JP4796653B2 - Cooling system - Google Patents

Description

  The present invention relates to a semiconductor unit, a cooling device used therefor, and a manufacturing method thereof, and more specifically, a semiconductor unit in which a plurality of semiconductor elements are mounted on a substrate and the cooling device is disposed on the semiconductor elements, The present invention relates to a cooling device used therefor and a manufacturing method thereof.

  In order to achieve high-density mounting of a semiconductor unit in which a plurality of semiconductor elements are mounted on a multilayer wiring board (MCM), a large number of bumps (connection terminals) may be formed on the entire surface of the semiconductor element and mounted on the substrate. Has been done.

  In this case, since the semiconductor units are mounted at a high density, the amount of heat generated from the semiconductor element becomes relatively large, and therefore it is necessary to efficiently remove the heat.

  In order to achieve this object, conventionally, for example, a method of collectively covering the back surface side of the semiconductor element with a metal cooling member has been adopted. When the cooling member to which the heat generated from the semiconductor element is transmitted is air-cooled, the cooling member is provided with a large number of fins and cooled while ventilating. On the other hand, when it is necessary to remove heat more efficiently, liquid cooling is performed by circulating a refrigerant or the like in the cooling member. In general, in the case of the latter liquid cooling compared to the former air cooling, the cost of the cooling device is increased, and downsizing of the entire device is hindered.

  In the case of using any of the above-described cooling means such as air cooling or liquid cooling, in order to efficiently remove heat, the heat conduction between the semiconductor element that is a heat generation source and the object to be cooled and the cooling member is good. It is essential that both are in close contact as is done. However, it is not easy to obtain good adhesion by simply bonding the semiconductor element and the cooling member as they are.

  For this reason, in order to eliminate a gap that may be generated between the semiconductor element and the cooling member and may become a heat transfer resistance, a compound having a good thermal conductivity is applied to the back surface of the semiconductor element, and the semiconductor element and the cooling member are connected via the compound. Have been made. In this case, the compound is individually applied to each semiconductor element by using, for example, a syringe-like compound injection device while managing the application amount according to the injection pressure and the injection time.

  However, in the case of the conventional compound coating method described above, it is cumbersome to manage the compound coating amount of each semiconductor element to be uniform, and if the coating amount varies between the semiconductor elements, the semiconductor element via the compound and There is a possibility that adhesion between the cooling member and the cooling member may be impaired. On the other hand, when considering the dimensional error in the same lot of semiconductor elements, the assembly error on the substrate, etc., it is necessary to change the compound application amount of each semiconductor element. This method is also complicated.

  In addition, in the case of the conventional compound coating method, if the coating amount becomes excessive or the fluidity of the matrix component is too high, the matrix component mainly flows down from the periphery of the semiconductor element during compound coating, In some cases, the metal filler in the compound adheres to the substrate and bumps, and the metal filler in the compound causes a short circuit or malfunction of the apparatus, which is a malfunction.

  The present invention has been made in view of the above points, and in a semiconductor unit in which a semiconductor element and a cooling member are joined, good thermal conductivity can be ensured and therefore excellent in heat removal, and due to fouling due to a compound. It is an object of the present invention to provide a semiconductor unit with few defects such as a short circuit and a cooling device used for the semiconductor unit, and to provide a suitable manufacturing method of the semiconductor unit and the cooling device.

  A semiconductor unit according to the present invention is a semiconductor unit in which a plurality of semiconductor elements are mounted on a substrate and a cooling device is disposed on the semiconductor element. The cooling device includes a cooling device and a semiconductor element. An injection hole for injecting a compound containing a good thermal conductive filler is formed between the semiconductor element and the cooling device through the compound layer formed by injection from the injection hole. It is characterized by being. Here, the good heat conductive filler refers to a metal filler having a high thermal conductivity, an inorganic material filler such as ceramic, diamond, or silica.

  As a result, the semiconductor element and the cooling member are reliably bonded via the compound, and good thermal conductivity can be ensured. Therefore, the heat removal is excellent, and the compound is injected from the injection hole. It is possible to obtain a semiconductor unit with few short circuits and malfunctions caused by contamination.

