JP6520871B2 - Semiconductor module - Google Patents

Description

  The technology disclosed herein relates to a semiconductor module mounted on a cooler.

  Patent Document 1 discloses a semiconductor module that transfers heat generated in a semiconductor device to a cooler using a heat pipe. The heat pipe is embedded in an electrode plate disposed on the semiconductor element, and is configured to extend from the semiconductor element toward one side of the semiconductor element. A metal block is provided between the electrode plate of the portion where the heat pipe is embedded and the cooler. Thus, the heat generated in the semiconductor element is transferred to the cooler through the heat pipe and the metal block. By using the heat pipe, the heat generated in the semiconductor element can be efficiently transferred to the cooler.

WO 2011/064841

  In the semiconductor module of Patent Document 1, the heat pipe embedded in the electrode plate is configured to extend toward only one side of the semiconductor element. According to such a configuration, depending on the attitude of the semiconductor module, one end (high temperature portion) of the heat pipe corresponding to the semiconductor element is higher than the end (low temperature portion) of the heat pipe corresponding to the metal block And the cooling efficiency decreases. The present specification provides a semiconductor module capable of avoiding top heat and maintaining high cooling efficiency.

  One embodiment of the semiconductor module disclosed in the present specification is mounted on a cooler and used. The semiconductor module includes a semiconductor element disposed on the cooler, an electrode plate disposed on the semiconductor element, a heat pipe embedded in the electrode plate, and a transmission disposed between the electrode plate and the cooler. It has a heat part. The electrode plate extends beyond the semiconductor element along at least one direction between the one side and the other side of the semiconductor element when viewed from the stacking direction in which the cooler, the semiconductor element, and the electrode plate are stacked. ing. The heat pipe embedded in the electrode plate has a portion extending along one direction from the semiconductor element to both sides of the semiconductor element when viewed from the stacking direction. The heat transfer unit has a first heat transfer unit and a second heat transfer unit. The first heat transfer portion is disposed between the electrode plate and the cooler on one side of the semiconductor element, and configured to transfer the heat of the heat pipe in the electrode plate to the cooler. . The second heat transfer portion is disposed between the electrode plate and the cooler on the other side of the semiconductor element, and is configured to transfer the heat of the heat pipe in the electrode plate to the cooler. . In the semiconductor module of this embodiment, the heat pipes embedded in the electrode plate are configured to extend toward both sides of the semiconductor element when viewed from the stacking direction. For this reason, in the semiconductor module of this embodiment, for example, even if the portion of the heat pipe on one side of the semiconductor element is in the top heat state due to the attitude of the semiconductor module, it is on the other side of the semiconductor element. The heat pipe part does not reach the top heat condition. Thus, in the semiconductor module of this embodiment, the heat pipe is prevented from being in the top heat state. Therefore, the semiconductor module of this embodiment can maintain high cooling efficiency.

An outline of a circuit configuration of a power converter is shown. The principal part sectional view of the U phase arm among semiconductor modules is shown typically. The disassembled perspective view of the 1st structure of a U-phase arm is shown typically. An example of the layout of the heat pipe currently embed | buried in the electrode plate is shown. The other example of the layout of the heat pipe currently embed | buried in the electrode plate is shown.

  The features of the technology disclosed in the present specification will be summarized below. The technical elements described below are technical elements that are independent of each other and exhibit technical usefulness by themselves or various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

