Semiconductor device and method for manufacturing the same

Abstract

The object of the present invention is to provide a semiconductor device and a manufacturing method thereof that can suppress the influence of dimensional tolerance. The semiconductor device of the present invention comprises: a plurality of cooling plates (1), each of which has a cooling medium passage (11) inside; a spacer (5) that separates and stacks the cooling plates (1); a semiconductor package (2) that is arranged on at least one main surface of at least one cooling plate (1); and a spring plate (4) that is arranged between adjacent cooling plates (1) to preload the semiconductor package (2) toward the cooling plate (1).

Description

Technical Field

[0001] The present invention relates to a semiconductor device and a method for manufacturing the same, and in particular, to a structure of a semiconductor device used in a power control device and the like and a method for manufacturing the same. Background Art

[0002] Currently, a semiconductor device is disclosed, which comprises: a plurality of cooling tubes having refrigerant passages therein; a semiconductor package fixed to a main surface of each cooling tube; a sealed spacer, which stacks the plurality of cooling tubes into a partition-shaped cooling structure in a separated configuration, and the sealed spacer is used to maintain airtightness at the ends of the cooling structure; and a header, which is arranged at one end and the other end of the cooling structure so that an opening for the refrigerant to enter and exit each cooling tube is airtightly connected to the sealed spacer (for example, refer to patent document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2013-26368 Summary of the invention

[0004] In Patent Document 1, when assembling the semiconductor device, there is a possibility that the cooling pipe may be deformed due to the influence of the dimensional tolerance of each component constituting the semiconductor device.

[0005] The present invention has been made to solve such a problem, and an object of the present invention is to provide a semiconductor device and a method for manufacturing the semiconductor device capable of suppressing the influence of dimensional tolerance.

[0006] In order to solve the above-mentioned problems, the semiconductor device involved in the present invention has: a plurality of cooling plates, each of which has a refrigerant passage inside; a spacer that allows the cooling plates to be stacked separately; a semiconductor package that is arranged on at least one main surface of at least one cooling plate; and a spring plate that is arranged between adjacent cooling plates to pre-tighten the semiconductor package toward the cooling plate side.

[0007] Effects of the Invention

[0008] According to the present invention, a semiconductor device comprises: a plurality of cooling plates, each of which has a refrigerant passage inside; a spacer that allows the cooling plates to be stacked separately; a semiconductor package that is arranged on at least one main surface of at least one cooling plate; and a spring plate that is arranged between adjacent cooling plates to pre-tighten the semiconductor package toward the cooling plate side, thereby suppressing the influence of dimensional tolerances.

[0009] The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0011] Figure 2 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0012] Figure 3 This is a diagram showing an example of a cooling plate according to an embodiment of the present invention.

[0013] Figure 4 It is a cross-sectional view showing an example of a cooling plate according to an embodiment of the present invention.

[0014] Figure 5 FIG. 1 is a diagram showing an example of a semiconductor package according to an embodiment of the present invention.

[0015] Figure 6 It is a diagram showing an example of a spring plate according to an embodiment of the present invention.

[0016] Figure 7 It is a diagram showing an example of a spacer according to an embodiment of the present invention.

[0017] Figure 8 This is a diagram showing an example of a cover according to an embodiment of the present invention.

[0018] Fig. 9 This is a diagram showing an example of a tube according to an embodiment of the present invention.

[0019] Fig.10 It is a diagram showing an example of a manufacturing process of a semiconductor device according to an embodiment of the present invention.

[0020] Fig.11 It is a diagram showing an example of a manufacturing process of a semiconductor device according to an embodiment of the present invention.

[0021] Fig.12 It is a diagram showing an example of a manufacturing process of a semiconductor device according to an embodiment of the present invention.

[0022] Fig.13 It is a diagram showing an example of a manufacturing process of a semiconductor device according to an embodiment of the present invention.

[0023] Fig.14 It is a diagram showing an example of a manufacturing process of a semiconductor device according to an embodiment of the present invention.

[0024] Fig.15 It is a diagram showing an example of a manufacturing process of a semiconductor device according to an embodiment of the present invention.

[0025] Fig.16 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0026] Fig.17 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0027] Fig.18 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0028] Fig.19 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0029] Fig. 20 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0030] Fig.21 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0031] Fig. 22 It is a diagram showing an example of the arrangement of the spring plates according to the embodiment of the present invention.

[0032] Fig.23 It is a diagram showing an example of the arrangement of the spring plates according to the embodiment of the present invention.

