JP2014209614A - Heat radiator for electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiator for an electronic component which deals with variations in mounting height and tolerance etc. occurred when components are packaged and improves heat transfer performance from the electronic component to a heat spreader.SOLUTION: In a heat radiator 1 for an electronic component, a CPU 3 installed on a substrate 2 is thermally connected with a heat sink 30 through a heat spreader 10. The heat spreader 10 includes multiple micro-fins 13 provided on an inner surface 11a facing the CPU 3. The micro-fins 13 are integrated with the heat spreader 10 and are formed so as to elastically deform while making a surface contact with the CPU 3.

Description

  The present invention relates to a heat dissipating device for an electronic component for radiating heat from an electronic component such as a central processing unit and cooling the electronic component.

  Electronic components such as a central processing unit (CPU) of a personal computer tend to increase year by year as their speed and performance increase. However, on the contrary, the semiconductor chip size has become the same size or smaller than the conventional size due to the advancement of fine silicon circuit technology, and the heat flux per unit area is high. Therefore, in order to avoid problems caused by the temperature rise, it is required to effectively dissipate and cool electronic components. Therefore, the electronic component is provided with a heat radiating device including a heat pipe, a heat spreader (IHS), and the like. Since there is a gap between the interface of the electronic component and the interface of the heat dissipation device, it is known that the electronic component can be further radiated and cooled by placing a high thermal conductivity member (TIM) and filling the gap. . A device provided with such a heat dissipation device is described in Patent Document 1.

  Briefly explaining the structure described in Patent Document 1, a metal foil having a cross-sectional wave shape having thermal conductivity is arranged between an electronic component that generates heat and a heat sink. This metal foil is a member having elasticity or a compressible member in a direction in which a load is applied. In the gap between the corrugated metal foil, the heat sink, and the electronic component, a high thermal conductivity member (TIM) is disposed.

US Patent Publication No. 2002/0015288

  By the way, in order to lower the thermal resistance of the metal foil described in Patent Document 1, it is necessary to reduce the height of the corrugation and increase the number of contact surfaces of the metal foil in contact with the heat sink and the electronic component. Conceivable. For that purpose, it is necessary to shorten the interval between adjacent contact surfaces of the metal foil (in other words, to reduce the pitch), but on the other hand, the processing to reduce the pitch of the adjacent contact surfaces of the metal foil is not possible. Fine processing is required, and the processing work is difficult. Furthermore, since the surface of the electronic component that generates heat has minute irregularities, there is a gap between the contact surface of the metal foil and the surface of the electronic component due to deviation or tolerance when the heat sink and the metal foil are assembled to the electronic component. As a result, there is a possibility that a gap is generated, resulting in an increase in thermal resistance, and there is room for improvement in this respect.

  The present invention has been made paying attention to the above technical problem, and can cope with variations in mounting height and tolerance when packaged, and improve the heat transfer performance from the electronic component to the heat spreader. An object of the present invention is to provide a heat dissipation device for electronic parts.

  To achieve the above object, according to the present invention, an electronic component installed on a substrate is thermally connected to a heat sink via a heat spreader, and heat generated in the electronic component is diffused by the heat spreader. In the heat dissipating device for an electronic component configured to dissipate heat of the heat spreader by the heat sink, the heat spreader is integrated with at least one of an inner surface facing the electronic component and an outer surface facing the heat sink. A plurality of micro fins, wherein the micro fins are integrated with the heat spreader and configured to be in surface contact with at least one of the electronic component and the heat sink. To do.

  This invention is the heat dissipating device for electronic parts according to the above invention, wherein the micro fins are formed by raising the surface portion of the heat spreader thinly.

  This invention is the heat dissipating device for electronic parts according to the above invention, wherein a gap between the adjacent micro fins is filled with a high thermal conductivity member.

  According to the present invention, in the above invention, the electronic component includes a first electronic component and a second electronic component having different mounting heights, and the micro fin is provided on the inner surface and is elastically deformed. And the second fin, the first fin is in surface contact with the first electronic component, the second fin is in surface contact with the second electronic component, and the height from the inner surface to the tip of the first fin is high. And the heat radiation apparatus for electronic components characterized by being comprised in the height from which the height from the said inner surface to the front-end | tip part of said 2nd fin differs.

  In the present invention, an electronic component installed on a substrate is thermally connected to a heat sink via a heat spreader, heat generated in the electronic component is diffused by the heat spreader, and heat of the heat spreader is radiated by the heat sink. In the heat dissipating device for an electronic component configured as described above, the heat spreader includes a plurality of metal wires disposed on the opposite side of the outer surface facing the heat sink and integrated with the inner surface facing the electronic component. The metal wire has both end portions joined to the inner surface, and an arch portion that is arranged away from the inner surface so as to connect the both end portions and is formed in an arch shape having a predetermined height from the inner surface. And the arch portion is configured to come into contact with the electronic component.

  According to the present invention, in the above invention, the electronic component includes a first electronic component and a second electronic component having different mounting heights, and the metal wire is provided on the inner surface and is elastically deformed. A wire and a second wire, wherein the first wire is in surface contact with the first electronic component, the second wire is in surface contact with the second electronic component, and the height of the arch portion in the first wire; The heat dissipating device for an electronic component is configured to have a height different from a height of the arch portion in the second wire.

  This invention is the heat dissipating device for electronic parts according to the above invention, wherein a gap between the metal wires is filled with a high thermal conductive member.

