JP2019079839A - Semiconductor power module - Google Patents

Abstract

To obtain a semiconductor power module in which overheat prevention related to destruction of a plurality of semiconductor elements is realized by one temperature detection element.SOLUTION: A semiconductor power module includes an insulating substrate, a plurality of semiconductor elements disposed on one surface of the insulating substrate via a die bonding material, a dissipation plate provided on the other surface of the insulating substrate, and a temperature detection element provided in one of the plurality of semiconductor elements, and the thermal resistance from the surface in contact with the die bonding material of the semiconductor element provided with the temperature detection element to the other surface not in contact with the insulating substrate of the heat dissipation plate is larger than the thermal resistance from the surface in contact with the die bonding material of the semiconductor element without the temperature detection element to the other surface not in contact with the insulating substrate of the dissipation plate.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a semiconductor power module used in a power conversion device mounted on an electrically powered vehicle such as a plug-in hybrid vehicle or an electric vehicle.

  The semiconductor power module is suitable for use at high voltage and large current, and is not limited to electric vehicles, but is widely used in many products from industrial equipment to home appliances and information terminals, and is used in many power conversion devices. The power conversion device is a device having a switching circuit for controlling power, and is connected to a motor drive inverter mounted on an electric vehicle, a step-down converter for converting high voltage into low voltage, and external power supply equipment. An electric power component such as a charger for charging an on-vehicle battery is applicable. The power converter comprises a plurality of semiconductor power modules.

  The semiconductor power module mainly includes a plurality of semiconductor elements for controlling electric power, a substrate on which the semiconductor elements are disposed, and a circuit wiring electrically connected to the semiconductor elements, and the semiconductor as needed. The control IC of the element is also included. The semiconductor elements constituting the semiconductor power module tend to generate a large amount of heat because they handle high voltage and large current. In order to avoid destruction of the semiconductor element resulting from heat generation, it is important to grasp the operating temperature of each semiconductor element.

  In a conventional semiconductor power module, a diode for temperature detection is provided in each of a plurality of semiconductor elements. The respective temperature detection diodes are connected in parallel to each other, and based on the output voltage in this state, the temperature detection of the semiconductor power module is performed via the temperature detection circuit. From the temperature detection result obtained, destruction due to heat generation of each semiconductor element is prevented (see, for example, Patent Document 1).

JP 10-38964 A

  In Patent Document 1 described above, a diode for temperature detection is incorporated in each semiconductor element in order to prevent excessive temperature rise, that is, to prevent breakage due to heat generation of the semiconductor element. However, in the temperature detection method of such a semiconductor power module, a temperature difference of 14 ° C. is generated between the respective semiconductor elements by parallel connection of three diodes for temperature detection, so an excessive margin for the allowable temperature is required. It becomes. Therefore, when the output of the power conversion device is increased, there is a problem that the size of the semiconductor power module is increased according to the margin. In addition, since a diode for temperature detection is provided in all the semiconductor elements, there is also a problem that the manufacturing process becomes complicated and the cost of the semiconductor element is greatly increased by the addition of the manufacturing process for forming the diode for temperature detection. . If all the semiconductor elements are provided with diodes for temperature detection, the size of the semiconductor elements becomes large, which causes a problem of a significant increase in cost. In addition, there is also a problem that a semiconductor power module including a plurality of semiconductor devices and a power conversion apparatus including the plurality of semiconductor power modules increase in size due to the enlargement of semiconductor devices. Furthermore, since it is necessary to connect a plurality of diodes for temperature detection to the temperature detection circuit, there is also a problem that the space for wiring management is increased, and the semiconductor power module and the power conversion device are enlarged.

  In recent years, the use of wide band gap semiconductors such as silicon carbide and gallium nitride based materials for semiconductor elements used in semiconductor power modules is increasing. Since the wide band gap semiconductor has many element defects of the base material, the yield is increased by reducing the size of the semiconductor element. Therefore, in order to reduce the manufacturing cost of a high-power semiconductor power module, it is required to reduce the size of the wide band gap semiconductor device and connect a plurality of devices in parallel. However, the above-described enlargement of the semiconductor device is a particularly serious problem in the use of a wide band gap semiconductor using a plurality of devices.