  In the semiconductor unit according to the present invention, a concave portion having a slightly smaller planar dimension than the semiconductor element is formed in the cooling device, and the compound layer is provided in the concave portion. Here, that the planar dimension of the recess is slightly smaller than the semiconductor element means a dimension that is appropriately set in a range in which the compound does not flow down from the outer periphery of the semiconductor element and contaminate the substrate or the like. The same applies to the following.

  As a result, since almost all of the compound stays in the recess and does not flow out, it is possible to obtain a semiconductor unit with fewer short circuits and malfunctions caused by contamination of the substrate or the like due to the compound.

  Further, in the semiconductor unit according to the present invention, a vent hole for discharging residual gas and the solvent in the compound is further formed in the cooling device, and a frame-like shape is formed between the semiconductor element and the cooling device. A spacer is provided, and the compound layer is provided in a frame of the spacer.

  As a result, the compound is completely prevented from flowing out to the substrate or the like, so that a semiconductor unit with less short circuit or malfunction due to contamination of the substrate or the like by the compound can be obtained.

  The cooling device according to the present invention is a cooling device for disposing on a plurality of semiconductor elements mounted on a substrate, and the cooling device contains a good thermal conductive filler between the semiconductor elements. An injection hole for injecting the compound to be injected is formed at least.

  Thereby, the cooling device which can be used suitably for the semiconductor unit of this invention can be obtained.

  In the cooling device according to the present invention, the cooling device includes a compound injection part having the injection hole and a heat dissipation part, and the compound injection part and the heat dissipation part are detachably provided. And

  Thereby, the compound injection part and the semiconductor element can be easily and integrally formed, and a heat radiation part appropriately selected according to the heat generation and heat removal conditions of the semiconductor unit can be attached thereto. . As the heat dissipating part, a heat dissipating fin, a water cooling unit or the like can be appropriately employed.

  Also, a semiconductor unit manufacturing method according to the present invention is a semiconductor unit manufacturing method in which a plurality of semiconductor elements are mounted on a substrate and a cooling device is disposed on the semiconductor elements. A compound containing a good thermal conductive filler is injected from the injection hole to form a layer of the compound between the semiconductor element and the cooling device, and the semiconductor element and the cooling device are connected to the compound layer. It joins via, It is characterized by the above-mentioned.

  As a result, the semiconductor element and the cooling member are surely bonded to each other through the compound layer, so that good thermal conductivity can be ensured, and therefore excellent in heat removal, and a defect such as a short circuit caused by contamination due to the compound. A semiconductor unit with less can be obtained.

  Further, in the method of manufacturing a semiconductor unit according to the present invention, the compound is injected from the injection hole into the recess formed on the lower surface of the cooling device, and the recess is formed from the minute opening formed in communication from the recess to the outside. It is characterized in that a layer of the compound is formed while flowing out the residual gas therein and mainly the matrix components in the compound.

  Thereby, by flowing an appropriate amount of matrix components in a range that does not contaminate the substrate or the like, the metal filler filling density in the applied compound can be increased, and the thermal conductivity can be improved.

  The semiconductor unit manufacturing method according to the present invention is characterized in that the injection is completed when the minute opening is closed by the metal filler and the injection resistance rapidly increases.

  Thus, the semiconductor element and the cooling member are reliably bonded via the compound by detecting the time when the injection resistance of the compound has suddenly increased, for example, as an injection flow rate change or an injection pressure change and managing the injection amount. Therefore, it is possible to easily manage an appropriate amount of the compound applied necessary for the measurement without needing to measure in advance.

  A cooling device manufacturing method according to the present invention is a cooling device manufacturing method for disposing on a plurality of semiconductor elements mounted on a substrate, and a compound is formed from an injection hole formed in the cooling device. It is characterized by injecting.

