Semiconductor device

Abstract

The invention provides a semiconductor device, which can prevent the heat dissipation performance from being reduced. The cooling device is provided on the rear surface of the heat dissipation plate, and is provided with a storage section (31), a guide section (32), and a guide plate. One end of the guide part (32) is connected to the inner side of the short side wall (31b), the other part of the guide part (32) is connected to the end of the short side wall (31b) via the inflow port (31g), and the guide part (32) is formed on the bottom surface so as to divide a guide region (32i) communicating with the inflow port (31g) and a storage region (31i) outside the guide region (32i). Furthermore, the guide section (32) is configured so that the guide region (32i) of the guide section (32) becomes smaller as the guide region (32i) moves away from the inflow port (31g) when viewed from the inflow direction of the inflow port (31g) of the reservoir section (31) toward the guide region (32i).

Description

Technical Field

[0001] The present invention relates to a semiconductor device. Background Art

[0002] The cooling device has an object to be cooled arranged on the front. The cooling device circulates a refrigerant inside to cool the object to be cooled (for example, see Patent Documents 1 to 3). In addition, the semiconductor device includes such a cooling device and a semiconductor module as the object to be cooled arranged on the cooling device (for example, see Patent Document 4).

[0003] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2014-116404 Patent Document 2: Japanese Patent Application Publication No. 2017-174991 Patent Document 3: Japanese Patent Application Publication No. 2013-058518 Patent Document 4: International Publication No. 2012 / 147544 Summary of the invention Technical issues An object of the present invention is to provide a semiconductor device that suppresses an increase in pressure loss of a refrigerant.

[0004] Technical Solution According to one aspect of the present invention, there is provided a semiconductor device comprising: a storage portion having a storage area divided by a bottom surface that is rectangular in plan view, a pair of long side surfaces, and a pair of short side surfaces, and an inlet is provided on one of the short side surfaces; a guide portion having one end connected to the inner side of the one short side surface and the other end connected to the one end of the one short side surface via the inlet, the guide portion being formed on the bottom surface in a manner of dividing a guide area communicating with the inlet and the storage area outside the guide area; a flat guide plate that is arranged on the guide portion in a manner of being spaced apart from the pair of long side surfaces in the storage portion with gaps therebetween. , a slit extending from one short side surface toward the other short side surface is formed in an area overlapping with the guide area; a semiconductor chip; and a heat sink, which includes a front side, a back side and a plurality of fins, and the back side is arranged on the storage portion, the plurality of fins are accommodated in the storage area on the guide plate, the front side is set with a configuration area for configuring the semiconductor chip, the back side is set with a cooling area corresponding to the configuration area, the plurality of fins are arranged in the cooling area, and the guide portion is constructed so that when observed from the inlet of the storage portion toward the inflow direction of the guide area, the guide area of ​​the guide portion becomes smaller as it moves away from the inlet.

[0005] In addition, the guide portion may include: a first guide wall, which extends from the one end toward the inflow direction when viewed from above and is inclined in a manner close to a center line passing through the center of the inlet and parallel to the pair of long side faces; a second guide wall, which extends from the other end toward the inflow direction and is inclined in a manner close to the center line; and a front end wall, which connects the ends of the first guide wall and the second guide wall in the inflow direction.

[0006] In addition, the guide portion may include: a first guide wall, which extends from the one end toward the inflow direction parallel to the pair of long side faces when viewed from above; a second guide wall, which extends from the other end toward the inflow direction parallel to the pair of long side faces; and a front end wall, which connects the ends of the first guide wall and the second guide wall in the inflow direction, and the bottom surface of the guide area is inclined in a manner that rises toward the guide plate side as it moves away from the inlet.

[0007] In addition, the guide portion may be provided with a protrusion protruding toward the guide region near the inlet.

[0008] In addition, the protrusion may be provided at a position facing the first guide wall and the second guide wall, respectively.

[0009] In addition, the protrusion may be provided on the bottom surface in the guide region.

[0010] In addition, the guide plate may have a pair of sub-slits formed on both sides of the slit, respectively, and parallel to the slit, wherein the pair of sub-slits extend from the inlet side to the protrusion in a plan view.

[0011] In addition, the width of the pair of sub-slits may be greater than or equal to 1 mm and less than or equal to 4 mm.

[0012] In addition, the guide portion may include: a first guide wall, which extends from the one end toward the inflow direction when viewed from above and is inclined in a manner close to a center line passing through the center of the inlet and parallel to the pair of long side faces; a second guide wall, which extends from the other end toward the inflow direction and is inclined in a manner close to the center line; a third guide wall, which is arranged on the center line and extends from the inlet toward the inflow direction; and a front end wall, which connects the ends of the first guide wall and the second guide wall in the inflow direction.

[0013] In addition, the guide plate may have the slits respectively formed in a region overlapping with the guide region sandwiched by the first guide wall and the third guide wall and a region overlapping with the guide region sandwiched by the third guide wall and the second guide wall in a plan view.

[0014] In addition, an outflow port facing the inflow port may be formed on another short side surface of the storage portion.

[0015] It should be noted that the above invention summary does not list all the essential features of the present invention. In addition, sub-combinations of these feature groups can also constitute inventions.

[0016] Technical Effects According to the disclosed technology, it is possible to suppress an increase in refrigerant pressure loss, improve cooling performance, and suppress a decrease in reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a top view of the semiconductor device according to the first embodiment.

[0018] Figure 2 It is a side view of the semiconductor device according to the first embodiment.

[0019] Figure 3 It is an exploded perspective view of the cooling device according to the first embodiment.

[0020] Figure 4 It is a top view of the cooling device (excluding the guide plate) according to the first embodiment.

[0021] Figure 5 is a cross-sectional view of the cooling device (excluding the guide plate) according to the first embodiment.

[0022] Figure 6 It is a top view of the cooling device according to the first embodiment.

[0023] Figure 7 It is a cross-sectional view of the cooling device according to the first embodiment.

[0024] Figure 8 This is a rear view of the heat sink according to the first embodiment.

[0025] Fig. 9 This is a first cross-sectional view of the semiconductor device according to the first embodiment.

[0026] Fig.10 This is a second cross-sectional view of the semiconductor device according to the first embodiment.

[0027] Fig.11 This is a first plan view showing the flow of the refrigerant in the cooling device according to the first embodiment.

[0028] Fig.12 This is a first cross-sectional view showing the flow of the refrigerant in the cooling device according to the first embodiment.

[0029] Fig.13This is a second plan view showing the flow of the refrigerant in the cooling device according to the first embodiment.

[0030] Fig.14 This is a second cross-sectional view showing the flow of the refrigerant in the cooling device according to the first embodiment.

[0031] Fig.15 It is a third plan view showing the flow of the refrigerant in the cooling device according to the first embodiment.

[0032] Fig.16 It is a top view of the cooling device (excluding the guide plate) of the reference example.

[0033] Fig.17 It is a top view of the cooling device of the reference example.

[0034] Fig.18 It is a top view of the cooling device (excluding the guide plate) according to the second embodiment.

[0035] Fig.19 is a cross-sectional view of the cooling device (excluding the guide plate) according to the second embodiment.

[0036] Fig. 20 It is a top view of the cooling device (excluding the guide plate) according to the third embodiment.

[0037] Fig.21 is a cross-sectional view of the cooling device (excluding the guide plate) according to the third embodiment.

[0038] Fig. 22 It is a top view of the cooling device according to the third embodiment.

[0039] Fig.23 is a cross-sectional view of the cooling device (excluding the guide plate) according to the fourth embodiment.

[0040] Fig.24 It is a top view of the cooling device according to the fourth embodiment.

[0041] Fig.25 It is a top view of the cooling device (excluding the guide plate) according to the fifth embodiment.

[0042] Fig.26 It is a top view of the cooling device according to the fifth embodiment.

[0043] Fig. 27 This is a graph showing the temperature of the semiconductor chip with respect to the arrangement position of the semiconductor chip.

