cooling device

Abstract

Provided is a cooling device that provides a better cooling effect. A cooling device that cools a semiconductor element mounted on a surface of a substrate includes a base that is mounted on a back surface of the substrate, and a bottom plate that is disposed apart from the base and has a guide inlet that guides refrigerant from a direction that faces the back surface, at a position that corresponds to the semiconductor element of the bottom plate.

Description

Technical Field

[0001] This disclosure relates to a cooling device. Background Technology

[0002] As a device for cooling semiconductor elements (chips), for example, the device described in Patent Document 1 is known. In the device described in Patent Document 1, a cooling water path is formed between multiple semiconductor modules, through which cooling water flows. By guiding the cooling water laterally from one end of the cooling water path, the semiconductor modules can be cooled sequentially.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-203138 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, as mentioned above, when multiple semiconductor elements are packaged, the heat generated by each semiconductor element is superimposed, and the temperature of the central part increases due to thermal interference from these semiconductor elements. Therefore, as in Patent Document 1, in a structure in which cooling water flows laterally from one end of the cooling water path, the cooling effect in the central part may be insufficient.

[0008] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide a cooling device that can achieve better cooling effect.

[0009] Technical solution

[0010] To solve the above problems, the cooling device disclosed herein is a cooling device for cooling semiconductor elements packaged on the surface of a substrate, comprising: a base mounted on the back side of the substrate; and a base plate disposed separately from the base, wherein an inlet for guiding refrigerant from a direction opposite to the back side is formed at a position corresponding to the semiconductor element on the base plate.

[0011] Beneficial effects

[0012] According to this disclosure, a cooling device that achieves better cooling performance can be provided. Attached Figure Description

[0013] Figure 1 This is a cross-sectional view showing the structure of the cooling device and the substrate according to the first embodiment of this disclosure.

[0014] Figure 2 This is a top view of the cooling device according to the second embodiment of this disclosure.

[0015] Figure 3 This is a top view showing an improved example of the cooling device according to the second embodiment of the present disclosure.

[0016] Figure 4 This is a top view of the cooling device according to the third embodiment of this disclosure.

[0017] Figure 5 This is a top view showing an improved example of the cooling device according to the third embodiment of this disclosure.

[0018] Figure 6 This is a top view showing another improved example of the cooling device according to the third embodiment of this disclosure.

[0019] Figure 7 This is a top view showing yet another improved example of the cooling device according to the third embodiment of this disclosure.

[0020] Figure 8 This is a top view showing yet another different improvement of the cooling device according to the third embodiment of this disclosure.

[0021] Figure 9 This is an enlarged view of the main parts of the cooling device according to the fourth embodiment of this disclosure.

[0022] Figure 10 This is a cross-sectional view showing the structure of the cooling device and the substrate according to the fifth embodiment of this disclosure.

[0023] Explanation of reference numerals in the attached figures

[0024] 100 cooling device

[0025] 1 substrate

[0026] 1a, 1c Copper Patterns

[0027] 1b substrate body

[0028] 1D bonding material

[0029] 2 Semiconductor components

[0030] 2a Bonding material

[0031] 10 bases

[0032] 10a surface

[0033] 10b back

[0034] 11, 11e heatsink

[0035] 11′ pin

[0036] 11a outer heatsink

[0037] 11b middle heatsink

[0038] 11c small heatsink

[0039] 11d large heatsink

[0040] 11s tilt section

[0041] 12 base plate

[0042] 13 Inlet Ports Detailed Implementation

[0043] <First Implementation Method>

[0044] (Structure of substrate and cooling device)

[0045] The following is for reference. Figure 1 The cooling apparatus 100 according to the first embodiment of this disclosure will be described. This cooling apparatus 100 is a device that cools a semiconductor element 2 encapsulated on a substrate 1 using a liquid refrigerant. Figure 1 As shown, substrate 1 has copper patterns 1a and 1c, substrate body 1b, and bonding materials 2a and 1d.

[0046] The substrate body 1b is formed into a plate shape, for example, from glass epoxy resin or phenolic resin. Copper patterns 1a and 1c are deposited on the front and back sides of the substrate body 1b, respectively. The desired printed wiring is formed on the copper patterns 1a and 1c by etching. The bonding material 2a is configured to fix the semiconductor element 2 to the copper pattern 1a.