  Thereby, the cooling device suitable for using in order to manufacture the semiconductor unit of this invention can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is for demonstrating the CPU unit which concerns on the 1st example of this Embodiment, a cooling device, and those manufacturing methods, (a) is the (a)-(a) line | wire cross section in (b) of a CPU unit FIG. 4B is a plan view of the CPU unit. FIG. 2 is an exploded view of the CPU unit of FIG. 1. It is a figure for demonstrating a compound injection | pouring apparatus. It is the elements on larger scale of a CPU unit for demonstrating the modification of the CPU unit which concerns on the 1st example of this Embodiment. It is for demonstrating the CPU unit which concerns on the 2nd example of this Embodiment, a cooling device, and those manufacturing methods, (a) is the (a)-(a) line | wire cross section in (b) of a CPU unit FIG. 4B is a plan view of the CPU unit. It is the elements on larger scale of a CPU unit for demonstrating the modification of the CPU unit which concerns on the 2nd example of this Embodiment. It is the perspective view which opened the server which mounted the CPU unit of this invention partially, and showed the state inside.

  A preferred embodiment (hereinafter referred to as this embodiment) of a semiconductor unit, a cooling device, and a manufacturing method thereof according to the present invention will be described below with reference to the drawings taking a CPU unit as an example.

  First, a CPU unit, a cooling device, and a manufacturing method thereof according to a first example of the present embodiment will be described with reference to FIG.

  The CPU unit 10 includes a substantially substrate 12, a plurality of semiconductor elements 14 mounted on the substrate 12, and a cooling device 16 provided on the semiconductor elements 14. A large number of IO pins 18 are erected on the lower surface 12a of the substrate 12 over substantially the entire surface. When the CPU unit 10 is mounted on a mother board 82 to be described later, the CPU unit 10 and the mother board 82 are electrically connected by the IO pin 18.

  A large number of solder bumps (connection terminals) 24 are provided on the lower surface 14 a of the semiconductor element 14, and the semiconductor element 14 and the substrate 12 are electrically connected via the solder bumps 24. On the other hand, a frame-like spacer (separation member) 13 is provided on the outer periphery of the upper surface 12 b of the substrate 12 in order to separate the cooling device 16 and the semiconductor element 14 from each other by a predetermined distance.

  In this case, the cooling device 16 includes a compound injection portion 16a shown in FIG. 1 and a heat radiation fin portion (heat radiation portion) 16b, which will be described later, which is detachably attached to the compound injection portion 16a. The compound injection part 16a is formed in a substantially rectangular parallelepiped shape. The compound injection portion 16a is formed with a concave portion 20 having a slightly smaller planar size than the semiconductor element 14 on the surface 16a-1 on the side facing the upper surface 12b of the semiconductor element 12. The compound injection portion 16a communicates with the concave portion 20 to inject the compound. An injection hole 22 is formed, and the injection hole 22 has an opening 22a on the upper surface 16a-2 of the compound injection part 16a. A protrusion 26 is formed on the outer periphery of the side surface 16a-3 of the compound injection part 16a so as to protrude in a stepped manner, and a screw hole 28 for inserting a screw 40 described later is formed on two sides of the protrusion 26. In addition, the screw hole 21 used when fixing the heat sink fin part 16b mentioned later is formed in the both ends of the upper surface 16a-2 of the compound injection | pouring part 16a.

  A frame 30 is provided so as to surround the substrate 12, and the substrate 12 is held in a state where the IO pin 18 is floated by a protrusion 32 extending to the lower portion of the frame 30, and the IO pin 18 is held in the frame 30. It arrange | positions in the state which faces the opening 34 of the lower surface 30a. At this time, the lower surface 30a of the frame 30 and the tip end portion 18a of the IO pin 18 are arranged on substantially the same plane. Screw holes 38 are formed on two sides of the frame body 30. The compound injection part 16a is fixed on the frame 30 by the screw hole 38 and the screw 40 inserted through the screw hole 28.

  Compound 44 is injected into injection hole 22 and recess 20 of compound injection part 16a, and a gap (micro opening) 42 of about 20 μm width formed between semiconductor element 14 and compound injection part 16a to form compound layer 44a. Has been. The compound 44 is obtained by blending, for example, 90 parts by weight of a metal filler 46 made of zinc oxide having an average particle diameter of 25 μm with 10 parts by weight of a solvent 48 made of silicon oil, and has good thermal conductivity. Most of the metal filler 46 having an average particle diameter of 25 μm is blocked by the gap 42 having a width of about 20 μm and remains in the recess 20.