[0033] Fig.24 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0034] Fig.25 This is a diagram showing an example of a cooling plate according to an embodiment of the present invention.

[0035] Fig.26 This is a diagram showing an example of a cooling plate according to an embodiment of the present invention.

[0036] Fig. 27 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0037] Fig.28 FIG. 1 is a diagram showing an example of a semiconductor package according to an embodiment of the present invention.

[0038] Fig.29 This is a diagram showing an example of a cooling plate according to an embodiment of the present invention.

[0039] Fig.30 This is a diagram showing an example of a cooling plate according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] Embodiments of the present invention will be described below with reference to the drawings.

[0041] <Implementation Method>

[0042] <Structure>

[0043] Figure 1 , 2 FIG. 1 is a diagram showing an example of a structure of a semiconductor device according to an embodiment of the present invention.

[0044] like Figure 1 , 2 As shown, the semiconductor device includes a cooling plate 1 , a semiconductor package 2 , heat dissipating grease 3 , a spring plate 4 , a spacer 5 , a tube 6 , a cover 7 , screws 8 , and nuts 9 .

[0045] Cooling plate 1 Figure 3 , 4 As shown, the cooling plate 1 has a screw hole 10 for the screw 8 to pass through and a coolant passage 11 for circulating a coolant such as water. Specifically, the cooling plate 1 has a coolant passage 11 in the stacking direction of the cooling plate 1 and in a direction perpendicular to the stacking direction. In the coolant passage 11, cooling fins 13 are provided to improve the cooling efficiency. An O-ring 12 is provided in the coolant passage 11. Figure 1 , 2 In the example of , five cooling plates 1 are stacked at intervals. In order to prevent deformation when the nut 9 is tightened to the screw 8, the uppermost and lowermost cooling plates 1 among the cooling plates 1 need to have higher rigidity than the other cooling plates 1. For example, the material of the uppermost and lowermost cooling plates 1 is an aluminum alloy, and the material of the other cooling plates 1 is thin pure aluminum. By using these materials, a thermal resistance suitable for cooling the semiconductor package 2 can be obtained.

[0046] Semiconductor package 2 such as Figure 5 As shown, it is a molded power module with a 2-in-1 package having an IGBT (Insulated Gate Bipolar Transistor) and a FWD (Free Wheeling Diode) inside. That is, the semiconductor package 2 is a 2-in-1 package having an upper bridge arm circuit and a lower bridge arm circuit. The semiconductor package 2 is set on the cooling plate 1 via the heat dissipation grease 3. The heat dissipation grease 3 has the function of dissipating the heat generated by the semiconductor package 2 to the cooling plate 1. Figure 1 , 2 In the example, a semiconductor package 2 is provided on the lower surface of the top cooling plate 1, and a semiconductor package 2 is provided on the upper surface of the bottom and second cooling plates 1 from the bottom. In addition, semiconductor packages 2 are provided on both surfaces of other cooling plates 1.

[0047] The spring plate 4 is disposed between adjacent cooling plates 1 to preload the semiconductor package 2 toward the cooling plate 1. Figure 1 , 2 In the example, the spring plate 4 is provided between the second cooling plate 1 from the bottom and the semiconductor package 2, and the spring plate 4 is provided between the semiconductor packages 2. The shape of the spring plate 4 is as follows: Figure 6 As shown, it is in a corrugated shape.

[0048] Spacer 5 Figure 7 As shown, there are screw holes 10 and refrigerant passages 11. In addition, the spacers 5 are provided to separate adjacent cooling plates 1. That is, the spacers 5 are provided to separate and stack the cooling plates 1.

[0049] Cover 7 Figure 8 As shown, the cover 7 has a screw hole 10, and the cover 7 blocks the refrigerant passage 11 provided in the cooling plate 1. Fig. 9 As shown, the tube 6 has a screw hole 10 and a refrigerant passage 11, and the tube 6 has the function of an inlet or outlet for the refrigerant. Figure 1 , 2 In the example of FIG. 5 , if the coolant flows in from one tube 6, the coolant passes through the coolant passages of the cooling plate 1 and the spacer 5 and flows out from the other tube 6. Thus, the heat generated in the semiconductor package 2 can be effectively reduced.

[0050] The screws 8 are passed through the screw holes 10 of the tube 6 , the cooling plate 1 , the spacer 5 , and the cover 7 , and are tightened by the nuts 9 , thereby fixing the tube 6 , the cooling plate 1 , the spacer 5 , and the cover 7 .