[0044] Fig.28 is a graph showing pressure loss.

[0045] Explanation of symbols 1: Semiconductor devices 2: Semiconductor unit 3: Cooling device 10, 10a, 10b, 10c: Insulated circuit substrate 11, 11a, 11b, 11c: Insulation board 12, 12a, 12b, 12c: Conductive pattern 13, 13a, 13b, 13c: Metal plates 14: Semiconductor chips 14a: Control electrode 14b: Output electrode 15: Heat sink 15a, 15c: long side 15b, 15d: Short side 15e: Front 15e1: Unit area 15f: Back 15f1: Cooling area 15g: fins 16: Joining parts 30: Shell 30a, 30c: long sidewall 30b, 30d: Short sidewall 30f: Bottom plate 30g: Inlet 30h: Outlet 30i: Storage area 30j: Inflow channel 30k: Outflow channel 31: Storage Department 31a, 31c: long sidewalls 31b, 31d: Short sidewalls 31g: Inflow port 31h: Outflow 31i: Storage area 32: Guidance 32a, 32c, 32e: guide wall 32b: Inflow 32d: Front wall 32f: bottom 32g: protrusion 32i: Boot area 33: Guide plate 33a, 33c: long side 33b, 33d: Short side 33e: Front 33f: Back 33g: Guide Slit 33g1: Secondary slit 33h: First recycling interval 33i: Second recovery gap DETAILED DESCRIPTION Hereinafter, the embodiment will be described with reference to the accompanying drawings. It should be noted that in the following description, "front" and "upper surface" represent the XY plane facing the upper side (+Z direction) in the semiconductor device 1 of the figure. Similarly, "up" represents the direction of the upper side (+Z direction) in the semiconductor device 1 of the figure. "Back" and "lower surface" represent the XY plane facing the lower side (-Z direction) in the semiconductor device 1 of the figure. Similarly, "lower" represents the direction of the lower side (-Z direction) in the semiconductor device 1 of the figure. The same directionality is also represented in other figures as needed. "High position" and "upper position" represent the position of the upper side (+Z direction) in the semiconductor device 1 of the figure. Similarly, "lower position" and "lower position" represent the position of the lower side (-Z direction) in the semiconductor device 1 of the figure. "Front", "upper surface", "up", "back", "lower surface", "lower", "side" are only expressions for the convenience of determining the relative positional relationship, and do not limit the technical idea of ​​the present invention. For example, "upper" and "lower" do not necessarily represent the vertical direction relative to the ground. That is, the directions of "up" and "down" are not limited to the direction of gravity. In the following description, "main component" means the case where it contains 80 vol% or more. In addition, "substantially the same" can be within the range of ±10%. In addition, "vertical", "orthogonal" and "parallel" can be within the range of ±10°.

[0046] [First embodiment] use Figure 1 and Figure 2 A semiconductor device will be described. Figure 1 It is a top view of the semiconductor device according to the first embodiment. Figure 2 1 is a side view of the semiconductor device of the first embodiment. Figure 2 Observe along the +Y direction Figure 1 A side view of the semiconductor device 1 is shown.

[0047] like Figure 1 and Figure 2As shown, the semiconductor device 1 includes a semiconductor unit 2, a heat sink 15, and a cooling device 3. The semiconductor unit 2 includes insulating circuit substrates 10a, 10b, 10c, and semiconductor chips 14 arranged on the front surfaces of the insulating circuit substrates 10a, 10b, 10c via bonding members 16. The insulating circuit substrates 10a, 10b, 10c include insulating plates 11a, 11b, 11c, conductive patterns 12a, 12b, 12c provided on the front surfaces of the insulating plates 11a, 11b, 11c, and metal plates 13a, 13b, 13c provided on the back surfaces of the insulating plates 11a, 11b, 11c. It should be noted that, hereinafter, when the insulating circuit substrates 10a, 10b, 10c are not distinguished, the insulating circuit substrate 10 is referred to as the insulating circuit substrate 10. When the insulating plates 11 a , 11 b , 11 c , the conductive patterns 12 a , 12 b , 12 c , and the metal plates 13 a , 13 b , 13 c are not distinguished from each other, the insulating plates 11 , the conductive patterns 12 , and the metal plates 13 are similarly referred to as the insulating plates 11 , the conductive patterns 12 , and the metal plates 13 .

[0048] The insulating plate 11 and the metal plate 13 are rectangular in plan view. The corners of the insulating plate 11 and the metal plate 13 may be R-chamfered or C-chamfered. The metal plate 13 is smaller than the insulating plate 11 in plan view and is formed inside the insulating plate 11.

[0049] The insulating plate 11 may be, for example, a ceramic substrate. The ceramic substrate is made of ceramic with good thermal conductivity. For example, the ceramic is made of a material containing aluminum oxide, aluminum nitride, or silicon nitride as a main component. In addition, such an insulating plate 11 is rectangular in a plan view.

[0050] The conductive pattern 12 is formed over the entire surface of the insulating plate 11 except for the edge. Preferably, when viewed from above, the end of the conductive pattern 12 facing the outer periphery of the insulating plate 11 overlaps with the end of the outer periphery of the metal plate 13. Therefore, the insulating circuit substrate 10 maintains a stress balance between it and the metal plate 13 on the back of the insulating plate 11. Excessive warping, cracking and other damage to the insulating plate 11 are suppressed. The conductive pattern 12 is made of a material with excellent conductivity. As such a material, for example, it is made of copper, aluminum or an alloy containing at least one of them. The conductive pattern 12 can also be plated with a material with excellent corrosion resistance. Such a material is, for example, nickel, nickel-phosphorus alloy, and nickel-boron alloy. The conductive pattern 12 for the insulating plate 11 is obtained by forming a metal plate on the front side of the insulating plate 11 and etching the metal plate. Alternatively, the conductive pattern 12 cut out in advance from the metal plate can be crimped to the front side of the insulating plate 11. It should be noted that the conductive pattern 12 included in the semiconductor device 1 of this embodiment is only an example. The number, shape, size, etc. of the conductive patterns may also be appropriately selected as required.

[0051] The metal plate 13 is made of a metal with excellent thermal conductivity. Such a material may be, for example, copper, aluminum, or an alloy containing at least one of them. Here, copper is included. In addition, in order to improve corrosion resistance, the surface of the metal plate 13 may also be plated. The plating material in this case contains nickel. Such a plating material is, for example, nickel, a nickel-phosphorus alloy, or a nickel-boron alloy.

[0052] As the insulating circuit substrate 10 having such a structure, for example, a DCB (Direct Copper Bonding) substrate or an AMB (Active Metal Brazed) substrate can be used. The insulating circuit substrate 10 conducts heat generated by a semiconductor chip 14 described later to the back side of the insulating circuit substrate 10 via the conductive pattern 12, the insulating plate 11, and the metal plate 13 to dissipate the heat.

[0053] The semiconductor chip 14 includes, for example, a switching element mainly composed of silicon. The switching element is, for example, an RC (Reverse-Conducting)-IGBT (Insulated Gate Bipolar Transistor). The RC-IGBT is a switching element in which a circuit is formed in which an IGBT and a FWD (Free Wheeling Diode) are connected in reverse parallel in one chip.

[0054] The semiconductor chip 14 has a collector electrode as an input electrode on the back side, a gate electrode as a control electrode 14b on the front side, and an emitter electrode as an output electrode 14a. It should be noted that the control electrode 14b can be provided at the center of one side of the front side of the semiconductor chip 14. Alternatively, the control electrode 14b does not need to be provided at the center of one side of the front side of the semiconductor chip 14, but can be offset relative to the center in the ±X direction.

[0055] As another switching element, a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor) composed mainly of silicon carbide may be used. The body diode of the power MOSFET functions as a FWD. Such a semiconductor chip 14, for example, has a drain electrode as an input electrode on the back surface, a gate electrode as a control electrode 14b on the front surface, and a source electrode as an output electrode 14a.