  In the present invention, an electronic component installed on a substrate is thermally connected to a heat sink via a heat spreader, heat generated in the electronic component is diffused by the heat spreader, and heat of the heat spreader is radiated by the heat sink. In the heat dissipating device for an electronic component configured as described above, the heat spreader includes a plurality of metal sheets disposed on a side opposite to the outer surface facing the heat sink and integrated with an inner surface facing the electronic component. The metal sheet has both end portions joined to the inner surface, and an arch portion that is disposed away from the inner surface so as to connect the both end portions and is formed in an arch shape having a predetermined height from the inner surface. The arch portion is configured to be elastically deformed by contact with the electronic component. .

  According to the present invention, in the above invention, the electronic component includes a first electronic component and a second electronic component having different mounting heights, and the metal sheet is provided on the inner surface and is elastically deformed. A sheet and a second sheet, wherein the first sheet is in surface contact with the first electronic component, the second sheet is in surface contact with the second electronic component, and the height of the arch portion in the first sheet A heat dissipating device for electronic parts, wherein the second sheet is configured to have a height different from the height of the arch portion.

  This invention is the heat dissipating device for electronic parts according to the above invention, wherein a gap between the metal sheets adjacent to each other is filled with a high thermal conductivity member.

  According to the present invention, since the micro fin is integrated with the heat spreader, no interfacial thermal resistance is generated between the micro fin and the heat spreader, and the heat transfer performance can be improved. In addition, since the microfin is configured to be elastically deformable, it is possible to cope with variations in mounting height and tolerance when the semiconductor package is formed. Therefore, it is possible to reduce the increase in thermal resistance, and it becomes easy to manufacture the electronic component heat dissipation device. Furthermore, since the microfin is elastically deformed while being in surface contact with the target member, the heat transfer efficiency is improved.

  According to the present invention, in addition to the effects of the above-described invention, since the micro fins that are erected by thinly cutting the heat spreader surface are formed, it is easy to narrow the gap between adjacent micro fins. Therefore, the number of microfins can be increased even with the same surface area. Therefore, the number of contact surfaces of the microfin can be increased and the contact area with the target member can be increased, so that the heat transfer efficiency can be improved. In addition, since the microfin can be easily manufactured, it is easy to manufacture the electronic component heat dissipation device.

  According to this invention, in addition to the effects of the above invention, the heat transfer performance can be improved because the high thermal conductivity member is filled so as to fill the gap between the microfins.

  According to this invention, in addition to the effects of the above invention, when electronic components such as a multichip module are packaged, it is possible to efficiently dissipate heat for the first and second electronic components having different mounting heights. it can. Even when the gap between the first electronic component and the heat spreader and the gap between the second electronic component and the heat spreader fluctuate, the first fin and the second fin are elastically deformed in response to the gap fluctuation. . For this reason, the contact state between the electronic component and the microfin is always maintained. That is, since the microfin can be elastically deformed so as to maintain the contact area, the heat transfer efficiency can be improved. Furthermore, the height of the first fin and the height of the second fin can be appropriately set so as to correspond to the mounting height of each electronic component. Thereby, not only the contact state between each fin and each electronic component is maintained, but also the elastic deformation occurs so that an excessive load is not applied from each fin to each electronic component. Therefore, the durability of the semiconductor package can be improved.

  According to this invention, since the metal wire is integrated with the heat spreader, the interface heat resistance does not occur between the metal and the heat spreader, and the heat transfer performance can be improved. In addition, since the metal wire is configured to be elastically deformable, it is possible to cope with variations in mounting height and tolerance when forming a semiconductor package. For this reason, it is possible to reduce the increase in the thermal resistance due to the decrease in the contact area, and it becomes easy to manufacture the electronic component heat dissipation device. Further, since the arch portion of the metal wire is elastically deformed so as to change the wire height while being in contact with the target member, the heat transfer efficiency is improved. In addition, the elastic body can be formed without the metal wire damaging the heat spreader.

  According to this invention, in addition to the effects of the above invention, when electronic components such as a multichip module are packaged, it is possible to efficiently dissipate heat for the first and second electronic components having different mounting heights. it can. Even when the gap between the first electronic component and the heat spreader and the gap between the second electronic component and the heat spreader fluctuate, the arch portion of the first wire and the second wire elastically deforms in response to the gap variation, so that the electronic The contact state between the component and the metal wire is maintained. That is, since the metal wire can be elastically deformed so as to maintain the contact area, the heat transfer efficiency can be improved. Furthermore, the height of the first wire and the height of the second wire can be appropriately set so as to correspond to the mounting height of each electronic component. Thereby, not only the contact state between each wire and each electronic component is maintained, but also elastic deformation is performed so that an excessive load is not applied from each wire to each electronic component. Therefore, the durability of the semiconductor package can be improved.

  According to this invention, in addition to the effects of the above invention, the heat transfer performance can be improved because the high thermal conductivity member is filled so as to fill the gap between the metal wires.

  According to this invention, since the metal sheet is integrated with the heat spreader, interfacial thermal resistance does not occur between the metal sheet and the heat spreader, and the heat transfer performance can be improved. Further, since the metal sheet is configured to be elastically deformable, it is possible to cope with variations in mounting height, tolerance, and the like when the semiconductor package is formed, particularly by elastic deformation of the arch portion. Therefore, it is possible to reduce the increase in thermal resistance, and it becomes easy to manufacture the electronic component heat dissipation device. Furthermore, since the arch portion of the metal sheet is elastically deformed while being in contact with the target member, the heat transfer efficiency is improved. In addition, according to the metal sheet, a sufficient contact area with the electronic component can be secured, so that the heat transfer performance can be improved.