  A semiconductor power module according to the present invention comprises: an insulating substrate; a plurality of semiconductor elements respectively disposed on one surface of the insulating substrate via a die bonding material; and a heat sink provided on the other surface of the insulating substrate. A temperature detection element provided in one semiconductor element among a plurality of semiconductor elements, from the surface in contact with the die bonding material of the semiconductor element provided with the temperature detection element to the other surface not in contact with the insulating substrate of the heat sink The thermal resistance is larger than the thermal resistance from the surface in contact with the die bonding material of the semiconductor element not provided with the temperature detection element to the other surface not in contact with the insulating substrate of the heat dissipation plate.

  According to the semiconductor power module according to the present invention, it is possible to realize the excessive temperature rise prevention relating to the destruction of a plurality of semiconductor elements with one temperature detection element.

It is a circuit diagram of the main circuit of the inverter using a semiconductor power module. It is a block diagram which shows an example of the hardware of a control circuit unit. FIG. 1 is a perspective view showing a schematic configuration of a semiconductor power module according to Embodiment 1 of the present invention. It is sectional drawing which shows schematic structure of the semiconductor power module which concerns on Embodiment 1 of this invention. It is sectional drawing which shows schematic structure of MOSFET of a vertical structure. It is sectional drawing which shows schematic structure of MOSFET of horizontal structure. FIG. 1 is a plan view of a semiconductor element and a solder according to Embodiment 1 of the present invention. It is a flowchart of control in Embodiment 1 of this invention. It is sectional drawing which shows schematic structure of another semiconductor power module which concerns on Embodiment 1 of this invention. It is sectional drawing which shows schematic structure of another semiconductor power module which concerns on Embodiment 1 of this invention. It is sectional drawing which shows schematic structure of the semiconductor power module which concerns on Embodiment 2 of this invention. It is sectional drawing which shows schematic structure of the semiconductor power module which concerns on Embodiment 3 of this invention. It is sectional drawing which shows schematic structure of the semiconductor power module which concerns on Embodiment 4 of this invention. It is a back view which shows schematic structure of another semiconductor power module which concerns on Embodiment 4 of this invention.

Embodiment 1
FIG. 1 is a circuit diagram of a main circuit 100 of an inverter which is a power conversion device using semiconductor power modules 1a to 1f. The main circuit 100 includes a control circuit unit 101 provided with a total of six semiconductor power modules 1a to 1f and connected to the temperature detection element 3 included in the semiconductor power modules 1a to 1f. The connection is made by the signal terminal 9. The main circuit 100 is composed of three phases of U phase, V phase and W phase. Each phase is composed of two arms, an upper arm and a lower arm, and each arm is provided with a semiconductor power module. For example, in the U-phase, the semiconductor power module 1a of the upper arm and the semiconductor power module 1b of the lower arm are provided. The semiconductor power modules 1a to 1f respectively include main circuit wires 8a and 8b. The main circuit wires 8a and 8b are terminals related to the output and the input of the semiconductor power modules 1a to 1f. In the circuit diagram shown in FIG. 1, the main circuit wiring 8b of the semiconductor power modules 1a, 1c, 1e constituting the upper arm and the main circuit wiring 8a of the semiconductor power modules 1b, 1d, 1f constituting the lower arm are combined with the capacitor 102. Connected The main circuit wiring 8a of the semiconductor power modules 1a, 1c and 1e constituting the upper arm is the U-phase and V phases of the main circuit wiring 8b of the semiconductor power modules 1b, 1d and 1f constituting the lower arm and the drive motor 103. It is connected with the phase and W phase. The control circuit unit 101 controls the power input to each semiconductor module according to the temperature detected by the temperature detection element 3. Specifically, although not shown, the control circuit unit 101 is connected to the power supply side of the power conversion device, and reduces, for example, the voltage applied to each semiconductor module.

