JP2019029383A - Semiconductor device - Google Patents

Abstract

To provide a semiconductor device which efficiently dissipates heat generated from a semiconductor element to achieve high credibility.SOLUTION: In a semiconductor device comprising a heat spreader 10 which has one surface 10a and another surface 10b and has a fin part 11 on the other surface 10b side, a semiconductor element 20 mounted on the one surface 10a and mold resin 30 which covers the heat spreader 10 and the semiconductor element 20 further comprises an insulation layer 40 provided on the other surface 10b including the fin part 11 and on lateral faces 10c connecting the one surface 10a and the other surface 10b. The insulation layer 40 is formed in a closed circular shape to surround the heat spreader 10 when viewed from a normal direction with respect to the other surface 10b in a region of an interface with the mold resin 30 out of the lateral faces 10c and in a region between an end on the one surface 10a side and an end on the other surface 10b side. This causes heat generated from a semiconductor element 20 to be diffused by the heat spreader 10 and subsequently dissipated to the outside; and adhesion between the lateral faces 10c and the mold resin 30 is increased thereby to achieve a semiconductor device having high heat dissipation properties and high credibility.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a semiconductor device including a semiconductor module in which a semiconductor element and a heat spreader that dissipates heat from the semiconductor element are sealed with a resin to form an integrated structure.

  Conventionally, Patent Document 1 discloses a cooling structure including a heat sink that dissipates heat when a heating element such as a semiconductor power element is driven. The cooling structure has a heating element, a heat sink, an insulating adhesive layer that connects the heating element and the heat sink, a mold resin that covers a part of the heat sink and the heating element, and a flow path through which a cooling fluid such as water flows. A cooling fluid flow container. The cooling structure has a structure in which a portion of the heat sink exposed from the mold resin is disposed in contact with the cooling fluid so that heat of the heating element is conducted to the heat sink and the heat sink is cooled by the cooling fluid. Has been.

JP 2009-135524 A

  However, this cooling structure has an insulating adhesive layer interposed between the heating element and the heat sink, so that heat generated from the heating element is difficult to be transmitted to the heat sink, and has a structure with high thermal resistance, that is, a structure with low heat dissipation. It has become. In order to improve heat dissipation, it is conceivable to use a DBA (Direct Bonded Aluminum) substrate or a DBC (Direct Bonded Copper) substrate as a heat sink. In this case, although the thermal resistance can be lowered, the cost increases. End up.

  Also, if a cooling fluid such as water enters the interface between the heat sink and the mold resin from the contact surface side with the heat sink, it will cause deterioration of the heating element and insulating adhesive layer, resulting in defects such as poor insulation and increased thermal resistance. There is room for improvement from the viewpoint of improving reliability.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor device having high heat dissipation and reliability, including a heating element such as a semiconductor element, a heat spreader, and a resin member covering the heating element. .

  In order to achieve the above object, a semiconductor device according to claim 1 includes a heat spreader (10) having one surface (10a) and the other surface (10b) in a front / back relationship, and a semiconductor element (20) mounted on the one surface. ), A mold resin (30) covering a part of the semiconductor element and the heat spreader, and an insulating layer (40) formed in a partial region including the other surface of the surface of the heat spreader. In such a configuration, the heat spreader has the other surface exposed from the mold resin, and the other surface is formed with a concave and convex fin portion (11), and the insulating layer covers the fin portion and the heat spreader Of these, the surface connecting one surface and the other surface is the side surface (10c), and is an interface region with the mold resin of the side surface, and at least a part of the region between the end portion on the one surface side and the end portion on the other surface side In FIG. 3, the heat spreader is formed in a closed ring shape as viewed from the normal direction to one surface.

  As a result, the heat generated from the semiconductor element mounted on one surface of the heat spreader is diffused from the one surface side of the heat spreader to the other surface side where the fin portion serving as the cooling portion is formed, and then the fin portion to which the heat is transmitted becomes the insulating layer. It becomes a structure cooled by being exposed to a cooling fluid via. In addition, the insulating layer covers the other surface including the fin portion and surrounds the heat spreader as viewed from the normal direction to the one surface in the interface region with the mold resin in the side surface that connects the one surface and the other surface of the heat spreader. It is formed in a closed ring shape. Therefore, a part of the side surface of the heat spreader is covered with the mold resin through the insulating layer, thereby improving the adhesion with the mold resin, and a cooling fluid such as water enters between the side surface of the heat spreader and the mold resin. It becomes the structure where the malfunction by is suppressed. Therefore, the heat generated from the semiconductor element is efficiently dissipated, and problems caused by the intrusion of a cooling fluid such as water into the interface between the heat spreader and the mold resin are suppressed. It becomes a high semiconductor device.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