[0056] In addition, a semiconductor chip composed of silicon as the main component and including a group of switching elements and diode elements can be used instead of the semiconductor chip 14. The switching element is, for example, a power MOSFET or an IGBT. The semiconductor chip including the switching element, for example, has an input electrode on the back (a drain electrode in the power MOSFET and a collector electrode in the IGBT), a control electrode 14b (gate electrode) and an output electrode 14a on the front (a source electrode in the power MOSFET and an emitter electrode in the IGBT). In addition, the diode element, for example, uses an SBD (Schottky Barrier Diode) or a PiN (P-intrinsic-N) diode as a FWD. The semiconductor chip including the diode element has an output electrode (cathode electrode) as the main electrode on the back and an input electrode (anode electrode) as the main electrode on the front.

[0057] The back side of the semiconductor chip 14 is joined to the conductive pattern 12 by a joining component 16. It should be noted that the joining component 16 is a solder or a sintered body. The solder is composed of a lead-free solder with a predetermined alloy as the main component. The predetermined alloy contains tin. Such alloys are, for example, at least any one of an alloy composed of tin-silver-copper, an alloy composed of tin-zinc-bismuth, an alloy composed of tin-copper, an alloy composed of tin-silver-indium-bismuth, and an alloy composed of tin-antimony. The solder may contain additives. Examples of additives include nickel, germanium, cobalt, or silicon. In addition, the sintered material in the case of joining by sintering is, for example, powder of silver, iron, copper, aluminum, titanium, nickel, tungsten, or molybdenum.

[0058] The heat sink 15 includes a front face 15e which is rectangular in plan view, a back face 15f on the opposite side of the front face 15e, and long side faces 15a, short side faces 15b, long side faces 15c, and short side faces 15d which surround the front face 15e and the back face 15f in sequence. The front face 15e of the heat sink 15 is provided with a unit area 15e1 for arranging the semiconductor unit 2. The insulating circuit substrates 10a, 10b, and 10c of the semiconductor unit 2 are arranged in a row along the long side faces 15a and 15c in the unit area 15e1 of the front face 15e. At this time, the metal plate 13 of the insulating circuit substrate 10 is joined to the front face 15e by the joining member 16 mentioned above. The heat sink 15 is made of a metal having excellent thermal conductivity. As such a material, for example, it is made of copper, aluminum, or an alloy containing at least one of them. Here, copper is included. In addition, in order to improve corrosion resistance, the surface of the heat sink 15 may also be plated. The plating material in this case contains nickel. Such a plating material is, for example, nickel, a nickel-phosphorus alloy, or a nickel-boron alloy. The heat sink 15 will be described in detail later.

[0059] In this embodiment, the semiconductor unit 2 is arranged on the heat sink 15, so that six semiconductor chips 14 are arranged in a row along the long sides 15a and 15c of the heat sink 15. These semiconductor chips 14 are identified as (a) to (f) in order from the outlet 30h described later.

[0060] The cooling device 3 is provided on the back side 15f of the heat sink 15. The cooling device 3 includes a housing 30. The housing 30 includes a long side wall 30a, a short side wall 30b, a long side wall 30c, and a short side wall 30d. The long side wall 30a, the short side wall 30b, the long side wall 30c, and the short side wall 30d are arranged opposite to the heat sink 15 in a plan view, and sequentially surround the rectangular bottom plate 30f and the periphery of the bottom plate 30f (see Figure 3 ). The heights of the long side wall 30a, the short side wall 30b, the long side wall 30c and the short side wall 30d are equal. The back side 15f of the heat sink 15 is installed on the upper part of the long side wall 30a, the short side wall 30b, the long side wall 30c and the short side wall 30d. In addition, the edges in the +Z direction of the long side wall 30a, the short side wall 30b, the long side wall 30c and the short side wall 30d may also have barbs facing outward. As a result, the area engaged with the back side 15f of the heat sink 15 is increased, and the close contact with the back side 15f of the heat sink 15 is improved. An inlet 30g is formed in the short side wall 30b. An outlet 30h is formed in the short side wall 30d. The inlet 30g and the outlet 30h are connected to the inside of the shell 30.

[0061] Such a cooling device 3 may include a pump and a radiator. The pump causes the refrigerant to flow into the inlet 30g of the cooling device 3, and the refrigerant flowing in from the inlet 30g circulates in the cooling device 3. While the refrigerant circulates in the cooling device 3, it obtains heat from the semiconductor unit 2. The refrigerant circulating in the cooling device 3 flows out from the outlet 30h. The radiator receives the refrigerant flowing out of the cooling device 3, and dissipates the heat from the semiconductor unit 2 contained in the refrigerant to the outside. The pump causes the refrigerant after the heat is dissipated to flow into the cooling device 3 again from the inlet 30g and circulate. The refrigerant is, for example, water, antifreeze (ethylene glycol aqueous solution), or long-acting coolant. It should be noted that the details of the cooling device 3 will be described later.

[0062] The front side 15e of the heat sink 15 of the semiconductor device 1 may be provided with a housing (not shown) for housing the semiconductor unit 2. The housing may be integrally formed with, for example, an N-type terminal, a P-type terminal, and an output terminal. In the housing, these terminals are respectively connected to the semiconductor unit 2. In addition, in the semiconductor unit 2, the semiconductor unit 2 and various terminals may be connected by wiring components (not shown). Examples of wiring components include wires and lead frames. It should be noted that the housing is molded by injection molding using a thermoplastic resin containing a filler. It should be noted that such resins include, for example, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, or polyamide (PA) resin. The filler may be composed of, for example, glass fiber, glass beads, calcium carbide, talc, magnesium oxide, and aluminum hydroxide.

[0063] In addition, the housing may be encapsulated by an encapsulation component. The encapsulation component is, for example, a thermosetting resin mixed with a filler. The thermosetting resin is, for example, an epoxy resin, a phenolic resin, a maleimide resin, or a polyester resin. The filler is a ceramic having insulating properties and high thermal conductivity. Such a filler is, for example, silicon oxide, aluminum oxide, boron nitride, or aluminum nitride.

[0064] Next, use Figure 3~Figure 10 The cooling device 3 will be described. Figure 3 It is an exploded perspective view of the cooling device according to the first embodiment. Figure 4 is a top view of the cooling device (excluding the guide plate) of the first embodiment, Figure 5 is a cross-sectional view of the cooling device (excluding the guide plate) according to the first embodiment. Figure 6 is a top view of the cooling device of the first embodiment, Figure 7 It is a cross-sectional view of the cooling device according to the first embodiment. Figure 8 It is a rear view of the heat sink according to the first embodiment. Fig. 9 is a first cross-sectional view of the semiconductor device according to the first embodiment, Fig.10 This is a second cross-sectional view of the semiconductor device according to the first embodiment.

[0065] It should be explained that Figure 5 yes Figure 4 Cross-sectional view at the single-dot chain line YY. Figure 7 yes Figure 6 Cross-sectional view at the single-dot chain line YY. Fig. 9 yes Figure 1 Cross-sectional view at the single-dot chain line YY. Fig.10 yes Figure 1 and Figure 2 Cross-sectional view at the single-point dash line XX.

[0066] like Figure 3As shown, the cooling device 3 includes the above-mentioned housing 30, the guide portion 32 included in the housing 30, and the guide plate 33 provided on the guide portion 32. As described above, the housing 30 includes the bottom plate 30f, the long side wall 30a, the short side wall 30b, the long side wall 30c and the short side wall 30d, and uses them to surround the storage area 30i.