  One embodiment of the semiconductor module disclosed in the present specification is mounted on a cooler and used. The semiconductor module is used, for example, to configure a converter that transforms and outputs a DC voltage and an inverter that converts and outputs a DC voltage and an AC voltage. The semiconductor module includes a semiconductor element disposed on the cooler, an electrode plate disposed on the semiconductor element, a heat pipe embedded in the electrode plate, and a transmission disposed between the electrode plate and the cooler. A heat unit may be provided. The semiconductor material of the semiconductor device is not particularly limited, but in one example, silicon (Si), silicon carbide (SiC) or gallium nitride (GaN) is exemplified. The type of the semiconductor element is not particularly limited, but in one example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) and an IGBT (Insulated Gate Bipolar Transistor) are exemplified. The semiconductor element may be configured as a chip in which the switching element and the free wheeling diode are integrated. The electrode plate extends beyond the semiconductor element along at least one direction between the one side and the other side of the semiconductor element when viewed from the stacking direction in which the cooler, the semiconductor element, and the electrode plate are stacked. ing. The heat pipe embedded in the electrode plate has a portion extending along one direction from the semiconductor element to both sides of the semiconductor element when viewed from the stacking direction. The type of heat pipe is not particularly limited, but in one example, a type utilizing self-oscillation and a type utilizing capillary action are exemplified. The heat transfer unit has a first heat transfer unit and a second heat transfer unit. The first heat transfer portion is disposed between the electrode plate and the cooler on one side of the semiconductor element, and configured to transfer the heat of the heat pipe in the electrode plate to the cooler. . The second heat transfer portion is disposed between the electrode plate and the cooler on the other side of the semiconductor element, and is configured to transfer the heat of the heat pipe in the electrode plate to the cooler. .

  In the semiconductor module of the above embodiment, each of the first heat transfer unit and the second heat transfer unit may have a metal block. Thereby, the heat of the heat pipe can be efficiently transferred to the cooler.

  In the semiconductor module of the above embodiment, the heat pipe extends continuously along the one direction between the one side and the other side of the semiconductor element, as viewed in the stacking direction, beyond the semiconductor element. May be configured. Alternatively, in the semiconductor module of the above embodiment, the heat pipe may have the first heat pipe and the second heat pipe. The first heat pipe is configured to extend along one direction from one semiconductor element to one side of the semiconductor element when viewed from the stacking direction. The second heat pipe is configured to extend in one direction from the semiconductor element to the other side of the semiconductor element when viewed from the stacking direction. In the semiconductor module of any of the embodiments, the heat pipe is prevented from being in the top heat state.

  As shown in FIG. 1, the semiconductor module 10 constitutes an inverter circuit connected between the DC power supply 11 and the AC motor 13. The semiconductor module 10 switches the DC voltage supplied from the DC power supply 11 to convert the DC voltage into an AC voltage and supplies the AC voltage to the AC motor 13.

  The semiconductor module 10 includes a low voltage side wiring 14N configured to be connectable to the low voltage side terminal 11N of the DC power supply, a high voltage side wiring 14P configured to be connectable to the high voltage side terminal 11P of the DC power supply 11, and a low voltage side. It has three phase arms 10U, 10V and 10W connected in parallel between the wire 14N and the high voltage side wire 14P.

  The U-phase arm 10U has a first switching element SW1 and a second switching element SW2 connected in series between the low voltage side wiring 14N and the high voltage side wiring 14P, and a first return flow to the first switching element SW1. The diode D1 is connected in parallel, and the second free wheeling diode D2 is connected in parallel to the second switching element SW2. One end of the U-phase output wiring Uout is connected to the connection point of the first switching element SW1 and the second switching element SW2, and the other end of the U-phase output wiring Uout is connected to the AC motor 13.

  The V-phase arm 10V has a third switching element SW3 and a fourth switching element SW4 connected in series between the low-voltage side wiring 14N and the high-voltage side wiring 14P. The diode D3 is connected in parallel, and a fourth free wheeling diode D4 is connected in parallel to the fourth switching element SW4. One end of the V-phase output wiring Vout is connected to the connection point of the third switching element SW3 and the fourth switching element SW4, and the other end of the V-phase output wiring Vout is connected to the AC motor 13.