1 is a schematic plan view illustrating a semiconductor device according to a first embodiment. It is sectional drawing which shows the cross section between the dashed-dotted lines II-II in FIG. It is a figure which shows a fin part among the semiconductor devices of 1st Embodiment, (a) is the plane schematic diagram seen from the other surface side of the heat spreader, (b) is the dashed-two dotted line IIIb- in (a). It is sectional drawing which shows the cross section between IIIb. It is a figure which shows a mode that the semiconductor device of 1st Embodiment was mounted | worn with the cooler provided with the flow path which flows a cooling fluid. It is sectional drawing which shows the example of arrangement | positioning of the insulating layer in a semiconductor device. It is a figure which shows the relationship between arrangement | positioning of the insulating layer in a semiconductor device, and thermal resistance. It is sectional drawing which shows the semiconductor device of 2nd Embodiment. It is sectional drawing which shows the semiconductor device of 3rd Embodiment. It is a perspective view which shows the semiconductor device of 4th Embodiment. FIG. 10 is a cross-sectional view of the semiconductor device shown in FIG. 9. It is a figure which shows the semiconductor device of 5th Embodiment, (a) is a perspective view of the semiconductor device of 5th Embodiment, (b) is the semiconductor of 5th Embodiment between XIB-XIB in (a). It is sectional drawing of an apparatus. It is sectional drawing which shows the semiconductor device of other embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
The semiconductor device S1 of the first embodiment will be described with reference to FIGS. The semiconductor device S1 of this embodiment is used for a semiconductor device mounted on a vehicle such as an automobile.

  FIG. 1 shows an example of a planar layout when the semiconductor device S1 of the present embodiment is viewed from the one surface 10a side of the heat spreader 10 to be described later, and outlines of the mold resin 30 to be described later are indicated by broken lines. In FIG. 2, the thickness of an insulating layer 40 and a surface protective layer 41, which will be described later, are exaggerated for easy understanding of the configuration. FIG. 3A shows a state in which the fin portion 11 to be described later is viewed from the other surface 10b side. For convenience, the horizontal direction in FIG. The vertical direction is the y-axis direction, and the normal direction to the xy plane is the z-axis direction. Further, in FIG. 3A, in order to make the arrangement of the pins 12 described later easy to understand, the center lines along the x-axis direction and the y-axis direction of the pins 12 are indicated by alternate long and short dash lines, and the diameter of the pins 12 is represented. The auxiliary lines are indicated by broken lines. In FIG. 3B, the left-right direction in FIG. 3B is the x-axis direction, the vertical direction to the x-axis is the z-axis direction on the paper surface, and the normal direction to the xz plane is the y-axis direction. An auxiliary line for representing the height of 12 is indicated by a broken line. In FIG. 5, the boundary lines when the heat spreader 10 described later is divided into three regions, that is, the conductor portion 101, the heat diffusion portion 102, and the cooling portion 103 for convenience, are indicated by broken lines.

  As shown in FIG. 1 or FIG. 2, the semiconductor device S <b> 1 of this embodiment electrically connects the heat spreader 10, the lead parts 14 and 15, the semiconductor element 20, and the lead parts 14 and 15 and the semiconductor element 20. Wiring members 23 and 24 to be provided, and a mold resin 30 covering them. And the heat spreader 10 has the one surface 10a and the other surface 10b which have a front-back relationship, and the fin part 11 made into the uneven | corrugated shape is formed in the other surface 10b.

  The heat spreader 10 is made of a metal material having a high thermal conductivity such as Cu or Al and having a low electric resistance, and serves to diffuse heat generated from the semiconductor element 20 and as a current path of the semiconductor element 20. The heat spreader 10 is configured by, for example, a substantially square plate, and includes a lead portion 13 that projects from one side of the square plate. A part of the lead part 13 is exposed from the mold resin 30, and the plate thickness is made thinner than the part other than the lead part 13 in the heat spreader 10, and serves as a wiring member.

  As shown in FIG. 2, the other surface 10 b of the heat spreader 10 is exposed from the mold resin 30. On the other surface 10b of the heat spreader 10, a fin portion 11 having an uneven shape is formed.

  For example, as shown in FIG. 3B or FIG. 4, the fin portion 11 has an uneven shape by forming a plurality of columnar pins 12 protruding from the other surface 10 b of the heat spreader 10. The fin portion 11 is exposed to a cooling fluid such as water or air through an insulating layer 40 to be described later, thereby releasing the heat generated from the semiconductor element 20 toward the cooling fluid and lowering the temperature of the semiconductor device S1. Serves as a cooling unit.

  For example, as shown in FIG. 3A, the pins 12 are linearly and regularly arranged along the x-axis direction and the y-axis direction in FIG. In the present embodiment, the distance between the pin 12 and the other pin 12 adjacent along the x-axis direction is the same as the distance between the other pin 12 adjacent along the y-axis direction. Has been placed. For example, as shown in FIG. 3B, the pin 12 has a cylindrical shape protruding vertically from the other surface 10 b with the direction from the one surface 10 a to the other surface 10 b as the upward direction in the normal direction to the other surface 10 b. It is said that.

  For example, as shown in FIG. 3A or FIG. 3B, the pin 12 has an interval between another pin 12 adjacent in the x-axis direction and X adjacent to the other in the y-axis direction. The distance from the pin 12 is Y, the height is H, and each is 4 mm. As shown in FIG. 3A, if the diameter of the pin 12 is D, the diameter D of the pin 12 is, for example, 2 mm.

