JP2015159149A - Cooling device and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device and a semiconductor device that can increase the flow rate of refrigerant passing through fins while implementing the function of positioning refrigerant flow path forming members.SOLUTION: A cooling device has: a first refrigerant flow path forming member having a recess portion; a second refrigerant flow path forming member which has plural pin fins arranged in a staggered arrangement, is formed to confront the first refrigerant flow path forming member so that the plural pin fins are disposed in the recess portion, and forms a refrigerant flow path portion in cooperation with the first refrigerant flow path forming member; a refrigerant inlet provided at one end side in a first direction of the first refrigerant path forming member; a refrigerant outlet provided at the other end side in the first direction of the first refrigerant flow path forming member; and a projecting portion formed on a side wall which extends in the first direction and defines the recess portion of the first refrigerant flow path forming member, the projecting portion projecting in a second direction intersecting to the first direction and coming into contact with the outer peripheral surfaces of the predetermined fin pins.

Description

  The present disclosure relates to a cooling device and a semiconductor device.

  2. Description of the Related Art Conventionally, a cooling structure in which a refrigerant flows so as to pass between fins of a heat sink is known (see, for example, Patent Documents 1 and 2).

JP 2012-222327 A JP 2013-99214 A

  By the way, in this kind of cooling structure, there is a gap between the outermost fin and the case, and this gap has little resistance. Therefore, the refrigerant passing through the gap tends to have a larger flow rate than the refrigerant passing between the fins.

  In Patent Document 1 and Patent Document 2, the positioning function between the heat sink (base plate) and the case (cooling path constituent member) is not considered.

  Therefore, an object of the present disclosure is to provide a cooling device and a semiconductor device capable of increasing the flow rate of the refrigerant passing between the fins while realizing the positioning function between the refrigerant flow path forming members.

According to one aspect of the present disclosure, a first refrigerant flow path forming member including a recess;
A plurality of pin fins arranged in a zigzag manner are provided, and the plurality of pin fins are provided facing the first refrigerant flow path forming member so as to be arranged in the recess, and cooperate with the first refrigerant flow path forming member A second refrigerant flow path forming member that forms a refrigerant flow path section,
A refrigerant inlet provided on one end side in the first direction of the first refrigerant flow path forming member;
A refrigerant outlet provided on the other end side in the first direction of the first refrigerant flow path forming member;
A side wall of the recess of the first refrigerant flow path forming member, formed on the side wall extending in the first direction, protruding in a second direction intersecting the first direction, and on an outer peripheral surface of the predetermined pin fin A cooling device is provided that includes an abutting protrusion.

  According to the present disclosure, it is possible to obtain a cooling device or the like that can increase the flow rate of the refrigerant passing between the fins while realizing the positioning function between the refrigerant flow path forming members.

It is a perspective view showing roughly semiconductor device 1 by one example. 1 is a perspective view schematically showing a semiconductor device 1 in a state without a case. It is the perspective view which looked at the case 70 from the upper side. 1 is a plan view schematically showing a semiconductor device 1 in a top view. It is explanatory drawing of the flow control function of the refrigerant | coolant by the protrusion part 740. FIG. It is a figure which shows each modification.

  Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a perspective view schematically showing a semiconductor device 1 according to an embodiment. 2A and 2B are perspective views schematically showing the semiconductor device 1 in a state without a case, where FIG. 2A shows the upper side and FIG. 2B shows the lower side.

  The vertical direction of the semiconductor device 1 differs depending on the mounting state of the semiconductor device 1, but in the following, for convenience, the side where the semiconductor chips 10A and 10B in the Z direction in FIG. To do.

  The semiconductor device 1 may constitute an inverter for driving a motor used in, for example, a hybrid vehicle or an electric vehicle. Hereinafter, the semiconductor device 1 will be described as an inverter for driving a motor.

  As shown in FIG. 1, the semiconductor device 1 includes semiconductor chips 10 </ b> A and 10 </ b> B, a heat spreader 20, an insulating layer 30, a heat sink 40, and a case 70.

  For example, each of the semiconductor chips 10A and 10B forms each arm of an inverter, and as shown in FIG. 1, six sets are provided corresponding to three phases. The semiconductor chip 10A is a semiconductor chip made of IGBT (Insulated Gate Bipolar Transistor), and the semiconductor chip 10B is a semiconductor chip made of FWD (Free Wheeling Diode). The semiconductor chip 10A may include another switching element such as a MOSFET (Metal Oxide Semiconductor Field-Effect Transistor) instead of the IGBT. The semiconductor chips 10A and 10B are joined to the heat spreader 20 by solder (not shown).