  The W-phase arm 10W includes a fifth switching element SW5 and a sixth switching element SW6 connected in series between the low voltage side wiring 14N and the high voltage side wiring 14P, and a fifth return flow to the fifth switching element SW5. The diode D5 is connected in parallel, and a sixth free wheeling diode D6 is connected in parallel to the sixth switching element SW6. One end of the W-phase output wiring Wout is connected to the connection point of the fifth switching element SW5 and the sixth switching element SW6, and the other end of the W-phase output wiring Wout is connected to the AC motor 13. As an example, in the present embodiment, MOSFETs are used for the switching elements SW1 to SW6, and Schottky diodes are used for the freewheeling diodes D1 to D6.

  Hereinafter, although the form of U phase arm 10U is explained in detail, other V phase arm 10V and W phase arm 10W also have the same form. For example, three semiconductor modules 10 similar to U-phase arm 10U described below may be prepared and stacked in the longitudinal direction, or they may be arranged in the plane direction. . Alternatively, in the semiconductor module 10, the low voltage side (lower side) semiconductor elements (SW1, 3, 5 and D1, 3, 5) of each phase arm are arranged in a plane direction and the high voltage side (upper side) semiconductor element A structure in which (SW1, 3, 5 and D1, 3, 5) are arranged in the plane direction may be prepared and stacked. The semiconductor module 10 can be constructed in various forms using the technology of the basic unit described below. In the following, an example in which the first switching element SW1 and the first free wheeling diode D1 are integrated as a chip and the second switching element SW2 and the second free wheeling diode D2 are integrated as an integrated chip is described. explain. Hereinafter, a chip in which the first switching element SW1 and the first free wheeling diode D1 are integrated is described as a first switching element SW1, and a chip in which the second switching element SW2 and the second free wheeling diode D2 are integrated is a second switching element Described as SW2.

  As shown in FIG. 2, the U-phase arm 10U includes a first structure 10Ua and a second structure 10Ub. The first structure 10Ua corresponds to the low pressure side (lower side) of the U-phase arm 10U. The second structural body 10Ub corresponds to the high pressure side (upper side) of the U-phase arm 10U. The first structural body 10Ua and the second structural body 10Ub are disposed between the pair of coolers 22 and disposed so as to face each other between the insulating interposing plates 26. The insulating interposition plate 26 is sandwiched between the first structural body 10Ua and the second structural body 10Ub. The force for sandwiching the insulating interposition plate 26 may be generated, for example, by screwing a bolt passing through a bolt through hole (not shown) formed in the pair of coolers 22 using a nut. . As a material of the insulating interposition plate 26, silicon oxide may be used as an example. The first structural body 10Ua and the second structural body 10Ub are characterized in that they have a common form, as can be seen when one is rotated 180 degrees around the y-axis.

  Each of the first structural body 10Ua and the second structural body 10Ub has the insulating substrate 24. The insulating substrate 24 is, for example, an insulating substrate in which a metal layer 24a of aluminum, an insulating layer 24b of aluminum nitride, and a circuit layer 24c of aluminum are stacked in this order from the surface of the cooler 22.

  The first structural body 10Ua includes a first output bus bar Uout1, a low voltage side bus bar 10N, a first switching element SW1, a low voltage side electrode plate 32, a low pressure side heat pipe 33, a first low voltage side heat transfer portion 34, and a second low voltage side transmission. The heat unit 36 and the low pressure side support unit 38 are provided.

  The first output bus bar Uout1 is provided on the insulating substrate 24, and has a substantially flat plate shape having a longitudinal direction in the x-axis (see FIG. 3). The first output bus bar Uout1 is fixed to the surface of the circuit layer 24c of the insulating substrate 24 by brazing. The first output bus bar Uout1 is connected to the drain electrode and the anode electrode of the first switching element SW1 (see FIG. 3) and electrically connected to the U-phase output wire Uout (see FIG. 1). The first output bus bar Uout1 and the first switching element SW1 are connected via solder.

  The low voltage side bus bar 10N is provided on the insulating substrate 24 and has a substantially flat plate shape having a longitudinal direction in the x-axis (see FIG. 3). The low voltage side bus bar 10N is fixed to the surface of the circuit layer 24c of the insulating substrate 24 by brazing. The low voltage side bus bar 10N is electrically connected to the source electrode and the cathode electrode of the first switching element SW1 through the first low voltage side heat transfer portion 34 and the low voltage side electrode plate 32, and the low voltage side wire 14N (see FIG. 1) electrically connected.

