JP7407577B2 - heat sink - Google Patents

Description

The present invention relates to a heat sink for cooling a semiconductor laser element.

In a laser light source device using a semiconductor laser element, when a current is supplied to the semiconductor laser element, the semiconductor laser element becomes an oscillation source of laser light and a heat generation source that emits a large amount of heat. It is known that the oscillation wavelength of a semiconductor laser device changes depending on the temperature, and when the temperature increases, the luminous efficiency decreases and long-term reliability deteriorates. Therefore, the laser light source device is provided with a cooling structure to keep the semiconductor laser element at an appropriate temperature.

Patent Document 1 discloses that an upper heat sink, an intermediate heat sink, and a lower heat sink each having one end as a heat receiving end are laminated in three layers (upper and lower), and the upper surface of the lower heat sink, the lower surface and upper surface of the intermediate heat sink, and the top surface of the upper heat sink. A heat radiator is disclosed in which a water channel is formed by a groove provided on the lower surface. In the heat sink described in Patent Document 1, the intermediate heat sink has an upper plate, a middle plate, and a lower plate stacked one above the other. The lower plate has a large number of water inlets made of round holes, and a groove-shaped inflow channel that communicates with the water inlets and heads toward an end opposite to a heat-receiving end provided on the upper surface of the lower plate. The middle plate has a water passage hole that is a round hole that communicates with the other end of the outflow channel of the lower plate. The upper plate has a large number of water outlets made of round holes, and a groove-shaped double channel whose one end communicates with the water outlet and whose other end communicates with the water hole provided on the lower surface of the upper plate. In this manner, the heat radiator described in Patent Document 1 includes a folded water channel on the intermediate heat radiating plate on the heat receiving end side. Thereby, the heat transmitted via the upper heat sink from the semiconductor laser element disposed at the heat receiving end of the upper heat sink is effectively cooled.

Japanese Patent Application Publication No. 2005-294769

By the way, in the radiator described in Patent Document 1, in order to efficiently exhaust heat, a water channel having a microchannel structure with a narrow channel width is employed. Further, in the heat radiator described in Patent Document 1, a complicated flow path is formed by overlapping a plurality of plates with complicated shapes, and high heat dissipation performance is achieved by increasing pressure loss and flow velocity. When cooling water flows through a waterway with such a microchannel structure, in order to improve the heat transfer coefficient between the waterway wall and the cooling water, the average flow velocity of the entire waterway must reach 3 m/s to 5 m/s. , the maximum flow velocity is expected to reach 5 m/s to 7 m/s. If cooling is performed in this state, the cooling water will corrode the radiator, and the thermal resistance will deteriorate over time. Then, there is a problem that the semiconductor laser element is not sufficiently cooled, and the life of the semiconductor laser element is shortened. Further, there is a possibility that water leakage may occur due to corrosion of the water channel, and in that case, there is a problem that there remains a concern about the long-term reliability of the laser light source device.

The present invention has been made in view of the above, and an object of the present invention is to obtain a heat sink that can suppress erosion and corrosion caused by cooling water compared to the conventional one while suppressing the temperature rise of an element that generates heat during operation. With the goal.

In order to solve the above-mentioned problems and achieve the objects, the present invention provides a heat sink that cools an element that generates heat during operation, which includes a main body portion provided with an internal water channel through which cooling water flows, and a side surface forming the internal water channel. and a plurality of pin fins protruding from the fins. A first channel extending in a first direction and a second channel extending in a second direction intersecting the first direction intersect in a plane perpendicular to the extending direction. A plurality of pin fins having a parallelogram shape are arranged. The aspect ratio, which is the ratio of the height to the width of the first flow path and the second flow path, is 5 or more. The first channel and the second channel have a width of 200 μm or more and 600 μm or less, a depth of 3 mm or more and 5 mm or less, and are arranged in parallel in the width direction at a pitch of 1 mm or less. The first channel and the second channel have the same width. The first flow path and the second flow path intersect at an angle of 20 degrees or more and 100 degrees or less (excluding angles of 30.2 degrees or more and 36.0 degrees or less). The plurality of pin fins have a diamond shape.

Advantageous Effects of Invention According to the present invention, it is possible to suppress erosion and corrosion caused by cooling water while suppressing a rise in temperature of an element that generates heat during operation, compared to the conventional technique.

A top view showing an example of the configuration of a heat sink according to Embodiment 1. II-II sectional view in Figure 1 III-III sectional view in Figure 2 A diagram showing an example of the relationship between the crossing angle of the pin fins of a heat sink, pressure loss, and thermal resistance. A bottom view showing an example of the procedure for manufacturing the top part of the heat sink body according to Embodiment 1. A bottom view showing an example of the procedure for manufacturing the top part of the heat sink body according to Embodiment 1. A bottom view showing an example of the procedure for manufacturing the top part of the heat sink body according to Embodiment 1. A bottom view showing an example of the procedure for manufacturing the top part of the heat sink body according to Embodiment 1. IX-IX sectional view in Figure 5 XX sectional view of Figure 6 XI-XI sectional view in Figure 7 XII-XII sectional view in Figure 8 A top view showing an example of a procedure for manufacturing the bottom of the heat sink body according to Embodiment 1. A top view showing an example of a procedure for manufacturing the bottom of the heat sink body according to Embodiment 1. A top view showing an example of a procedure for manufacturing the bottom of the heat sink body according to Embodiment 1. XVI-XVI sectional view in Figure 13 XVII-XVII sectional view in Figure 14 XVIII-XVIII sectional view in Figure 15 1 is a cross-sectional view schematically showing an example of a procedure of a method for manufacturing a heat sink according to Embodiment 1; FIG. 1 is a cross-sectional view schematically showing an example of a procedure of a method for manufacturing a heat sink according to Embodiment 1; FIG. A diagram showing an example of flow velocity distribution in the flat flow path of the heat sink according to Embodiment 1. A top view showing an example of the configuration of a heat sink according to Embodiment 2. XXIII-XXIII sectional view in Figure 22 XXIV-XXIV sectional view of Figure 23 A top view schematically showing an example of the procedure for manufacturing the bottom of the heat sink body according to Embodiment 2. A top view schematically showing an example of the procedure for manufacturing the bottom of the heat sink body according to Embodiment 2. A top view schematically showing an example of the procedure for manufacturing the bottom of the heat sink body according to Embodiment 2. XXVIII-XXVIII sectional view of Figure 25 XXIX-XXIX sectional view in Figure 26 XXX-XXX sectional view of Figure 27 Cross-sectional view showing an example of the configuration of a heat sink according to Embodiment 3 A bottom view schematically showing an example of the procedure for manufacturing the top part of the heat sink body according to Embodiment 3. A bottom view schematically showing an example of the procedure for manufacturing the top part of the heat sink body according to Embodiment 3. A bottom view schematically showing an example of the procedure for manufacturing the top part of the heat sink body according to Embodiment 3. A bottom view schematically showing an example of the procedure for manufacturing the top part of the heat sink body according to Embodiment 3. XXXVI-XXXVI cross-sectional view of Figure 32 XXXVII-XXXVII cross-sectional view of Figure 33 XXXVIII-XXXVIII cross-sectional view in Figure 34 XXXIX-XXXIX cross-sectional view in Figure 35 A diagram showing an example of the relationship between the width of the first flow path and the second flow path and the thermal resistance and flow velocity of cooling water according to Embodiment 3.

