes the fluid in the evaporator to vaporize building a vapor pressure in the heat pipe. The heat pipe expands in the direction of the condenser causing the condenser section to make intimate contact with the inside of the housing. The vapors condense at the condenser section and are brought back to the evaporator section via the circumferential wick, the walls of the bellows vessel and the wick slab.

Journal ArticleDOI
TL;DR: In this article, a numerical model for calculating the emission characteristics of diode laser arrays and broad-area devices operating well above threshold is discussed, which uses the beam propagation technique for determining the field intensities for several lateral modes, while simultaneously and self-consistently solving for the two-dimensional current flow through the laser structure and subsequent carrier diffusion in the active region.
Abstract: A numerical model for calculating the emission characteristics of diode laser arrays and broad-area devices operating well above threshold is discussed. This model uses the beam propagation technique for determining the field intensities for several lateral modes, while simultaneously and self-consistently solving for the two-dimensional current flow through the laser structure and the subsequent carrier diffusion in the active region. The active-region temperature distribution is also computed in a self-consistent manner, based on the flow of heat generated in the active region through the layered device structure to a constant-temperature heat sink. The model is applied by investigating the sensitivity of the lasing modes of a broad-area diode laser to variations in the lateral temperature distribution. >

Patent
07 Jan 1988
TL;DR: A heat sink for convective cooling of circuit packages or components by direct impinging fluid operation employing a housing having an inlet port and a plurality of radially fluid flow passages communicating with the inlet with each passage also having an outlet port is described in this article.
Abstract: A heat sink apparatus for convective cooling of circuit packages or components by direct impinging fluid operation employing a housing having an inlet port and a plurality of radially fluid flow passages communicating with the inlet port with each passage also having an outlet port A fluid deflection member is supported with the housing in line with the inlet port and is provided with a deflection surface adapted to redirect the fluid flow from the inlet port to the air flow passages

Patent
09 May 1988
TL;DR: In this paper, the heat sink covers an aperture in the board and the semiconductor die is secured to the heat sinks inside the cavity thereby formed, and the assembly is placed in a transfer mold.
Abstract: A molded pin-grid-array package includes a heat sink available at the face opposite to the pins. The heat sink is secured to a printed wiring board that has plated through holes therein that form the desired pin-grip-array and wires are secured in the holes to form the package pins. The heat sink covers an aperture in the board and the semiconductor die is secured to the heat sink inside the cavity thereby formed. After the semiconductor die is attached and the bonding pads connected to the metal traces on the board, the assembly is placed in a transfer mold. Plastic encapsulant is then transfer molded to encapsulate the semiconductor die and to extend flush with the heat sink to form a skirt around the periphery of the board. This leaves the molded package with an available heat sink face for efficient cooling after the package is mounted for ultimate use.

Patent
13 Jun 1988
TL;DR: In this paper, a graphite core oriented by compression to obtain very high lateral thermal conductivity and relatively low density is disclosed, held by two outer skins made up of folds of carbon fibers embedded in an epoxy resin matrix.
Abstract: A mounting that forms a heat sink for printed circuit boards comprising a graphite core oriented by compression to obtain very high lateral thermal conductivity and relatively low density is disclosed. This core is held by two outer skins made up of folds of carbon fibers embedded in an epoxy resin matrix. A metallic frame made of invar makes the mounting rigid, thus giving mountings that conduct heat very well while at the same time being light.

Patent
12 Feb 1988
TL;DR: In this paper, a printed wiring board is comprised of a combination of layers providing a good thermal match with surface mount components, and an integral thermal interface region is used to dissipate the heat from the core.
Abstract: A printed wiring board is comprised of a combination of layers providing a good thermal match with surface mount components. The board consists of a core surrounded by multiple layers of dielectric and conductive materials optimized for their thermal expansion qualities. The core is also used as a heat sink for drawing excess heat from the components. An integral thermal interface region is used to dissipate the heat from the core.