  The first output bus bar Uout1 and the low-pressure side bus bar 10N extend in the opposite direction from the insulating substrate 24 in the x-axis direction. Copper (Cu) may be used as an example of the material of the first output bus bar Uout1 and the low voltage side bus bar 10N. Although illustration of the bus bar for the gate electrode of the first switching element SW1 is omitted, in order to avoid interference with other bus bars, in the direction different from the other bus bars (in this example, in the y-axis direction) It is desirable to be provided so as to extend along the insulating substrate 24.

  The low voltage side electrode plate 32 is provided on the first switching element SW1, and when viewed from the stacking direction (z-axis direction), the space between one side and the other side of the first switching element SW1 is It extends beyond the first switching element SW1 along the x-axis direction. The low voltage side electrode plate 32 and the first switching element SW1 are connected via solder.

  The low pressure side heat pipe 33 is embedded in the low pressure side electrode plate 32, and is a self-oscillation type heat pipe. Instead of this example, the low pressure side heat pipe 33 may be a wick type heat pipe utilizing capillary action. The low-pressure side heat pipe 33 has a portion extending along the x-axis direction from the first switching element SW1 toward both sides of the first switching element SW1 when viewed from the stacking direction (z-axis direction).

  As shown in FIG. 4A, when viewed from the stacking direction (z-axis direction), the low-pressure side heat pipe 33 extends between one side and the other side of the first switching element SW1 in the x-axis direction. It is configured to extend continuously along the first switching element SW1. The low pressure side heat pipe 33 has a heat medium passage configured to reciprocate along the x-axis direction, and the heat medium passage has a plurality of straight portions extending along the x-axis direction. A hydraulic fluid is sealed in the heat medium passage, and the hydraulic fluid vibrates to transport heat. The first switching element SW1 is disposed at the central position of the low-pressure side heat pipe 33, that is, at the central position of the plurality of linear portions of the heat medium path. Instead of this example, as shown in FIG. 4B, the low pressure side heat pipe 33 may have a first heat pipe 33a and a second heat pipe 33b. The first heat pipe 33a extends along the x-axis direction from the first switching element SW1 to one side (the left side in the figure) of the first switching element SW1 when viewed from the stacking direction (z-axis direction) Is configured as. The second heat pipe 33b extends along the x-axis direction from the first switching element SW1 toward the other side (right side in the drawing) of the first switching element SW1 when viewed from the stacking direction (z-axis direction) Is configured as. In this example, the first switching element SW1 is disposed corresponding to one end of the first heat pipe 33a and also disposed corresponding to one end of the second heat pipe 33b.

  As shown in FIGS. 2 and 3, the first low-pressure side heat transfer section 34 is formed of a metal block in which a metal material is formed in a prismatic shape, and low voltage is applied to one side of the first switching element SW1. It is disposed between the side electrode plate 32 and the low voltage side bus bar 10 N, that is, between the low voltage side electrode plate 32 and the cooler 22. The first low-pressure side heat transfer section 34 is disposed in a positional relationship overlapping with the low-pressure side heat pipe 33 embedded in the low-voltage side electrode plate 32 when viewed from the stacking direction (z-axis direction) (see FIG. 4A, 4B). Thus, the first low-pressure side heat transfer section 34 is configured to transfer the heat of the low-pressure side heat pipe 33 embedded in the low-pressure side electrode plate 32 to the cooler 22. The first low-pressure side heat transfer section 34 is connected to each of the low-pressure side bus bar 10N and the low-pressure side electrode plate 32 via solder. The first low-pressure side heat transfer section 34 is configured using a low electrical resistance and high thermal conductivity material. As a material of the first low-pressure side heat transfer section 34, copper (Cu) may be used as an example.