  The control circuit unit 101 includes a processor 104 and a storage device 105 as an example of hardware is shown in FIG. Although the storage device is not shown, it comprises volatile storage devices such as random access memory and non-volatile auxiliary storage devices such as flash memory. Also, instead of the flash memory, an auxiliary storage device of a hard disk may be provided. The processor 104 executes a program input from the storage device 105. In this case, a program is input from the auxiliary storage device to the processor 104 via the volatile storage device. Further, the processor 104 may output data such as the operation result to the volatile storage device of the storage device 105, or may store the data in the auxiliary storage device via the volatile storage device.

  FIG. 3 is a perspective view showing a schematic configuration of the semiconductor power module 1a according to the first embodiment of the present invention, and FIG. 4 is a cross section showing a schematic configuration of the semiconductor power module 1a according to the first embodiment of the present invention. FIG. In FIG. 3, the main circuit wires 8a and 8b are omitted for easy understanding of the schematic configuration. FIG. 4 is a cross-sectional view taken along a broken line A-A in FIG. 3 and the electrode pads of each semiconductor element are omitted. The semiconductor power module 1a is a main circuit wiring 8a in which a plurality of semiconductor elements 2a to 2f are disposed on the conductive pattern 5 provided on the insulating substrate 6 via solders 4 and 4a and main input / output is performed, 8b is provided. Each component will be described in detail below.

  The semiconductor elements 2a to 2f are, for example, IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors). The basic structures of the semiconductor elements 2a to 2f include a horizontal structure in which current flows only in the direction of the surface of the element substrate which is a base material, and a vertical structure in which current flows in the sectional direction of the element substrate. In the case of the lateral structure, the electrode pad is formed only on one side of the element substrate. On the other hand, in the case of the vertical structure, electrode pads are formed on both sides of the element substrate. FIG. 5 shows a schematic cross-sectional configuration of the vertical MOSFET, and FIG. 6 shows a schematic cross-sectional configuration of the lateral MOSFET. In the vertical structure, the source pad 13 (including the main circuit and control) and the gate pad 14 are formed on the surface of the element substrate 12, and the drain pad 15 is formed on the back surface. In the lateral structure, the source pad 13 (including the main circuit and control), the gate pad 14 and the drain pad 15 are formed on the surface of the element substrate 12. For the element substrate 12, a wide band gap semiconductor such as silicon, silicon carbide, gallium nitride based material, or diamond is used. Each electrode pad is made of, for example, aluminum. Here, an example using a MOSFET using silicon as the element substrate 12 in a vertical structure corresponding to a high voltage or a large current is shown.

  In the semiconductor power module 1a, a total of six semiconductor elements 2a to 2f are arranged in two rows. Each divided region of the surface of the semiconductor elements 2a to 2f is an electrode pad. The temperature detection element 3 is a diode for temperature detection which is built in only the semiconductor element 2a installed at the end. The diode for temperature detection is integrally manufactured in the manufacturing process of the semiconductor element 2a. By using a diode built in the semiconductor element 2a, it is possible to detect the temperature of the semiconductor element 2a with high accuracy. In addition, the diode can be operated up to near the allowable temperature limit of the semiconductor element 2a. The temperature detection element 3 is not limited to the above-described diode for temperature detection, and may be a thermistor.

  The signal terminal 9 is a terminal that connects the temperature detection element 3 and the control circuit unit 101. The signal terminal 9 is a conductive metal, and is made of, for example, a copper material. The temperature detection element 3 and the signal terminal 9 are connected by a conductive wire 10. The material of the wire 10 is, for example, aluminum or gold. Since the signal terminal 9 is provided only in proximity to the semiconductor element 2a, the length of the wire 10 is short, the number is as small as one, the routing is minimized, and the space is small. Thereby, the semiconductor power module 1a can be miniaturized.

  The conductive pattern 5 is a conductive metal pattern joined to the drain pad 15 on the back surface of the semiconductor elements 2a to 2f, and is, for example, a copper pattern. Bonding is performed via the solder 4 which is a die bonding material. Since the drain pads 15 are bonded onto the same conductive pattern 5, they have the same potential. A resist 11 is provided on the surface of the conductive pattern 5 on which the semiconductor elements 2a to 2f are not provided. The resist 11 is a film having an insulating property, protects the surface of the conductive pattern 5, and suppresses discharge with each wiring or surface electrode.