EMBODIMENT OF THE INVENTION Below, the heat sink based on embodiment of this invention is demonstrated in detail based on drawing. Note that the present invention is not limited to these embodiments.

Embodiment 1.
FIG. 1 is a top view showing an example of the configuration of a heat sink according to the first embodiment. FIG. 2 is a sectional view showing an example of the configuration of the heat sink according to the first embodiment, and is a sectional view taken along line II-II in FIG. FIG. 3 is a cross-sectional view showing an example of the configuration of the heat sink according to the first embodiment, and is a cross-sectional view taken along line III--III in FIG. Note that in these figures, the thickness direction of the heat sink 1 is taken as the Z axis. Further, the direction in which cooling water flows in and out of the heat sink 1 perpendicular to the Z axis is defined as the X axis, and the axis perpendicular to the X axis and the Z axis is defined as the Y axis. Furthermore, in the following description, two relative positional relationships on the Z axis may be expressed using "above" or "below".

The heat sink 1 cools elements that generate heat during operation. An example of the device is a semiconductor laser device. In the following, a case where the device is a semiconductor laser device will be described as an example. The heat sink 1 includes a main body part 10 having an internal water channel that is a flow path for flowing cooling water therein, and water channel joint members 41a and 41b connected to the main body part 10. The main body part 10 has a main body bottom part 20 having an internal water channel, and a main body top part 30 which is disposed overlappingly on the main body bottom part 20 and on which an element to be cooled is mounted. The main body bottom 20 and the main body top 30 are closely connected to each other so that cooling water does not leak from the joint.

As shown in FIGS. 2 and 3, the main body bottom 20 has a rectangular shape in a plan view. The main body bottom 20 has a substantially U-shaped groove-shaped flat channel 22 on the upper surface side. The flat flow path 22 includes a first flat flow path 22a located on the positive side of the Y-axis and extending in the X-axis direction, and a second flat flow path 22a located on the negative side of the Y-axis and extending in the X-axis direction. It has a passage 22b and a third flat passage 22c that connects the first flat passage 22a and the second flat passage 22b and extends in the Y-axis direction. The main body bottom 20 also includes a circular pipe flow path 23a that connects the waterway joint member 41a arranged on the positive side of the Y-axis and the first flat flowpath 22a, and a waterway joint arranged on the negative side of the Y-axis. It has a circular tube flow path 23b connecting between the member 41b and the second flat flow path 22b. The circular tube flow path 23a penetrates between the cooling water supply surface 20a, which is a side surface disposed on the negative side of the X-axis of the main body bottom 20, and the first flat flow path 22a, and is designed to have a circular cross section. This is the channel that was removed. The circular tube flow path 23b is a flow path that penetrates between the cooling water supply surface 20a of the main body bottom 20 and the second flat flow path 22b, and is hollowed out so that its cross section is circular. The flat channel 22 and the circular pipe channels 23a and 23b constitute an internal water channel.

The water channel coupling members 41 a and 41 b are provided on the cooling water supply surface 20 a of the main body bottom 20 so as to be connected to the ends of the circular pipe flow paths 23 a and 23 b of the main body bottom 20 . Cooling water can be supplied to the heat sink 1 from the outside via the water channel coupling members 41a and 41b. Here, it is assumed that cooling water is supplied from the water channel joint member 41a, and cooling water that has passed through the internal water channel is discharged from the water channel joint member 41b.

As shown in FIGS. 1 and 2, the main body top 30 has a rectangular shape in plan view and has the same size as the main body bottom 20. The top portion 30 of the main body has an element mounting surface 31 on the upper surface on which a semiconductor laser element to be cooled is mounted. The element mounting surface 31 is located within a region corresponding to the third flat flow path 22c when the main body top 30 is aligned and overlapped with the main body bottom 20.

The main body top portion 30 has a plurality of pin fins 32 on the lower surface thereof, which are arranged to protrude toward the negative side of the Z-axis. The pin fins 32 are pin-shaped fins. A channel group 33G is formed in which channels 33 having a channel width of 200 μm or more and 600 μm or less and a channel depth of 3 mm or more and 5 mm or less are arranged in the width direction at a pitch of 1 mm or less, A pin fin 32 is arranged. The aspect ratio of a cross section perpendicular to the extending direction of the flow path 33 formed between adjacent pin fins 32 is 5 or more, and has a flat shape.