  As shown in FIGS. 2 and 3, the second low-pressure side heat transfer section 36 is formed of a metal block in which a metal material is formed in a prismatic shape, and a low pressure is applied to the other side of the first switching element SW1. It is disposed between the side electrode plate 32 and the insulating layer 24 b, that is, between the low pressure side electrode plate 32 and the cooler 22. The second low voltage side heat transfer portion 36 is disposed in the through hole formed in the first output bus bar Uout1 and the circuit layer 24c, and is electrically isolated from the first output bus bar Uout1 and the circuit layer 24c. . The second low-pressure side heat transfer section 36 is disposed in a positional relationship overlapping with the low-pressure side heat pipe 33 embedded in the low-voltage side electrode plate 32 when viewed from the stacking direction (z-axis direction) (see FIG. 4A, 4B). Thus, the second low-pressure side heat transfer section 36 is configured to transfer the heat of the low-pressure side heat pipe 33 embedded in the low-pressure side electrode plate 32 to the cooler 22. The second low-pressure side heat transfer section 36 is connected to each of the low-pressure side electrode plate 32 and the insulating layer 24 b via a solder. The second low pressure side heat transfer section 36 is configured using a high thermal conductivity material. As a material of the second low-pressure side heat transfer section 36, copper (Cu) may be used as an example.

  As shown in FIGS. 2 and 3, the low voltage side support portion 38 is formed of a metal block in which a metal material is formed in a prismatic shape, and the first output bus bar is formed on the other side of the first switching element SW1. It is disposed between Uout 1 and the insulating interposition plate 26. The low pressure side support portion 38 is provided to stabilize the position of the first structural body 10Ua in the pair of coolers 22.

  As shown in FIG. 2, the second structural body 10Ub includes a second output bus bar Uout2, a high voltage side bus bar 10P, a second switching element SW2, a high voltage side electrode plate 42, a high pressure side heat pipe 43, and a first high voltage side heat transfer. A portion 44, a second high pressure side heat transfer portion 46, and a high pressure side support portion 48 are provided. As described above, the first structural body 10Ua and the second structural body 10Ub have a common form, and the second output bus bar Uout2 of the second structural body 10Ub, the high voltage side bus bar 10P, the second switching element SW2 and the high voltage side electrode plate 42 The high pressure side heat pipe 43, the first high pressure side heat transfer section 44, the second high pressure side heat transfer section 46, and the high pressure side support section 48 respectively correspond to the low pressure side bus bar 10N and the first output bus bar Uout1 of the first structure 10Ua. The first switching element SW1, the low voltage side electrode plate 32, the low voltage side heat pipe 33, the first low voltage side heat transfer portion 34, the second low voltage side heat transfer portion 36, and the low voltage side support portion 38 correspond. In the second structure 10Ub, the second output bus bar Uout2 is electrically connected to the U-phase output wire Uout (see FIG. 1), and the high voltage side bus bar 10P is electrically connected to the high voltage side wire 14P (see FIG. 1). Ru.

  U-phase arm 10U further includes a conductor portion 28. The conductor portion 28 is provided between the first output bus bar Uout1 of the first structure 10Ua and the second output bus bar Uout2 of the second structure 10Ub, and electrically connects the first output bus bar Uout1 and the second output bus bar Uout2 Connect. In one example, a foam metal is used for the conductor portion 28.

Next, the features of the U-phase arm 10U will be listed.
(1) In U-phase arm 10U, heat pipes 33 and 43 embedded in electrode plates 32 and 42 face both sides of switching elements SW1 and SW2 when viewed from the stacking direction (z-axis direction) Are configured to extend (see FIGS. 4A and 4B). Therefore, in U-phase arm 10U, for example, the posture of U-phase arm 10U inclines around the y-axis, so that the portions of heat pipes 33, 43 on one side of switching elements SW1, SW2 are in the top heating state. Even in this case, the portions of the heat pipes 33 and 43 on the other side of the switching elements SW1 and SW2 do not get into the top heat state. Thus, in the U-phase arm 10U, the heat pipes 33, 43 are prevented from being in the top heat state. U-phase arm 10U can maintain high cooling efficiency.