  The heat spreader 20 is provided corresponding to each set of the semiconductor chips 10A and 10B. The heat spreader 20 is a member that absorbs and diffuses heat generated in the semiconductor chips 10A and 10B, respectively. The heat spreader 20 is formed from a metal having excellent thermal diffusibility, such as copper or aluminum.

  The insulating layer 30 may be composed of a resin adhesive or a resin sheet. The insulating layer 30 may be formed of a resin using alumina as a filler, for example. As shown in FIG. 1, the insulating layer 30 is provided between the heat spreader 20 and the heat sink 40 and is bonded to the heat spreader 20 and the heat sink 40. The insulating layer 30 ensures high thermal conductivity from the heat spreader 20 to the heat sink 40 while ensuring electrical insulation between the heat spreader 20 and the heat sink 40.

  The heat sink 40 is formed of a material having good thermal conductivity, and is formed of a metal such as aluminum, for example. As described above, the upper surface of the heat sink 40 is bonded to the heat spreader 20. As shown in FIG. 2, the heat sink 40 includes fins 42 on the lower surface side. The fins 42 are pin fins as shown in FIG. The fins 42 are staggered. That is, each fin 42 is disposed so as to form an equilateral triangle (or an isosceles triangle) when the centers of three adjacent fins 42 are connected. The heat sink 40 may be composed of two or more members. For example, the heat sink 40 may be configured by combining a first metal plate and a second metal plate including the fins 42.

  The case 70 cooperates with the heat sink 40 to form a coolant channel. The case 70 and the heat sink 40 are an example of a cooling device for cooling the semiconductor chips 10A and 10B. Details of the configuration of the cooling device will be described later.

  FIG. 3 is a perspective view of the case 70 as viewed from above.

  The case 70 may be a case dedicated to an inverter or a case of a drive unit (for example, a planetary gear mechanism or a motor). The case 70 is formed by casting aluminum, for example.

  As shown in FIG. 3, the case 70 includes a recess 72 whose upper side is open. As shown in FIG. 3, the recess 72 forms a space having a substantially rectangular cross section. As shown in FIG. 3, the recess 72 has a substantially flat bottom surface. However, the recess 72 may have a step or the like on the bottom surface.

  The case 70 cooperates with the heat sink 40 to form the coolant channel portion 720. That is, in the state where the heat sink 40 is attached to the case 70 as shown in FIG. 1, the coolant channel portion 720 is formed between the recess 72 of the case 70 and the lower surface of the heat sink 40. The fins 42 are disposed in the refrigerant flow path portion 720. That is, in the state where the heat sink 40 is attached to the case 70 as shown in FIG. The tips of the fins 42 are separated from the bottom surface of the recess 72. A seal member (not shown) may be provided between the lower surface of the heat sink 40 and the upper surface of the outer peripheral portion 74 of the case 70. In the following, “inner side” and “outer side” are defined as “inner side” on the side closer to the center C and “outer side” on the far side with respect to the center C (see FIG. 1) of the refrigerant flow path 720. .

  The case 70 is formed with a refrigerant inlet 730 and a refrigerant outlet 732 so that the refrigerant substantially flows in the X direction in a range where the fins 42 in the refrigerant flow path portion 720 exist. In practice, the flow of the refrigerant in the refrigerant flow path portion 720 is in the X direction as the overall schematic flow. However, the refrigerant in the refrigerant flow path portion 720 flows in various directions while passing between the fins 42 of the heat sink 40 or through the gaps between the fins 42 of the heat sink 40 and the side walls 726 and 728 of the case 70. Moreover, the flow of the refrigerant in the refrigerant flow path part 720 may be in an oblique direction as a whole (for example, an oblique direction from the refrigerant inlet provided at the diagonal position toward the refrigerant outlet).

  Specifically, a refrigerant inlet 730 is formed on one end side in the X direction of the case 70. The refrigerant inlet 730 is an opening that communicates with the refrigerant flow path portion 720 and may be provided at an arbitrary position on one end side in the X direction of the case 70. For example, in the example shown in FIG. 3, the refrigerant inlet 730 is a horizontally long opening formed in the side wall 724 on one end side in the X direction in the recess 72, but is formed on the bottom surface on one end side in the X direction in the recess 72. It may be an opening, or may be an opening formed in the side wall 726 or 728 in the Y direction on one end side in the X direction in the recess 72. Further, the shape of the opening of the refrigerant inlet 730 is also arbitrary.