Patent
22 Feb 1988
TL;DR: In this article, a method for bonding thermally-stable polycrystalline polydiamond or CBN compacts to carbide supports is described, where the carbide support is placed in thermal contact with a heat sink and the thermally stable polycrystaline compact is placed at a heat source during the brazing operation.
Abstract: Disclosed is a method for bonding thermally-stable polycrystalline diamond or CBN compacts to carbide supports wherein the carbide support is placed in thermal contact with a heat sink and the thermally-stable compact is placed in thermal contact with a heat source during the brazing operation.

Patent
25 Aug 1988
TL;DR: In this paper, after a circuit component has been mounted on a bed of a lead frame, it is fixed by laying a ceramic or the like between the bed and a heat sink so that this assembly can be resin-sealed.
Abstract: PURPOSE:To enhance the heat-dissipating performance and to reduce the ON resistance by a method wherein, after a circuit component has been mounted on a bed of a lead frame, it is fixed by laying a ceramic or the like between the bed and a heat sink so that this assembly can be resin-sealed. CONSTITUTION:A semiconductor device 3 is fixed to a bed part 2 of a lead frame 1. Then, an electrode which has been formed on the semiconductor device 3 is connected to an external lead of the lead frame by using a metal thin wire 5. Then, a heat sink 8 is provided an Ag paste 9 is coated on one face of the heat sink a ceramic plate 6 is mounted on the face so as to be united in addition, an adhesive 7 is coated on the ceramic plate 6 the bed part 2 where the semiconductor device 3 is fixed is bonded to the ceramic plate. Then, this assembly is put in a metal mold and is sealed by using a mold resin 10 in such a way that one plane face of the heat sink 8 is exposed.

Journal ArticleDOI
TL;DR: In this paper, the authors illustrate that the optimal operating temperature for solar-driven heat engines is relatively insensitive to the engine design point, and they also discuss potential misconceptions regarding the maximum power point and the Curzon-Ahlborn efficiency of finite-time thermodynamics.

Patent
17 Mar 1988
TL;DR: In this paper, a high efficiency forced air heat sink assembly employs a split feed transverse flow configuration to minimize the length of the air flow path through at least two separated fin structures.
Abstract: A high efficiency forced air heat sink assembly employs a split feed transverse flow configuration to minimize the length of the air flow path through at least two separated fin structures. Different embodiments use different fin structure material configurations including honeycomb, corrugated and serpentine. Each such embodiment uses a thermally conductive plate having opposed exterior surfaces; one for receiving a component to be cooled and one for receiving the fin structures. The serpentine structured fin embodiment employs a plurality of fin supports extending from the plate and forming a plurality of channels for receiving the fin structures. A high thermal conductivity bondant, such as metal-filled epoxy, may be used to bond the fin structures to either the plate or the fin supports. Dip brazing and soldering may also be employed depending upon the materials selected.

Patent
08 Jul 1988
TL;DR: In this paper, a broad-area dielectric interfacing composed of dual filled layers of compliant silicone rubber in sandwiching relation to a porous glass-cloth carrier, one of the layers being pre-vulcanized and the other being subsequently cured and bonded in place.
Abstract: Withdrawal and dissipation of heat from an electronic solid-state device by an associated heat-sink structure are promoted by a relatively thin broad-area dielectric interfacing composed of dual filled layers of compliant silicone rubber in sandwiching relation to a porous glass-cloth carrier, one of the layers being pre-vulcanized and the other being subsequently cured and bonded in place once the composite interfacing has been applied to heat-sink surfaces adapted for abutment with the device for the intended heat transfer. The soft rubber interfacing offers good dielectric and insulating and voltage-breakdown characteristics even when well loaded with thermally-conductive oxides, and intimate voidless surface contacts and high-quality thermal matching are fostered both along abutting compliant surfaces of the pre-cured portion of the interfacing and along fully bonded surfaces of the portion cured in situ. Processing which makes such interfacing eminently practical and particularly advantageous to the user includes initial application of filled uncured rubber to one side of the sheet of the porous carrier, followed by its vulcanization and then by application of a further uncured amount to the opposite side of the carrier, with a protective peel-off plastic covering being used to facilitate handling and release-cutting of desired smaller wafer configurations from the large-area composite; uncured sides of the smaller peeled wafers are than mated with appropriate parts of heat sinks and cured, thereby producing heat sinks integrated with securely-bonded thermally-matching dielectric interfacing in readiness for unions with devices from which heat must be dissipated efficiently.