Two channels 33 adjacent in the X-axis direction in the channel group 33G, that is, a first channel 33 extending in the first direction and a second channel extending in the second direction. The pin fins 32 have a rhombus shape, which is a special form of a parallelogram in a plan view, so that certain channels 33 intersect with each other at an angle θ of 20 degrees or more and 100 degrees or less. Hereinafter, the angle θ at which the cooling water flowing from the positive direction to the negative direction of the Y axis intersects will be referred to as an intersection angle. A pin fin arrangement region 32R, in which the pin fins 32 are arranged, corresponds to the element mounting surface 31. The size of the element mounting surface 31, that is, the size of the area where the pin fins 32 are arranged, is equal to or larger than the size of the semiconductor laser element, taking into consideration heat dissipation performance. In this example, the diagonal lines of the diamond-shaped pin fins 32 are arranged to be parallel to the X-axis and the Y-axis.

In order to efficiently dissipate the heat generated when a semiconductor laser element (not shown) mounted on the element mounting surface 31 of the heat sink 1 oscillates, the main body bottom 20, the main body top 30, and the water channel joint members 41a and 41b are made of thermally conductive material. Constructed from superior materials. The main body bottom 20, the main body top 30, and the waterway coupling members 41a, 41b are made of a metal material such as copper (Cu), for example. Alternatively, a metal material such as Cu that has been subjected to nickel plating and gold plating may be used, assuming anticorrosion measures and solder mounting of the semiconductor laser element.

FIG. 4 is a diagram illustrating an example of the relationship between the crossing angle of the pin fins of the heat sink, pressure loss, and thermal resistance. In this figure, the horizontal axis indicates the intersection angle θ of adjacent channels 33 in the X-axis direction. The vertical axis on the left side shows the thermal resistance value, and the vertical axis on the right side shows the pressure loss. Note that the thermal resistance value is calculated by dividing the temperature difference between the maximum temperature of the semiconductor laser element mounted on the element mounting surface 31 and the temperature of the cooling water by the amount of heat generated. Note that here, it is assumed that the flow path 33 has a width of 200 μm and a depth of 4 mm. Further, it is assumed that the average flow velocity of the cooling water within the pin fin arrangement region 32R is 1.5 m/s. Then, the pressure loss and thermal resistance are calculated when the intersection angle θ is 20 degrees, 40 degrees, 60 degrees, 80 degrees, and 100 degrees.

From this graph, as the intersection angle θ increases, the thermal resistance decreases, but the pressure loss increases. Therefore, as the intersection angle θ increases, a higher performance chiller is used for feeding water into the heat sink 1. Further, the effect of improving the thermal resistance value is saturated when the intersection angle θ is around 100 degrees. Therefore, the intersection angle θ of the pin fins 32 is selected within the range of 20 degrees or more and 100 degrees or less, depending on the specifications of the chiller used.

The operation of such a heat sink 1 will be explained. For example, in FIG. 3, cooling water is supplied to the water channel joint member 41a from a chiller (not shown). The cooling water flows to the third flat flow path 22c via the circular tube flow path 23a and the first flat flow path 22a. In the third flat channel 22c, a channel group 33G is formed by the pin fins 32, and the cooling water flows through the channels 33 in this channel group 33G in the negative direction of the Y-axis. When the cooling water reaches the second flat flow path 22b, it returns to the chiller (not shown) via the circular pipe flow path 23b and the water channel joint member 41b.

The internal water channel of the heat sink 1 according to the first embodiment has a configuration in which the channel group 33G is arranged in the pin fin arrangement region 32R so that the intersection angle θ is in the range of 20 degrees or more and 100 degrees or less. Further, the channels 33 constituting the channel group 33G have a width of 200 μm or more and 600 μm or less, a depth of 3 mm or more and 5 mm or less, and are arranged at a pitch of 1 mm or less in the width direction. In this way, the internal water channel of the heat sink 1 according to the first embodiment does not have a complicated configuration, unlike the internal water channel in the radiator described in Patent Document 1. Therefore, the average flow velocity of the cooling water flowing into the heat sink 1 can be lowered compared to the case of the radiator described in Patent Document 1. That is, the average flow velocity can be lowered to 3 m/s or less. As a result, erosion of the heat sink 1 caused by the cooling water is suppressed. Further, since corrosion of the heat sink 1 is suppressed, occurrence of water leakage due to corrosion of the water channel is also suppressed, and the long-term reliability of the laser light source device in which the heat sink 1 is mounted with a semiconductor laser element can be improved.

Next, a method for manufacturing such a heat sink 1 will be explained. 5 to 20 are diagrams schematically showing an example of the procedure of the method for manufacturing a heat sink according to the first embodiment. 5 to 8 are bottom views showing an example of a procedure for manufacturing the top part of the heat sink body according to the first embodiment. 9 to 12 are cross-sectional views illustrating an example of a procedure for manufacturing the top portion of the heat sink body according to the first embodiment. 9 is a cross-sectional view taken along line IX-IX in FIG. 5, FIG. 10 is a cross-sectional view taken along line XX in FIG. 6, FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. FIG. 8 is a sectional view taken along line XII-XII of No. 8. 13 to 15 are top views showing an example of a procedure for manufacturing the bottom of the heat sink body according to the first embodiment. 16 to 18 are cross-sectional views illustrating an example of a procedure for manufacturing the bottom of the heat sink body according to the first embodiment. 16 is a sectional view taken along line XVI-XVI in FIG. 13, FIG. 17 is a sectional view taken along line XVII-XVII in FIG. 14, and FIG. 18 is a sectional view taken along line XVIII-XVIII in FIG. 19 and 20 are cross-sectional views schematically showing an example of the procedure of the method for manufacturing a heat sink according to the first embodiment.

First, a method for manufacturing the main body top portion 30 will be described with reference to FIGS. 5 to 12. As shown in FIGS. 5 and 9, a rectangular parallelepiped block material 30A is prepared. In one example, the block material 30A is made of Cu. Next, as shown in FIGS. 6 and 10, the block material 30A is processed to produce a protrusion-shaped portion 32A in which the pin fin arrangement region 32R is more protruding than other regions. That is, the area other than the protrusion-shaped part 32A is cut so that the thickness of the area other than the protrusion-shaped part 32A becomes a plate-like part having a predetermined thickness. In one example, the protrusion-shaped portion 32A is processed by mechanical cutting or electric discharge wire cutting.