  The pins 12 are not limited to the arrangement example described above, but are arranged in a row along the x-axis direction, and a row of pins 12 adjacent to the row 12 in the y-axis direction. 12 may be a staggered arrangement in which the positions of the pins 12 in the x-axis direction are alternately shifted or other arrangements. In addition, the pin 12 may have not only a cylindrical shape but also a polygonal column shape or other shapes, and a shape that protrudes not only in the vertical direction upward from the other surface 10b but also in a tilted direction in the other direction. May be. Further, the distances X and Y between the pins 12 and the diameter D and height H of the pins 12 may be appropriately changed.

  The semiconductor element 20 is a semiconductor power element such as an IGBT (Insulated Gate Field Effect Transistor), for example, and is mounted on one surface 10a of the heat spreader 10 via a bonding material such as solder (not shown) as shown in FIG. Yes.

  The semiconductor element 20 has, for example, a rectangular plate shape as shown in FIG. 1, a first electrode (not shown) is formed on the surface on the heat spreader 10 side, and the second electrode 21 and the third electrode 22 are on the opposite surface on the heat spreader 10 side. Is formed. In the present embodiment, for example, when the semiconductor element 20 is an IGBT, the first electrode is a collector, the second electrode 21 is an emitter, and the third electrode 22 is a gate. The semiconductor element 20 is formed by a normal semiconductor process.

  In the above description, the example in which the semiconductor element 20 is an IGBT has been described. However, the semiconductor element 20 may be a semiconductor element such as a FWD (free wheel diode), or may be a semiconductor element in which an IGBT and an FWD are formed. Good.

  In the present embodiment, the first electrode is electrically connected to the heat spreader 10 via solder or the like. The second electrode 21 is connected to a wiring member 23 made of, for example, copper via solder (not shown) or the like, and is electrically connected to the lead portion 14 made of copper or the like via the wiring member 23. For example, a wire 24 made of aluminum or the like is wire-bonded to the third electrode 22, and the third electrode 22 is electrically connected to the lead portion 15 made of copper or the like via the wire 24. Similarly to the lead portion 13, the lead portions 14 and 15 are made thinner than the plate thickness of the heat spreader 10 other than the lead portion 13, and serve as wiring members.

  As shown in FIG. 1 or FIG. 2, the mold resin 30 is made of a resin material such as a thermosetting resin or a thermoplastic resin, and is different from the other surface 10b in the heat spreader 10, and one of the lead portions 14 and 15. Part, semiconductor element 20 and wiring members 23 and 24 are covered.

  In the present embodiment, the insulating layer 40 is formed in a region of the heat spreader 10 that includes the other surface 10b including the fin portion 11 and a part of the side surface 10c that connects the one surface 10a and the other surface 10b. The insulating layer 40 is an interface region with the mold resin 30 in the side surface 10c and is a method for the other surface 10b in at least a partial region between the end portion on the one surface 10a side and the end portion on the other surface 10b side. It is formed to be a closed ring surrounding the heat spreader 10 when viewed from the line direction. The reason for this will be explained later.

  For example, as shown in FIG. 4, the insulating layer 40 is set when the semiconductor device S <b> 1 is set using an O-ring (not shown) or the like to the cooler 200 including the flow path 201 through which the cooling fluid flows with the fin portion 11 side facing. It is an insulating member for ensuring insulation between the cooler 200 and the semiconductor device.

  The cooler 200 is made of a metal material having a high thermal conductivity such as aluminum, and has an opening 202 for setting the semiconductor device S1 and exposing the fin portion 11 of the semiconductor device S1 to the flow path 201. It is formed and it is made into arbitrary shapes as needed. Further, when the semiconductor device S1 is set in the cooler 200, it is preferable from the viewpoint of improving cooling efficiency that the fin portion 11 is disposed so as to contact the inner wall surface of the flow path 201 of the cooler 200. Further, FIG. 4 shows an example in which a step 10d is formed on the other surface 10b side from the viewpoint of reducing the gap between the opening 202 of the cooler 200 and the heat spreader 10 as much as possible. Thus, as for semiconductor device S1, the shape by the side of other surface 10b may be changed suitably as needed.

  The insulating layer 40 is made of, for example, a resin material or a ceramic material, and is formed by a technique such as thermal spraying, spin coating, thermocompression bonding, or vacuum pressure bonding. The insulating layer 40 depends on the thermal conductivity (W / mK) of the material used from the viewpoint of ensuring insulation and reliability, but in the stacking direction with respect to the other surface 10b or the side surface 10c on which the insulating layer is formed. The thickness is preferably in the range of 10 to 650 μm. Moreover, it is preferable that the insulating layer 40 is comprised with the resin material or ceramic material in the range whose thermal conductivity is 0.01-100 W / mK from a viewpoint of heat dissipation ensuring.

  In the present embodiment, the portion of the insulating layer 40 on the other surface 10b side including the fin portion 11 is covered with a surface protective layer 41 as shown in FIG.

  The surface protective layer 41 is formed so as to cover a portion of the insulating layer 40 on the other surface 10b side from the viewpoint of protecting the insulating layer 40 and improving heat dissipation. The surface protective layer 41 plays a role of protecting the insulating layer 40 particularly when water or LLC is used as a cooling fluid. More specifically, the surface protective layer 41 fulfills a rust and corrosion prevention function, particularly when water is used as a cooling fluid.