Patent
06 Dec 1988
TL;DR: A flexible hosing for circulation of a heat transfer fluid to effect heat exchange within a concrete or other type of slab is described in this article, where a locator wire is embedded within the hosing to transmit a locating signal so that the position of hosing within the slab may be accurately determined.
Abstract: A flexible hosing for circulation of a heat transfer fluid to effect heat exchange within a concrete or other type of slab. An inner wall comprising nylon, rayon or other similar material forms an inner wall of the hosing to resist corrosive attack by the heat transfer fluid. A locator wire is embedded within the hosing for transmission of a locating signal so that the position of the hosing within the slab may be accurately determined. The wire may also serve as an electrical resistance heating element should the heat transfer fluid become frozen, or should it be desired that the heat exchange system be operated without an external boiler or other heat source.

Patent
05 Aug 1988
TL;DR: In this article, a thermal coupling is proposed to promote heat transfer between a heat source and a heat sink with abutting surfaces using a deposition of a thermally conductive substance having a melting point temperature less than the temperature of the heat source.
Abstract: The invention is a thermal coupling to promote heat transfer between a heat source and a heat sink with abutting surfaces using a deposition of a thermally conductive substance having a melting point temperature less than the temperature of the heat source such that the substance when heated will be in a liquid state capable of effectively transferring heat between the heat source and the heat sink. The deposition is situated between and contacts the abutting surfaces of the heat source and the heat sink. The substance is contained using a sealant to completely enclose the substance between the heat source and heat sink surface while an adhesive is used to secure the heat source to the heat sink.

PatentDOI
TL;DR: In this paper, an acoustic cooling engine consisting of an elongated resonant pressure vessel having first and second ends is described. But the authors focus on the acoustic power of the system.
Abstract: A heat-driven acoustic cooling engine having no moving parts receives heat from a heat source. The acoustic cooling engine comprises an elongated resonant pressure vessel having first and second ends. A compressible fluid having a substantial thermal expansion coefficient and capable of supporting an acoustic standing wave is contained in the resonant pressure vessel. The heat source supplies heat to the first end of the vessel. A first heat exchanger in the vessel is spaced-apart from the first end and receives heat from the first end. A first thermodynamic element is adjacent to the first heat exchanger and converts some of the heat transmitted by the first heat exchanger into acoustic power. A second thermodynamic element has a first end located spaced-apart from the first thermodynamic element and a second end farther away from the first thermodynamic element than is its first end. The first end of the second thermodynamic element heats while its second end cools as a consequence of the acoustic power. A second heat exchanger is adjacent to and between the first and second thermodynamic elements. A heat sink outside of the vessel is thermally coupled to and receives heat from the second heat exchanger. The resonant pressure vessel can include a housing less than one-fourth wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir.

Patent
12 Jan 1988
TL;DR: In this article, a thermal transfer assembly includes a first assembly having a group of generally parallel cooling fins coupled to the package, such as cooling plate, is a second assembly also including a plurality of generally paralell cooling fins.
Abstract: In order to provide thermal coupling of a package, particularly a package containing electronic components, and a heat sink, a thermal transfer assembly includes a first assembly having a group of generally parallel cooling fins coupled to the package. Coupled to the heat sink, such as cooling plate, is a second assembly also including a plurality of generally parallel cooling fins. The second set of cooling fins is positioned on the heat sink so that when the heat sink is in a predetermined position with respect to the package, the cooling fins overlap. The overlapping cooling fins permit efficient transfer of heat thus permitting heat generated in the package to be conveyed to the heat sink. The overlapping fins also permit convenient disassembly and reassembly for test and maintenance procedures. Techniques for fabrication of the thermal transfer assembly are described along with procedures for improving the operation of the heat transfer assembly. Parameters optimizing the performance of thermal transfer assembly are discussed. The individual components of the thermal transfer unit can be used separately as heat exchange units.