Thereafter, as shown in FIGS. 7 and 11, a channel groove group 331G consisting of a plurality of parallel channel grooves 331 is created in the protrusion-shaped portion 32A. The channel groove 331 intersects the Y axis at an angle of θ/2. In one example, the channel groove group 331G is produced by mechanical cutting using a metal saw. Specifically, the channel groove 331 is formed by inserting a metal saw into the protruding portion 32A at an angle of θ/2 with respect to the Y axis and inserting the blade of the metal saw to a predetermined depth. Then, by repeating the same processing at equal pitches, a channel groove group 331G in which a plurality of mutually parallel channel grooves 331 are arranged is produced. At this time, a plurality of channel grooves 331 may be simultaneously formed using a dedicated metal saw equipped with a plurality of blades. The width of the metal saw is 200 μm or more and 600 μm or less, and the depth into which the metal saw is inserted is 3 mm or more and 5 mm or less. Further, the pitch of the metal saw blade is 1 mm or less, and θ is 10 degrees or more and 50 degrees or less.

Similarly, as shown in FIGS. 8 and 12, a channel groove group 332G consisting of a plurality of parallel channel grooves 332 extending in different directions is produced in the protrusion-shaped portion 32A. The channel groove 332 intersects the Y axis at an angle of −θ/2, and intersects the channel groove 331 produced in FIGS. 7 and 11 at an angle of θ. The flow path groove group 332G is produced by mechanical cutting using a metal saw in the same manner as in FIGS. 7 and 11. As a result, the pin fin 32 having a diamond shape in plan view is two-dimensionally arranged on the lower surface of the main body top part 30 in the protrusion-shaped part 32A. In the pin fin 32, the channel grooves 331 and 332 in two directions intersect at an intersection angle θ in a range of 20 degrees or more and 100 degrees or less. Further, the pin fins 32 form a channel group 33G in which channels 33 having a width of 200 μm or more and 600 μm or less and a depth of 3 mm or more and 5 mm or less are arranged in the width direction at a pitch of 1 mm or less. In other words, the channel groove 331 and the channel groove 332 become a channel 33 including a first channel extending in the first direction of the internal water channel and a second channel extending in the second direction.

In addition, although the case where the channel groove groups 331G and 332G are produced by mechanical cutting using a metal saw has been described above, they may be produced by electric discharge wire cutting. Furthermore, after the pin fins 32 are processed, the block material 30A may be subjected to anti-corrosion plating treatment such as nickel plating. Through the above steps, the main body top portion 30 is manufactured.

Next, a method for manufacturing the main body bottom 20 will be described with reference to FIGS. 13 to 18. As shown in FIGS. 13 and 16, a rectangular parallelepiped block material 20A is prepared. In one example, the block material 20A is made of Cu. Next, as shown in FIGS. 14 and 17, the block material 20A is processed to form the flat channel 22. The flat flow path 22 includes a first flat flow path 22a provided on the positive direction side of the Y-axis and extending in the X-axis direction, and a second flat flow path 22a provided on the negative direction side of the Y-axis and extending in the X-axis direction. It includes a flat flow path 22b and a third flat flow path 22c connecting between the first flat flow path 22a and the second flat flow path 22b. The flat channel 22 is a groove formed by digging the block material 20A to a predetermined depth from the upper surface side. In one example, the flat channel 22 is produced by mechanical cutting.

Thereafter, as shown in FIGS. 15 and 18, a circular pipe channel 23a connects the cooling water supply surface 20a, which is the side surface on the negative side of the X axis of the block material 20A, to the end of the first flat channel 22a. is formed inside the block material 20A, and a circular pipe flow path 23b connecting the cooling water supply surface 20a to the end of the second flat flow path 22b is similarly formed inside the block material 20A. The circular tube flow paths 23a and 23b extend in the X-axis direction. At this time, when fixing the water channel coupling members 41a, 41b to the main body bottom 20 with screws, screws for attaching the water channel coupling members 41a, 41b around the circular pipe channels 23a, 23b on the cooling water supply surface 20a. The hole is machined. Moreover, after the formation of the circular pipe channels 23a and 23b, anti-corrosion plating treatment such as nickel plating may be performed on the block material 20A. Through the above steps, the main body bottom portion 20 is manufactured.

Finally, a method for assembling the heat sink 1 will be described with reference to FIGS. 19 and 20. As shown in FIG. 19, the surface of the main body top 30 on which the pin fins 32 are formed and the surface of the main body bottom 20 on which the flat channel 22 is formed are arranged to face each other. Thereafter, as shown in FIG. 20, the two are integrated. For integration, brazing bonding using a brazing material, soldering bonding using a solder material, bonding using a resin adhesive, penetrating electron beam welding, or diffusion bonding between Cu particles can be used. When cooling a semiconductor laser device, which is one of the uses of the heat sink 1, even the melting point of the bonding material used when mounting the semiconductor laser device on the device mounting surface 31 will cause the integrated body top 30 A method is adopted in which the joint portion of the bottom portion 20 is not melted and broken. For example, in the case of joining by brazing, soldering, or adhesive, a material with a higher melting point than the joining material used when mounting the semiconductor laser device is used as the brazing material, solder material, or adhesive, respectively. . In addition, in order to suppress corrosion between dissimilar metals during cooling water circulation, each brazing material, solder material, or adhesive used for brazing, soldering, or adhesion during integration should be Therefore, it is desirable to use materials with similar ionization tendencies. Further, in order to suppress melt fracture and corrosion between dissimilar metals, it is desirable to use electron beam welding or diffusion bonding as the integration method.