[0047] Multiple (e.g., three) semiconductor elements 2 are disposed on the substrate 1. The semiconductor elements 2, such as power transistors or power MOSFETs, generate heat during operation. These semiconductor elements 2 are arranged spaced apart from each other on the substrate 1. Furthermore, the semiconductor elements 2 are electrically connected to the aforementioned copper pattern 1a.

[0048] Next, the structure of the cooling device 100 will be described. For example... Figure 1 As shown, the cooling device 100 includes a base 10 and a base plate 12. These bases 10 and base plates 12 are integrally formed from metal materials with good thermal conductivity, such as aluminum or copper. The cooling device 100 can also be modeled using additive manufacturing (AM).

[0049] The base 10 is fixed to the back side of the substrate 1 (i.e., the side facing the opposite side to the surface where the semiconductor element 2 is packaged) by a bonding material 1d. The base 10 is plate-shaped with an area larger than that of the substrate 1. An inlet 13 for introducing refrigerant from the outside is formed in the central portion of the base plate 12 in the first direction d1 (i.e., the central portion of the area where the plurality of semiconductor elements 2 are disposed). Refrigerant is introduced from the base plate 12 toward the base 10 through the inlet 13. It should be noted that, in addition to low-temperature water, LLC (long-life coolant), ethylene glycol, etc., are preferably used as refrigerants. The refrigerant flowing in from the inlet 13 flows separately in two directions along the base 10.

[0050] (Effects)

[0051] Next, the operation of the cooling device 100 will be explained. When the semiconductor element 2 is operating, it generates heat due to internal resistance and other reasons. As mentioned above, when multiple semiconductor elements 2 are arranged in a concentrated manner, the temperature in the central part of the concentrated area becomes particularly high due to thermal interference. If this heat generation intensifies, it may lead to thermal runaway or damage to the semiconductor element 2. Therefore, in this embodiment, a structure is adopted to cool these semiconductor elements 2 using the cooling device 100.

[0052] First, the refrigerant introduced into the flow path F through the inlet 13 changes direction by colliding with the back surface 10b of the base 10, and flows towards both sides of the first direction d1. Figure 1 (The arrow in the image indicates the direction of the process). During this process, semiconductor element 2 is cooled based on the heat absorbed by the refrigerant.

[0053] According to the above structure, refrigerant can be directly supplied from the inlet 13 to the central part of the concentrated area of ​​the semiconductor element 2. This allows for more efficient cooling of the semiconductor element 2. On the other hand, for example, when the refrigerant flows unidirectionally from one end of the flow path F to the other, its temperature rises as it moves downstream, potentially preventing the desired cooling effect from being achieved. However, according to the above structure, since the inlet 13 is located directly below the semiconductor element 2, this possibility is reduced, ensuring a continuous and normal supply of cryogenic refrigerant to the semiconductor element 2.

[0054] The first embodiment of the present invention has been described above. It should be noted that various changes and modifications can be made to the above-described configuration without departing from the spirit of the present invention.

[0055] <Second Implementation Method>

[0056] Next, refer to Figure 2The second embodiment of this disclosure will be described. Furthermore, for structures identical to those in the first embodiment described above, the same reference numerals will be used, and detailed descriptions will be omitted. Figure 2 As shown, in this embodiment, a plurality of heat sinks 11 are provided on the back surface 10b of the base 10. Each heat sink 11 protrudes in a direction away from the base 10. More specifically, these heat sinks 11 extend in a first direction d1 along the back surface 10b of the base 10, and are spaced apart in a second direction d2 intersecting the first direction d1. Thus, a flow path F for refrigerant flow is formed between the heat sinks 11.

[0057] The heat sink 11 has an outer heat sink 11a and a middle heat sink 11b. The outer heat sink 11a is located at the outermost edge in the second direction d2. That is, the outer heat sink 11a forms the shape of the cooling device 100. Compared with the other heat sinks 11, the outer heat sink 11a has a larger plate thickness. In addition, the outer heat sink 11a extends over the entire area of ​​the base 10 in the first direction d1.