  FIG. 7 is a plan view of the semiconductor elements 2a to 2f and the solders 4a and 4 according to the first embodiment of the present invention. The thermal resistance from the surface in contact with the solder 4a which is the die bonding material of the semiconductor element 2a provided with the temperature detection element 3 to the other surface not in contact with the insulating substrate 6 of the heat sink 7 does not have the temperature detection element 3 provided. It is configured to be larger than the thermal resistance from the surface of the semiconductor elements 2b to 2f in contact with the solder 4 to the other surface of the heat sink 7 not in contact with the insulating substrate 6. By configuring the area of the solder 4a to be bonded to the conductive pattern 5 smaller than the area to be bonded to the conductive pattern 5 of the solder 4, the thermal resistance is increased. The area of the solder 4 can be adjusted by changing the area of the resist 11 on the conductive pattern 5 or changing the amounts of the solder 4 a and the solder 4 supplied. By using a solder widely used as a die bonding material, the semiconductor elements 2a to 2f are joined at low cost in an easy process.

  The insulating substrate 6 is a substrate composed of an insulating ceramic material, and is made of, for example, aluminum nitride having excellent thermal conductivity. The conductive pattern 5 is provided on one surface, and the semiconductor elements 2a to 2f are provided. The heat sink 7 is provided on the other side.

  The heat sink 7 is joined to the other surface of the insulating substrate 6 facing the conductive pattern 5 by, for example, solder. The heat sink 7 is a metal member for promoting heat radiation, and is made of, for example, copper or aluminum excellent in thermal conductivity. In order to further promote heat dissipation, cooling fins may be further provided on the other surface facing the insulating substrate 6.

  The main circuit wires 8a and 8b are terminals connected to the outside of the semiconductor power module 1a with respect to the input and output of the semiconductor elements 2a to 2f. The main circuit wirings 8a and 8b are conductive metal bus bars and are made of, for example, a copper material. The main circuit wiring 8a is connected to the source pads for the main circuit of the semiconductor elements 2a, 2b and 2c, and is folded back on the semiconductor element 2a at the end and parallel to the connection with the semiconductor elements 2b and 2c. Arranged in two layers. This is to reduce parasitic inductance. The main circuit wiring 8 b is connected to the conductive pattern 5. Although not shown here, the semiconductor power module 1a has terminals other than the main circuit wires 8a and 8b, and these terminals are connected to control source pads and gate pads via wires. In addition, these terminals are connected to the control circuit unit 101. These wires, terminals, and wires are sealed with an insulating resin.

  Next, the operation of the semiconductor power module 1a according to the first embodiment of the present invention will be described. The heat generated in the semiconductor elements 2a to 2f during operation is transmitted to the heat sink 7 mainly from the back surface of the semiconductor elements 2a to 2f through the solder 4, the solder 4a, the conductive pattern 5 and the insulating substrate 6, and dissipated Ru. Since the area of the solder 4a in contact with the semiconductor element 2a provided with the temperature detection element 3 is small and the thermal resistance is large compared to the other solders 4, the temperature of the semiconductor element 2a is higher than the temperatures of the other semiconductor elements 2b to 2f. To rise. For example, comparing the case of the solder 4a in contact with the semiconductor element 2a having a square shape of 10 mm on one side and the solder 4 in which the side of 12 mm is in contact with the semiconductor elements 2b to 2f of the same shape, When 200 A is applied to 2 f for 60 seconds, the temperature of the solder 4 a becomes about 10 ° C. higher than that of the solder 4. Since this temperature difference is reflected in the temperature difference between the semiconductor element 2a and the semiconductor elements 2b to 2f, the temperature of only the semiconductor element 2a is detected, and the input power is controlled to destroy all of the semiconductor elements 2a to 2f. Prevention of excessive temperature rise is realized.