  According to the present invention, in addition to the above effects, when electronic components such as a multichip module are packaged, it is possible to efficiently dissipate heat for the first and second electronic components having different mounting heights. . Even when the gap between the first electronic component and the heat spreader and the gap between the second electronic component and the heat spreader fluctuate, the arch portions of the first sheet and the second sheet are elastically deformed in response to the gap fluctuation, so that the electronic The contact state between the component and the metal sheet is maintained. That is, since the metal sheet can be elastically deformed so as to maintain the contact area, the heat transfer efficiency can be improved. Furthermore, the height of the first sheet and the height of the second sheet can be appropriately set so as to correspond to the mounting height of each electronic component. Thereby, not only the contact state between each sheet and each electronic component is maintained, but also elastic deformation is performed so that an excessive load does not act on each electronic component from each sheet. Therefore, the durability of the semiconductor package can be improved.

  According to this invention, in addition to the effects of the above invention, the heat transfer performance can be improved because the high thermal conductivity member is filled so as to fill the gap between the metal sheets.

It is sectional drawing which showed typically the thermal radiation apparatus for electronic components of a 1st Example. (A) is explanatory drawing which showed the area | region A shown in FIG. 1, (b) is explanatory drawing for demonstrating the process in which a microfin is shape | molded. It is sectional drawing which showed typically the thermal radiation apparatus for electronic components of 2nd Example. It is sectional drawing which showed typically the heat radiator for electronic components of 3rd Example. It is sectional drawing which showed typically the heat radiator for electronic components of 4th Example. (A) is explanatory drawing which showed the case where the 1st fin and the 2nd fin were formed in the same height, (b) showed the case where the 1st fin was formed lower than the 2nd fin. It is explanatory drawing. It is sectional drawing which showed typically the modification of 4th Example. It is sectional drawing which showed typically the heat radiator for electronic components of 5th Example. (A) is explanatory drawing for demonstrating the metal wire (metal sheet) integrated with the heat spreader, (b) is the metal wire (metal sheet) which is elastically deforming shown in FIG. It is explanatory drawing for demonstrating. It is explanatory drawing which showed the example of an arrangement | sequence of metal wires. (A) is explanatory drawing which showed the case where the 1st wire (1st sheet) and the 2nd wire (2nd sheet) were formed in the same height, (b) is the 1st wire (1st sheet) ) Is an explanatory view showing a case in which it is formed lower than the second wire (second sheet).

  Hereinafter, the present invention will be described based on specific examples.

  First, a heat radiating device for electronic parts in a first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the electronic component heat dissipation device 1 of the first embodiment includes a central processing unit (hereinafter referred to as “CPU”) 3, which is an electronic component provided on a substrate 2, and a heat spreader 10 and high thermal conductivity. A configuration is provided in which a member (hereinafter referred to as “TIM”) 20 is thermally connected to a heat sink 30 that is a heat radiating portion. The electronic component heat dissipation device 1 includes a heat spreader 10, a TIM 20, and a heat sink 30. The heat generated by the CPU 3 is diffused by the heat spreader 10 and radiated by the heat sink 30.

  The CPU 3 has a structure similar to that conventionally known, and is a rectangular member having a thickness of several millimeters in which a circuit is formed on a silicon chip. That is, the CPU 3 is a semiconductor chip. As shown in FIG. 1, the CPU 3 is disposed on the substrate 2 by being electrically connected to the substrate 2, which is a package substrate, by bumps 4. The substrate 2 is connected to a mother board (not shown). That is, the electronic component heat dissipation device 1 can be used for a semiconductor package. Note that the electronic component targeted by the present invention may be an electronic component that generates heat during operation of an integrated circuit, memory, CPU, or the like.

  The heat spreader 10 is a heat diffusion plate for diffusing the heat generated by the CPU 3 and is thermally connected to the CPU 3. For example, the heat spreader 10 is formed of a material having high thermal conductivity such as copper or aluminum. The heat spreader 10 is formed in a known shape such as a bowl shape as a whole, and is configured to come into contact with the CPU 3. As shown in FIG. 1, the heat spreader 10 includes a square plate-like flat plate portion 11 serving as a heat diffusion plate, a cylindrical body portion 12 bent from the periphery of the flat plate portion 11 and extending toward the substrate 2, and a CPU 3. And a plurality of micro fins 13 for receiving the heat of the CPU 3 in contact with each other. The micro fins 13 are provided on the inner surface 11a of the flat plate portion 11, and are arranged inside the heat spreader 10 in a packaged state. The detailed configuration of the internal structure of the heat spreader 10 will be described later.

  Further, outside the heat spreader 10, the heat spreader 10 is thermally connected to the heat sink 30 via the TIM 20. The TIM 20 is a heat transfer member for transferring the heat transferred from the CPU 3 to the heat spreader 10 to the heat sink 30. The TIM 20 includes an organic material, an inorganic material, or a combination of an organic material and an inorganic material. For example, the TIM 20 is composed of thermal grease or a heat conductive sheet having a high heat transfer coefficient. As shown in FIG. 1, the TIM 20 is provided between the outer surface 11 b of the flat plate portion 11 and the heat sink 30 in the heat spreader 10. When the TIM 20 is a thermally conductive sheet having adhesiveness, the heat sink 30 is attached to the heat spreader 10 by the TIM 20. The heat spreader 10 and the heat sink 30 may be joined to each other by soldering, brazing, or an adhesive.