[0058] According to the above structure, since the heat dissipation area is increased by the heat sink 11, the semiconductor element 2 can be cooled more effectively.

[0059] Furthermore, in the cooling device 100 described above, the outermost heat sink 11 (outer heat sink 11a) located in the second direction d2 among the plurality of heat sinks 11 has a larger plate thickness compared to the other heat sinks 11.

[0060] In the cooling device 100, high-pressure refrigerant flows within the flow path F, while low-pressure refrigerant, after cooling, flows outside the outer heat sink 11a. Therefore, a pressure difference is generated between the inside and outside of the outer heat sink 11a. According to this structure, since the outer heat sink 11a has a relatively large thickness, it can sufficiently withstand the pressure difference. This reduces the possibility of deformation of the outer heat sink 11a.

[0061] The second embodiment of the present invention has been described above. It should be noted that various changes and modifications can be made to the above configuration without departing from the spirit of the invention. For example, instead of the heat sink 11, as... Figure 3 Alternatively, pins 11' can be used. Pins 11' protrude from the base plate 12 toward the base 10, and multiple pins 11' are spaced apart from each other in the first direction d1 and the second direction d2. This structure achieves the same effect as described above.

[0062] <Third Implementation Method>

[0063] Next, refer to Figure 4The third embodiment of this disclosure will now be described. It should be noted that the same reference numerals are used for components identical to those in the embodiments described above, and detailed descriptions thereof are omitted. For example... Figure 4 As shown, in this embodiment, the heat sink 11 has an outer heat sink 11a, a middle heat sink 11b, a small heat sink 11c, and a large heat sink 11d. The outer heat sink 11a is located at the outermost edge in the second direction d2. That is, the outer heat sink 11a forms the shape of the cooling device 100. Compared with the other heat sinks 11, the outer heat sink 11a has a larger plate thickness. In addition, the outer heat sink 11a extends over the entire area of ​​the base 10 in the first direction d1.

[0064] Large heat sinks 11d are spaced apart from the outer heat sinks 11a in the second direction d2. The large heat sinks 11d have the same length as the outer heat sinks 11a in the first direction d1. Between these outer heat sinks 11a and the large heat sinks 11d, a pair of intermediate heat sinks 11b and a small heat sink 11c are arranged. The intermediate heat sinks 11b are smaller than the large heat sinks 11d in the first direction d1, and the small heat sink 11c is smaller than the intermediate heat sinks 11b in the first direction d1. Furthermore, these intermediate heat sinks 11b, small heat sinks 11c, and large heat sinks 11d are fixed to the base 10 with their centers aligned in the first direction d1. Therefore, the width of the flow path F (its dimension in the second direction d2) gradually increases towards both sides of the first direction d1. Additionally, the closer to the center of the first direction d1, the greater the number (density) of the heat sinks 11. Multiple sets of heat sinks 11 satisfying this relationship are arranged periodically in the second direction d2.

[0065] When the inlet 13 is used as a reference, the spacing between the heat sinks 11 gradually widens as they move away from the inlet 13 on both sides in the first direction d1.

[0066] In the aforementioned cooling device 100, a plurality of heat sinks 11 extend along a first direction d1 of the base 10 and are spaced apart along a second direction d2, thereby forming a flow path F extending along the first direction d1 between them. Furthermore, the width of the flow path F gradually widens as it moves away from the inlet 13 along the first direction d1.

[0067] According to the above structure, the spacing of the flow paths F between the heat sinks 11 becomes relatively narrower near the inlet 13. That is, the heat sinks 11 become relatively denser. Therefore, the contact area between the heat sinks 11 and the refrigerant is ensured near the inlet 13 where the semiconductor element 2 is located. As a result, the cooling effect of the refrigerant can be improved near the inlet 13 where the semiconductor element 2 is located.

[0068] Furthermore, in the aforementioned cooling device 100, the spacing between the heat sinks 11 gradually widens as they leave the inlet 13.

[0069] Based on the above structure, the width of the flow path F can be varied simply by changing the spacing between the heat sinks 11. This makes the device configuration easier and more economical.