  The CPU unit 10 according to the first example of the present embodiment configured as described above has, for example, a case where there is a dimensional error in the same lot of the semiconductor elements 14 or an assembly error on the substrate 12. However, the semiconductor element 14 and the compound injection part 16a are reliably joined via the compound 44, and good thermal conductivity can be ensured, so that the heat removal property is excellent. In addition, the compound 44 is less likely to flow out onto the substrate 12 as compared with the conventional method in which the cooling member is joined after applying the compound to each of the semiconductor elements 14. Therefore, the contamination of the substrate 12 and the like by the compound 44 is less likely to occur. There are few shorts and malfunctions that are caused. Moreover, the compound injection | pouring part 16a comprised as mentioned above can be used suitably for CPU unit 10. FIG.

  A method of manufacturing the CPU unit 10 and the compound injection part 16a will be described below with reference to FIG.

  First, each member of the board | substrate 12, the compound injection | pouring part 16a, the frame 30, and the spacer 13 which mounted the semiconductor element 14 with the following procedures is prepared.

  The substrate 12 on which the semiconductor element 14 is mounted is prepared by mounting a plurality of semiconductor elements 14 on which the solder bumps 24 are provided on the upper surface 12b of the substrate 12 on which the IO pins 18 are provided, by a conventional method.

  Further, for example, a rectangular parallelepiped member made of a copper material is prepared, the protruding portion 26 is formed by cutting, and the protruding portion 26 is screwed with a tap to form the screw hole 28. Furthermore, a dimension of about 20 mmL × 20 mmW, for example, is provided at a position corresponding to the arrangement interval of the semiconductor elements 14 on one surface (lower surface 16a-1) of the main surface (surface having a larger area) of the rectangular parallelepiped member by machining. A plurality of recesses 20 having dimensions of about 18 mmL × 18 mmW × 0.1 mmH, which are slightly smaller than the semiconductor element 14, are formed. An injection hole 22 having a diameter of about 1 mm that communicates with the recess 20 and opens in the upper surface 16a-2 is formed using a drill. Thereby, the compound injection | pouring part 16a is prepared.

  Further, a rectangular frame 30 made of, for example, a metal material having a thermal expansion coefficient close to that of the substrate 12 is prepared, and a projecting portion 32 that circulates is formed in the lower portion of the frame 30. The opening at the top of the frame 30 is provided with substantially the same planar dimensions as the substrate 12. Screw holes 38 are formed on the upper surfaces of the two opposite sides of the frame body 30 by screw machining.

  Also, a frame-like spacer 13 made of, for example, a metal material having a thermal expansion coefficient close to that of the substrate 12 is prepared. The height of the spacer 13 (vertical direction in FIG. 1A) is, for example, about 20 μm larger than the height of the semiconductor element 14 provided with the solder bumps 24.

  Next, an assembling method of the CPU unit 10 using the above members will be described.

  First, the frame body 30 is placed on a fixed base (not shown), and the substrate 12 on which the semiconductor element 14 is mounted is placed in the frame body 30 with the IO pins 18 facing downward. Next, spacers 13 are arranged on the substrate 12 so as to surround all of the plurality of semiconductor elements 14. Next, the compound injection part 16 a is disposed on the semiconductor element 14 with the recess 20 facing downward. At this time, the compound injection part 16 a is positioned by the spacer 13 so as to have the gap 42 between the semiconductor element 14. Next, the screw 40 is inserted into the screw holes 28 and 38 and fixed to the frame body 30 and the compound injection part 16a, whereby the CPU unit 10 is integrated and preparation for injecting the compound 44 is completed.

  Here, the compound injection apparatus 50 shown in FIG. 3 is prepared.

  The compound injection device 50 includes a syringe 52, a dispenser 54, and an injection amount monitor 56.