  FIG. 8 shows a flowchart related to the control of the operation. Each step (S31 to S33) continues until the operation of the semiconductor power module 1a is stopped. At S31, the temperature of the semiconductor element 2a is detected. The detected temperature is output to the control circuit unit 101 via the signal terminal 9. The control circuit unit 101 is provided with a predetermined temperature threshold, and it is determined in S32 whether the input temperature has reached the threshold. For example, in a semiconductor power module having an operating temperature range of 150 ° C., the threshold is set to 140 ° C. When the threshold is reached, the decrease of the power input to the semiconductor power module 1a is started in S33. As long as it is reached, the reduction in power will continue. If not reached, temperature detection continues. By the control shown here, it is possible to prevent the excessive temperature rise of the semiconductor elements 2b to 2f only by performing control to prevent the excessive temperature rise of the semiconductor element 2a, and the heat of the semiconductor power module 1a and the power converter Destruction is prevented.

  Next, another configuration example of the semiconductor power module 1a according to the first embodiment will be described with reference to FIG. In FIG. 7, the surface area of the solder 4a in contact with the semiconductor element 2a provided with the temperature detection element 3 is reduced. However, as shown in FIG. 9, the height of the solder 4a in the thickness direction of the semiconductor element 2a is increased. It may be a configuration. Even if the height is changed, the thermal resistance increases as compared to the solder 4, so the temperature of the semiconductor element 2a rises higher than the temperatures of the semiconductor elements 2b to 2f. For example, the thickness of the solder 4 in contact with the semiconductor elements 2b to 2f each having a square shape of 10 mm is 1 mm, and the thickness of the solder 4a in contact with the semiconductor element 2a having the same shape is increased by 50% from the solder 4. As compared with the case of 5 mm, when 200 A is applied to the semiconductor elements 2 a to 2 f for 60 seconds, the temperature of the solder 4 a is higher by about 10 ° C. than the solder 4. In addition, since the position of the semiconductor element 2a rises with the change of the height of the solder 4a, the facing portion 8c is provided on the contact surface of the main circuit wiring 8a.

  Next, another configuration example of the semiconductor power module 1a according to the first embodiment will be described with reference to FIG. FIG. 10 is a cross-sectional view showing a schematic configuration of a semiconductor power module 1a using semiconductor elements 16a to 16c of a lateral structure. In FIG. 4, since the semiconductor elements 2a to 2f of the vertical structure are used, the conductive pattern 5 is provided on the entire surface of one surface, but the semiconductor elements 16a to 16c of the horizontal structure having no electrode pad are used on the back surface. In this case, it is not necessary to provide the conductive pattern 5 on the entire surface.

  As described above, in the semiconductor power module 1a according to the first embodiment of the present invention, the temperature is maximized by reducing the surface area of the solder 4a in contact with the semiconductor element 2a provided with the temperature detection element 3 or increasing the height. The temperature detection element 3 is used to detect the temperature of only one of the semiconductor elements 2a that is to be used to control the input power, thereby achieving prevention of excessive temperature rise related to the destruction of all the semiconductor elements 2a to 2f. it can. Even in the semiconductor power module 1a having the plurality of semiconductor elements 2a to 2f, only one semiconductor element 2a having the temperature detection element 3 may be provided, so that the manufacturing process of the semiconductor elements 2a to 2f is not complicated. The increase in the cost of the semiconductor elements 2a to 2f and the cost of the semiconductor power module 1a can be suppressed. Further, the wiring space for the temperature detection element 3 is small, and the semiconductor power module 1a can be miniaturized. Furthermore, since the temperature detecting element 3 is not provided in the semiconductor elements 2b to 2f, it is not necessary to consider an excessive margin with respect to the allowable temperature, and the semiconductor power module 1a can be miniaturized.

Second Embodiment
FIG. 11 is a cross-sectional view showing a schematic configuration of a semiconductor power module 1a according to a second embodiment of the present invention. In the first embodiment, the die bonding material is solder 4 or 4a and the temperature detection element 3 is built in the semiconductor device 2a. However, in the second embodiment, the die bonding material is Ag sintering 17, 17a. The temperature detection element 3 uses a thermistor. The semiconductor element 2g is a semiconductor element whose temperature is detected by the temperature detection element 3 provided separately without incorporating the temperature detection element 3 therein. The other components are the same as those described in the first embodiment, and thus the same reference numerals are given and description thereof is omitted.