[0067] like Figure 4 and Figure 5 As shown, the housing 30 includes a storage portion 31 in a storage area 30i. The storage portion 31 is formed with a long side wall 31a, a short side wall 31b, a long side wall 31c, and a short side wall 31d in the storage area 30i and on the bottom plate 30f. The long side wall 31a, the short side wall 31b, the long side wall 31c, and the short side wall 31d are formed on the bottom plate 30f in a rectangular shape when viewed from above, and define the storage area 31i. The connection between the long side wall 31a, the short side wall 31b, the long side wall 31c, and the short side wall 31d can be an R-surface. In addition, similarly, the connection between the long side wall 31a, the short side wall 31b, the long side wall 31c, and the short side wall 31d relative to the bottom plate 30f can also be an R-surface. As a result, as will be described later, the refrigerant flowing through the storage portion 31 is prevented from stagnating at each corner portion included in the storage portion 31 , and is likely to flow smoothly.

[0068] The long side wall 31a, the short side wall 31b, the long side wall 31c and the short side wall 31d of the storage part 31 are respectively opposite to the long side wall 30a, the short side wall 30b, the long side wall 30c and the short side wall 30d of the housing 30. The storage area 31i is located at the center of the ±X direction and the ±Y direction in the storage area 30i when viewed from above. The long side wall 31a, the short side wall 31b, the long side wall 31c and the short side wall 31d of the storage part 31 are equal in height. The long side wall 31a, the short side wall 31b, the long side wall 31c and the short side wall 31d of the storage part 31 are equal in height to the long side wall 30a, the short side wall 30b, the long side wall 30c and the short side wall 30d of the housing 30.

[0069] It should be noted that the outside of the storage area 31i and the inside of the storage area 30i of the housing 30 may be sealed by a sealing member. Alternatively, the entire housing 30 may be formed into a block shape by a sealing member, and a space corresponding to the storage area 31i may be opened inside the block.

[0070] An inlet 31g and an outlet 31h are formed in the short side walls 31b and 31d of the storage portion 31, respectively. The inlet 31g and the outlet 31h are connected to the guide area 32i and the storage area 31i described later, respectively. The inlet 31g and the outlet 31h are arranged to be in a straight line along the ±X direction with respect to the inlet 30g and the outlet 30h of the housing 30. That is, the inlets 30g and 31g are opposite to the outlets 30h and 31h, respectively.

[0071] Such inlet 30g, 31g and outlet 30h, 31h may be, for example, circular. The inlet 30g, 31g and outlet 30h, 31h may have the same diameter. The diameter of the inlet 30g, 31g and outlet 30h, 31h may be, for example, 20% or more and 70% or less of the width of the short side wall 31b, 31d of the storage portion 31 in the ±Y direction.

[0072] The inlets 30g, 31g and the outlets 30h, 31h are located at half the height of the guide area 32i described later in the ±Z direction. Therefore, the inlets 30g, 31g and the outlets 30h, 31h are formed on the short side walls 30b, 30d of the housing 30 and the short side walls 31b, 31d of the storage portion 31, respectively, corresponding to the positions.

[0073] In addition, the inlet ports 30g and 31g are connected by the inlet passage 30j. The outlet ports 30h and 31h are connected by the outlet passage 30k. The inlet passage 30j and the outlet passage 30k are also in a straight line. The inlet passage 30j and the outlet passage 30k may be cylindrical, and the entire inner surface may be substantially flat without any concave-convex shape.

[0074] It should be noted that the formation position of the outflow ports 30h and 31h is not limited to the short side walls 30d and 31d. For example, the outflow ports 30h and 31h may be formed in the storage area 31i and on the bottom plate 30f which is closer to the front end (-X direction) side than the front end wall 32d of the guide portion 32 described later. In this case, the outflow passage 30k penetrates the bottom plate 30f along the ±Z direction. Alternatively, the outflow port 31h may be formed on the short side wall 31d in a manner opposite to the inflow port 31g, and the outflow port 30h may be formed on the outside of the storage area 31i and on the bottom plate 30f in the storage area 30i. In this case, the outflow passage 30k may connect the outflow ports 30h and 31h in the storage area 30i. In addition, the formation position of the inflow ports 30g and 31g is not limited to the short side walls 30b and 31b. For example, the inlet ports 30g and 31g may be formed in the bottom plate 30f on the short side wall 31b side of the guide region 32i described later. In this case, the inlet passage 30j penetrates the bottom plate 30f in the ±Z direction. Alternatively, the inlet port 31g and the outlet port 31h may be formed on the short side wall 31b so as to face each other, and the inlet port 30g may be formed on the bottom plate 30f outside the storage region 31i and inside the storage region 30i. In this case, the inlet passage 30j may connect the inlet ports 30g and 31g inside the storage region 30i.

[0075] like Figure 3~Figure 5As shown, the guide portion 32 is arranged on the bottom plate 30f in the storage area 31i of the storage portion 31. The guide wall 32a, the front end wall 32d and the guide wall 32c of the guide portion 32 are connected integrally, and the guide portion 32 includes one end and the other end. One end is included in the guide wall 32a and is connected to the short side wall 31b of the storage portion 31. The other end is included in the guide wall 32c and is connected to the short side wall 31b of the storage portion 31. The lower ends (-Z direction) of the guide wall 32a, the front end wall 32d and the guide wall 32c are connected to the bottom plate 30f. The connection parts between the guide wall 32a, the front end wall 32d and the guide wall 32c can be R-surface. In addition, similarly, the connection parts of the guide wall 32a, the front end wall 32d and the guide wall 32c relative to the bottom plate 30f can also be R-surface. As a result, as will be described later, the refrigerant flowing through the guide portion 32 is prevented from stagnating at each corner portion included in the guide portion 32 , and is likely to flow smoothly.

[0076] The heights (±Z directions) of the guide wall 32a, the front end wall 32d, and the guide wall 32c are equal. The heights (±Z directions) of the guide wall 32a, the front end wall 32d, and the guide wall 32c are smaller than the heights of the housing 30 and the storage portion 31, and may be, for example, about 50% of the heights of the housing 30 and the storage portion 31. In addition, the inner surfaces of the guide wall 32a, the front end wall 32d, and the guide wall 32c may not have any concave-convex shapes but may be substantially flat.

[0077] One end of the guide wall 32a is connected to the inner side of the short side wall 31b included in the storage portion 31. Here, one end of the guide wall 32a is connected to the side of the inlet 31g of the short side wall 31b in a plan view. The guide wall 32a extends from one end toward the short side wall 31d. At this time, the guide wall 32a extends toward the short side wall 31d and approaches the center line (at the center of the center of the short side walls 31b and 31d) parallel to the long side walls 31a and 31c in a plan view. Figure 4 In the figure, the single-point dashed line YY corresponds to the center line) and is inclined.

[0078] The other end of the guide wall 32c is also connected to the inner side of the short side wall 31b of the storage section 31. Here, the other end of the guide wall 32c is connected to the short side wall 31b on the opposite side of the one end of the guide wall 32a across the inlet 31g. That is, the other end of the guide wall 32c is connected to the side of the short side wall 31b on the opposite side of the inlet 31g from the one end of the guide wall 32a across the inlet 31g. The guide wall 32c extends from the other end toward the short side wall 31d. At this time, the guide wall 32c moves toward (approaches) the center line (at Figure 4 In the figure, the single-point dashed line YY corresponds to the center line) and is inclined.

[0079] The front end wall 32d is connected to the front end (-X direction) of the guide walls 32a and 32c. The front end wall 32d is opposite to the short side wall 31d of the storage section 31. That is, the front end wall 32d is parallel to the short side wall 31d of the storage section 31. In addition, the front end wall 32d is arranged with a gap relative to the short side wall 31d of the storage section 31. The front end wall 32d is located at the center of the short side walls 31b and 31d of the storage section 31 in the ±Y direction when viewed from above. The width of the front end wall 32d in the ±Y direction when viewed from above is smaller than the length of the short side wall 31b from the part connected to one end of the guide wall 32a to the part connected to the other end of the guide wall 32c. In addition, the width of the front end wall 32d in the ±Y direction when viewed from above is smaller than the diameter of the inlet 31g.