  The heat sink 30 is a heat radiating member for radiating heat transmitted from the CPU 3 via the heat spreader 10 and the TIM 20. For example, the heat sink 30 is formed of a material having high thermal conductivity such as copper or aluminum. As shown in FIG. 1, the heat sink 30 includes a plate-like base plate 31 disposed so as to face the flat plate portion 11 of the heat spreader 10, and a plurality of radiating fins 32 formed so as to protrude from the base plate 31. It has. The inner surface 31 a of the base plate 31 faces the outer surface 11 b of the flat plate portion 11. The TIM 20 is sandwiched between the inner surface 31a and the outer surface 11b. Further, the heat radiating fins 32 are integrated with the base plate 31 and protrude from the outer surface 31 b of the base plate 31. That is, the electronic component heat dissipation device 1 transmits the heat of the CPU 3 to the inner surface 31a side of the base plate 31 via the heat spreader 10 and the TIM 20, and conducts heat from the outer surface 31b side of the base plate 31 to the heat radiating fins 32. It is configured.

  Here, the internal structure of the heat spreader 10 in the electronic component heat dissipation device 1 will be described. As shown in FIG. 1, the heat spreader 10 is disposed so as to straddle the CPU 3 and attached to the substrate 2. The flat plate portion 11 of the heat spreader 10 is disposed above the CPU 3, and the inner surface 11 a of the flat plate portion 11 faces the surface 3 a of the CPU 3. The area of the inner surface 11a of the flat plate part 11 is set wider than the area of the surface 3a of the CPU 3. Further, the body 12 of the heat spreader 10 has an end on the substrate 2 side fixed to the surface 2 a of the substrate 2.

  The height of the body 12 is set to be approximately equal to the height of the CPU 3. That is, the height H (hereinafter referred to as “inner surface height”) H from the surface 2 a of the substrate 2 to the inner surface 11 a of the flat plate portion 11 is set to be substantially equal to the height h of the CPU 3. The height h of the CPU 3 is a mounting height of the CPU 3 and is a height from the surface 2 a of the substrate 2 to the surface 3 a of the CPU 3. In the first embodiment, the inner surface height H is set slightly higher than the height h1 of the CPU 3. That is, a gap (hereinafter referred to as “gap”) G is formed between the inner surface 11 a of the flat plate portion 11 and the surface 3 a of the CPU 3. Therefore, inside the heat spreader 10, the micro fins 13 are arranged so as to fill the gap G.

  The micro fin 13 is configured to be elastically deformable and integrated with the heat spreader 10. As shown in FIG. 2A, the microfin 13 includes a tip portion 13 a that is in surface contact with the surface 3 a of the CPU 3, a root portion 13 c that is a connection portion between the inner surface 11 a of the flat plate portion 11, and the tip portion 13 a and the root. An upright portion 13b that conducts heat with the portion 13c is provided. That is, the micro fin 13 is formed so that a part of the heat spreader 10 protrudes from the inner surface 11 a side of the flat plate portion 11.

  The upright portion 13 b is disposed to be inclined with respect to the inner surface 11 a of the flat plate portion 11 and is not in contact with the CPU 3. The micro fin 13 shown in FIG. 2A is in an elastically deformed state, and is elastically deformed so that the boundary between the rising portion 13b and the tip portion 13a is bent. By such elastic deformation, the tip portion 13a is in surface contact along the shape of the surface 3a of the CPU 3. The shape of the surface 3a of the CPU 3 is formed in a minute convex shape of μm such that the center rises toward the flat plate portion 11 side. The cross-sectional shape of the surface 3a shown in FIG.

  Further, as shown in FIG. 2B, the microfin 13 is formed by thinly raising the surface of the inner surface 11 a of the flat plate portion 11 with the blade portion 50 a of the cutting tool 50, and the root portion 13 c is formed with the flat plate portion 11. A plurality of upright portions 13b are formed so as to be inclined with respect to the inner surface 11a in an integrated state. The microfins 13 have a thickness of several tens of μm and a height of about several hundreds of μm, and the gap between adjacent microfins 13 can be set to several tens of μm. For example, in order to further improve the heat transfer rate from the CPU 3 to the heat spreader 10, a gap between adjacent micro fins 13 may be filled with TIM such as thermal grease having a high heat transfer rate.

  As shown in FIG. 1, when the heat spreader 10 is assembled to the substrate 2 and packaged, the tips 13a of the micro fins 13 come into contact with the CPU 3, and the distance between the inner surface 11a of the flat plate portion 11 and the surface 3a of the CPU 3 is narrowed. It is elastically deformed by receiving a load in the direction. As an example of the elastic deformation, the tip portion 13a side of the upright portion 13b is bent by the load described above. That is, the tip portion 13 a is elastically deformed so as to follow the surface shape of the CPU 3. In short, a large contact area between the tip portion 13a and the CPU 3 can be secured by the elastic deformation of the micro fin 13.

  As another elastic deformation example, the above-described load causes elastic deformation with the base portion 13c as a fulcrum, and the upright portion 13b is inclined so as to reduce the inclination angle with respect to the inner surface 11a of the flat plate portion 11. Alternatively, the upright portion 13b is elastically deformed so as to bend. For example, when the gap G described above changes due to deviation or tolerance when the heat spreader 10 is assembled to the substrate 2, the microfin 13 is elastically deformed so that the inclination angle of the upright portion 13 b becomes small, or the upright portion It can be elastically deformed so that 13b bends. That is, the micro fin 13 is elastically deformed so as to absorb the fluctuation of the gap G while maintaining the contact area between the tip portion 13a and the CPU 3.

  Furthermore, the space | interval between adjacent microfin 13 can be easily shortened by shaving the surface of the inner surface 11a of the flat plate part 11 thinly. Furthermore, since the micro fins 13 are integrally formed with the heat spreader 10, a process of attaching a separate micro fin to the heat spreader 10 is not necessary.