  Ag sinterings 17 and 17a are sintered bodies of silver nanoparticles. In particular, when using a wide band gap semiconductor, the operating temperature is also expected to exceed 250 ° C., and a solder whose melting point is below this temperature can not cope with it, but in a junction using Ag sintering 17, 17a, the operating temperature Even if the temperature exceeds 250 ° C., the bonding is stably maintained, and the thermal conductivity is also high.

  As in the first embodiment, the area of the Ag sintering 17a in contact with the semiconductor element 2g in contact with the conductive pattern 5 is smaller than the area of the Ag sintering 17 in contact with the semiconductor elements 2b to 2f. By reducing the area in the heat dissipation path from the semiconductor element 2g to the heat sink 7, the thermal resistance related to the semiconductor element 2g is increased. When Ag paste is used as the material constituting the Ag sinterings 17 and 17a, the adjustment of the area of the Ag sintering is adjusted by the area of the opening of the metal mask used at the time of paste printing. In the case of using a preform material which has been formed in advance as the material constituting the Ag sinterings 17 and 17a, a preform material having a small size may be used only under the semiconductor element 2g.

  The thermistor used as the temperature detection element 3 is provided on the conductive pattern 5 in the vicinity of the side surface of the semiconductor element 2 g and is connected to the signal terminal 9 through the wire 10. The Ag sintering 17 has a thermal conductivity higher than that of solder, and can accurately detect the temperature of the semiconductor element 2g without incorporating the temperature detection element 3 in the semiconductor element 2g. It is not necessary to manufacture the semiconductor element 2a, and in the manufacturing process of the semiconductor elements 2b to 2g and the manufacturing process of the semiconductor power module 1a, complication is avoided and productivity is not lost.

  As described above, in the semiconductor power module 1a according to the second embodiment of the present invention, the Ag sinterings 17 and 17a are used as the die bonding material. Therefore, even if the temperature detection element 3 is provided separately from the semiconductor element 2g, accuracy is high. The temperature of the semiconductor element 2g can be detected. In addition, even in the high temperature operation of the semiconductor power module 1a, the junction is stably maintained, and application to a wide band gap semiconductor is also possible.

Third Embodiment
FIG. 12 is a cross-sectional view showing a schematic configuration of a semiconductor power module 1a according to a third embodiment of the present invention. In the semiconductor power module 1a according to the third embodiment, the die bonding materials are Ag sinterings 17 and 17b, and the outer shape of the Ag sintering 17b is smaller than that of the semiconductor element 2g only in the semiconductor element 2g. The semiconductor element 2g is a semiconductor element whose temperature is detected by the temperature detection element 3 provided separately without incorporating the temperature detection element 3 therein. The other components are the same as those described in the first embodiment, and thus the same reference numerals are given and description thereof is omitted.

  The area of the Ag sintering 17b in contact with the semiconductor element 2g in contact with the conductive pattern 5 is smaller than the area of the Ag sintering 17 in contact with the semiconductor elements 2b to 2f and the area of the Ag sintering 17a in FIG. By further reducing the area in the heat dissipation path from the semiconductor element 2g to the heat sink 7, the thermal resistance related to the semiconductor element 2g is further increased. Since the solder itself melts at the time of bonding, it is difficult for the solder to wet and to be bonded in an area smaller than the outline of the semiconductor element 2g. However, it becomes possible in Ag sintering which can be joined without melting the whole. In addition, in the case of bonding using Ag sintering, pressure is generally accompanied at the time of bonding. Therefore, during bonding, pressure is also applied to the semiconductor element, so the external area of the Ag sintering 17b can not be made extremely smaller than that of the semiconductor element 2g, but in particular if it is a semiconductor element of high strength substrate material such as silicon carbide. , That will also be possible. The adjustment of the area of the Ag sintering 17b is the same as that of the second embodiment.

  The thermistor used as the temperature detection element 3 is provided on the top of the semiconductor element 2 g and is connected to the signal terminal 9 via the wire 10. Since the semiconductor device 2g is provided in contact with the upper portion of the semiconductor device 2g, the temperature of the semiconductor device 2g can be accurately detected without incorporating the temperature detection device 3 in the semiconductor device 2g. Since it is not necessary to manufacture the semiconductor element 2a incorporating the temperature detection element 3, complication is avoided and the productivity is impaired in the manufacturing process of the semiconductor elements 2b to 2g and the manufacturing process of the semiconductor power module 1a. Absent. The thermistor may be provided separately from the main circuit wiring 8a. This is because the main circuit wiring 8a may also generate heat when it is energized, and the accuracy of the temperature detection of the semiconductor element 2g may be reduced.