[0070] The third embodiment of the present invention has been described above. It should be noted that various changes and modifications can be made to the above configuration without departing from the spirit of the invention. For example, a pin 11' can be used instead of the heat sink 11 described above. Figure 5 As shown, the width of the flow path F gradually widens as it leaves the inlet 13 in the first direction d1.

[0071] According to the above structure, the spacing of the flow paths F between the pins 11' becomes relatively narrower near the inlet 13. That is, the pins 11' become relatively denser. This ensures the contact area between the pins 11' and the refrigerant. As a result, the cooling effect of the refrigerant can be improved near the inlet 13 where the semiconductor element 2 is located.

[0072] Furthermore, such as Figure 6 As shown, a structure can also be adopted in which the thickness of the heat sink 11e gradually decreases as it moves away from the inlet 13 towards both sides in the first direction d1. This structure also allows for a change in the width of the flow path F, achieving the same effect as the structure described above.

[0073] In addition, such as Figure 7 As shown, a structure can also be adopted in which the size of the second direction d2 of the pin 11' gradually increases as it leaves the inlet 13, while the number of pins 11' per unit area gradually decreases.

[0074] Based on the above structure, the width of the flow path F can be varied simply by changing the size of the pins 11′ and the number (density) of the pins 11′ per unit area. This makes the device construction easier and more economical.

[0075] Alternatively, it can also be used Figure 8 The structure is shown. In the example in the figure, the dimension of the second direction d2 of the pins 11' gradually decreases as they leave the inlet 13. Therefore, the spacing between the pins 11' gradually widens as they leave the inlet 13.

[0076] Based on the above structure, the width of the flow path F can be varied simply by changing the size of pin 11' and the spacing between pins 11'. This makes the device configuration easier and more economical.

[0077] <Fourth Implementation Method>

[0078] Next, refer to Figure 9 The fourth embodiment of this disclosure will now be described. It should be noted that the same reference numerals are used for components identical to those in the embodiments described above, and detailed descriptions thereof are omitted. As shown in the figure, in this embodiment, inclined portions 11s are formed at both ends of the heat sink 11. The inclined portions 11s are inclined such that they gradually move away from the back surface 10b of the base 10 toward both sides in the first direction d1.

[0079] Based on the above structure, such as Figure 9 As indicated by the arrows, due to the formation of the inclined portion 11s, the flow path length of the refrigerant introduced from the inlet 13 can be kept constant throughout the entire region in the height direction of the heat sink 11. More specifically, the flow path length of the refrigerant component flowing from the inlet 13 to the side closer to the back surface 10b (arrow f1) and the flow path length of the refrigerant component flowing from the inlet 13 to the side away from the back surface 10b (arrow f2) can be equal to each other. As a result, the refrigerant flow rate is uniform throughout the entire region of the heat sink 11, which further improves the cooling effect of the heat sink 11.

[0080] The fourth embodiment of this disclosure has been described above. It should be noted that various changes and modifications can be made to the above-described configuration without departing from the spirit of the present invention.

[0081] <Fifth Implementation Method>

[0082] Next, refer to Figure 10 The fifth embodiment of this disclosure will now be described. It should be noted that the same reference numerals are used for the same components as in the embodiments described above, and detailed descriptions thereof are omitted. As shown in the figure, in this embodiment, a recess 10r is formed in the central portion of the back surface 10b of the base 10 (i.e., the central portion of the region where a plurality of semiconductor elements 2 are disposed), recessed toward the surface 10a. In other words, in the region where the recess 10r is formed, the thickness of the base 10 is smaller compared to other regions. Furthermore, the cross-sectional shape of the recess 10r is, for example, triangular. It should be noted that the recess 10r may have a rectangular cross-section or an arc-shaped cross-section.

[0083] According to the above structure, since a recess is formed in the region adjacent to the inlet 13 where the semiconductor element 2 is located, the thermal resistance of the base 10 in this region is lower than that in other regions. This promotes the heat absorption effect of the refrigerant on the semiconductor element 2, thereby cooling the semiconductor element 2 more effectively.

[0084] The fifth embodiment of this disclosure has been described above. It should be noted that various changes and modifications can be made to the above configuration without departing from the spirit of the invention. For example, in the fifth embodiment described above, an example of forming a recess 10r in the central portion of a plurality of semiconductor elements 2 was described. However, a recess 10r may also be formed directly below the central portion of each semiconductor element 2.