  The syringe 52 is formed in a cylindrical shape, a short columnar piston 58 that can move up and down is provided inside the syringe 52, and an injection needle 52 a is provided at the lower end of the syringe 52. The dispenser 54 is for introducing a pressure fluid such as air into the syringe 52 into the syringe 52 while controlling the pressure fluid such as air to a constant pressure to press the piston 58 at a constant pressure, and a pressure fluid conduit 54a is connected to the main body 54a. A flange 54c is provided at the distal end of the conduit 54b and closes the upper opening of the syringe 52. The injection amount monitor 56 is for measuring the remaining amount in the syringe 52 of the compound 44 fed into the syringe 52, in other words, for measuring the injection amount into the compound injection portion 16a, and a signal line connected to the main body 56a. One end of 56 b is connected to a laser displacement meter 56 c provided in the syringe 52.

  The compound injection device 50 is prepared in a state where an appropriate amount of the compound 44 is fed into and filled in the syringe 52 from the vicinity (not shown) of the conduit 54b, and the syringe is closed by the flange 54c. When the compound 44 is injected, a pressure fluid controlled to a constant pressure by the dispenser 54 is fed into the syringe 52 from the conduit 54b. Accordingly, the piston 58 is pressed downward, and the compound 44 is gradually discharged from the injection needle 52a. The displacement amount of the piston 58 is detected by the laser displacement meter 56c, and the signal is sent to the main body 56a of the injection amount monitor 56 to grasp the injection amount. When the discharge pressure of the injection needle 52a increases, the lowering speed (displacement speed) of the piston 58 rapidly decreases because the inside of the syringe 52 is maintained at a predetermined pressure. The change in the descending speed is grasped by the injection amount monitor 56.

  The injection needle 52a of the compound injection device 50 configured as described above is inserted into the injection hole 22 of the compound injection portion 16a of the CPU unit 10, and the compound 44 is injected.

  The compound 44 reaches the recess 20 from the injection hole 22 in a state where the metal filler 46 is almost uniformly dispersed in the solvent 48. During this time, the residual gas remaining in the injection hole 22 and the recess 20 is discharged to the outside from the gap 42 between the compound injection portion 16 a and the semiconductor element 14. When the compound 44 further reaches the gap 42, the solvent 48 is discharged from the gap 42 with a part of the metal filler 46 having a particle diameter smaller than that of the gap 42 of about 20 μm. Accordingly, the accumulated metal filler 46 gradually accumulates at the entrance of the gap 42 and finally closes the entrance of the gap 42 (see the partially enlarged view of FIG. 1A). When the entrance of the gap 42 is closed by the metal filler 46, the discharge pressure of the compound injection device 50 is rapidly increased. Thus, it is determined that the filling of the compound 44 is completed.

  Finally, a heat radiating fin portion 16b, which is another member constituting the cooling device 16, is disposed on the upper surface of the compound injection portion 16a.

  The heat dissipating fin portion 16b is provided with a plurality of fins 19 standing on the plane portion 17 disposed opposite to the upper surface of the compound injection portion 16a, and screw holes 23 are formed at both ends of the plane portion 17. ing. After applying the compound to the upper surface 16a-2 of the compound injection part 16a (not shown), the screw 25 is inserted into the screw holes 23 and 21, and the heat radiation fin part 16b is fixed to the compound injection part 16a. The compound injection part 16a and the heat radiation fin part 16b are integrated.

  The CPU unit 10 is completed by the manufacturing method described above.

  According to the manufacturing method of the CPU unit 10 and the compound injection part 16a described above, the filling density of the metal filler 46 in the compound layer 44a is mainly caused by flowing out an appropriate amount of the solvent 48 within a range that does not contaminate the substrate 12 and the like. CPU unit 10 with improved thermal conductivity can be obtained. In this case, by appropriately adjusting the average particle diameter of the metal filler 46 and the size of the gap 42, the degree to which the compound 44, particularly, the metal filler 46 in the compound 44 flows out of the gap 42 can be adjusted.