[0051] <Manufacturing method>

[0052] Figures 10 to 15 It is a diagram showing an example of a manufacturing process of the semiconductor device involved in this embodiment.

[0053] like Fig.10 As shown in FIG. 1 , a semiconductor package 2 is placed on the upper surface of the cooling plate 1 via a heat dissipating grease 3. Next, as shown in FIG. Fig.11 As shown, a pipe 6 is provided on the lower surface of the cooling plate 1 , and screws 8 are passed through screw holes 10 of the cooling plate 1 and the pipe 6 .

[0054] Next, if Fig.12 As shown, a spring plate 4 is placed on the semiconductor package 2. In addition, screws 8 are passed through screw holes 10 of the spacer 5, and the spacer 5 is placed on the cooling plate 1.

[0055] Next, if Fig.13As shown in the figure, the semiconductor package 2 is set on the upper surface of the cooling plate 1 via the heat dissipation grease 3. Then, the screws 8 are passed through the screw holes 10 of the cooling plate 1, and the cooling plate 1 is set on the spacer 5 and the spring plate 4. Thereafter, the spring plate 4 is set on the semiconductor package 2. In addition, the screws 8 are passed through the screw holes 10 of the spacer 5, and the spacer 5 is set on the cooling plate 1.

[0056] Next, the semiconductor package 2 is placed on both sides of the cooling plate 1 via the heat dissipating grease 3. Then, the screws 8 are passed through the screw holes 10 of the cooling plate 1, and the cooling plate 1 is placed on the spacer 5 and the spring plate 4. Thereafter, the spring plate 4 is placed on the semiconductor package 2. In addition, the screws 8 are passed through the screw holes 10 of the spacer 5, and the spacer 5 is placed on the cooling plate 1. This operation is repeated twice.

[0057] Next, the semiconductor package 2 is placed on the lower surface of the cooling plate 1 via the heat dissipation grease 3. Then, the screws 8 are passed through the screw holes 10 of the cooling plate 1, and the cooling plate 1 is placed on the spacer 5 and the spring plate 4. After the steps so far, Fig.14 Status shown.

[0058] Next, if Fig.15 As shown, the screw 8 is passed through the screw hole 10 of the cover 7, and the cover 7 is set on the upper surface of the cooling plate 1. Finally, the nut 9 is tightened to the end of the screw 8. In this way, the tube 6, the cooling plate 1, the spacer 5 and the cover 7 are fixed. At this time, the refrigerant passage 11 of the cooling plate 1 is connected to the refrigerant passage 11 of the spacer 5 via the O-ring 12. By tightening the nut 9, pressure is applied to the O-ring 12, and the airtightness of the refrigerant passage 11 at the joint between the cooling plate 1 and the spacer 5 can be ensured.

[0059] After the above manufacturing process, the Figure 1 , 2 The semiconductor device of the stacked structure shown in FIG. Figure 1 , 2 In the example of , the semiconductor device is a 14-in-1 semiconductor device having two elements constituting a boost converter, six elements constituting a regenerative inverter, and six elements constituting a traction inverter.

[0060] As described above, according to the present embodiment, since the spring plate 4 is provided between the adjacent cooling plates 1 , it is possible to suppress the influence of the dimensional tolerance of the semiconductor device having a stacked structure.

[0061] <Modification>

[0062] Hereinafter, modifications of the semiconductor device according to the present embodiment will be described.

[0063] <Variation 1>

[0064] exist Figure 1 , 2 In the above description, the case where the semiconductor package 2 is a 2-in-1 package including an upper arm circuit and a lower arm circuit is described, but the present invention is not limited to this.

[0065] For example, Fig.16 As shown, the semiconductor package 2 may be a 1-in-1 package having either an upper arm circuit or a lower arm circuit. As described above, the structure of the semiconductor package 2 can be arbitrarily selected.

[0066] <Variation 2>

[0067] The number of semiconductor packages 2 disposed on the cooling plate 1 may be one or more. Fig.17 As shown in FIG. 1 , by providing a semiconductor package 2 on the cooling plate 1, a 2-in-1 semiconductor device constituting a boost converter can be realized. Fig.18 As shown in FIG. 1 , by arranging three semiconductor packages 2 on the cooling plate 1, a 6-in-1 semiconductor device constituting a traction inverter or a regenerative inverter can be realized. Fig.19 As shown, by arranging three semiconductor packages 2 on the upper surface of the lower cooling plate 1 and arranging three semiconductor packages 2 on the lower surface of the upper cooling plate 1, a 12-in-1 semiconductor device constituting a traction inverter and a regenerative inverter can be realized. As described above, the structure of the semiconductor package 2 and the method of arranging it relative to the cooling plate 1 can be arbitrarily selected.