(2) As described above, in the U-phase arm 10U, the first structural body 10Ua and the second structural body 10Ub have a common form. Therefore, U-phase arm 10U can be constructed by preparing structures 10Ua and 10Ub which are one type of basic unit, and furthermore, V-phase arm 10V and W-phase arm 10W should be constructed similarly. Can. That is, according to the technology of the present embodiment, the semiconductor module 10 can be constructed by preparing the structures 10Ua and 10Ub which are one type of basic unit. The semiconductor module 10 can be evaluated as having a simple configuration with a small number of parts.

  As mentioned above, although the specific example of this invention was described in detail, these are only an illustration and do not limit a claim. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above. The technical elements described in the present specification or the drawings exhibit technical usefulness singly or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques exemplified in the present specification or the drawings can simultaneously achieve a plurality of purposes, and achieving one of the purposes itself has technical utility.

10: semiconductor module 10N: low voltage side bus bar 10P: high voltage side bus bar 10U: U phase arm 10V: V phase arm 10W: W phase arm 10Ua: first structural body 10Ub: second structural body 22: cooler 24: insulating substrate 26 Insulating interposition plate 28: conductor portion 32, 42: electrode plate 33, 43: heat pipe 34, 44: first heat transfer portion 36, 46: second heat transfer portion 38, 48: support portion

Claims (6)

A semiconductor module mounted on a cooler,
A semiconductor element disposed on the cooler;
An electrode plate disposed on the semiconductor element;
A heat pipe embedded in the electrode plate;
A heat transfer unit disposed between the electrode plate and the cooler;
The electrode plate is preferably arranged along at least one side between one side and the other side of the semiconductor element when viewed from the stacking direction in which the cooler, the semiconductor element, and the electrode plate are stacked. Extends beyond the semiconductor device,
The heat pipe embedded in the electrode plate has a portion extending along the one direction from the semiconductor element toward both sides of the semiconductor element when viewed from the stacking direction.
The heat transfer unit is
It is arranged between the electrode plate and the cooler on the one side of the semiconductor element, and is configured to transfer the heat of the heat pipe in the electrode plate to the cooler. A first heat transfer section,
It is disposed between the electrode plate and the cooler on the other side of the semiconductor element, and is configured to transfer the heat of the heat pipe in the electrode plate to the cooler. And a second heat transfer section,
The semiconductor module is electrically connected to an external wiring through at least one of the first heat transfer portion and the second heat transfer portion and the electrode plate.   The semiconductor module according to claim 1, wherein each of the first heat transfer portion and the second heat transfer portion has a metal block.   The heat pipe may extend continuously along the one direction between the one side and the other side of the semiconductor element and beyond the semiconductor element when viewed from the stacking direction. The semiconductor module according to claim 1, wherein the semiconductor module is configured. The heat pipe is
A first heat pipe configured to extend along the one direction from the semiconductor element toward the one side of the semiconductor element when viewed from the stacking direction;
A second heat pipe configured to extend along the one direction from the semiconductor element toward the other side of the semiconductor element when viewed from the stacking direction. Or the semiconductor module as described in 2. When a structure formed of the semiconductor element, the electrode plate , the heat pipe, and the heat transfer portion is a first structure, the semiconductor device further includes a second structure having a common form with the first structure.
The first structure and the second structure are disposed to face each other in the stacking direction with an insulating interposition plate interposed therebetween,
The semiconductor module according to any one of claims 1 to 4, wherein each of the first structure body and the second structure body is disposed such that an electrode plate is positioned on the side of the insulating interposition plate.   The semiconductor module according to claim 5, wherein the semiconductor element of the first structure and the semiconductor element of the second structure are not arranged in an overlapping positional relationship when viewed from the stacking direction.