  As described above, in the semiconductor power module 1a according to the third embodiment of the present invention, since the Ag sintering 17b having a further reduced area is used for the semiconductor element 2g for detecting temperature, the temperature difference with the semiconductor elements 2b to 2f is This becomes even more remarkable, and more effectively, overheat prevention relating to destruction can be realized.

Fourth Embodiment
FIG. 13 is a cross-sectional view showing a schematic configuration of a semiconductor power module 1a according to a fourth embodiment of the present invention. The semiconductor power module 1a according to the fourth embodiment is provided with a control IC 18 and an air gap 19 in addition to the configuration shown in FIG. In FIG. 13, the signal terminal 9 shown in FIG. 4 is omitted because it is unnecessary, and the other configuration is the same as that described in the first embodiment, and therefore, the same reference numerals are given. Omit.

  In the figure, the control IC 18 is connected to the temperature detection element 3 incorporated in the semiconductor element 2a by the wire 10, and suppresses the output power of the semiconductor power module 1a according to the output of the temperature detection element 3. is there. Although not shown in the figure, the control IC 18 is also connected to the semiconductor elements 2a to 2f. In the first embodiment, the temperature of the semiconductor element 2a is output to the control circuit unit 101 and controlled from the outside, but in the fourth embodiment, since the control IC 18 is provided on the conductive pattern 5, The management is simplified, and the semiconductor power module 1a can be miniaturized. The control steps are the same as in the first embodiment. Here, the control IC 18 is provided on the conductive pattern 5 so as to be close to the semiconductor element 2a. However, the present invention is not limited to this, and other places may be used as long as they can be connected to the temperature detection element 3. .

  A gap 19 is provided on the contact surface of the heat sink 7 located under the semiconductor element 2 a with the insulating substrate 6. The void 19 is an air layer. By providing an air layer having a high thermal resistance in the path of heat radiation from the semiconductor element 2a to the heat dissipation plate 7, the thermal resistance relating to the semiconductor element 2a is further increased. Further, in consideration of the expansion of the air inside the space 19, a through hole may be provided to penetrate the heat sink 7 from the space 19.

  In order to promote heat dissipation, as shown in FIG. 14, a cooler 20 may be provided on the other surface of the heat dissipation plate 7 facing the insulating substrate 6 to cool the heat dissipation plate 7. The cooler 20 includes a refrigerant circulation pump, and circulates a refrigerant such as water for cooling the heat radiation plate 7 in the direction of the arrow in the pipe 20 a. The arrangement of the semiconductor elements 2a to 2f viewed from the back surface side is indicated by a broken line. The pipe 20a is configured such that the flow of the refrigerant finally passes through the semiconductor element 2a among the plurality of semiconductor elements 2a to 2f. Passing through the semiconductor element 2 a last time does not promote heat radiation of the semiconductor element 2 a as compared to the semiconductor elements 2 b to 2 f. This is because, until the refrigerant reaches the lower part of the semiconductor element 2a, the temperature of the refrigerant rises due to the heat received by the heat radiation of the semiconductor elements 2b to 2f. Here, the pipe 20a is provided to pass through the lower part of the semiconductor elements 2a to 2f once, but the invention is not limited to this. Even if the number of turns of the pipe 20a is increased, the pipe 20a may be provided a plurality of times. Good. A heat exchanger or the like can be used to cool the refrigerant whose temperature has risen. As the refrigerant, ion-exchanged water, water containing antifreeze, scale remover, corrosion inhibitor, etc. may be used.