  Further, the micro fin 13 is formed integrally with the heat spreader 10, and there is no interfacial thermal resistance with the heat spreader 10. Therefore, thermal conductivity can be improved as compared with thermal grease having high thermal conductivity, a metal foil having a cross-sectional wave shape having thermal conductivity, and the like.

  As described above, according to the heat dissipating device for electronic parts of the first embodiment, it can be easily manufactured and the thermal resistance generated between the electronic parts and the heat spreader can be reduced. Even when the gap between the electronic component and the heat spreader fluctuates, the microfin is elastically deformed in response to the gap variation, so that the contact state between the electronic component and the microfin is maintained. Furthermore, since the microfin can be elastically deformed so as to maintain the contact area, the heat transfer efficiency can be improved.

  Next, with reference to FIG. 3, the heat radiating device for electronic parts of the second embodiment will be described. In the second embodiment, unlike the first embodiment described above, the micro fins are provided on the outer surface side of the heat spreader. In the description of the second embodiment, the description of the same configuration as that of the first embodiment described above is omitted, and the reference numerals thereof are cited.

  As shown in FIG. 3, in the electronic device heat dissipation device 200 of the second embodiment, the CPU 3 is thermally connected to the heat spreader 10 via a high thermal conductivity member (hereinafter referred to as “TIM”) 40. The TIM 40 is a heat transfer member for transferring heat from the CPU 3 to the heat spreader 10. As the TIM 40, there are a TIM 40 made of an organic material, an inorganic material, or a combination of an organic material and an inorganic material. For example, the TIM 40 is composed of thermal grease or a heat conductive sheet having a high heat transfer coefficient.

  Specifically, in the heat dissipating device 200 for electronic components, the TIM 40 is disposed between the surface 3 a of the CPU 3 and the inner surface 11 a of the flat plate portion 11 in the heat spreader 10. The inner surface 11a is a flat surface. That is, unlike the first embodiment described above, in the second embodiment, no micro fin is provided on the inner surface 11a.

  Furthermore, in the heat spreader 10 of the second embodiment, a plurality of micro fins 14 are provided on the outer surface 11 b of the flat plate portion 11. The microfin 14 may be formed by the same molding method as the microfin 13 of the first embodiment described above. That is, the micro fins 14 are formed such that the surface of the outer surface 11b of the flat plate portion 11 is thinly shaved and tilted with respect to the outer surface 11b. As shown in FIG. 3, the elastically deformable micro fin 14 is integrated with the heat spreader 10, and the end of the micro fin 14 is in surface contact with the base plate 31 of the heat sink 30. In other words, in the second embodiment, the arrangement of the micro fins and the TIM is replaced with the configuration of the first embodiment described above.

  As shown in FIG. 3, when the heat sink 30 is attached to the heat spreader 10 and packaged, the end portions of the micro fins 14 come into contact with the base plate 31, and the inner surface 11 a of the flat plate portion 11 and the inner surface 31 a of the base plate 31. The micro fin 14 is elastically deformed by receiving a load in a direction in which the interval is narrowed. As an example of elastic deformation of the microfin 14, it can be elastically deformed similarly to the microfin 13 of the first embodiment described above. In short, a large contact area between the micro fin 14 and the heat sink 30 can be secured by elastic deformation of the micro fin 14. In order to further improve thermal conductivity, a gap between adjacent micro fins 14 is filled with a TIM such as thermal grease having high thermal conductivity that transfers heat generated by the electronic component to the heat sink 30. Also good.

  As explained above, according to the electronic component heat dissipation device of the second embodiment, it can be easily manufactured, and the thermal resistance generated between the heat spreader and the heat sink can be reduced. Even when the gap between the heat spreader and the heat sink varies, the micro fins are elastically deformed in response to the variation, so that the contact state between the heat spreader and the heat sink is maintained. Furthermore, since the microfin can be elastically deformed so as to maintain the contact area, the heat transfer efficiency can be improved.

  In addition, although the 2nd Example mentioned above demonstrated the example in which the micro fin heat-transmitted between a heat spreader and a heat sink was provided in the heat spreader, the micro fin may be provided in the base plate of a heat sink. In short, it is only necessary that a plurality of micro fins are formed integrally with any one member of the interface part of the heat dissipating device for electronic parts to which the heat generated by the electronic parts is transmitted.

  Next, with reference to FIG. 4, the heat radiating device for electronic parts of the third embodiment will be described. In the third embodiment, the arrangement of the micro fins is different from the first embodiment and the second embodiment described above, and the micro fins are provided on both surfaces of the flat plate portion of the heat spreader. In the description of the third embodiment, the description of the same configuration as that of the first embodiment or the second embodiment described above is omitted, and the reference numerals thereof are cited.

  As shown in FIG. 4, the electronic component heat dissipation device 300 of the third embodiment is configured such that the CPU 3 is thermally connected to the heat sink 30 via the heat spreader 10. Specifically, the heat spreader 10 includes micro fins 13 provided on the inner surface 11 a of the flat plate portion 11 and micro fins 14 provided on the outer surface 11 b of the flat plate portion 11. That is, the electronic component heat dissipation device 300 includes the micro fins 13 disposed inside the heat spreader 10 and the micro fins 14 disposed outside the heat spreader 10.