  In the first example of the present embodiment, the compound injection device 50 is configured to sequentially inject the compound at each position of the injection hole 22, but the present invention is not limited thereto, and is mounted on the substrate 12. A configuration may be adopted in which the compound can be simultaneously injected into the plurality of injection holes 22 formed corresponding to the plurality of semiconductor elements 14, and in this case, the injection operation can be efficiently performed.

  Next, a modified example of the CPU unit and the method of manufacturing the CPU unit according to the first example of the present embodiment will be described with reference to FIG.

  The modification has basically the same configuration as that of the first example of the present embodiment, and differs from the first example of the present embodiment in that there is a gap between the semiconductor element 14 and the compound injection portion 16a. 42 is smaller than that of the first example of the present embodiment. That is, when the gap in the first example of the present embodiment is, for example, about 20 μm, the gap in the modified example is about 10 μm.

  According to the CPU unit 60 and the method for manufacturing the CPU unit 60 according to the modification of the first example of the present embodiment, the metal filler 46 having an average particle diameter of 25 μm hardly flows out from the gap 42, and therefore The compound 44 can be injected efficiently and economically, and the CPU unit 60 with improved thermal conductivity can be obtained. Even if a dimensional error within the same lot of the semiconductor elements 14 or an assembly error on the substrate 12 occurs, for example, about ± 5 μm in the height direction between the semiconductor elements 14, the gap 42 Is set to a smaller size, the outflow of the metal filler 46 from the gap 42 can be sufficiently prevented.

  Next, the CPU unit 62, the cooling device 63 (compound injection part 63a) and the manufacturing method thereof according to the second example of the present embodiment will be described with reference to FIG.

  The second example of the present embodiment is basically the same as the first example of the present embodiment. In FIG. 5, the same components as those of the first example of the present embodiment are implemented in the present embodiment. The same reference numerals as those in the first example of the embodiment are attached, and the description is omitted.

  The CPU unit 62 according to the second example of the present embodiment differs from the CPU unit 10 according to the first example of the present embodiment in the following two points.

  The first point is that the compound injection part 63 a is further provided with a vent hole 64 communicating with the recess 20 in addition to the recess 20 and the injection hole 22, and the vent hole 64 is also connected to the injection hole 22. Similarly, the upper surface 63a-2 of the compound injection part 63a has an opening 64a. The opening 64a may be formed on the side surface of the compound injection part 63a. The vent hole 64 is formed with a diameter of about 1 mm. Further, the compound injection portion 63a is not formed with the recess 20 as in the compound injection portion 16a.

  The second point is that a frame-shaped outflow prevention spacer (separation member) 66 that goes around the outer periphery of the upper surface 14 b of the semiconductor element 14 is provided. The outflow prevention spacer 66 is made of, for example, a material such as a resin that does not allow the filler to pass therethrough, and its height direction (vertical direction in FIG. 5A) is, for example, 50 μm. Instead of the spacer 13 in the CPU unit 10, in the CPU unit 62, the outflow prevention spacer 66 serves as a positioning member that determines the distance between the compound injection portion 63 a and the semiconductor element 14. Instead, a compound layer 44 a is formed in the space formed by the compound injection part 63 a, the semiconductor element 14, and the outflow prevention spacer 66. Further, in the state where the compound injection portion 63a is mounted on the outflow prevention spacer 66, the outflow prevention spacer 66 is provided so as to surround the injection hole 22 and the vent hole 64, and like the gap 42 in the CPU unit 10, It has the effect | action which restrict | limits the outflow of a compound, In this case, the contamination of the board | substrate 12 etc. by the outflow of the compound 44 is prevented completely.

  According to the CPU unit 62 according to the second example of the present embodiment configured as described above, the space portion for forming the compound layer 44a formed between the compound injection portion 63a and the semiconductor element 14. Is blocked by the outflow prevention spacer 66, and the residual gas and solvent flow out of the vent hole 64. Therefore, the compound 44 does not flow out onto the substrate 12, so that the short circuit caused by contamination by the compound 44 occurs. And a CPU unit free from malfunctions can be obtained.

  In this case, no vent hole is formed. On the other hand, when a porous material is used as the spacer, only the solvent 48 is hardly caused to flow out of the metal filler 46 by appropriately setting the pore diameter of the porous material. Can be discharged.