  A refrigerant outlet 732 is formed on the other end side of the case 70 in the X direction. The refrigerant outlet 732 is an opening that communicates with the refrigerant flow path portion 720 and may be provided at an arbitrary position on the other end side in the X direction of the case 70. For example, in the example shown in FIG. 3, the coolant outlet 732 is a horizontally long opening formed in the side wall 723 on the other end side in the X direction in the recess 72, but is formed on the bottom surface on the other end side in the X direction in the recess 72. The opening formed in the side wall 726 or 728 of the Y direction on the other end side of the X direction in the recessed part 72 may be sufficient. Further, the shape of the opening of the refrigerant outlet 732 is also arbitrary.

  Projections 740 are formed on the side walls 726 and 728 in the Y direction of the recesses in the case 70. The protrusion 740 protrudes in the direction intersecting the X direction, that is, inward in the Y direction. In addition, as shown in FIG. 3, the side walls 726 and 728 in the Y direction of the concave portion may be formed in a planar shape except for the protruding portion 740. The protruding portion 740 preferably extends over the entire height direction (Z direction) of the refrigerant flow path portion 720. That is, the protrusion 740 preferably extends from the bottom surface of the recess to the top surface of the outer peripheral portion 74 of the case 70. The protrusion 740 is typically an equal cross section, but may have different cross sections at different positions in the Z direction. As shown in FIG. 3, the protrusion 740 may be provided on the side closer to the refrigerant outlet 732 in the X direction than the center C (that is, on the downstream side of the center C). In addition, each protrusion part 740 of the side walls 726 and 728 may have a symmetric configuration with respect to a plane including a line passing through the center C and parallel to the X direction.

  FIG. 4 is a plan view schematically showing the semiconductor device 1 in a top view, (A) is an overall view, and (B) is an enlarged view of a P portion. In FIG. 4, the inside is shown in perspective for the purpose of showing the relationship between the fins 42 and the protruding portions 740. Further, the dotted line in FIG. 4B is an explanatory dotted line and is not a dotted line representing a configuration. In FIG. 4B, the region of the projecting portion 740 is hatched with diagonal lines for convenience of viewing. In FIG. 4, the semiconductor chips 10 </ b> A and 10 </ b> B are hatched at the base for the purpose of easily showing these installation areas.

  As shown in FIG. 4B, the protruding portion 740 contacts the outer peripheral surface of a specific fin among the plurality of fins 42. In the example shown in FIG. 4B, the projecting portion 740 contacts the outer peripheral surfaces of the fins 42A and 42B. At this time, the protrusion 740 contacts the outer peripheral surfaces of the fins 42A and 42B in such a manner that the displacement of the heat sink 40 in the X direction and the Y direction is regulated via the fins 42A and 42B. That is, the protrusion 740 performs a positioning function between the heat sink 40 and the case 70 in cooperation with the fins 42A and 42B.

  In the example illustrated in FIG. 4, the contact surface of the protrusion 740 with the fins 42 </ b> A and 42 </ b> B has a curved shape corresponding to each outer peripheral surface of the fins 42 </ b> A and 42 </ b> B. In the example illustrated in FIG. 4, the contact surface of the protrusion 740 with the fin 42 </ b> A contacts the entire outer periphery of the fin 42 </ b> A in the Y direction (180 degrees or more), and the contact surface of the protrusion 740 with the fin 42 </ b> B. Is in contact with a part of the outer peripheral surface of the fin 42B on the outer side in the Y direction. In the example shown in FIG. 4, the protrusion 740 is formed so as to be separated from the nearby fins 42C, 42D, and 42E other than the fins 42A and 42B by a distance L1 in each radial direction of the fins 42C, 42D, and 42E. Is done. In FIG. 4B, the positions separated by the distance L1 in the radial directions of the fins 42C, 42D, and 42E are indicated by dotted lines.

  As shown in FIG. 4B, the protrusion 740 extends in a range that does not overlap with the installation region of the semiconductor chip 10A in a top view. That is, as shown in FIG. 4B, the protruding portion 740 does not protrude up to a range below the semiconductor chip 10A in top view. In the example shown in FIG. 4, the protrusion 740 extends to the edge of the installation area of the semiconductor chip 10 </ b> A in a top view, but may end before the edge of the installation area of the semiconductor chip 10 </ b> A.