  In the electronic component heat dissipation device 300, when the heat of the CPU 3 is radiated by the heat sink 30, the heat of the CPU 3 is transferred to the heat spreader 10 via the micro fins 13, and the heat of the heat spreader 10 is transferred to the heat sink 30 via the micro fins 14. Heat transfer. For example, in order to further improve the heat transfer rate from the CPU 3 to the heat sink 30, each micro fin 13 and 14 may be filled with a TIM such as thermal grease having a high heat transfer rate in the gap between adjacent micro fins. Further, the example in which the micro spreader for transferring heat between the heat spreader 10 and the heat sink 30 is provided in the heat spreader 10 has been described. However, the micro fin is provided on the base plate 31 of the heat sink 30 as in the second embodiment described above. It may be provided.

  As described above, according to the electronic component heat dissipation device of the third embodiment, the effects of the first embodiment and the second embodiment described above can be combined.

  Next, the electronic component heat dissipation device of the fourth embodiment will be described. The fourth embodiment is a modification of the first embodiment and the third embodiment described above, and is configured to be able to target a multichip module (MCM) in which a plurality of electronic components are provided on a substrate. This is a heat radiating device for electronic parts. For example, when a plurality of electronic components is a combination of a CPU and a semiconductor memory, the thickness of the CPU may be different from the thickness of the semiconductor memory. In the heat dissipating device for electronic parts of the fourth embodiment, the heat of each electronic part can be dissipated by one heat spreader when a plurality of electronic parts having different heights are mounted. In the description of the fourth embodiment, the description of the same configuration as the first embodiment or the third embodiment described above will be omitted, and the reference numerals thereof will be cited.

  As shown in FIG. 5, a CPU 3 and an electronic component 5 are provided at different positions on the substrate 2 of the fourth embodiment. The electronic component 5 includes a CPU, a semiconductor memory, and the like, and is formed in a chip shape like the CPU 3. Further, the CPU 3 is formed thicker than the electronic component 5. That is, in a state where the CPU 3 and the electronic component 5 are attached to the substrate 2, the height h <b> 1 of the CPU 3 is higher than the height h <b> 2 of the electronic component 5. The height h2 of the electronic component 5 is the mounting height of the electronic component 5, and is the distance from the surface 2a of the substrate 2 to the electronic component 5a. The height h1 of the CPU 3 and the height h2 of the electronic component 5 include the heights of bumps (not shown in FIG. 5) that electrically connect the CPU 3 and the electronic component 5 to the substrate 2.

  In the electronic component heat dissipation device 400 of the fourth embodiment, the CPU 3 and the electronic component 5 provided on the substrate 2 are configured to be thermally connected to the flat plate portion 11 of the heat spreader 10 through the micro fins 13. Yes. That is, the plurality of electronic components include at least the CPU 3 and the electronic component 5. For convenience of explanation, a case where two electronic components including the CPU 3 and the electronic component 5 are provided will be described, but the number of electronic components is not limited to two and may be three or more. The combination of the plurality of electronic components may be a combination including at least one CPU.

  Specifically, the heat spreader 10 is disposed so as to straddle the CPU 3 and the electronic component 5. The flat plate portion 11 is disposed on the CPU 3 and the electronic component 5, and the inner surface 11 a of the flat plate portion 11 faces the surface 3 a of the CPU 3 and the surface 5 a of the electronic component 5. Further, the micro fin 13 is in contact with the CPU 3 and the electronic component 5.

  The micro fin 13 includes a plurality of first fins 131 that contact the CPU 3 and a plurality of second fins 132 that contact the electronic component 5. The height of the 1st fin 131 can be set to the height which can contact the surface 3a of CPU3. Further, the height of the second fin 132 can be set to a height at which the second fin 132 can contact the electronic component 5. The height of the fin is the distance from the inner surface 11a of the flat plate portion 11 to the tip of the micro fin 13 in the vertical direction shown in FIG. The tip of the microfin 13 is the portion farthest from the inner surface 11a.

  For example, as shown in FIG. 6A, in the electronic component heat dissipation device 400, the first fin 131 and the second fin 132 are set to the same height L, and the micro fins 13 have a uniform height as a whole. It can be comprised so that it may become. In this case, since the height h1 of the CPU 3 is higher than the height h2 of the electronic component 5, the first fin 131 is more elastically deformed than the second fin 132 when packaged.

  Alternatively, as illustrated in FIG. 6B, the electronic component heat dissipation device 400 can be configured such that the height L <b> 1 of the first fin 131 is lower than the height L <b> 2 of the second fin 132. In this case, when packaged, the amount of elastic deformation of the first fin 131 and the amount of elastic deformation of the second fin 132 can be brought close to each other, and the microfin 13 can be uniformly elastically deformed as a whole.

  Further, in the electronic component heat dissipation device 400, it is only necessary that the heat spreader 10 and the heat sink 30 are thermally connected, and the configuration of the connection portion is not particularly limited. For example, as shown in FIG. 5, a TIM 20 is provided between the outer surface 11 b of the heat spreader 10 and the inner surface 31 a of the heat sink 30. Alternatively, as shown in FIG. 7, a configuration in which micro fins 14 are provided on the outer surface 11 b of the heat spreader 10 is provided.

  The electronic component 5 is a second CPU having the same configuration as the CPU 3, and the configuration of the electronic component heat dissipation device 400 can be applied even when the thickness of the CPU 3 matches the thickness of the electronic component 5. .

  As explained above, according to the heat dissipating device for electronic parts of the fourth embodiment, when the target is a multichip module, heat generated by a plurality of electronic parts having different mounting heights can be efficiently dissipated. Even when the gap between the electronic component and the heat spreader fluctuates, the microfin is elastically deformed in response to the gap variation, so that the contact state between the electronic component and the microfin is maintained. Furthermore, since the microfin can be elastically deformed so as to maintain the contact area, the heat transfer efficiency can be improved.