[0080] The inlet 32b is formed between one end of the guide wall 32a and the other end of the guide wall 32c of the guide portion 32. The width (±Y direction) of the inlet 32b may be approximately equal to the diameter of the inlet 31g and larger than the diameter of the inlet 31g.

[0081] The guide portion 32 is thus provided in the storage portion 31, so that a guide area 32i surrounded by the guide portion 32 and the short side wall 31b is formed. In addition, the guide portion 32 is divided into the guide area 32i and the storage area 31i outside the guide area 32i. It should be noted that the inlet 32b of the guide portion 32 is connected to the guide area 32i. Therefore, from the inlet 30g, through the inlet passage 30j, the inlet 31g, and 32b, it is connected to the guide area 32i.

[0082] like Figure 3 , Figure 6 as well as Figure 7 As shown, the guide plate 33 is in the shape of a flat plate and includes a front face 33e which is rectangular in a plan view, a back face 33f on the opposite side of the front face 33e, and long side faces 33a, short side faces 33b, long side faces 33c, and short side faces 33d which surround them in sequence. The guide plate 33 is arranged on the guide portion 32 in the storage portion 31. The lengths of the long side faces 33a and 33c of the guide plate 33 in the ±X direction are the same as the lengths of the storage portion 31 in the same direction. The widths of the short side faces 33b and 33d of the guide plate 33 in the ±Y direction are smaller than the width of the storage portion 31 in the same direction. If such a guide plate 33 is arranged on the guide portion 32, a first recovery gap 33h and a second recovery gap 33i are formed between the long side faces 33a and 33c of the guide plate 33 and the long side walls 31a and 31c of the storage portion 31 in a plan view. It should be noted that the width of the first recovery gap 33h and the second recovery gap 33i in the ±Y direction can be, for example, 1 mm.

[0083] In addition, the guide plate 33 is formed with a guide slit 33g that passes through from the front surface 33e to the back surface 33f. When the guide plate 33 is arranged on the guide portion 32, the guide slit 33g overlaps with the guide region 32i in a plan view, and extends in a straight line from the inlet 32b toward the front end wall 32d to the front end wall 32d. In addition, when the guide plate 33 is arranged on the guide portion 32, the guide slit 33g is formed on the center line of the guide plate 33 passing through the inlet 32b of the guide portion 32 and the center of the front end wall 32d in a plan view (the same as the center line of the guide plate 33). Figure 6 The width of the guide slit 33g (in the ±Y direction) is greater than one sixth and less than one fifth of the width of the inlet 32b in the same direction when viewed from above. In the first embodiment, the width of the guide slit 33g is, for example, greater than 2 mm and less than 4 mm, and specifically may be 2 mm.

[0084] When viewed from the inlet 32b of the guide portion 32 toward the guide region 32i, the guide region 32i surrounded by the guide portion 32, the bottom plate 30f, and the guide plate 33 becomes smaller as it moves away from the inlet 32b. The guide portion 32 and the bottom plate 30f are formed to constitute the guide region 32i.

[0085] Next, the heat sink 15 to which the cooling device 3 is connected with the back surface 15f will be described. As described above, the heat sink 15 includes the front surface 15e, the back surface 15f, the long side surface 15a, the short side surface 15b, the long side surface 15c, and the short side surface 15d, which are rectangular in plan view. Figure 8 As shown, the heat sink 15 is formed with a plurality of fins 15g in the range of the back side 15f corresponding to the unit area 15e1 of the front side 15e (cooling area 15f1). The fins 15g are columnar. The columnar shape may be a cylinder or a prism. The plurality of fins 15g are formed in a manner perpendicular to the back side 15f of the heat sink 15.

[0086] like Fig. 9 and Fig.10 As shown in FIG. 1 , the semiconductor unit 2 is arranged on the front surface 15e of the heat sink 15, and the heat sink 15 is arranged in the housing 30. At this time, the back surface 15f of the heat sink 15 is arranged on the storage portion 31, and the plurality of fins 15g of the heat sink 15 are stored in the storage area 31i on the guide plate 33 in the storage portion 31. That is, the back side (-Z direction side) of the plurality of fins 15g of the heat sink 15 is surrounded by the guide plate 33, and the four sides are surrounded by the long side wall 31a, the short side wall 31b, the long side wall 31c, and the short side wall 31d in this order.

[0087] Next, use Figure 11~Figure 15 The flow of the refrigerant in the cooling device 3 will be described. Fig.11is a first plan view showing the flow of the refrigerant in the cooling device according to the first embodiment, Fig.12 This is a first cross-sectional view showing the flow of the refrigerant in the cooling device according to the first embodiment. Fig.13 is a second plan view showing the flow of the refrigerant in the cooling device according to the first embodiment, Fig.14 This is a second cross-sectional view showing the flow of the refrigerant in the cooling device according to the first embodiment. Fig.15 It is a third plan view showing the flow of the refrigerant in the cooling device according to the first embodiment.

[0088] It should be noted that in the above-mentioned figures, the flow of the refrigerant is indicated by the dashed arrows. In addition, in the above-mentioned figures, the heat sink 15 and the guide plate 33 are omitted as necessary to illustrate the flow of the refrigerant. Fig.12 yes Fig.11 Cross-sectional view at the single-dot chain line YY. Fig.14 Observed along the -X direction Fig.13 The resulting perspective side view.

[0089] First, a refrigerant is pumped in from the inlet 30g of the cooling device 3. Fig.11 and Fig.12 As shown, the refrigerant flowing in from the inlet 30g passes through the inlet passage 30j, enters the guide area 32i from the inlet 31g and 32b, and moves straight in the -X direction. When the refrigerant fills the guide area 32i to a certain extent, the refrigerant flows out of the guide plate 33 from the guide slit 33g of the guide plate 33.

[0090] When viewed from the inflow direction from the inflow port 32b toward the guide region 32i, the guide region 32i becomes smaller as it moves away from the inflow port 32b. Therefore, the pressure difference between the front end wall 32d side and the inflow port 32b side relative to the refrigerant entering the guide region 32i becomes smaller, and the refrigerant is also easy to flow out from the vicinity of the inflow port 32b of the guide slit 33g. Therefore, the refrigerant flowing into the guide region 32i flows out from the entire guide slit 33g approximately uniformly.

[0091] like Fig.13 As shown, the refrigerant flowing from the guide slit 33g into the storage area 31i on the guide plate 33 flows between the plurality of fins 15g toward the first recovery gap 33h and the second recovery gap 33i on the long side surfaces 33a and 33c of the guide plate 33. The refrigerant flowing between the plurality of fins 15g receives heat conducted from the semiconductor unit 2 through the heat sink 15 and the plurality of fins 15g.

[0092] like Fig.14As shown, the refrigerant flowing from the guide slit 33g toward the first recovery gap 33h and the second recovery gap 33i flows from the first recovery gap 33h and the second recovery gap 33i into the storage area 31i surrounded by the guide plate 33, the long side wall 31a, the short side wall 31b, the long side wall 31c and the short side wall 31d.

[0093] like Fig.15 As shown, the refrigerant having flowed into the storage area 31i below the guide plate 33 in this way flows toward the outflow port 30h in the storage area 31i outside the guide area 32i, and flows out from the outflow port 30h.

[0094] The heat radiator receives the refrigerant flowing out of the cooling device 3 and radiates the heat contained in the refrigerant to the outside. The pump causes the refrigerant after the heat dissipation to flow into the cooling device 3 again from the inlet 30g and circulates the refrigerant.

[0095] Here, use Fig.16 and Fig.17 A cooling device according to a reference example will be described. Fig.16 It is a top view of the cooling device (excluding the guide plate) of the reference example. Fig.17 2 is a top view of a cooling device of a reference example. Fig.16 A plan view of the cooling device 300 is shown with the guide plate 33 removed.