  As shown in FIG. 4, the side walls 726 and 728 in the Y direction of the recess are separated from the fins 42 at portions other than the protrusions 740. That is, the side walls 726 and 728 of the concave portion in the Y direction do not contact the outer peripheral surface of the fin 42 at a portion other than the protruding portion 740. The side walls 726 and 728 in the Y direction of the recess are separated by a predetermined distance L or more in the Y direction with respect to the nearest fin 42 at a portion other than the protrusion 740. The predetermined distance L may be determined in consideration of manufacturing tolerances, assembly tolerances, and the like. In the example shown in FIG. 4, the predetermined distance L matches the distance L1 between the fins 42, but is typically set longer than the distance L1 between the fins 42.

  5A and 5B are explanatory views of the refrigerant flow restriction function by the protruding portion 740. FIG. 5A shows a comparative configuration without the protruding portion 740, and FIG. 5B shows the configuration shown in FIG. Example).

  In the comparative configuration without the projecting portion 740, the refrigerant flows through the gap between the side wall of the case 70 ′ and the outermost fin 42 in the Y direction, as schematically shown by the arrow Q 1 in FIG. Therefore, there is a problem that the flow rate of the refrigerant passing between the fins 42 below the semiconductor chips 10A and 10B decreases.

  On the other hand, according to the present embodiment, as schematically shown by arrows Q1 and Q2 in FIG. 5B, the gap between the side wall 726 of the case 70 and the outermost fin 42 in the Y direction. The refrigerant flowing through is regulated by the protrusions 740 and is directed inward in the Y direction. Thereby, as schematically shown by the arrow Q2 in FIG. 5B, the refrigerant flows between the fins 42, and the flow rate of the refrigerant passing between the fins 42 below the semiconductor chips 10A and 10B is compared. Increase compared to the example. Thereby, the cooling efficiency of the semiconductor chips 10A and 10B can be increased.

  According to the cooling device for the semiconductor device 1 of the present embodiment described above, the following effects can be obtained.

  According to this embodiment, by forming the protrusion 740 on the side wall 726 of the case 70, the flow rate of the refrigerant flowing through the gap between the side wall 726 of the case 70 and the outermost fin 42 in the Y direction is reduced. The flow rate of the refrigerant passing between the fins 42 can be increased. Thereby, the cooling efficiency of the semiconductor chips 10A and 10B can be increased.

  Further, according to the present embodiment, as described above, the projecting portion 740 can perform the positioning function between the heat sink 40 and the case 70 in cooperation with the fins 42A and 42B. Thus, according to the present embodiment, the protruding portion 740 can have a positioning function as well as a function of regulating the flow of the refrigerant. Thereby, the necessity for providing the structure for positioning separately can be reduced.

  Further, according to the present embodiment, the protruding portion 740 is separated from the neighboring fins 42C, 42D, and 42E other than the fins 42A and 42B by the distance L1 in the radial directions of the fins 42C, 42D, and 42E. Formed. Thereby, the positioning function and the function of regulating the refrigerant flow can be realized without reducing the heat dissipation capability through these fins 42C, 42D and 42E. However, as will be described later, the configuration of the protruding portion 740 can be variously changed.

  Further, according to the present embodiment, the protruding portion 740 does not contact the entire circumference of the outer peripheral surfaces of the fins 42A and 42B, but contacts only a part of the outer peripheral surfaces of the fins 42A and 42B. The heat dissipation function via 42B can be partially ensured. However, in a modified example, the protrusion 740 may abut over the entire outer periphery of the fin 42A and / or the fin 42B (that is, a cylindrical hole may be formed in the protrusion 740). .

  Further, according to the present embodiment, since the protruding portion 740 protrudes to the installation area of the semiconductor chip 10A in a top view, the flow rate of the refrigerant passing between the fins 42 below the semiconductor chip 10A can be efficiently increased. it can. Further, since the protruding portion 740 extends in a range that does not overlap with the installation area of the semiconductor chip 10A in a top view, it is possible to reduce the obstruction of the heat dissipation function via the fins 42 immediately below the semiconductor chip 10A. it can. However, in the modified example, the protruding portion 740 may extend in a range overlapping the installation area of the semiconductor chip 10A in a top view.