  Next, a heat radiating device for electronic parts according to a fifth embodiment will be described. The fifth embodiment is a modification of the above-described fourth embodiment, and includes a configuration in which an elastically deformable metal wire or metal sheet is provided instead of the micro fins 13 disposed inside the heat spreader 10. ing. In the description of the fifth embodiment, the description of the same configuration as that of the above-described fourth embodiment is omitted, and the reference numerals thereof are cited.

  Here, with reference to FIG. 8, a heat radiating device for electronic parts provided with a metal wire will be described as a fifth embodiment. As shown in FIG. 8, the electronic component heat dissipation device 500 of the fifth embodiment is such that the CPU 3 and the electronic component 5 are thermally connected to the flat plate portion 11 of the heat spreader 10 via a plurality of metal wires 15. It is configured.

  The metal wire 15 is a linear heat conductive member formed of a material having high heat conductivity such as gold, copper, or aluminum. For example, when the heat spreader 10 is made of copper, the metal wire 15 is also made of copper. Moreover, each metal wire 15 adjacent in the width direction and the depth direction is configured to be elastically deformed independently.

  For example, the metal wire 15 has an outer diameter of 10-50 μm. Desirably, the metal wire 15 having an outer diameter of 20 μm, a wire height of 300 μm, a pitch of 90 μm, and a wire length of about 700 μm is included.

  As shown in FIG. 9A, the metal wire 15 is formed in an arch shape so that both end portions 151 are joined to the inner surface 11a of the heat spreader 10 by bonding or welding. The arch portion 152 is formed. The inner surface 11a of the flat plate portion 11 is a flat surface and may be subjected to a surface treatment for bonding such as gold plating. The arch portion 152 is entirely disposed away from the inner surface 11a, and is formed in an arch shape so that the wire height L3 becomes a predetermined value. Furthermore, the width direction interval of the both ends 151 in one metal wire 15 is set narrower than the width of the CPU 3 and the width of the electronic component 5. That is, the plurality of metal wires 15 are configured to contact the CPU 3 and the electronic component 5 in the width direction. The wire height L3 indicates that the metal wire 15 is not in contact with the CPU 3 or the electronic component 5, and is set larger than the gap G described above.

  For example, the electronic component heat dissipation device 500 has a configuration in which the metal wires 15 are regularly arranged at a predetermined pitch as shown in FIG. In the arrangement example shown in FIG. 10, one end portion 151a is arranged at a position different from the other end portion 151b in the depth direction, and the arch portion 152 is inclined with respect to the width direction. That is, when the case where the arch part 152 is arranged in parallel to the width direction and the case where the arch part 152 is inclined with respect to the width direction are compared, the distance between the both ends 151 is the same in the width direction, and the wire height L3. Are the same, the latter can increase the length of the metal wire 15 per wire. In short, by arranging the metal wire 15 as shown in FIG. 10, it is possible to secure many contact portions with the CPU 3 or the electronic component 5 for each metal wire 15. In order to further improve the heat transfer rate from the CPU 3 and the electronic component 5 to the heat spreader 10, a TIM such as thermal grease having a high heat transfer rate is provided so as to fill the gap G in the region where the metal wire 15 is provided. It may be a filled configuration. That is, the TIM is filled so as to fill the gap between the metal wires 15 adjacent in the width direction and the depth direction and the gap between the arch portion 152 of the metal wire 15 and the inner surface 11a of the flat plate portion 11. .

  FIG. 9B shows a state in which the metal wire 15 is elastically deformed in contact with the CPU 3 or the electronic component 5 when the semiconductor package is formed from the state shown in FIG. 9A. . That is, FIG. 9B is an explanatory view for explaining the elastically deformed metal wire 15 shown in FIG. When the heat spreader 10 is assembled to the substrate 2 and packaged, each metal wire 15 receives a load in a direction in which the arch portion 152 comes into contact with the CPU 3 (electronic component 5) and the gap G is narrowed. Is elastically deformed so as to be low. The wire height Lp of the metal wire 15 that is elastically deformed as shown in FIG. 9B is lower than the wire height L3 and becomes the height of the gap G. In this way, the metal wire 15 is elastically deformed so that the wire height changes, so that the arch portion 152 is elastically deformed so as to follow the shape of the surface 3a (surface 5a) of the CPU 3 (electronic component 5). To do.

  Further, as shown in FIG. 8, the metal wire 15 includes a plurality of first wires 15 </ b> A that contact the CPU 3 and a plurality of second wires 15 </ b> B that contact the electronic component 5. The height of the first wire 15A is set to a height at which the first wire 15A can contact the surface 3a of the CPU 3. Further, the height of the second wire 15B is set to a height at which the second wire 15B can contact the electronic component 5.

  For example, as shown in FIG. 11 (a), in the electronic component heat dissipation device 500, the first wire 15A is set to the same height L3 as the second wire 15B, and the metal wire 15 has an overall uniform height. It can be comprised so that it may become. In this case, since the height h1 of the CPU 3 is higher than the height h2 of the electronic component 5, the first wire 15A is more elastically deformed than the second wire 15B when packaged.

  Alternatively, as shown in FIG. 11B, the electronic component heat dissipation device 500 can be configured such that the height L4 of the first wire 15A is lower than the height L5 of the second wire 15B. In this case, when packaged, the amount of elastic deformation of the first wire 15A and the amount of elastic deformation of the second wire 15B can be brought close to each other, and the metal wire 15 can be uniformly elastically deformed as a whole. .