[0096] The guide portion 32 of the cooling device 300 of the reference example is different from the guide portion of the cooling device 3 of the first embodiment. The guide wall 32a, the front end wall 32d and the guide wall 32c of the cooling device 300 are integrally connected. Fig.16 As shown, the guide walls 32a and 32c are provided in parallel with the long side walls 31a and 31c of the storage portion 31. In the reference example, the front end wall 32d connects the front end sides (-X direction) of the guide walls 32a and 32c. The front end wall 32d is in an arc shape that bulges toward the short side wall 31d.

[0097] As in the first embodiment, if the guide plate 33 is also disposed on the guide portion 32, a first recovery gap 33h and a second recovery gap 33i are formed between the long side surfaces 33a and 33c of the guide plate 33 and the long side walls 31a and 31c of the storage portion 31 in a plan view. Fig.17 As shown, when the guide plate 33 is arranged on the guide portion 32, the guide slit 33g is also formed on the center line (same as the center line of the guide plate 33) passing through the inlet 32b of the guide portion 32 and the center of the front end wall 32d in a plan view. Fig.17In such a reference example, the guide area 32i surrounded by the bottom plate 30f, the guide portion 32 and the guide plate 33 is substantially in the shape of a cube.

[0098] As in the first embodiment, when the refrigerant flows into the cooling device 300 from the inlet 30g, the refrigerant enters the guide region 32i from the inlet 31g and 32b through the inlet passage 30j. When the refrigerant fills the guide region 32i to a certain extent, the refrigerant flows out of the guide plate 33 from the guide slit 33g of the guide plate 33.

[0099] At this time, when the width of the guide slit 33g is narrow (for example, about 1 mm), the refrigerant can flow out uniformly from the entire guide slit 33g. However, when the guide slit 33g is narrow, the pressure loss of the refrigerant increases. Therefore, for example, the driving cost of the pump increases.

[0100] On the other hand, when the guide slit 33g has a wide width (for example, about 2 mm), the refrigerant cannot be uniformly discharged from the entire guide slit 33g.

[0101] In the reference example, when the inflow direction from the inlet 31g (inlet 32b) of the storage portion 31 toward the guide region 32i is observed, the guide region 32i hardly changes even if it is far from the inlet 32b. The closer the refrigerant flowing into the guide region 32i is to the front end wall 32d of the guide region 32i, the higher the pressure. For the refrigerant, the flow velocity on the inlet 32b side of the guide slit 33g is lower than the flow velocity on the front end wall 32d side when viewed from above.

[0102] Therefore, the flow rate of the refrigerant flowing out of the guide slit 33g is greater on the front wall 32d side than on the inlet 32b side. As a result, the heat dissipation on the front 15e of the heat sink 15 deviates according to the position. That is, for the front 15e of the heat sink 15, the heat dissipation on the inlet 30g (inlet 32b) side is lower than the heat dissipation on the outlet 30h (front wall 32d) side. Along with this, the heat dissipation of the semiconductor chip 14 included in the semiconductor unit 2 on the front 15e of the heat sink 15 will also deviate. If the heat dissipation of the semiconductor unit 2 deviates, the reliability of the semiconductor device 1 is reduced. It should be noted that the details of the heat dissipation will be described later.

[0103] Therefore, the semiconductor device 1 of the first embodiment includes a semiconductor chip 14, a heat sink 15, and a cooling device 3. The heat sink 15 includes a front surface 15e having a cell region 15e1 in which the semiconductor chip 14 is arranged, a back surface 15f having a cooling region 15f1 corresponding to the cell region 15e1, and a plurality of fins 15g provided in the cooling region 15f1.

[0104] The cooling device 3 is provided on the back side 15f of the heat sink 15, and includes a storage portion 31, a guide portion 32, and a guide plate 33. The storage portion 31 has a storage area 31i, and an inlet 31g is provided on one short side wall 31b. The storage area 31i is surrounded and divided by a bottom plate 30f having a rectangular shape in a plan view, a pair of long side walls 31a, 31c, and a pair of short side walls 31b, 31d.

[0105] One end of the guide portion 32 is connected to the inner side of the short side wall 31b, and the other end is connected to the inner side of the short side wall 31b via the inlet 31g. The guide portion 32 is divided into a guide area 32i communicating with the inlet 31g and a storage area 31i outside the guide area 32i and is formed on the bottom plate 30f.

[0106] The guide plate 33 is arranged on the guide portion 32 in the storage area 31i in a manner that separates the first recovery gap 33h and the second recovery gap 33i from the long side walls 31a and 31c, respectively, and is in the shape of a flat plate with a guide slit 33g extending from the short side wall 31b toward the short side wall 31d formed in the area overlapping with the guide area 32i.

[0107] When the cooling device 3 is mounted on the back surface 15f of the heat sink 15, the plurality of fins 15g are stored in the storage area 31i on the guide plate 33. In such a cooling device 3, the guide portion 32 is further configured such that, when viewed from the inlet 31g of the storage portion 31 toward the inflow direction of the guide area 32i, the guide area 32i of the guide portion 32 becomes smaller as it moves away from the inlet 31g.

[0108] Therefore, for the refrigerant entering the guide area 32i, the pressure difference between the front end wall 32d side and the inlet 32b side becomes smaller, and the refrigerant is also easy to flow out from the vicinity of the inlet 32b of the guide slit 33g. Therefore, the refrigerant flowing into the guide area 32i flows out from the entire guide slit 33g approximately uniformly. Therefore, the deviation of heat dissipation caused by the position of the front surface 15e of the heat sink 15 is reduced, the semiconductor unit 2 can be uniformly cooled, and the driving cost of the pump can be suppressed by suppressing the pressure loss, and the reliability reduction of the semiconductor device 1 can be suppressed.

[0109] [Second embodiment] When viewed from the inlet 31g of the reservoir 31 toward the inflow direction of the guide area 32i, the guide area 32i surrounded by the guide 32, the bottom plate 30f, and the guide plate 33 needs to be configured so that the guide area 32i becomes smaller as it moves away from the inlet 31g. In the first embodiment, the guide walls 32a and 32c of the guide 32 are inclined so as to approach the center line of the short side walls 31b and 31d as they move from the short side wall 31b toward the short side wall 31d.

[0110] use Fig.18 and Fig.19 A cooling device according to a second embodiment will be described. Fig.18 It is a top view of the cooling device (excluding the guide plate) according to the second embodiment. Fig.19 : is a cross-sectional view of the cooling device (excluding the guide plate) of the second embodiment. Fig.19 yes Fig.18 Cross-sectional view at the single-dot chain line YY.

[0111] As in the first embodiment, the guide portion 32 of the second embodiment has a guide wall 32a, a front end wall 32d, and a guide wall 32c integrally connected, and includes one end and the other end. In addition, as in the first embodiment, the one end and the other end are connected to the short side wall 31b via the inlet 31g.

[0112] However, in the second embodiment, if Fig.18 As shown, the guide walls 32a, 32c extend from the short side wall 31b toward the short side wall 31d in parallel with the long side walls 31a, 31c. The front end wall 32d integrally connects the front ends (-X direction) of the guide walls 32a, 32c. Fig.18 In the embodiment, the front end wall 32d and the long side walls 31a and 31c are connected at right angles. The connection portion may be R chamfered or C chamfered. In addition, the front end wall 32d may also be as follows Fig.16 That's an arc shape.

[0113] In the second embodiment, the guide portion 32 is formed on the bottom plate 30 f , and the bottom surface 32 f surrounded by the guide portion 32 is inclined so as to rise from the short side wall 31 b toward the short side wall 31 d (to the +Z side).

[0114] Thus, when viewed in the inflow direction from the inlet 31g of the reservoir 31 toward the guide region 32i, the guide region 32i surrounded by the guide portion 32, the bottom surface 32f, and the guide plate 33 (not shown) becomes smaller as it moves away from the inlet 31g.