Thereafter, the water channel coupling members 41a and 41b are fixed to the cooling water supply surface 20a of the bottom portion 20 of the main body. In one example, the water channel coupling members 41a, 41b are fixed to the main body bottom 20 using screws. In other examples, the water channel joint members 41a and 41b may be fixed to the main body bottom 20 by welding. Through the above steps, the heat sink 1 shown in FIGS. 1 to 3 is obtained.

In addition, in the above description, after forming the flat channel 22 in the main body bottom part 20, the case where the circular tube channels 23a and 23b are formed in FIG. 15 and FIG. 18 was explained. However, after forming the flat channel 22 in the main body bottom 20, the main body top 30 and the main body bottom 20 may be integrated, and then the circular pipe channels 23a and 23b may be formed.

FIG. 21 is a diagram showing an example of the flow velocity distribution in the flat channel of the heat sink according to the first embodiment. Here, the flow velocity distribution of the flat channel 22 in the heat sink 1 having a channel group 33G in which a plurality of channels 33 having a width of 200 μm and a depth of 4 mm intersect at a crossing angle of 60 degrees is shown. . Cooling water is flowed from the first flat flow path 22a toward the second flat flow path 22b such that the average flow velocity at the entrance of the pin fin arrangement region 32R is 1.5 m/s.

Under such conditions, as shown in FIG. 21, the maximum flow velocity is about 4 m/s at the maximum near the exit of the pin fin arrangement region 32R. This maximum flow velocity is smaller than the maximum flow velocity estimated in the water channel of the microchannel structure in the radiator described in Patent Document 1. Further, the average flow velocity in the pin fin arrangement region 32R is also smaller than the average flow velocity estimated in the water channel of the radiator described in Patent Document 1. In this way, the average flow velocity and maximum flow velocity in the water channel can be suppressed compared to the conventional method while suppressing the temperature rise of the semiconductor laser element.

By lowering the flow rate, the effects of erosion and corrosion due to cooling water circulation are reduced, and the life of the heat sink 1 body is extended. Furthermore, the cooling performance of the heat sink 1 is ensured, which has the effect of extending the life of the semiconductor laser element. Moreover, since the structure is such that cooling water is supplied into the inside of the heat sink 1 via the water channel joint members 41a and 41b, a plurality of heat sinks 1 can be arranged adjacently.

According to the heat sink 1 according to the first embodiment, a channel 33 having a shape in which pin fins 32 having a diamond shape in a plan view are arranged is formed in a pin fin arrangement region 32R that is equal to or larger than the size of a semiconductor laser element. The pin fins 32 are arranged such that a channel group 33G is formed in which channels 33 having a width of 200 μm or more and 600 μm or less and a depth of 3 mm or more and 5 mm or less are arranged in the width direction at a pitch of 1 mm or less. . Further, two adjacent channels 33 were arranged to intersect at an intersection angle θ in a range of 20 degrees or more and 100 degrees or less. In this way, by forming a flat flow path 33 with a high aspect ratio by arranging the diamond-shaped pin fins 32, the heat exhaust performance can be improved compared to straight-shaped fins even when the flow rate and pressure loss of cooling water are low. It is also possible to improve In other words, even when cooling water is flowed at a lower average flow rate than in the case of the heat sink described in Patent Document 1, the heat generated in the mounted semiconductor laser element is exhausted in the pin fin arrangement region 32R, and the temperature of the semiconductor laser element is increased. can be maintained at a predetermined temperature. Furthermore, the average velocity and maximum flow velocity of the cooling water in the internal water channel of the heat sink 1 can be reduced compared to the radiator having the microchannel structure water channel described in Patent Document 1. Compared to the described heat radiator, erosion and corrosion in the internal water channels of the heat sink 1 can be suppressed.

Further, a pin fin arrangement region 32R is provided on the surface of the top portion 30 of the main body opposite to the element mounting surface 31, and the size of the pin fin arrangement region 32R is set to be equal to or larger than the size of the element to be mounted. As a result, the distance between the cooling source and the heat generating source can be shortened, and the heat exhaust area can be increased, so that thermal resistance can be reduced.

Embodiment 2.
FIG. 22 is a top view showing an example of the configuration of the heat sink according to the second embodiment. FIG. 23 is a cross-sectional view showing an example of the configuration of the heat sink according to the second embodiment, and is a cross-sectional view taken along line XXIII-XXIII in FIG. 22. FIG. 24 is a cross-sectional view showing an example of the configuration of the heat sink according to the second embodiment, and is a cross-sectional view taken along line XXIV-XXIV in FIG. 23. Note that in these figures, the thickness direction of the heat sink 1A is taken as the Z axis. Further, the direction in which cooling water flows in and out of the heat sink 1A perpendicular to the Z-axis is defined as the Y-axis, and the axis perpendicular to the Y-axis and the Z-axis is defined as the X-axis. Furthermore, in the following description, two relative positions on the Z-axis may be expressed using "above" or "below". Further, in the following, portions different from those in Embodiment 1 will be explained, and the same components as in Embodiment 1 will be denoted by the same reference numerals, and their explanation will be omitted.

In the first embodiment, a case was shown in which the water channel coupling members 41a and 41b were provided on one side surface of the heat sink 1A, but in the second embodiment, the water channel coupling members 41a and 41b were provided on opposite sides of the main body bottom 20. provided. In the illustrated example, a water channel joint member 41a is provided on the cooling water supply surface 20a, which is a side surface perpendicular to the Y axis, and a water channel joint member 41b is provided on the cooling water discharge surface 20b, which is a side surface opposite to the cooling water supply surface 20a. will be provided. That is, the internal waterway from the waterway coupling member 41a to the waterway coupling member 41b has a straight shape without a curved portion.

As shown in FIG. 22, the element mounting surface 31 is provided in a region including the center portion of the upper surface of the main body top portion 30 in the Y-axis direction. Further, as shown in FIGS. 23 and 24, the plurality of pin fins 32 are provided on the lower surface of the main body top portion 30 corresponding to the element mounting surface 31. Note that the structure of the plurality of pin fins 32 and the shape of the flow path 33 formed by the plurality of pin fins 32 are the same as in the first embodiment.