  In addition, in the case of the heat radiating device for electronic parts provided with the metal sheet as the fifth embodiment, the metal wire described above is replaced with the metal sheet. Further, the first wire is read as the first sheet, the second wire as the second sheet, and the wire height as the sheet height. For example, the metal sheet is composed of a sheet material such as a heat conductive sheet or a metal tape. For example, as the metal sheet, a thermally conductive tape material having a thickness of about 10-50 μm and a width of about 200 μm-1 mm can be used.

  Also, in order to further improve the heat transfer rate from the CPU 3 and the electronic component 5 to the heat spreader 10, a TIM such as thermal grease having a high heat transfer rate is filled so as to fill the gap G in the region where the metal sheet is provided. It may be a configured. That is, the TIM is filled so as to fill the gap between the metal sheets adjacent in the width direction and the gap between the arch portion of the metal sheet and the inner surface 11a of the flat plate portion 11.

  As described above, according to the heat dissipating device for electronic parts of the fifth embodiment, when the multichip module is a target, heat generated by a plurality of electronic parts having different mounting heights can be efficiently dissipated. . Even when the gap between the electronic component and the heat spreader fluctuates, the metal wire (metal sheet) is elastically deformed in response to the gap variation, so that the contact state between the electronic component and the metal wire (metal sheet) is Kept. Furthermore, since the metal wire (metal sheet) can be elastically deformed so as to maintain a contact state with the electronic component in the packaged state, the heat transfer efficiency can be improved.

  DESCRIPTION OF SYMBOLS 1 ... Heat dissipation device for electronic components, 2 ... Board | substrate, 3 ... Central processing unit (CPU), 5 ... Electronic components, 10 ... Heat spreader, 11 ... Flat plate part, 11a ... Inner surface, 11b ... Outer surface, 13, 14 ... Microfin 15 ... Metal wire (metal sheet), 20 ... High thermal conductivity member (TIM), 30 ... Heat sink.

Claims (10)

An electronic component installed on a substrate is thermally connected to a heat sink via a heat spreader, and heat generated by the electronic component is diffused by the heat spreader, and heat of the heat spreader is dissipated by the heat sink. In the heat dissipation device for electronic parts,
The heat spreader includes a plurality of micro fins integrated with at least one of an inner surface facing the electronic component and an outer surface facing the heat sink,
The heat dissipating device for an electronic component, wherein the micro fin is integrated with the heat spreader and is in surface contact with at least one of the electronic component and the heat sink.   The heat dissipating device for electronic parts according to claim 1, wherein the micro fin is formed by thinly cutting a surface portion of the heat spreader and standing up.   The heat dissipation device for an electronic component according to claim 1 or 2, wherein a gap between the adjacent micro fins is filled with a high thermal conductivity member. The electronic component includes a first electronic component and a second electronic component having different mounting heights,
The micro fin includes a first fin and a second fin that are provided on the inner surface and elastically deform,
The first fin is in surface contact with the first electronic component;
A second fin is in surface contact with the second electronic component;
The height from the inner surface to the tip of the first fin and the height from the inner surface to the tip of the second fin are different from each other. A heat dissipating device for electronic parts according to claim 1. An electronic component installed on a substrate is thermally connected to a heat sink via a heat spreader, and heat generated by the electronic component is diffused by the heat spreader, and heat of the heat spreader is dissipated by the heat sink. In the heat dissipation device for electronic parts,
The heat spreader includes a plurality of metal wires disposed on the side opposite to the outer surface facing the heat sink and integrated on the inner surface facing the electronic component,
The metal wire includes both end portions joined to the inner surface, and an arch portion that is disposed away from the inner surface so as to connect the both end portions and is formed in an arch shape having a predetermined height from the inner surface. ,
The said arch part is comprised so that the said electronic component may be contacted, The heat radiating device for electronic components characterized by the above-mentioned. The electronic component includes a first electronic component and a second electronic component having different mounting heights,
The metal wire includes a first wire and a second wire that are provided on the inner surface and elastically deform,
A first wire is in surface contact with the first electronic component;
A second wire is in surface contact with the second electronic component;
6. The heat dissipating device for an electronic component according to claim 5, wherein a height of the arch portion in the first wire is different from a height of the arch portion in the second wire.   The heat dissipating device for electronic parts according to claim 5 or 6, wherein a gap between the metal wires is filled with a high thermal conductivity member. An electronic component installed on a substrate is thermally connected to a heat sink via a heat spreader, and heat generated by the electronic component is diffused by the heat spreader, and heat of the heat spreader is dissipated by the heat sink. In the heat dissipation device for electronic parts,
The heat spreader includes a plurality of metal sheets disposed on the side opposite to the outer surface facing the heat sink and integrated with the inner surface facing the electronic component,
The metal sheet includes both end portions joined to the inner surface, and an arch portion disposed apart from the inner surface so as to connect the both end portions and formed in an arch shape having a predetermined height from the inner surface. ,
The heat dissipating device for an electronic component, wherein the arch portion is configured to be elastically deformed by contacting the electronic component. The electronic component includes a first electronic component and a second electronic component having different mounting heights,
The metal sheet includes a first sheet and a second sheet that are provided on the inner surface and elastically deform,
The first sheet is in surface contact with the first electronic component;
The second sheet is in surface contact with the second electronic component;
The heat dissipating device for electronic parts according to claim 8, wherein the height of the arch portion in the first sheet is different from the height of the arch portion in the second sheet.   The heat dissipation device for electronic parts according to claim 8 or 9, wherein a gap between adjacent metal sheets is filled with a high thermal conductivity member.

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