  Next, a modification of the CPU unit 70 and the method for manufacturing the CPU unit 70 according to the second example of the present embodiment will be described with reference to FIG.

  The CPU unit 70 according to the modification differs from the CPU unit 62 according to the second example of the present embodiment in that a filter 72 is attached to the entrance of the air vent hole 64. The filter 72 is formed of a resin material having a hole diameter of, for example, 5 μm, and can capture the metal filler 46 having a diameter exceeding 10 μm, for example.

  According to the modification of the second example of the present embodiment configured as described above, the metal filler 46 is captured by the filter 72, and only the residual gas and the solvent 48 flow out from the vent hole 64. The compound 44 can be injected efficiently and economically, and the CPU unit 70 with improved thermal conductivity can be obtained.

  In this case, if the filter 72 is provided at the outlet of the vent hole 64, the thermal conductivity of the CPU unit 70 can be further improved by filling the vent hole 64 with the metal filler 46.

  Next, an electronic device in which the CPU unit according to the present invention is mounted will be described with reference to FIG. 7, taking a server using the CPU unit 10 as an example.

  A plurality of CPU units 10 are mounted on one motherboard 82 together with the RAM unit 80 and the like. Then, a plurality of mother boards 82 are accommodated in the casing 84a of the server 84 together with other electronic components.

  Inside the casing 84a, air is forcibly circulated by a cooling fan (not shown) to cool the CPU unit 10 and the like. In this case, since the CPU unit 10 has improved thermal conductivity, it can be efficiently cooled.

  Here, instead of the heat radiation fin portion 16b of the CPU unit 10, a cooling device provided with a line for circulating the refrigerant may be used, and liquid cooling may be performed by the refrigerant cooling device provided outside the housing 84a.

With respect to the embodiment of the present invention described above, the following modes can be further considered.
(1) A method of manufacturing a semiconductor unit in which a compound member is injected by forming a minute opening between a semiconductor element and a cooling device by disposing a separation member that separates the semiconductor element and the cooling device by a predetermined distance.
(2) A method for manufacturing a semiconductor unit in which a compound hole is injected by forming a vent hole as a minute opening on a surface other than the surface where the concave portion of the cooling device is formed.
(3) A method of manufacturing a semiconductor unit in which a filter for capturing a metal filler is provided in a minute opening and a compound is injected.

  In a semiconductor unit in which a plurality of semiconductor elements are mounted on a substrate and a cooling device is disposed on the semiconductor elements, the cooling device has a good thermal conductive filler between the cooling device and the semiconductor elements. According to a semiconductor unit, an injection hole for injecting a compound containing the semiconductor element is formed, and the semiconductor element and the cooling device are joined via the compound layer formed by injection from the injection hole. Since the element and the cooling device are joined through a compound layer formed by injecting from the injection hole, good thermal conductivity can be ensured, and thus heat removal is excellent, and the compound is injected from the injection hole. Therefore, it is possible to obtain a semiconductor unit with less short circuit and malfunction due to contamination of the substrate or the like due to the compound.

  Furthermore, according to the semiconductor unit in which the concave portion having a slightly smaller planar size than the semiconductor element is formed in the cooling device, and the compound layer is provided in the concave portion, the compound layer is formed in the cooling device. Therefore, it is possible to obtain a semiconductor unit with less short circuit or malfunction due to contamination of the substrate or the like due to the compound. it can.

  Alternatively, a vent hole for discharging residual gas and the solvent in the compound is further formed in the cooling device, and a frame-like spacer is provided between the semiconductor element and the cooling device. According to the semiconductor unit provided in the frame of the spacer, the compound layer is provided with vent holes and frame-like spacers, so that the compound may flow out to the substrate or the like. It is possible to obtain a semiconductor unit that is completely prevented and has fewer short-circuits and malfunctions caused by contamination of the substrate due to the compound.