  The surface protective layer 41 is made of, for example, a metal whose main component is any one of the group consisting of Cu, Al, Ni, Ti, W, Mo, Co, Zn, Au, and Ag, or an oxide of the metal. . The surface protective layer 41 may be made of, for example, an alloy including two or more metals from the above group, an oxide of the alloy, or a fluorine resin. For example, the surface protective layer 41 is made of alumite as an oxide of Al if Al is used among the metals in the above group.

  The surface protective layer 41 is laminated on the insulating layer 40 by a technique such as plating, sputtering, vapor deposition, or metal foil welding. The surface protective layer 41 preferably has a thickness in the stacking direction of 0.02 to 100 μm, particularly from the viewpoint of protecting the insulating layer 40.

  The surface protective layer 41 is composed mainly of one metal selected from the above group or an alloy having two or more metals, but includes other metals and inevitable impurities. It may be. Further, the “main component” refers to a component that occupies, for example, 85 to 99.99 vol% in the entire surface protective layer 41.

  The above is the configuration of the semiconductor device S1 of the present embodiment, which is manufactured by a normal semiconductor mounting process.

  Next, the effect obtained when the insulating layer 40 is formed on the side of the other surface 10b including the fin portion 11 of the heat spreader 10 will be described with reference to FIGS.

  The present inventors diligently studied about improvement of heat dissipation in a semiconductor device having a configuration in which a semiconductor power element is mounted on a heat spreader. As a result, it has been found that the heat dissipation of the semiconductor device varies greatly depending on the arrangement of the insulating layer 40.

  Specifically, as shown in FIGS. 5A to 5C, the present inventors use three semiconductor devices having different arrangements of the insulating layer 40 as models, and simulate the thermal resistance in these semiconductor devices. Estimated.

  In the simulation, the heat spreader 10 is divided into three regions, that is, the conductor portion 101, the heat diffusion portion 102, and the cooling portion 103 for convenience. Specifically, the conductor portion 101 is a region including the one surface 10 a on which the semiconductor element 20 is mounted in the heat spreader 10. The thermal diffusion unit 102 is a region sandwiched between the conductor unit 101 and the cooling unit 103 with the region including the other surface 10 b on which the fin unit 11 is formed in the heat spreader 10 as the cooling unit 103.

  In the semiconductor device shown in FIG. 5A, an insulating layer 40 is formed between the conductor portion 101 and the thermal diffusion portion 102. In the semiconductor device shown in FIG. 5B, an insulating layer 40 is formed between the thermal diffusion unit 102 and the cooling unit 103. The semiconductor device shown in FIG. 5C has an insulating layer 40 formed on the cooling unit 103, and has a structure corresponding to the arrangement of the insulating layer 40 of the semiconductor device S1 of the present embodiment.

  In addition, the arrangements A, B, and C of the insulating layer on the horizontal axis in FIG. 6 correspond to the semiconductor devices shown in FIGS. 5A, 5B, and 5C, respectively. The insulating layer 40 is formed in a position away from the semiconductor element 20 in the order of A, B, and C.

  Note that the plate thicknesses of the conductor portion 101, the thermal diffusion portion 102, and the cooling portion 103 in the semiconductor device shown in FIG. 5 were 0.3 mm, 2.0 mm, and 1.0 mm, respectively. The thickness of the cooling part 103 is different from that of the fin part. In the trial calculation of the thermal resistance, the thermal conductivity of the material constituting the insulating layer 40 was set to 1 W / mK, and the conditions other than the arrangement of the insulating layer 40 were the same.

  According to the simulation, as shown in FIG. 6, it has been found that the thermal resistance decreases as the insulating layer 40 is formed farther from the one surface 10 a on which the semiconductor element 20 is mounted in the heat spreader 10. Specifically, when the thermal resistance of the semiconductor device in arrangement A is 1, the thermal resistance of the semiconductor device in arrangement B is 0.35, and the thermal resistance of the semiconductor device in arrangement C is 0.24. That is, the result shown in FIG. 6 suggests that the thermal resistance can be reduced by about 76% with respect to the semiconductor device of the arrangement A by using the arrangement C corresponding to the semiconductor device of the present embodiment. In addition, since this simulation is a trial calculation when the insulating layer 40 is made of a material whose thermal conductivity is 1 to 2 digits smaller than that of the metal material, even if a material having a low thermal conductivity is used as the insulating layer 40. This shows that the heat dissipation of the semiconductor device is improved.

  The reason why the thermal resistance decreases as the insulating layer 40 is arranged farther from the semiconductor element 20 is considered to be that heat generated in the semiconductor element 20 is diffused and then released from the cooling unit 103. .

  Next, the arrangement of the insulating layer 40 on the side surface 10c of the heat spreader 10 will be described.

  The insulating layer 40 is formed to be a closed ring surrounding the heat spreader 10 when viewed from the normal direction to the one surface 10a or the other surface 10b in the interface region with the mold resin 30 in the side surface 10c. Since the side surface 10 c is covered with the mold resin 30 through the insulating layer 40 in this way, the difference in linear expansion coefficient between the heat spreader 10 and the mold resin 30 is alleviated, and the side surface 10 c between the heat spreader 10 and the mold resin 30 is reduced. Adhesion is improved.