Journal ArticleDOI
TL;DR: In this article, a heat-transfer study is conducted for the steady-state internal thermal resistance of a multichip packaging technology for VLSI-based systems, where chips flip-chip soldered and interconnected on a silicon substrate.
Abstract: A heat-transfer study is conducted for the steady-state internal thermal resistance of a multichip packaging technology for VLSI-based systems. This technology, which is known as advanced VLSI packaging (AVP), has chips flip-chip soldered and interconnected on a silicon substrate. AVP's thermal management approach is to dissipate chip power through the silicon substrate to a heat sink or other packaging levels. The authors found a need to control the chip-to-substrate interface; therefore, they use a three-dimensional heat conduction analysis to characterize this interface. They simulate thermal performance of typical AVP assemblies affected by thermal vias, solder bump heights, high-power I O drivers, and chip sizes. The authors also analyze and measure the internal resistances of an experimental package consisting of three WE32100 chips. These resistances are predicted as 3.7, 4.7, and 5.0 degrees C/W, respectively; they are confirmed by the experimental data. The authors demonstrate the low thermal resistance achieved: 3.0 degrees C/W for a 1-cm square chip and 10 degrees C/W for a 0.25-cm square chip. They also provide their insight into the roles of different conduction paths involved. >

Patent
30 Aug 1988
TL;DR: An LED array printhead as discussed by the authors comprises an elongate support bar of generally rectangular cross section with a row of LED array chips mounted end-to-end along one of the narrow elongate edge faces of the bar.
Abstract: An LED array printhead comprises an elongate support bar of generally rectangular cross section with a row of LED array chips mounted end-to-end along one of the narrow elongate edge faces of the bar. The bar is sandwiched between heat sink members confronting its wide faces. The heat sink members dissipate heat from the bar and also support circuit board means electrically connected to the LED chips.

Patent
14 Sep 1988
TL;DR: An improved heat transfer arrangement for use in a unique multi-function, industrial heat treat furnace which employs a sealed, closed end, heat exchanger shell member containing the work is described in this paper.
Abstract: An improved heat transfer arrangement for use in a unique multi-function, industrial heat treat furnace which employs a sealed, closed end, heat exchanger shell member containing the work The heat transfer arrangement includes a totally contained, internal recirculation system which develops an especially configured annular jet stream that produces highly efficient, convective heat transfer with the shell member After heat transfer between the entrained gases in the jet stream with the shell member has occurred, the jet flow is reversed at one end of the shell and impinged against the workpiece, the spent stream being reformed into the annular jet at the opposite end of the shell member

Patent
26 Apr 1988
TL;DR: In this article, a semiconductor laser device arranged so that at least one of cladding layers is formed of a thin AlGaInP layer having a larger energy band gap as compared with an active layer adjacent to the active layer and an AlGaAs layer having high thermal conductivity.
Abstract: A semiconductor laser device arranged so that at least one of cladding layers is formed of a thin AlGaInP layer having a larger energy band gap as compared with an active layer adjacent to the active layer and an AlGaAs layer having a high thermal conductivity as compared with that of the AlGaInP layer and the larger energy band gap as compared with the active layer, which is located between the AlGaInP layer and a heat sink, whereby a heat generated in the active layer is effectively radiated to the heat sink, thus the semiconductor laser being made capable of continuously emitting a laser light of a short wavelength at a room temperature.