  As described above, in the semiconductor power module 1a according to the fourth embodiment of the present invention, since the control IC 18 is provided, wiring arrangement can be simplified, and the semiconductor power module 1a can be miniaturized. Further, since the air gap 19 is provided in the lower part of the semiconductor element 2a for detecting the temperature, the temperature difference with the semiconductor elements 2b to 2f becomes more remarkable, and the overheat temperature prevention related to the destruction can be realized more effectively. it can. Further, since the cooler 20 for circulating the refrigerant is provided so as to finally pass through the semiconductor element 2a that detects the temperature, the temperature difference with the other semiconductor elements 2b to 2f becomes more remarkable, and it relates to the destruction more effectively. Excessive temperature rise prevention can be realized.

  The configurations shown in the above first to fourth embodiments are an example of the configuration of the present invention, and modifications are made such that combinations or some of the embodiments are omitted without departing from the scope of the present invention. It goes without saying that it is also possible to

1a to 1f semiconductor power modules, 2a to 2f semiconductor elements, 3 temperature detecting elements, 4 solders, 5 conductive patterns, 6 insulating substrates, 7 heat sinks, 8 main circuit wires, 9 signal terminals, 10 wires, 11 resists, 12 Element substrate, 13 source pad, 14 gate pad, 15 drain pad, 16 semiconductor element, 17 Ag sintering, 18 control IC, 19 air gap, 20 cooler, 100 main circuit, 101 control circuit, 102 capacitor, 103 drive Motor, 104 processor, 105 storage device

Claims (15)

An insulating substrate,
A plurality of semiconductor elements disposed on one surface of the insulating substrate via a die bonding material;
A heat sink provided on the other surface of the insulating substrate;
A temperature detection element provided in one of the plurality of semiconductor elements;
The thermal resistance from the surface in contact with the die bond material of the semiconductor element provided with the temperature detection element to the other surface not in contact with the insulating substrate of the heat dissipation plate is the die bond material of the semiconductor element not provided with the temperature detection element The semiconductor power module is characterized in that the thermal resistance from the surface in contact with the surface to the other surface not in contact with the insulating substrate of the heat dissipation plate is larger. The semiconductor power module according to claim 1, wherein the plurality of semiconductor elements are disposed on the conductive pattern provided on one surface of the insulating substrate via the die bonding material. The semiconductor power according to claim 1 or 2, wherein the thermal resistance of the die bonding material in contact with the semiconductor element provided with the temperature detection element is larger than the thermal resistance of the die bonding material in contact with the other semiconductor elements. module. The area of the die bonding material in contact with the semiconductor element provided with the temperature detection element, which is joined to the insulating substrate or the conductive pattern, is smaller than the area of the die bonding material in contact with other semiconductor elements. The semiconductor power module according to claim 3. 4. The semiconductor device according to claim 1, wherein the height of the die bonding material in contact with the semiconductor device having the temperature detection element is greater than the height of the die bonding material in contact with the other semiconductor device. The semiconductor power module as described in. The semiconductor power module according to any one of claims 1 to 5, wherein the die bond material is a solder. The semiconductor power module according to any one of claims 1 to 5, wherein the die bonding material is Ag sintering. 8. The semiconductor power module according to claim 7, wherein at least one surface of the outer peripheral side surface of the Ag sintering is positioned inside the outer peripheral side surface of the semiconductor device provided with the temperature detection element. The semiconductor power module according to any one of claims 1 to 8, wherein a signal terminal connected to the temperature detection element is provided in proximity to the semiconductor element provided with the temperature detection element. The semiconductor power module according to any one of claims 1 to 9, wherein the temperature detection element is a diode provided inside a semiconductor element. The semiconductor power module according to any one of claims 1 to 9, wherein the temperature detection element is a thermistor. The semiconductor power module according to any one of claims 1 to 11, further comprising a control IC for suppressing the output power of the semiconductor power module according to the output of the temperature detection element. The semiconductor power module according to any one of claims 1 to 12, wherein the plurality of semiconductor elements are formed of a wide band gap semiconductor material. The semiconductor power module according to claim 13, wherein the wide band gap semiconductor material is one of silicon carbide, gallium nitride based material, or diamond. A cooler provided on the other surface of the heat sink;
The semiconductor power according to any one of claims 1 to 14, wherein the refrigerant circulating in the pipe provided in the cooler finally passes through the lower surface of the semiconductor element provided with the temperature detection element. module.

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