  When the adhesion is thus improved, as shown in FIG. 4, when a part of the other surface 10 b and the fin portion 11 are exposed to a cooling fluid such as water, the cooling fluid is heated between the heat spreader 10 and the mold resin 30. It becomes difficult to penetrate in between. Therefore, problems such as deterioration of the insulating layer 40 and the semiconductor element 20 due to the cooling fluid entering the semiconductor device S1 are suppressed, and the structure is improved in reliability.

  In the present embodiment, as shown in FIG. 2, the example in which the insulating layer 40 is formed over the entire side surface 10c is shown. However, the insulating layer 40 is a closed ring surrounding the heat spreader 10 on the side surface 10c. It does not necessarily have to be formed all over the side surface 10c. The insulating layer 40 is preferably formed in a region of the side surface 10c at the end portion on the other surface 10b side, in other words, a region including a region that can serve as a cooling fluid intrusion path.

  According to the present embodiment, the insulating layer 40 is disposed on the other surface 10b side far from the semiconductor element 20 in the heat spreader 10, and is formed in a closed ring shape on the side surface 10c of the heat spreader 10, so that heat dissipation and It becomes a highly reliable semiconductor device.

(Second Embodiment)
A semiconductor device S2 of the second embodiment will be described with reference to FIG. FIG. 7 shows a cross section of the semiconductor device according to the present embodiment at a position corresponding to FIG. 2 described in the first embodiment.

  As shown in FIG. 7, the semiconductor device S <b> 2 of the present embodiment is configured to further include another heat spreader 50 in addition to the semiconductor device S <b> 1 of the first embodiment. The semiconductor device S2 of the present embodiment includes the first heat spreader 10 and the second heat spreader 50, and has a double-sided heat dissipation structure in which heat generated from the semiconductor element 20 is radiated by the heat spreaders 10 and 50. This is different from the first embodiment. In the present embodiment, this difference will be mainly described.

  In order to make it easy to distinguish the constituent elements of the second heat spreader 50 from the constituent elements of the first heat spreader 10, in the following description, for convenience, the insulating layer 40 of the first heat spreader 10 is used as the first insulating layer, and the surface The protective layer 41 is a first surface protective layer.

  As shown in FIG. 7, the second heat spreader 50 is thermally connected to the semiconductor element 20 through one surface 50 a via solder (not shown). The second heat spreader 50 has a second fin portion 51 formed on the other surface 50b opposite to the one surface 50a.

  As shown in FIG. 7, in the second heat spreader 50, the other surface 50 b including the second fin portion 51 is exposed from the mold resin 30 in the same manner as the first heat spreader 10, and the other surface 50 b and the one surface 50 a and the other surface 50 b. A second insulating layer 52 is formed on the side surface 50c connecting the two. In the second heat spreader 50, a region on the other surface 50 b side including the second fin portion 51 in the second insulating layer 52 is covered with the second surface protective layer 53.

  In addition, the 2nd heat spreader 50, the 2nd insulating layer 52, and the 2nd surface protective layer 53 are comprised by the material similar to the 1st heat spreader 10, a 1st insulating layer, and a 1st surface protective layer, respectively. A portion of the second insulating layer 52 formed on the other surface 50 b side is covered with the second surface protective layer 53. Furthermore, the second heat spreader 50 functions as a current circuit and a heat dissipation member by using the second heat spreader 50 instead of the lead portion 14 and the wiring member 23 or the lead portion 15 and the wiring member 24 in the first embodiment. To do.

  Similarly to the first embodiment, for example, when wire bonding is performed on an electrode functioning as a gate electrode of the semiconductor element 20, a spacer member (not shown) is used from the viewpoint of preventing contact between the wire and the heat spreader. May be. Specifically, for example, a spacer member made of a metal such as copper and inserted electrically and thermally between the semiconductor element 20 and the second heat spreader 50 is inserted. May be.

  According to the present embodiment, since the heat generated from the semiconductor element 20 is dissipated on both sides by the two heat spreaders 10 and 50, in addition to the effects of the first embodiment, a semiconductor device with higher heat dissipation. It becomes.

(Third embodiment)
A semiconductor device S3 of the third embodiment will be described with reference to FIG. FIG. 8 shows a cross section of the semiconductor device S3 of the present embodiment, at a position corresponding to FIG. 2 described in the first embodiment.

  The semiconductor device S3 of the present embodiment includes the heat spreaders 10, 50, 60, 70 and the two semiconductor elements 20, 80. In such a configuration, the group including the heat spreaders 10 and 50 and the semiconductor element 20 and the group including the heat spreaders 60 and 70 and the semiconductor element 80 each function as one semiconductor circuit. The two semiconductor elements 20, 80 and a part of the heat spreaders 10, 50, 60, 70 are sealed with the mold resin 30, and the heat spreader 50 and the heat spreader 60 are electrically connected. As described above, the semiconductor device S3 of the present embodiment is different from the second embodiment in that it has a so-called 2-in-1 structure. In the present embodiment, this difference will be mainly described.

  As shown in FIG. 8, the first heat spreader 10 has a semiconductor element 20 mounted on one surface 10a. As for the 1st heat spreader 10, the fin part 11 is formed in the part corresponding to the position in which the semiconductor element 20 was mounted among the other surfaces 10b. The other surface 10b and the side surface 10c are covered with the insulating layer 40 as in the first embodiment. The other surface 10 b side is covered with a surface protective layer 41 including the fin portions 11.