Further, as shown in FIG. 24, the main body bottom 20 includes a groove-shaped flat channel 22 extending in the Y-axis direction. Further, a circular pipe flow path 23a is provided between the end surface of the flat flow path 22 in the negative direction of the Y-axis and the cooling water supply surface 20a of the main body bottom 20, and the end surface of the flat flow path 22 in the positive direction of the Y-axis A circular pipe flow path 23b is provided between the cooling water discharge surface 20b of the main body bottom portion 20 and the cooling water discharge surface 20b of the main body bottom portion 20. The water channel joint member 41a is fixed at the position of the circular pipe flow path 23a on the cooling water supply surface 20a, and the water channel joint member 41b is fixed at the position of the circular pipe flow path 23b on the cooling water discharge surface 20b.

As in the first embodiment, the main body bottom 20, the main body top 30, and the water channel joint members 41a, 41b are made of thermally conductive material in order to efficiently dissipate the heat generated from the semiconductor laser element mounted on the element mounting surface 31. It is made of a material such as Cu, which has excellent properties.

Next, a method for manufacturing such a heat sink 1A will be explained. Note that the manufacturing process of the main body top part 30 and the process of integrating the main body top part 30 and the main body bottom part 20 are the same as those in Embodiment 1, so the description thereof will be omitted. 25 to 30 are diagrams schematically showing an example of a procedure for manufacturing the bottom of the heat sink body according to the second embodiment. 25 to 27 are top views schematically showing an example of a procedure for manufacturing the bottom of the heat sink body according to the second embodiment. 28 to 30 are cross-sectional views schematically showing an example of a procedure for manufacturing the bottom of the heat sink body according to the second embodiment. 28 is a cross-sectional view taken along line XXVIII-XXVIII in FIG. 25, FIG. 29 is a cross-sectional view taken along line XXIX-XXIX in FIG. 26, and FIG. 30 is a cross-sectional view taken along line XXX-XXX in FIG. 27.

First, as shown in FIGS. 25 and 28, a rectangular parallelepiped block material 20B is prepared. In one example, the block material 20B is made of Cu. Next, as shown in FIGS. 26 and 29, the block material 20B is processed to form the flat channel 22. The flat channel 22 is a groove formed by digging a predetermined depth from the top surface of the block material 20B. In one example, the flat channel 22 is produced by mechanical cutting.

Thereafter, as shown in FIGS. 27 and 30, the circular pipe flow path 23a connecting the cooling water supply surface 20a, which is the side surface on the negative side of the Y axis of the block material 20B, to the end of the flat flow path 22 is blocked. It is formed inside the material 20B. Further, a circular pipe flow path 23b connecting the cooling water discharge surface 20b on the positive side of the Y axis of the block material 20B to the end of the flat flow path 22 is formed inside the block material 20B. The circular tube flow paths 23a and 23b extend in the Y-axis direction. At this time, when the water channel joint members 41a and 41b are fixed to the main body bottom 20 with screws, the circumference of the circular pipe flow path 23a on the cooling water supply surface 20a and the circumference of the circular pipe flow path 23b on the cooling water discharge surface 20b. , threaded holes for attaching the water channel coupling members 41a, 41b are machined. Moreover, after the formation of the circular pipe channels 23a and 23b, anti-corrosion plating treatment such as nickel plating may be performed on the block material 20B. Through the above steps, the main body bottom portion 20 is formed.

In addition, in the above description, the case where the waterway coupling members 41a and 41b are fixed to the main body bottom part 20 by screwing was illustrated, but the waterway coupling members 41a and 41b may be fixed to the main body bottom part 20 by a welding method. Further, as in the first embodiment, after forming the flat channel 22 in the bottom portion 20 of the main body, the top portion 30 of the main body and the bottom portion 20 of the main body may be integrated, and then the circular pipe channels 23a and 23b may be formed. good.

In the second embodiment, the heat sink 1A has a straight internal water channel from the cooling water inlet to the outlet. That is, there is no curvature of the water channel at the boundary between the cooling water inlet and the pin fin arrangement region 32R, and no curvature of the water channel at the boundary between the pin fin arrangement region 32R and the cooling water outlet. As a result, in addition to the effects of the first embodiment, the flow velocity can be made uniform and the maximum flow velocity can be lowered.

Embodiment 3.
FIG. 31 is a cross-sectional view showing an example of the configuration of a heat sink according to the third embodiment. FIG. 31 corresponds to the III-III cross-sectional view of FIG. 2 of the first embodiment. In addition, the different parts from Embodiment 1 will be explained below. Further, the same components as those in Embodiments 1 and 2 are given the same reference numerals, and their explanations will be omitted.

In the heat sink 1B according to the third embodiment, the widths of the intersecting channels 33 are changed in order to equalize the flow rate of cooling water flowing through the channels 33 in the pin fin arrangement region 32R. Further, the pin fin 32 has a parallelogram shape in a plan view. More specifically, the flow area of the first flow path 33a provided in the direction along the flow is made smaller, and the flow path area of the second flow path 33b provided in the direction opposite to the flow is increased. That is, the width of the second flow path 33b is made larger than the width of the first flow path 33a. As a result, even if the cooling water supply port, the pin fin arrangement region 32R, and the discharge port are not arranged in a straight manner, and the cooling water flows into the pin fin arrangement region 32R in a curved manner, it is possible to The difference in pressure loss that occurs between the first flow path 33a and the second flow path 33b in the direction opposite to the flow can be reduced. The size of the pin fin arrangement region 32R is desirably equal to or larger than the size of the semiconductor laser element in consideration of heat dissipation performance.