[0085] In addition, as is common to all embodiments, the heat sink 11 and the pin 11' can be integrally formed with the base plate 12 or they can be provided separately.

[0086] <Postscript>

[0087] For example, the cooling device 100 described in each of the following embodiments.

[0088] (1) The cooling device 100 according to the first aspect is a cooling device 100 for cooling a semiconductor element 2 packaged on the surface of a substrate 1, comprising: a base 10 mounted on the back side of the substrate 1; and a base plate 12 disposed separately from the base 10, wherein an inlet 13 for guiding refrigerant from a direction opposite to the back side is formed at a position corresponding to the semiconductor element 2 on the base plate 12.

[0089] According to the above structure, refrigerant can be directly supplied to the semiconductor element 2 from the inlet 13. As a result, the semiconductor element 2 can be cooled more effectively.

[0090] (2) The cooling device 100 involved in the second aspect has a plurality of heat sinks 11 disposed between the base 10 and the bottom plate 12.

[0091] According to the above structure, since the heat dissipation area is increased by the heat sink 11, the semiconductor element 2 can be cooled more effectively.

[0092] (3) In the cooling device 100 involved in the third aspect, the plurality of heat sinks 11 extend along a first direction d1 along the base 10 and are spaced apart along a second direction d2 that intersects the first direction d1, thereby forming a flow path F extending along the first direction d1 between each other, and the width of the flow path F gradually widens as it leaves the inlet 13 in the first direction d1.

[0093] According to the above structure, the spacing of the flow paths F between the heat sinks 11 becomes relatively narrower near the inlet 13. That is, the heat sinks 11 become relatively denser. This ensures the contact area between the heat sinks 11 and the refrigerant. As a result, the cooling effect of the refrigerant can be improved near the inlet 13 where the semiconductor element 2 is located.

[0094] (4) In the cooling device 100 involved in the fourth aspect, the spacing between the heat sinks 11 gradually widens as they leave the inlet 13.

[0095] Based on the above structure, the width of the flow path F can be changed simply by altering the spacing between the heat sinks 11. This makes the device configuration easier and more economical.

[0096] (5) In the cooling device 100 involved in the fifth aspect, as it leaves the inlet 13, the thickness of the heat sink 11 in the second direction d2 gradually decreases.

[0097] Based on the above structure, the width of the flow path F can be changed simply by altering the thickness of the heat sink 11. This makes the device configuration easier and more economical.

[0098] (6) In the cooling device 100 involved in the sixth aspect, the outermost heat sink 11 in the second direction d2 of the plurality of heat sinks 11 has a larger plate thickness compared with the other heat sinks 11.

[0099] The above structure can fully withstand the differential pressure borne by the outermost heat sink 11. This reduces the possibility of deformation of the heat sink 11.

[0100] (7) In the cooling device 100 of the seventh aspect, at least a portion of the plurality of heat sinks 11 have both ends of the first direction d1 inclined as they extend away from the back surface toward both sides of the first direction d1.

[0101] With the above structure, because the two ends of the heat sink 11 are inclined, the flow path length of the refrigerant introduced from the inlet 13 can be kept constant throughout the entire area in the height direction of the heat sink 11. As a result, the flow rate of the refrigerant is uniform throughout the entire area of ​​the heat sink 11, which can further improve the cooling effect of the heat sink 11.

[0102] (8) The cooling device 100 involved in the eighth aspect has a plurality of pins 11' disposed between the base and the bottom plate.

[0103] According to the above structure, since the heat dissipation area is increased by pin 11', the semiconductor element 2 can be cooled more effectively.

[0104] (9) In the cooling device 100 of the ninth aspect, the plurality of pins 11′ are arranged along the first direction d1 of the base 10 and spaced apart along the second direction d2 that intersects the first direction d1, thereby forming a flow path F extending in the first direction d1 between each other, wherein the width of the flow path F gradually widens as it leaves the inlet 13 in the first direction d1.