  As shown in FIG. 8, the second heat spreader 50 faces the first heat spreader 10 and the semiconductor element 20, and the one surface 50 a side is thermally connected to the semiconductor element 20. As for the 2nd heat spreader 50, the fin part 51 is formed in the part corresponding to the position in which the semiconductor element 20 was mounted among the other surfaces 50b opposite to the one surface 50a. The other surface 50b and the side surface 50c are covered with the insulating layer 40 as in the first embodiment. The insulating layer 40 formed on the other surface 10 b side is covered with a surface protective layer 41 including the fin portions 11.

  The 2nd heat spreader 50 is electrically connected with the 3rd heat spreader 60, and projection part 54 used as a current course is formed. The protrusion 54 is electrically connected to a protrusion 64 formed on a third heat spreader 60 described later via a conductive bonding material 65 such as solder.

  As shown in FIG. 8, the third heat spreader 60 has a semiconductor element 80 mounted on one surface 60a. The third heat spreader 60 has a fin portion 61 formed at a portion corresponding to the position where the semiconductor element 80 is mounted on the other surface 60b. The other surface 60b and the side surface 60c are covered with an insulating layer 62 as in the first embodiment. The insulating layer 62 formed on the other surface 60 b side is covered with a surface protective layer 63 including the fin portions 61.

  The third heat spreader 60 is electrically connected to the second heat spreader 50, and a protrusion 64 used as a current path is formed. The protrusion 64 is electrically connected to the protrusion 54 via the bonding material 65.

  As shown in FIG. 8, the fourth heat spreader 70 faces the third heat spreader 60 and the semiconductor element 80, and the one surface 70 a side is thermally connected to the semiconductor element 80. In the fourth heat spreader 70, a fin portion 71 is formed at a portion corresponding to the position where the semiconductor element 80 is mounted on the other surface 70b opposite to the one surface 70a. The other surface 70b and the side surface 70c are covered with an insulating layer 72 as in the first embodiment. The other surface 70 b side is covered with a surface protective layer 73 including the fin portions 71.

  Similar to the semiconductor element 20, the semiconductor element 80 is an element including IGBT, FWD, and the like.

  In addition, although the fin parts 61 and 71 are the area | regions made into uneven | corrugated shape by providing a some pin like the said 1st Embodiment, the shape may be changed suitably. Further, similarly to the second embodiment described above, a spacer material (not shown) may be used as necessary.

  According to this embodiment, the two semiconductor elements 20 and 80 can be driven, and a semiconductor device with high heat dissipation and high reliability is obtained.

(Fourth embodiment)
A semiconductor device S4 of the fourth embodiment will be described with reference to FIGS. FIG. 10 corresponds to a cross section when the semiconductor device S4 of this embodiment is cut by a plane passing through the two extending directions of the cooling fluid introduction port 2c and the cooling fluid discharge port 2d in FIG. In FIG. 10, the insulating layer 40, the surface protective layer 41, the protrusions 54 and 64, and the bonding material 65 in the semiconductor module S <b> 3 described later are omitted for easy viewing.

  As shown in FIG. 9, the semiconductor device S4 of the present embodiment includes a plurality of semiconductor devices S3 of the third embodiment (referred to as “semiconductor module S3” in the following description), and includes an inverter having a cooling mechanism 2. This is an applied example. In the present embodiment, features other than the semiconductor module S3 will be mainly described.

  This inverter includes three semiconductor modules S3 having a plate shape and a cooling mechanism 2, and is for driving a load (such as a motor) (not shown) based on an external DC power supply. As the circuit configuration for driving the load, any circuit configuration of an inverter can be adopted, and the description thereof is omitted here.

  The cooling mechanism 2 is formed of a metal such as aluminum having a high thermal conductivity, and includes a plurality of plates 2a, fins 2b, a cooling fluid introduction port 2c, a cooling fluid discharge port 2d, and the like as shown in FIG. . The plurality of plates 2a and fins 2b are joined together by brazing or welding, with two plates 2a and one fin 2b as a set, with one fin 2b sandwiched between the two plates 2a. Yes. Thus, the plurality of plates 2a and fins 2b constitute a cooling fluid passage 2e through which a cooling fluid such as cooling water flows.

  The plurality of plates 2a are fitted with the semiconductor module S3, and are formed with openings 2aa for exposing the fin portions 11, 51, 61, 71 formed in the semiconductor module S3 to the cooling fluid passage 2e. The fin 2b is, for example, a wave fin having a wave shape in the direction perpendicular to the paper surface of FIG. The fin 2b has a plurality of cooling fluid passages 2e extending in the left-right direction on the paper surface when the crests and valleys of the undulated fin 2b come into contact with the two plates 2a sandwiching the fin 2b.

  A communication hole is formed in a portion of each plate 2a and fin 2b that intersects with cooling fluid introduction port 2c and cooling fluid discharge port 2d. The cooling fluid passages 2e formed by the plates 2a and the fins 2b are connected by a cooling fluid introduction port 2c and a cooling fluid discharge port 2d. For this reason, the cooling fluid introduced from the cooling fluid introduction port 2c is discharged through the cooling fluid discharge port 2d after passing through each cooling fluid passage 2e as indicated by an arrow in FIG.