[0068] In addition, Figures 17 to 19 In the above description, the case where two cooling plates 1 are stacked is described, but the present invention is not limited to this. For example, Fig.17 The structure and Fig.18 The structure can also be a structure formed by stacking Fig.17 The structure and Fig.19 The structure is composed of stacked structures.

[0069] <Variation 3>

[0070] The number of stacked semiconductor packages 2 can be freely selected. In other words, the number of stacked cooling plates 1 can also be variable. Fig. 20 As shown in FIG. 1 , a 6-in-1 semiconductor device constituting a traction inverter or a regenerative inverter can be realized. Fig.21 As shown, a 12-in-1 semiconductor device constituting a traction inverter and a regenerative inverter can be realized.

[0071] <Variation 4>

[0072] The semiconductor package 2 may include an insulating layer such as an insulating sheet inside. This allows the semiconductor package 2 to be insulated from the cooling plate 1 .

[0073] In addition, an insulating substrate may be provided outside the semiconductor package 2, that is, between the semiconductor package 2 and the cooling plate 1. Thus, the semiconductor package 2 and the cooling plate 1 can be insulated.

[0074] <Variant 5>

[0075] The configuration of the spring plate 4 is arbitrary. Fig. 22 As shown, the spring plate 4 can also be arranged so that the direction of forming the corrugations is perpendicular to the stacking direction of the cooling plate 1. Fig.23 As shown, the spring plate 4 can also be arranged so that the direction in which the corrugations are formed is parallel to the stacking direction of the cooling plates 1 .

[0076] <Variant 6>

[0077] like Fig.24 As shown, the semiconductor package 2 can use a semiconductor package with a mirror-type arrangement of main terminals. By combining the mirror-type semiconductor packages 2, the main terminals of each semiconductor package 2 can be aligned in the stacking direction, so that the arrangement of the main terminals between the semiconductor packages 2 can be optimized.

[0078] <Variant 7>

[0079] like Fig.25 As shown, the cooling plate 1 may also have a recess 14. That is, the cooling plate 1 may also have a recess 14 on the surface where the semiconductor package 2 is provided, and the recess 14 is used to provide the heat dissipation grease 3. By setting it as the above structure, it is possible to prevent the heat dissipation grease 3 from pumping out.

[0080] <Variant 8>

[0081] like Fig.26 As shown, the cooling plate 1 may include ribs 15. By adopting the above-mentioned structure, the mechanical strength of the cooling plate 1 can be improved.

[0082] <Variant 9>

[0083] like Fig. 27 As shown, the position of the tube 6 can be changed arbitrarily. Fig. 27 In the example of , the refrigerant flows in from the lower tube 6, and the refrigerant flows out from the upper tube 6. By setting it as the above structure, the refrigerant passage can be arbitrarily selected.

[0084] <Variation 10>

[0085] The semiconductor package 2 may include a semiconductor element mainly composed of SiC. Here, the main component refers to a component whose proportion relative to the whole is prominent compared to the non-main component, for example, a component that is present at a proportion several tens times or more compared to the non-main component.

[0086] <Variation 11>

[0087] The cooling plate 1 may have the cooling medium passage 11 in the stacking direction, and may not have the cooling medium passage 11 in the direction perpendicular to the stacking direction. Figure 4 In the embodiment, the cooling medium passage 11 is not provided in the portion where the cooling fins 13 are provided. In this case, the cooling plate 1 is formed of a material with high rigidity such as iron. In addition, the cooling plate 1 may be a cooling plate 1 that is a part of a plurality of stacked cooling plates 1.

[0088] By adopting the above-mentioned structure, the mechanical strength of the stack structure can be increased.

[0089] <Variation 12>

[0090] like Fig.28 As shown, the semiconductor package 2 may include a protrusion 16 for defining the installation position of the spring plate 4. The protrusion 16 is formed when the semiconductor package 2 is transfer molded. With the above-mentioned structure, the spring plate 4 can be positioned.

[0091] <Variation 13>

[0092] like Fig.29 As shown in FIG. 1 , the cooling plate 1 may also have a protrusion 17 for defining the installation position of the semiconductor package 2. Fig.30 As shown, the cooling plate 1 may include a recessed portion 18 for defining the installation position of the semiconductor package 2 .