[0105] According to the above structure, the spacing of the flow paths F between the pins 11' becomes relatively narrower near the inlet 13. That is, the pins 11' become relatively denser. This ensures the contact area between the pins 11' and the refrigerant. As a result, the cooling effect of the refrigerant can be improved near the inlet 13 where the semiconductor element 2 is located.

[0106] (10) In the cooling device 100 involved in the tenth aspect, the spacing between the pins 11' gradually widens as they leave the inlet 13.

[0107] Based on the above structure, the width of the flow path F can be varied simply by changing the spacing between pins 11'. This makes the device configuration easier and more economical.

[0108] (11) In the cooling device 100 involved in the eleventh aspect, as it leaves the inlet 13, the size of the second direction d2 of the pin 11′ gradually decreases.

[0109] Based on the above structure, the width of the flow path F can be changed simply by altering the dimensions of pin 11′. This makes the device construction easier and more economical.

[0110] (12) In the cooling device 100 involved in the twelfth aspect, as the pin 11' moves away from the inlet 13, the size of the second direction d2 of the pin 11' gradually increases, while the number of the pins 11' per unit area gradually decreases.

[0111] Based on the above structure, the width of the flow path F can be varied simply by changing the size of the pins 11′ and the number (density) of the pins 11′ per unit area. This makes the device construction easier and more economical.

[0112] (13) In the cooling device 100 according to the thirteenth aspect, a recess 10r is formed in the region adjacent to the inlet 13 of the base 10, which is recessed in the direction away from the inlet 13.

[0113] According to the above structure, since a recess 10r is formed in the region adjacent to the inlet 13 where the semiconductor element 2 is located, the thermal resistance of the base 10 in this region can be reduced. As a result, the semiconductor element 2 can be cooled more effectively.

Claims

1. A cooling device for cooling a semiconductor element packaged on the surface of a substrate, comprising: A base, which is mounted on the back side of the substrate; and A base plate, which is configured separately from the base; At the position corresponding to the semiconductor element on the base plate, an inlet is formed that guides the refrigerant from a direction opposite to the back surface. The cooling device has multiple heat dissipation fins disposed between the base and the bottom plate. The plurality of heat sinks extend in a first direction along the base and are spaced apart in a second direction intersecting the first direction, thereby forming flow paths between each other that extend in the first direction, and the width of the flow paths gradually widens as they leave the inlet in the first direction.

2. The cooling device according to claim 1, wherein, As they leave the inlet, the spacing between the heat sinks gradually widens.

3. The cooling device according to claim 1 or 2, wherein, As it leaves the inlet, the thickness of the heat sink in the second direction gradually decreases.

4. The cooling device according to claim 1 or 2, wherein, The outermost heat sink in the second direction among the plurality of heat sinks has a larger plate thickness compared to the other heat sinks.

5. The cooling device according to claim 1 or 2, wherein, In at least a portion of the plurality of heat sinks, the two ends in the first direction are inclined as they extend away from the back surface toward both sides in the first direction.

6. The cooling device according to claim 1 or 2, wherein, In the region adjacent to the inlet of the base, a recess is formed that is recessed in the direction away from the inlet.

7. A cooling device for cooling a semiconductor element packaged on the surface of a substrate, comprising: A base, which is mounted on the back side of the substrate; and A base plate, which is configured separately from the base; At the position corresponding to the semiconductor element on the base plate, an inlet is formed that guides the refrigerant from a direction opposite to the back surface. The cooling device has a plurality of pins disposed between the base and the bottom plate. The plurality of pins are arranged in a first direction along the base and spaced apart in a second direction intersecting the first direction, thereby forming flow paths between each other that extend in the first direction and whose width gradually increases as they leave the inlet in the first direction.

8. The cooling device according to claim 7, wherein, As they leave the inlet, the spacing between the pins gradually widens.

9. The cooling device according to claim 7 or 8, wherein, As the pin leaves the inlet, its size in the second direction gradually decreases.

10. The cooling device according to claim 7 or 8, wherein, As the pin leaves the inlet, its size in the second direction gradually increases, while the number of pins per unit area gradually decreases.

11. The cooling device according to claim 7 or 8, wherein, In the region adjacent to the inlet of the base, a recess is formed that is recessed in the direction away from the inlet.

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