[0115] In the case of forming the guide portion 32 of such a guide region 32i, similarly to the first embodiment, the pressure difference between the outlet 30h (front end wall 32d) side and the inlet 32b side for the refrigerant entering the guide region 32i becomes small, and the refrigerant is also easy to flow out from the vicinity of the inlet 32b of the guide slit 33g. Therefore, the refrigerant flowing into the guide region 32i flows out from the entire guide slit 33g approximately uniformly. Therefore, the deviation of the heat dissipation caused by the position of the front surface 15e of the heat sink 15 is reduced, the semiconductor unit 2 can be uniformly cooled, and the driving cost of the pump can be suppressed by suppressing the pressure loss, and the reliability reduction of the semiconductor device 1 can be suppressed.

[0116] [Third Embodiment] use Figure 20~Figure 22 A cooling device according to a third embodiment will be described. Fig. 20 is a top view of the cooling device (excluding the guide plate) of the third embodiment, Fig.21 is a cross-sectional view of the cooling device (excluding the guide plate) according to the third embodiment. Fig. 22 3 is a top view of a cooling device according to a third embodiment. Fig.21 yes Fig. 20 Cross-sectional view at the single-dot chain line YY.

[0117] The cooling device 3 of the third embodiment has protrusions 32g formed at positions facing the guide walls 32a and 32c included in the guide portion 32 of the cooling device 3 of the first embodiment. The protrusions 32g are formed on the inlet 31g side in a plan view.

[0118] Such a protrusion 32g can be formed at a position within 30% of the length of the guide walls 32a and 32c from the inlet 31g. In addition, the protrusion 32g relative to the guide area 32i is within a range that does not hinder the flow of the refrigerant, and only needs to protrude slightly. Fig.21 As shown, the protrusion 32g may be rod-shaped when viewed from the side, and may be formed from the lower end to the upper end parallel to the ±Z direction on the guide walls 32a, 32c. The protrusion 32g may be inclined at an obtuse angle relative to the bottom plate 30f. That is, the protrusion 32g may be inclined in such a way that its upper end approaches the side of the outflow port 31h (front end wall 32d). The protrusion 32g may be, for example, semicircular, triangular, or quadrilateral when viewed from above. Fig. 20 , a case of a semicircular shape is shown.

[0119] In addition, if Fig. 22As shown, the guide plate 33 is formed with auxiliary slits 33g1 on both sides (long side 33a, 33c side) of the guide slit 33g and within the range sandwiched by the guide walls 32a, 32c in a plan view. The auxiliary slits 33g1 extend from the short side wall 31b toward the short side wall 31d in parallel with the guide slit 33g to the protrusion 32g. In addition, the width of the auxiliary slit 33g1 in the ±Y direction can be the same as the width of the guide slit 33g in the same direction, for example, not less than 1 mm and not more than 4 mm.

[0120] In this case, similarly to the first embodiment, the pressure difference between the front end wall 32d side and the inlet 32b side for the refrigerant entering the guide area 32i becomes small, and the refrigerant is also easy to flow out from the vicinity of the inlet 32b of the guide slit 33g. At this time, the refrigerant entering the guide area 32i is easy to flow to the guide plate 33 side by the protrusion 32g. In addition, the guide plate 33 is formed with sub-slits 33g1 on both sides of the guide slit 33g and near the protrusion 32g. As a result, the refrigerant entering the guide area 32i flows out more reliably and roughly uniformly from the entire guide slit 33g and the sub-slit 33g1 than in the first embodiment.

[0121] The sub-slit 33g1 allows the refrigerant divided by the protrusion 32g to flow out. Therefore, the sub-slit 33g1 is preferably formed from the inlet 31g to at least the protrusion 32g with respect to the guide plate 33 in a plan view. The sub-slit 33g1 may extend beyond the protrusion 32g.

[0122] [Fourth Embodiment] In a fourth embodiment, using Fig.23 and Fig.24 A case where a protrusion is formed on the bottom plate 30f in addition to the third embodiment will be described. Fig.23 is a cross-sectional view of the cooling device (excluding the guide plate) according to the fourth embodiment. Fig.24 4 is a top view of a cooling device according to a fourth embodiment. Fig.23 yes Fig.24 Cross-sectional view at the single-dot chain line YY.

[0123] The cooling device 3 of the fourth embodiment is based on the cooling device 3 of the third embodiment, and the protrusion 32g is formed on the bottom plate 30f instead of the guide walls 32a and 32c. The protrusion 32g in this case is formed between the guide walls 32a and 32c in parallel with the short side walls 31b and 31d when viewed from above relative to the bottom plate 30f. The protrusion 32g can be formed to connect the guide walls 32a and 32c when viewed from above.

[0124] The protrusion 32g may protrude slightly relative to the guide region 32i so as not to hinder the flow of the refrigerant. The protrusion 32g may be columnar, semi-cylindrical, quadrangular, or triangular.

[0125] In addition, the auxiliary slit 33g1 formed in the guide plate 33 is also formed on both sides (long side 33a, 33c side) of the guide slit 33g and is formed within the range sandwiched by the guide walls 32a, 32c in a plan view, similarly to the third embodiment. The auxiliary slit 33g1 extends from the short side wall 31b toward the short side wall 31d in parallel with the guide slit 33g at least to the protrusion 32g.

[0126] In this case, similarly to the second embodiment, the pressure difference between the front end wall 32d side and the inlet 32b side for the refrigerant entering the guide area 32i becomes small, and the refrigerant is also easy to flow out from the vicinity of the inlet 32b of the guide slit 33g. In addition, the guide plate 33 is formed with sub-slits 33g1 on both sides of the guide slit 33g and near the protrusion 32g. As a result, the refrigerant entering the guide area 32i flows out more reliably and roughly uniformly from the entire guide slit 33g and the sub-slit 33g1 than in the first embodiment.

[0127] It should be noted that the protrusion 32g and the auxiliary slit 33g1 of the third embodiment and the fourth embodiment can also be applied to the second embodiment. In addition, the protrusion 32g of the third embodiment and the fourth embodiment can also be formed at the same time. That is, the protrusion 32g is formed at mutually opposing positions of the guide walls 32a and 32c of the guide portion 32, and further formed on the bottom plate 30f. In this case, the three protrusions 32g can be continuous, and the liquid can flow out from the entire guide slit 33g and the auxiliary slit 33g1 more reliably than in the third embodiment and the fourth embodiment.

[0128] [Fifth Embodiment] In the cooling device 3 of the fifth embodiment, Fig.25 and Fig.26 A description will be given of a case where the guide region 32i is divided into two regions in addition to the first embodiment. Fig.25 It is a top view of the cooling device (excluding the guide plate) according to the fifth embodiment. Fig.26 It is a top view of the cooling device according to the fifth embodiment.

[0129] like Fig.25 As shown, the cooling device 3 of the fifth embodiment is provided with another guide wall 32e between the guide walls 32a and 32c in addition to the guide portion 32 of the first embodiment, thereby forming two guide areas 32i.

[0130] In addition, if Fig.26 As shown in FIG. 1 , two guide slits 33g are formed on the guide plate 33 corresponding to the two guide areas 32i, respectively, and extending from the front surface 33e to the back surface 33f. That is, when viewed from above, the guide plate 33 has guide slits 33g formed in the area overlapping with the guide area 32i sandwiched by the guide walls 32a and 32e, and in the area overlapping with the guide area 32i sandwiched by the guide walls 32c and 32e, respectively.

[0131] In this case, when the guide plate 33 is arranged on the guide portion 32, each guide slit 33g is formed on the guide plate 33 so as to extend in a straight line from the inlet 31g toward the front end wall 32d to the front end wall 32d in a plan view. The width (±Y direction) of the guide slit 33g is preferably the same as that of the first embodiment. However, in order to form two guide slits 33g, due to limited space, the width may be narrower than that of the first embodiment. Here, it may be, for example, 1 mm.