  In the present embodiment, the projecting portion 740 is not limited to the configuration shown in FIG. 4, and may have other configurations as long as it has a positioning function and a function of regulating the refrigerant flow as described above. For example, in the example illustrated in FIG. 4, the protrusion 740 may be omitted from the fin 42 </ b> E side of the fin 42 </ b> B. Further, like the case 70A shown in FIG. 6A, the projecting portion 742 may have a cylindrical shape (the side wall 726 side is cut away) that contacts the fins 42A, 42C, and 42D. Also in this case, the protrusion 742 can regulate the displacement of the heat sink 40 in the X direction and the Y direction in cooperation with the fins 42A, 42C, and 42D. Further, the protrusion 742 can reduce the flow rate of the refrigerant flowing through the gap between the side wall 726 of the case 70 and the outermost fin 42 in the Y direction, and can increase the flow rate of the refrigerant passing between the fins 42. Further, as in the case 70B shown in FIG. 6B, the projecting portion 744 has a cylindrical shape that contacts the fins 42A, 42C, and 42D (the side wall 726 side is cut away) and a cylindrical shape that contacts the fins 42A, 42B, and 42E. (The side wall 726 side may be cut off). At this time, the protrusion 744 contacts the outer peripheral surface of the fin 42A within a relatively large peripheral range. Also in this case, the protrusion 744 can regulate the displacement of the heat sink 40 in the X direction and the Y direction in cooperation with the fins 42A to 42E. Further, the protrusion 744 can reduce the flow rate of the refrigerant flowing through the gap between the side wall 726 of the case 70 and the outermost fin 42 in the Y direction, and can increase the flow rate of the refrigerant passing between the fins 42.

  Although each embodiment has been described in detail above, it is not limited to a specific embodiment, and various modifications and changes can be made within the scope described in the claims. It is also possible to combine all or a plurality of the components of the above-described embodiments.

  For example, in the above-described embodiment, the protrusion 740 (the same applies to the protrusions 742 and 744) is formed in the region where the semiconductor chip 10A is disposed in the X direction as shown in FIG. May be formed in a region where the semiconductor chip 10B is disposed, or may be formed in a region where the semiconductor chip 10A and the semiconductor chip 10B are disposed in the X direction, or may be formed in the region where the semiconductor chip 10A and the semiconductor chip 10B are disposed in the X direction. You may form in the area | region between.

  Further, in the above-described embodiment, the protruding portion 740 (the same applies to the protruding portions 742 and 744) is formed at one place on each of the side walls 726 and 728 in the Y direction, but on each of the side walls 726 and 728. Two or more places may be formed.

  In the above-described embodiment, the case 70 that forms the refrigerant flow path portion 720 may be replaced with a member that does not have a function as a case.

  In the above-described embodiment, the semiconductor device 1 is applied to a vehicle inverter. However, the semiconductor device 1 is an inverter used for other purposes (railway, air conditioner, elevator, refrigerator, etc.). May be used. Furthermore, the semiconductor device 1 may be used in a device other than an inverter, for example, a converter or a high-frequency power module used in a power amplification circuit of a transmission unit of a wireless communication device.

DESCRIPTION OF SYMBOLS 1 Semiconductor device 10A, 10B Semiconductor chip 20 Heat spreader 30 Insulating layer 40 Heat sink 42 Fin 70, 70A, 70B Case 72 Recess 720 Refrigerant channel part 726, 728 Side wall 730 Refrigerant inlet 732 Refrigerant outlet 740, 742, 744 Protrusion part

Claims (4)

A first refrigerant flow path forming member comprising a recess;
A plurality of pin fins arranged in a zigzag manner are provided, and the plurality of pin fins are provided facing the first refrigerant flow path forming member so as to be arranged in the recess, and cooperate with the first refrigerant flow path forming member A second refrigerant flow path forming member that forms a refrigerant flow path section,
A refrigerant inlet provided on one end side in the first direction of the first refrigerant flow path forming member;
A refrigerant outlet provided on the other end side in the first direction of the first refrigerant flow path forming member;
A side wall of the recess of the first refrigerant flow path forming member, formed on the side wall extending in the first direction, protruding in a second direction intersecting the first direction, and on an outer peripheral surface of the predetermined pin fin A cooling device including a projecting portion that abuts.   The projecting portion regulates relative movement of the second refrigerant flow path forming member in the first direction and the second direction with respect to the first refrigerant flow path forming member in cooperation with the predetermined pin fin. Item 2. The cooling device according to Item 1.   The side wall of the recess extending in the first direction is planar except for the protruding portion, and the planar portion is separated from the plurality of pin fins by a predetermined distance or more in the perpendicular direction. The cooling device according to claim 1 or 2. The cooling device according to any one of claims 1 to 3,
A semiconductor element provided on the opposite side to the side on which the plurality of pin fins are formed in the second refrigerant flow path forming member,
The projecting portion extends in a range that does not overlap with an installation region of the semiconductor element when the surface is viewed directly from the bottom surface of the recess.

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