  In the cooling mechanism 2 configured as described above, a gap is provided between each set of the two plates 2a and the one fin 2b, and each semiconductor module S3 is sandwiched between the gaps to insulate the pair. It is fixed via a member or the like. For example, after two plates 2a and one fin 2b are joined to form one cooling fluid passage 2e, the fin portions 11 and 61 or the fin portions 51 and 71 of the semiconductor module S3 are formed in the opening 2aa of the plate 2a. Fit. Thereafter, another two plates 2a and one fin 2b are prepared, and one plate 2a is opened to the fin portions 11, 61 or the fin portions 51, 71 exposed from the cooling fluid passage 2e in the semiconductor module S3. Fit 2aa. Next, in this state, one plate 2a fitted into the semiconductor module S3 is joined to the other plate 2a and the fin 2b. By repeating this, the semiconductor module S3 is fixed to the cooling mechanism 2. In this manner, the inverter 1 including the three semiconductor modules S3 is configured.

  As shown in FIG. 10, each semiconductor module S3 has fin portions 11, 51, 61, 71 exposed to the cooling fluid passage 2e, and the fin portions 11, 51, 61, 71 are the inner wall surfaces of the cooling fluid passage 2e. It is supposed to be in a state of touching. Thereby, each semiconductor module S3 is cooled from the exposed surface to the cooling fluid passage 2e among the heat spreaders 10, 50, 60, and 70 by the cooling fluid introduced into the cooling mechanism 2.

  Each semiconductor module S3 is fitted on the cooling mechanism 2 so that the fins 11, 51, 61, 71 are formed on the surfaces of the heat spreaders 10, 50, 60, 70 on which the fins 11, 51, 61, 71 are formed. Steps are formed so that 61 and 71 protrude into the cooling fluid passage 2e. Specifically, steps 10d, 50d, 60d, and 70d are formed on the other surface sides of the heat spreaders 10, 50, 60, and 70, respectively. Further, as described in the first embodiment, the shape of the surface on which the fin portions 11, 51, 61, 71 are formed in the heat spreaders 10, 50, 60, 70 is limited to the example shown in FIG. However, it may be changed as appropriate.

  When applied to an inverter as in the present embodiment, a semiconductor module having higher heat dissipation and reliability than conventional ones is used, so that the inverter has higher heat dissipation and reliability.

(Fifth embodiment)
A semiconductor device S5 of the fifth embodiment will be described with reference to FIG. Although FIG. 11 shows an example in which the arrangement of the semiconductor modules S3 in the fourth embodiment is changed, in order to make the configuration easy to understand, the heat spreaders 50 and 70 side of the semiconductor modules S3 in the cooling mechanism 2 are arranged. The covering flow path is omitted. In FIG. 11, as in FIG. 10, the insulating layer 40, the surface protective layer 41, the protrusions 54 and 64, and the bonding material 65 in the semiconductor module S <b> 3 are omitted for easy viewing.

  The semiconductor device S5 of this embodiment is an inverter as in the fourth embodiment, but the three semiconductor modules S3 are not arranged so as to be stacked in one direction, and constitute the cooling mechanism 2. They are arranged side by side in the plane direction formed by one surface of the plate 2a. And the structure of the cooling mechanism 2 in this embodiment is changed from the structure demonstrated in the said 4th Embodiment with the arrangement change of semiconductor module S3. The semiconductor device S5 of the present embodiment is different from the fourth embodiment in the above points. In the present embodiment, this difference will be mainly described.

  As shown in FIG. 11, the three semiconductor modules S <b> 3 are arranged side by side along a planar direction formed by one surface of the plate 2 a constituting the cooling mechanism 2. In other words, when the arrangement of the semiconductor modules S3 in the fourth embodiment is stacked, in the present embodiment, the semiconductor modules S3 are laid flat on one plane.

  In this embodiment, the cooling mechanism 2 has a configuration in which two cooling fluid passages 2e are formed so as to sandwich three flatly placed semiconductor modules S3, and one cooling fluid passage 2e has three semiconductor modules. It is set as the structure shared as a flow path for cooling S3. That is, the cooling mechanism 2 is configured to cool the three semiconductor modules S3 from both sides by the two cooling fluid passages 2e.

  The cooling fluid passage 2e is composed of two plates 2a and one fin 2b in the fourth embodiment, but is composed of two plates 2a in the present embodiment.

  According to the present embodiment, since the thickness of the cooling mechanism 2 constituting the inverter becomes thinner than that of the fourth embodiment by placing the semiconductor module S3 flat, the thickness is further reduced while improving heat dissipation and reliability. It becomes an inverter.

(Other embodiments)
The semiconductor device described in each of the above embodiments is an example of the semiconductor device of the present invention, and is not limited to each of the above embodiments, but within the scope described in the claims. Can be changed as appropriate.

  For example, in each of the above embodiments, the example in which the portion on the other surface 10b side of the insulating layer 40 is covered with the surface protective layer 41 has been described. However, when air is used as the cooling fluid or when water or LLC is used as the cooling fluid, the semiconductor device is configured without the surface protective layer 41 when the insulating layer 40 is made of a highly water-resistant material. May be.