[0093] With the above-described structure, the semiconductor package 2 can be positioned.

[0094] In addition, the present invention can appropriately modify or omit the embodiments within the scope of the invention.

[0095] While the present invention has been described in detail, the above description is in all aspects illustrative and the invention is not limited thereto, and it is understood that numerous modifications not shown here are conceivable without departing from the scope of the invention.

[0096] Description of the label

[0097] 1 cooling plate, 2 semiconductor package, 3 heat dissipation grease, 4 spring plate, 5 spacer, 6 pipe, 7 cover, 8 screw, 9 nut, 10 screw hole, 11 refrigerant passage, 12 O-ring, 13 cooling fin, 14 recess, 15 rib, 16 protrusion, 17 protrusion, 18 recess.

Claims

1. A semiconductor device comprising: A plurality of cooling plates, each of which has a refrigerant passage therein; A spacer that allows the cooling plates to be stacked separately; a semiconductor package disposed on at least one main surface of at least one of the cooling plates; as well as A spring plate is disposed between adjacent cooling plates to preload the semiconductor package toward the cooling plate. Between the adjacent cooling plates, two semiconductor packages are arranged in the stacking direction, and the spring plate is arranged between the two semiconductor packages. Each of the cooling plates has a protrusion that defines a position at which the semiconductor package is installed on the main surface. The protrusion is provided along two opposite surfaces of the semiconductor package, and the protrusion is located outside the two opposite surfaces of the semiconductor package. The spacer is provided independently of the protrusion. At least one of the cooling plates has the coolant passage in the stacking direction and does not have the coolant passage in a direction perpendicular to the stacking direction.

2. The semiconductor device according to claim 1, wherein: The cooling plates at the uppermost layer and the lowermost layer of the stack of cooling plates have higher rigidity than the other cooling plates.

3. The semiconductor device according to claim 1 or 2, characterized in that: The semiconductor package includes a 2-in-1 package having an upper bridge arm circuit and a lower bridge arm circuit.

4. The semiconductor device according to claim 1 or 2, characterized in that: The semiconductor package includes a 1-in-1 package having either an upper arm circuit or a lower arm circuit.

5. The semiconductor device according to claim 1 or 2, characterized in that: With respect to at least one of the cooling plates, a plurality of the semiconductor packages are provided on at least one main surface of the cooling plate.

6. The semiconductor device according to claim 1 or 2, characterized in that: The number of stacked layers of the cooling plates is variable.

7. The semiconductor device according to claim 1 or 2, characterized in that: The semiconductor package has an insulating layer inside.

8. The semiconductor device according to claim 1 or 2, characterized in that: An insulating substrate is further provided between the semiconductor package and the cooling plate.

9. The semiconductor device according to claim 1 or 2, characterized in that: The spring plate is in a corrugated shape.

10. The semiconductor device according to claim 9, wherein: The spring plate is arranged such that a direction in which corrugations are formed is parallel to the stacking direction.

11. The semiconductor device according to claim 9, wherein: The spring plate is arranged such that a direction in which corrugations are formed is perpendicular to the stacking direction.

12. The semiconductor device according to claim 1 or 2, characterized in that: The semiconductor package is provided with a plurality of components in the stacking direction. Main terminals of the semiconductor packages are aligned in the stacking direction.

13. The semiconductor device according to claim 1 or 2, characterized in that: The cooling plate has a recessed portion on a surface where the semiconductor package is disposed, and the recessed portion is used to dispose grease.

14. The semiconductor device according to claim 1 or 2, characterized in that: The cooling plate has ribs.

15. The semiconductor device according to claim 1 or 2, characterized in that: A pipe for supplying a coolant to the coolant passage of each of the cooling plates is further provided.

16. The semiconductor device according to claim 1 or 2, characterized in that: The semiconductor package includes a semiconductor element mainly composed of SiC.

17. The semiconductor device according to claim 1 or 2, characterized in that: The semiconductor package has a protrusion that defines a position at which the spring plate is to be installed.

18. A method for manufacturing a semiconductor device, which is the method for manufacturing a semiconductor device according to claim 1, The method for manufacturing a semiconductor device comprises the following steps: (a) preparing a plurality of cooling plates including at least one cooling plate having the semiconductor package provided on at least one main surface thereof; and (b) The spring plate is disposed on the semiconductor package, and the plurality of cooling plates are stacked with the spacer interposed therebetween.

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