[0132] In addition, when viewed from the inlet 31g of the storage portion 31 toward the inflow direction of the guide region 32i, the two guide regions 32i of the fifth embodiment also become smaller as they are away from the inlet 31g. Therefore, the pressure difference between the front end wall 32d side and the inlet 32b side of the refrigerant entering the two guide regions 32i becomes smaller, and it is easy to flow out from the two guide slits 33g of the guide plate 33. Therefore, the refrigerant flowing into the guide region 32i flows out from the two entire guide slits 33g respectively in a substantially uniform manner. Therefore, the deviation of heat dissipation caused by the position of the front face 15e of the heat sink 15 becomes smaller, the semiconductor unit 2 can be uniformly cooled, the driving cost of the pump can be suppressed, and the reliability reduction of the semiconductor device 1 can be suppressed. It should be noted that the protrusion 32g of the third embodiment and the fourth embodiment can also be applied to the guide walls 32a, 32c, and 32e. In this case, the refrigerant flowing into the guide region 32i flows out from the two entire guide slits 33g more reliably and substantially uniformly.

[0133] Here, use Fig. 27 and Fig.28 The heat dissipation performance when the cooling devices 3 according to the third and fifth embodiments and the cooling device 300 according to the reference example are used in the above-mentioned embodiments will be described. Fig. 27 This is a graph showing the temperature of the semiconductor chip with respect to the arrangement position of the semiconductor chip. Fig.28 is a graph showing pressure loss.

[0134] It should be explained that Fig. 27 The horizontal axis represents the configuration position of the semiconductor chip 14, and the vertical axis represents the temperature of the semiconductor chip 14. The configuration position of the semiconductor chip 14 refers to the temperature of the semiconductor chip 14. Figure 1The semiconductor chip 14 is shown in (a) to (f) in order from the short side surface 15d (outlet 31h) side toward the short side surface 15b (inlet 31g) side. Fig. 27 T1 to T5 on the vertical axis represent measured values, and increase from T1 to T5.

[0135] in addition, Fig.28 The figure shows how much the pressure loss is reduced compared to the reference example (width: 1 mm). Fig.28 The horizontal axis represents the measurement object, and the vertical axis represents the pressure difference between the outlet 31h and the inlet 31g, that is, the pressure loss ([Pa]). Fig.28 P1 to P8 on the vertical axis represent measured values, and increase from P1 to P8. In addition, the reference examples used here are two cases where the width of the guide slit 33g is 1 mm and 2 mm.

[0136] The temperature of the semiconductor chip 14 included in the semiconductor unit 2 after cooling for a predetermined time was measured for the semiconductor devices including the cooling devices 300 of the two reference examples and the cooling devices 3 of the third embodiment and the fifth embodiment. In addition, the pressure of the refrigerant at the inlet 31g and the pressure of the refrigerant at the outlet 31h at this time were measured, and the difference was calculated.

[0137] As a result, according to Fig. 27 As can be seen from the graph, in both reference examples, the temperature on the inlet 31g side of the semiconductor chip 14 is higher than the temperature at other positions of the semiconductor chip 14. That is, it is considered that the heat dissipation on the inlet 31g side of the two reference examples is reduced. It should be noted that, when the reference examples are compared with each other, it can be seen that the one with a narrower slit width can suppress the reduction in heat dissipation on the inlet 31g side of the semiconductor chip 14.

[0138] On the other hand, it can be seen that in the third embodiment, the semiconductor chips 14 at all positions are cooled substantially equally. In the fifth embodiment, the decrease in heat dissipation is suppressed on the inlet 30g side compared with the reference example (slit width: 2 mm).

[0139] according to Fig.28 According to the graph, the pressure loss is most suppressed in the case of the third embodiment, which is reduced by about 35% compared with the reference example (slit width: 1 mm). In addition, in the case of the fifth embodiment, the pressure loss is reduced by about 20% compared with the reference example (width: 1 mm).

[0140] Therefore, according to Fig. 27 and Fig.28 As a result, in the case of the cooling device 3 of the third embodiment, the plurality of semiconductor chips 14 can be uniformly cooled, and the pressure loss can also be sufficiently suppressed.

[0141] In addition, the cooling device 3 of the fifth embodiment cannot uniformly cool the plurality of semiconductor chips 14 compared to the third embodiment, but improves the heat dissipation to the same extent as the reference example (width: 1 mm). In addition, the pressure loss of the cooling device 3 of the third embodiment can be suppressed compared to the reference example (width: 2 mm).

Claims

1. A semiconductor device, characterized in that: have: A storage portion having a storage area divided by a bottom surface that is rectangular in a plan view, a pair of long side surfaces, and a pair of short side surfaces, and an inlet is provided on one of the short side surfaces; a guide portion, one end of which is connected to the inner side of the one short side surface, and the other end of which is connected to the one end of the one short side surface via the inlet, the guide portion being formed on the bottom surface in a manner of dividing a guide area communicating with the inlet and the storage area outside the guide area; a flat guide plate disposed on the guide portion in the storage portion with a gap therebetween relative to the pair of long sides, and having a slit extending from the one short side toward the other short side formed in a region overlapping the guide region; Semiconductor chips; as well as A heat sink, comprising a front side, a back side and a plurality of fins, wherein the back side is arranged on the storage portion, the plurality of fins are accommodated in the storage area on the guide plate, the front side is provided with a configuration area for configuring the semiconductor chip, the back side is provided with a cooling area corresponding to the configuration area, and the plurality of fins are arranged in the cooling area, The guide portion is configured such that, when viewed from the inlet of the storage portion toward the inflow direction of the guide region, the guide region of the guide portion becomes smaller as it becomes farther from the inlet.

2. The semiconductor device according to claim 1, wherein: The guide portion comprises: a first guide wall extending from the one end toward the inflow direction in a plan view and inclined so as to approach a center line passing through the center of the inflow port and parallel to the pair of long side surfaces; a second guide wall extending from the other end toward the inflow direction and inclined in a manner close to the center line; and A front end wall connects the ends of the first guide wall and the second guide wall in the inflow direction.

3. The semiconductor device according to claim 1, wherein: The guide portion comprises: a first guide wall extending from the one end toward the inflow direction in parallel with the pair of long side surfaces in a plan view; a second guide wall extending from the other end portion toward the inflow direction in parallel with the pair of long side faces; and a front end wall connecting the ends of the first guide wall and the second guide wall in the inflow direction, The bottom surface of the guide region is inclined so as to rise toward the guide plate as it moves away from the inlet.

4. The semiconductor device according to claim 2, wherein: The guide portion is provided with a protrusion protruding toward the guide region near the inlet.

5. The semiconductor device according to claim 4, wherein: The protrusion is provided at a position facing the first guide wall and the second guide wall, respectively.

6. The semiconductor device according to claim 4, wherein: The protrusion is disposed on the bottom surface in the guide region.

7. The semiconductor device according to claim 5 or 6, characterized in that: The guide plate is provided with a pair of auxiliary slits on both sides of the slit, respectively, which are parallel to the slit. The pair of sub-slits extend from the inlet side to the protrusion in a plan view.

8. The semiconductor device according to claim 7, wherein: The width of the pair of sub-slits is greater than or equal to 1 mm and less than or equal to 4 mm.

9. The semiconductor device according to claim 1, wherein: The guide portion comprises: a first guide wall extending from the one end toward the inflow direction in a plan view and inclined so as to approach a center line passing through the center of the inflow port and parallel to the pair of long side surfaces; a second guide wall extending from the other end toward the inflow direction and inclined in a manner close to the center line; A third guide wall disposed on the center line and extending from the inlet toward the inflow direction; and A front end wall connects the ends of the first guide wall and the second guide wall in the inflow direction.

10. The semiconductor device according to claim 9, wherein: The guide plate has the slits formed in a region overlapping with the guide region sandwiched between the first guide wall and the third guide wall and a region overlapping with the guide region sandwiched between the third guide wall and the second guide wall, respectively, in a plan view.

11. The semiconductor device according to claim 1, wherein: An outflow port facing the inflow port is formed on the other short side surface of the storage portion.

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