  In each of the above embodiments, the example in which the insulating layer 40 is formed on the other surface 10b and the side surface 10c of the heat spreader 10 has been described. However, the insulating layer 40 is formed of the mold resin 30 on the surface of the heat spreader 10 as shown in FIG. It may be formed so as to cover the entire interface with. The insulating layer 40 may be formed at the interface between the semiconductor element 20 and the mold resin 30.

  Thereby, since the insulating layer 40 continuously covers the entire interface between the heat spreader 10 and the semiconductor element 20 and the mold resin 30, the adhesion with the mold resin 30 is improved, so that the reliability is further improved than the above embodiments. It becomes a high semiconductor device.

  FIG. 12 shows an example in which the insulating layer 40 is formed over the entire interface between the heat spreader 10 and the mold resin 30 in the semiconductor device S1 of the first embodiment, but each of the above embodiments other than the first embodiment. In this case, a similar insulating layer may be formed. Specifically, in embodiments other than the first embodiment, the insulating layer may be formed in the heat spreaders 10, 50, 60, 70 and the entire interface between the semiconductor elements 20, 80 and the mold resin 30. Good.

DESCRIPTION OF SYMBOLS 10 Heat spreader 11 Fin part 12 Pin 20 Semiconductor element 30 Mold resin 40 Insulating layer 41 Surface protective layer

Claims (10)

A heat spreader (10) having one side (10a) and the other side (10b) in a front-back relationship;
A semiconductor element (20) mounted on the one surface;
A mold resin (30) covering a part of the semiconductor element and the heat spreader;
An insulating layer (40) formed in a part of the surface of the heat spreader including the other surface;
In the heat spreader, the other surface is exposed from the mold resin, and a fin portion (11) having an uneven shape is formed on the other surface,
The insulating layer covers the fin portion and is a boundary surface between the one surface and the other surface of the heat spreader as a side surface (10c), and is an interface region with the mold resin among the side surfaces. A semiconductor device formed in a closed ring surrounding the heat spreader when viewed from the normal direction to the one surface in at least a part of the region between the end portion on the side and the end portion on the other surface side.   The semiconductor device according to claim 1, wherein the insulating layer is formed in a region including at least an end portion on the other surface side of the side surface.   The semiconductor device according to claim 2, wherein the insulating layer is formed on the entire surface of the interface with the mold resin.   4. The semiconductor device according to claim 1, wherein the insulating layer is made of a resin material or a ceramic material having a thermal conductivity in a range of 0.01 to 100 W / mK.   5. The semiconductor device according to claim 1, wherein the insulating layer has a thickness in a direction normal to a surface of the surface on which the insulating layer is formed within a range of 10 to 650 μm.   The part which covers the said fin part among the said insulating layers is a semiconductor device as described in any one of Claim 1 thru | or 5 covered with the surface protection layer (41) which has a rust prevention anti-corrosion function.   The surface protective layer is made of a metal mainly comprising any one of the group consisting of Cu, Al, Ni, Ti, W, Mo, Co, Zn, Au, and Ag, an oxide of the metal, or the group The semiconductor device according to claim 1, which is made of an alloy having two or more metals, an oxide of the alloy, or a fluorine resin. The heat spreader is a first heat spreader, the fin portion is a first fin portion, the insulating layer is a first insulating layer, and is disposed opposite to the first heat spreader with the semiconductor element interposed therebetween. Connected second heat spreader (50),
In the second heat spreader, the opposite surface (50b) of the surface on the first heat spreader side is exposed from the mold resin, and the second fin portion (51) having an uneven shape is formed on the opposite surface,
The second fin portion is covered with a second insulating layer (52),
8. The semiconductor device according to claim 1, wherein a portion of the second insulating layer that covers the opposite surface side is covered with a surface protective layer (71).   9. The semiconductor device according to claim 1, wherein the fin portion has an uneven shape by disposing a plurality of pins (12) protruding from the other surface apart from each other. The semiconductor element as a first semiconductor element, further comprising a second semiconductor element (80), a third heat spreader (60), and a fourth heat spreader (70),
The second semiconductor element is mounted on one surface (60a) of the third heat spreader,
The third heat spreader is formed with a third fin portion (61) having an uneven shape on the other surface (60b) opposite to the one surface,
The fourth heat spreader is disposed facing the third heat spreader and the second semiconductor element, is thermally connected to the second semiconductor element, and is on the other surface opposite to the second semiconductor element ( 70b) is formed with a concave and convex fourth fin portion (71),
The other surface of the third heat spreader and the other surface of the fourth heat spreader are exposed from the mold resin,
The other surface of the third heat spreader is covered together with the third fin portion in the order of a third insulating layer (62) and a surface protective layer (63),
The other surface of the fourth heat spreader is covered together with the fourth fin portion in the order of a fourth insulating layer (72) and a surface protective layer (73),
The first semiconductor element, the first heat spreader and the second heat spreader as a first module, the second semiconductor element, the third heat spreader and the fourth heat spreader as a second module, and the first module The semiconductor device according to claim 8, wherein the second module is electrically connected and partly covered with the mold resin.

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