  Also, a cooling device for disposing on a plurality of semiconductor elements mounted on a substrate, wherein the cooling device is an injection for injecting a compound containing a good thermal conductive filler between the semiconductor elements. According to the cooling device in which the hole is formed at least, since the injection hole for injecting the compound is formed, a cooling device that can be suitably used for the semiconductor unit of the present invention can be obtained.

  Further, the cooling device is composed of a compound injection portion having the injection hole and a heat radiating portion, and the cooling device according to the cooling device in which the compound injection portion and the heat radiating portion are detachably provided is injected. Since the compound injecting portion having holes and the heat radiating portion are detachably provided, the compound injecting portion and the semiconductor element can be easily and integrally formed. A heat radiating portion appropriately selected according to the thermal conditions can be attached.

  Also, in a method of manufacturing a semiconductor unit in which a plurality of semiconductor elements are mounted on a substrate and a cooling device is disposed on the semiconductor elements, a good heat conductive filler is contained from an injection hole formed in the cooling device. In a method of manufacturing a semiconductor unit, a compound layer is formed between the semiconductor element and the cooling device, and the semiconductor element and the cooling device are bonded to each other through the compound layer. According to the present invention, the compound containing the metal filler is injected from the injection hole formed in the cooling device, and the semiconductor element and the cooling device are bonded via the compound layer, so that the semiconductor element and the cooling member are reliably bonded. As a result, it is possible to obtain a semiconductor unit that can ensure good thermal conductivity, and therefore has excellent heat removal performance, and has few defects such as short circuits caused by fouling due to the compound. It is possible.

  Further, the compound is injected from the injection hole into the recess formed in the lower surface of the cooling device, and the residual gas in the recess and the main component in the compound are formed through the minute opening formed in communication from the recess to the outside. According to the method of manufacturing a semiconductor unit in which the compound layer is formed while allowing the matrix component to flow out, the compound is injected into the recess of the cooling device, and the residual gas and mainly the matrix component in the compound are discharged from the minute opening. In order to form a compound layer, the metal filler filling density in the applied compound can be increased by flowing out an appropriate amount of matrix components within a range that does not contaminate the substrate and the like, and thermal conductivity is improved. be able to.

  Further, according to the method of manufacturing a semiconductor unit in which the injection is completed when the minute opening is blocked by the metal filler and the injection resistance rapidly increases, the injection is completed when the injection resistance is rapidly increased by being blocked by the metal filler. By detecting the time when the injection resistance of the compound has suddenly increased, for example, as an injection flow rate change or an injection pressure change, and managing the injection amount, the semiconductor element and the cooling member can be reliably bonded via the compound. Therefore, it is possible to easily manage an appropriate amount of the compound applied necessary for the measurement without needing to measure in advance.

  According to another aspect of the present invention, there is provided a method of manufacturing a cooling device for disposing on a plurality of semiconductor elements mounted on a substrate, wherein the compound is injected from an injection hole formed in the cooling device. Since the compound is injected from the injection hole formed in the cooling device, a cooling device suitable for use in manufacturing the semiconductor unit of the present invention can be obtained.

10, 60, 62, 70 CPU unit 12 Substrate 13 Spacer 14 Semiconductor element 16 Cooling device 16a, 63a Compound injection part 16b Fin for heat dissipation 18 IO pin 20 Recess 22 Injection hole 30 Frame body 42 Gap 44 Compound 44a Compound layer 50 Compound injection device 54 Dispenser 56 Injection volume monitor 64 Vent hole 66 Outflow prevention spacer 72 Filter 84 Server

Claims (3)

A cooling device for disposing on a plurality of semiconductor elements mounted on a substrate,
An injection hole for injecting a compound containing a good thermal conductive filler is formed between the cooling device and the semiconductor element,
A vent hole for discharging residual gas and the solvent in the compound from between the cooling device and the semiconductor element is further formed,
A cooling device, wherein a filter having a hole diameter smaller than the diameter of the filler is formed at the inlet or outlet of the vent hole.   The cooling device according to claim 1, wherein the cooling device includes a compound injection portion having the injection hole and a heat dissipation portion, and the compound injection portion and the heat dissipation portion are detachably provided. .   The cooling device according to claim 1, wherein the filter is made of a resin material.