Here, the direction along the flow and the direction opposite to the flow in the pin fin arrangement region 32R will be explained. The direction in which the cooling water flows in the circular pipe channel 23a and the first flat channel 22a on the cooling water inlet side of the pin fin arrangement region 32R is defined as DF, and the direction perpendicular to DF is defined as DP. Note that in this example, DF is parallel to the X-axis, and DP is parallel to the Y-axis. Let FL1 be the direction in which the cooling water flows in the first flow path 33a provided in the pin fin arrangement region 32R, and let FL2 be the direction in which the cooling water flows in the second flow path 33b. When these directions FL1 and FL2 are decomposed into a component in the DF direction and a component in the DP direction, the case where the direction of the component in the DF direction matches the direction in which the cooling water flows is called a "direction along the flow." ”. Further, a case where the direction of the component in the DF direction does not match the direction in which the cooling water flows, that is, a case where the direction of the component in the DF direction is opposite to the direction in which the cooling water flows is referred to as a "direction opposite to the flow". In the case of FIG. 31, the direction FL1 in which the cooling water flows in the first flow path 33a is a direction along the flow, and the direction FL2 in which the cooling water flows in the second flow path 33b is a direction opposite to the flow. That is, the narrow first flow path 33a is a flow path in the direction along the flow, and the wide second flow path 33b is a flow path in the direction opposite to the flow.

Next, a method for manufacturing such a heat sink 1B will be explained. Note that the manufacturing process of the main body bottom part 20 and the process of integrating the main body top part 30 and the main body bottom part 20 are the same as in Embodiment 1, so a description thereof will be omitted. 32 to 39 are diagrams schematically illustrating an example of a procedure for manufacturing the top portion of the heat sink body according to the third embodiment. 32 to 35 are bottom views schematically showing an example of a procedure for manufacturing the top part of the heat sink body according to the third embodiment. 36 to 39 are cross-sectional views schematically showing an example of a procedure for manufacturing the top portion of the heat sink body according to the third embodiment. 36 is a sectional view taken along XXXVI-XXXVI in FIG. 32, FIG. 37 is a sectional view taken along XXXVII-XXXVII in FIG. 33, FIG. 38 is a sectional view taken along XXXVIII-XXXVIII in FIG. 34, and FIG. 35 is a sectional view taken along XXXIX-XXXIX.

First, as shown in FIGS. 32 and 36, a rectangular parallelepiped block material 30B is prepared. In one example, the block material 30B is made of Cu. Next, as shown in FIGS. 33 and 37, the block material 30B is processed to produce a protrusion-shaped portion 32B in which the pin fin arrangement region 32R is more protruding than other regions. That is, the area other than the protrusion-shaped part 32B is cut so that the thickness of the area other than the protrusion-shaped part 32B becomes a predetermined thickness. In one example, the protrusion-shaped portion 32B is processed by mechanical cutting or electric discharge wire cutting.

Thereafter, as shown in FIGS. 34 and 38, a channel groove group 333G consisting of a plurality of parallel channel grooves 333 is created in the protrusion-shaped portion 32B. In one example, the channel groove group 333G is produced by mechanical cutting using a metal saw. Specifically, the channel groove 333 is formed by inserting a metal saw into the protruding portion 32B at a predetermined angle with respect to the Y axis and inserting the blade of the metal saw to a predetermined depth. Then, by repeating the same processing at equal pitches, a channel groove group 333G in which a plurality of mutually parallel channel grooves 333 are arranged is produced. Further, the flow path groove group 333G is angled so as to face the flow of the cooling water at the boundary position between the first flat flow path 22a and the third flat flow path 22c. At this time, a plurality of channel grooves 333 may be simultaneously formed using a dedicated metal saw equipped with a plurality of blades. The width of the metal saw is 200 μm or more and 600 μm or less, and the depth into which the metal saw is inserted is 3 mm or more and 5 mm or less. Further, the pitch of the blades of the metal saw is 1 mm or less.

Similarly, as shown in FIGS. 35 and 39, a flow path consisting of a plurality of parallel flow grooves 334 extending in a direction different from the flow groove group 333G and having a width different from that of the flow groove 333. A groove group 334G is created in the protrusion-shaped portion 32B. In one example, the channel groove group 334G is produced by mechanical cutting using a metal saw having a width different from that of the metal saw used to produce the channel groove group 333G. Specifically, the channel groove 334 is formed by inserting a metal saw into the protruding portion 32B at a predetermined angle with respect to the Y axis and inserting the blade of the metal saw to a predetermined depth. Ru. Then, by repeating the same processing at equal pitches, a channel groove group 334G in which a plurality of mutually parallel channel grooves 334 are arranged is produced. Moreover, the flow path groove group 334G is angled so as to be in the direction along the flow of the cooling water at the boundary position between the first flat flow path 22a and the third flat flow path 22c. As a result, the pin fins 32 having a parallelogram shape in a plan view are two-dimensionally arranged on the lower surface of the main body top portion 30 in the protrusion-shaped portion 32B. The pin fins 32 form a channel group 33G in which a first channel 33a and a second channel 33b having a width of 200 μm or more and 600 μm or less and a depth of 3 mm or more and 5 mm or less are arranged in the width direction at a pitch of 1 mm or less. It is formed. However, here, the width of the channel groove 334 is made smaller than the width of the channel groove 333. That is, the channel groove 334 becomes a first channel 33a extending in the first direction of the internal water channel, and the channel groove 333 becomes a second channel 33b extending in the second direction of the internal channel.

In addition, although the case where the channel groove group 333G and the channel groove group 334G are produced by mechanical cutting using a metal saw has been described above, they may be produced by electrical discharge wire cutting. Furthermore, after processing the pin fins 32, anti-corrosion plating treatment such as nickel plating may be performed on the block material 30B. Through the above steps, the main body top portion 30 is manufactured.

FIG. 40 is a diagram illustrating an example of the relationship between the widths of the first flow path and the second flow path and the thermal resistance and flow velocity of cooling water according to the third embodiment. In this figure, the horizontal axis indicates the width of the second flow path 33b. The vertical axis on the left side shows the thermal resistance of the cooling water, and the vertical axis on the right side shows the maximum flow rate of the cooling water. Here, the width of the first flow path 33a along the flow is constant at 200 μm, and the width of the second flow path 33b facing the flow is set to 200 μm, 300 μm, and 400 μm. Find the flow velocity.

As shown in FIG. 40, the maximum flow velocity varies depending on the combination of the width of the first flow path 33a in the direction along the flow and the width of the second flow path 33b in the direction opposite to the flow. Furthermore, it can be seen that there is an optimum value for reducing the maximum flow velocity in the second flow path 33b. From FIG. 40, when the width of the first flow path 33a is 200 μm and the width of the second flow path 33b is 300 μm, the maximum flow velocity is about 3.4 m/s, and the measured width of the second flow path 33b is is the smallest among However, when the width of the second flow path 33b is 200 μm and 400 μm, the maximum flow velocity is around 4 m/s. In this way, the maximum flow velocity can be reduced when the width of the second flow path 33b is larger than the width of the first flow path 33a and smaller than twice the width of the first flow path 33a. Note that the thermal resistance value is approximately 0.16 K/W when the width of the second flow path 33b is 200 μm, 300 μm, or 400 μm.

The maximum flow velocity when the width of the second flow path 33b is within the above range is smaller than the maximum flow velocity estimated in the water channel of the microchannel structure in the radiator described in Patent Document 1. By reducing the maximum flow rate, the influence of erosion and corrosion due to circulation of cooling water is reduced.

According to the heat sink 1B according to the third embodiment, a channel having a shape in which pin fins 32 having a parallelogram shape in a plan view are arranged is formed in a pin fin arrangement region 32R that is equal to or larger than the size of a semiconductor laser element. . Further, the parallelogram-shaped pin fins 32 are arranged so that the passage area of the second passage 33b facing the flow is larger than the passage area of the first passage 33a along the flow. Thereby, the flow velocity of the cooling water in the pin fin arrangement region 32R can be reduced, and the flow velocity distribution in the first flow path 33a and the second flow path 33b is reduced. That is, the flow velocity within the pin fin arrangement region 32R is made uniform. As a result, heat exhaust performance can be improved. In particular, the maximum flow velocity can be reduced by making the width of the second flow path 33b larger than the width of the first flow path 33a and smaller than twice the width of the first flow path 33a. By reducing the maximum flow rate, the effects of erosion and corrosion due to cooling water circulation are reduced. As a result, the life of the heat sink 1B body is extended, the cooling performance is ensured, and the life of the semiconductor laser element can be extended.

The configurations shown in the embodiments described above are examples of the contents of the present invention, and can be combined with other known techniques, and the configurations can be modified without departing from the gist of the present invention. It is also possible to omit or change parts.

1, 1A, 1B heat sink, 10 main unit, 20 main unit bottom, 20A, 20B, 30A, 30B block material, 20a cooling water supply surface, 20b cooling water discharge surface, 22 flat flow path, 22a first flat flow path, 22b 2nd flat flow path, 22c 3rd flat flow path, 23a, 23b circular tube flow path, 30 main body top, 31 element mounting surface, 32 pin fin, 32A, 32B protrusion-shaped portion, 32R pin fin arrangement area, 33 flow path, 33G Channel group, 33a first channel, 33b second channel, 41a, 41b channel coupling member, 331, 332, 333, 334 channel groove, 331G, 332G, 333G, 334G channel groove group.

Claims (5)

In heat sinks that cool elements that generate heat during operation,
a main body portion provided with an internal waterway through which cooling water flows;
a plurality of pin fins protruding from a side surface forming the internal waterway;
Equipped with
A plane perpendicular to the extending direction such that a first channel extending in a first direction and a second channel extending in a second direction intersecting the first direction intersect at the internal water channel. the plurality of pin fins having a parallelogram shape are arranged within;
The aspect ratio, which is the ratio of the height to the width of the first flow path and the second flow path , is 5 or more,
The first channel and the second channel have a width of 200 μm or more and 600 μm or less, a depth of 3 mm or more and 5 mm or less, and are arranged in parallel in the width direction at a pitch of 1 mm or less,
the first flow path and the second flow path have the same width;
The first flow path and the second flow path intersect at an angle of 20 degrees or more and 100 degrees or less (excluding an angle of 30.2 degrees or more and 36.0 degrees or less),
The heat sink , wherein the plurality of pin fins have a rhombic shape . In heat sinks that cool elements that generate heat during operation,
a main body portion provided with an internal waterway through which cooling water flows;
a plurality of pin fins protruding from a side surface forming the internal waterway;
Equipped with
A first flow path extending in a first direction and a second flow path extending in a second direction intersecting the first direction intersect at the internal waterway in a plane perpendicular to the extending direction. the plurality of pin fins having a parallelogram shape are arranged within;
The aspect ratio, which is the ratio of the height to the width of the first flow path and the second flow path, is 5 or more,
The first channel and the second channel have a width of 200 μm or more and 600 μm or less, a depth of 3 mm or more and 5 mm or less, and are arranged in parallel in the width direction at a pitch of 1 mm or less ,
The heat sink , wherein the width of the second flow path is larger than the width of the first flow path and smaller than twice the width of the first flow path . The plurality of pin fins are arranged in a second region of a side surface forming the internal waterway corresponding to a first region of the main body portion where the element is mounted, and a second surface opposite to the first surface of the main body portion. It is arranged so that it protrudes towards the
The heat sink according to claim 1 or 2 , wherein the second region has a size larger than the size of the element. a first water channel joint member that supplies the cooling water to the internal water channel of the main body;
a second water channel joint member that discharges the cooling water that has passed through the internal water channel;
Furthermore,
The heat sink according to any one of claims 1 to 3 , wherein the first water channel coupling member and the second water channel coupling member are provided on the same side surface of the main body. a first water channel joint member that supplies the cooling water to the internal water channel of the main body;
a second water channel joint member that discharges the cooling water that has passed through the internal water channel;
Furthermore,
The heat sink according to any one of claims 1 to 3 , wherein the second water channel coupling member is provided on a side surface of the main body portion opposite to a side surface on which the first water channel coupling member is provided. .

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