JP2013122993A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device which inhibits breakage of an insulating substrate.SOLUTION: A semiconductor device comprises: a first metal plate; a semiconductor element mounted on one surface of the first metal plate; a first insulating substrate arranged on another surface of the first metal plate; and an encapsulation resin encapsulating the first metal plate, the semiconductor element and the first insulating substrate. A fluent thermally-conductive material is coated of formed between the first metal plate and the first insulating substrate.

Description

  The present invention relates to a semiconductor device.

  Conventionally, a metal plate is provided on both front and back surfaces, and one metal plate is used as a main electrode, and a pair of insulating substrates provided with lead electrodes connected to the main electrode, and the metal plate used as the main electrode of each insulating substrate. The semiconductor element sandwiched between the main electrodes, the metal plate surface of each insulating substrate opposite to the metal plate serving as the main electrode, and a part of each lead electrode are exposed, A semiconductor device comprising a resin layer for sealing each insulating substrate and the semiconductor element and each lead electrode, wherein the main electrode of one of the insulating substrates is connected to an anode (or emitter) electrode of the semiconductor element There has been a semiconductor device provided with a raised portion raised from a surrounding portion as a portion (see, for example, Patent Document 1).

JP 2010-232365 A

  By the way, in the conventional semiconductor device, the main electrode is provided with a raised portion.

  For this reason, when the insulating substrate is connected to the surface opposite to the surface where the raised portions of the main electrode are formed by brazing or the like, uneven stress is applied to the insulating substrate due to stress concentration on the convex portion, There was a risk of damage to the insulating substrate.

  In view of the above, an object of the present invention is to provide a semiconductor device in which breakage of an insulating substrate is suppressed.

  A semiconductor device according to an embodiment of the present invention includes a first metal plate, a semiconductor element mounted on one surface of the first metal plate, and a first disposed on the other surface of the first metal plate. An insulating substrate; and a sealing resin that seals the first metal plate, the semiconductor element, and the first insulating substrate, and has a fluidity between the first metal plate and the first insulating substrate. A heat conducting member is applied or formed.

  A semiconductor device in which damage to the insulating substrate is suppressed can be provided.

1 is a diagram illustrating a drive system including an electric motor driven by a power supply circuit including the semiconductor device of Embodiment 1. FIG. 1 is an exploded perspective view of a semiconductor device according to a first embodiment. 1 is a perspective view showing an internal structure of a semiconductor device according to a first embodiment. 1 is a perspective view showing a semiconductor device according to a first embodiment. 2 is a cross-sectional view of the semiconductor device of First Embodiment. FIG. 2 is a diagram showing an equivalent circuit of the semiconductor device 100 according to the first embodiment. FIG. 5 is a diagram showing a manufacturing process of the semiconductor device 100 of the first embodiment. FIG. 5 is a diagram showing a manufacturing process of the semiconductor device 100 of the first embodiment. FIG. FIG. 6 is a diagram showing a cross-sectional structure of a semiconductor device according to a second embodiment. FIG. 4 is a diagram illustrating a cross-sectional structure of a semiconductor device according to a third embodiment. FIG. 10 is a diagram showing a part of the manufacturing process of the semiconductor device 300 of the third embodiment. FIG. 10 is an exploded perspective view of a semiconductor device according to a fourth embodiment. FIG. 10 is a perspective view showing an internal structure of a semiconductor device according to a fourth embodiment. FIG. 6 is a diagram showing a cross-sectional structure of a semiconductor device according to a fourth embodiment.

  Hereinafter, embodiments to which the semiconductor device of the present invention is applied will be described.

<Embodiment 1>
FIG. 1 is a diagram illustrating a drive system including an electric motor driven by a power supply circuit including the semiconductor device of the first embodiment.

  The drive system 10 includes an electric motor 1, a power supply circuit 2, a drive control unit 3, an HVECU (Hybrid Vehicle Electronic Control Unit) 4, and a resolver 5, and is used for, for example, a hybrid vehicle.

  The electric motor 1 is a motor generator (MG) mounted on a vehicle and functions as a motor when electric power is supplied from a battery 6 included in the power supply circuit 2, and is driven by an engine (not shown) or It is a three-phase synchronous rotating electrical machine that functions as a generator when braking a vehicle.

  Here, a mode in which a motor / generator having a motor function and a generator function is used as one electric motor 1 will be described. However, this is an example, and only one rotating electric machine having only a motor function is described. One rotating electrical machine having only the function of a generator may be used. A plurality of motor generators may be used.

  When a plurality of motor / generators are used, any one of the electric motors 1 may be used as a generator for charging the battery 6, and any other electric motor 1 may be used as a drive motor that mainly generates power.

  The power supply circuit 2 includes a battery 6, a smoothing capacitor 7 </ b> A, a buck-boost converter 8, a smoothing capacitor 7 </ b> B, and an inverter 9.

  The battery 6 is a chargeable / dischargeable secondary battery. As the battery 6, for example, a lithium ion assembled battery or a nickel hydride assembled battery having a terminal voltage of about 200V to about 300V, or a capacitor can be used.

  Smoothing capacitor 7 </ b> A is provided between battery 6 and buck-boost converter 8, and suppresses voltage fluctuation on the battery 6 side in power supply circuit 2.

  The step-up / down converter 8 includes a reactor and a plurality of switching elements, boosts the voltage on the battery 6 side in the power supply circuit 2 and outputs the boosted voltage to the inverter 9 side, and steps down the voltage on the inverter 9 side to reduce the voltage on the battery 6 side. Output to.

  The step-up / step-down converter 8 boosts, for example, a voltage of about 200 V to about 300 V on the battery 6 side to a high voltage of about 500 V to 700 V, for example, using the energy storage action of the reactor. Further, when the power from the inverter 9 side is supplied as charging power to the battery 6 side, the step-up / down converter 8 steps down the voltage on the inverter 9 side and outputs it to the battery 6 side.

  Smoothing capacitor 7 </ b> B is provided between buck-boost converter 8 and inverter 9, and suppresses voltage fluctuation on inverter 9 side in power supply circuit 2.

  The inverter 9 converts DC power into AC three-phase drive power and supplies it to the motor 1, and converts AC three-phase regenerative power regenerated by the motor 1 into DC power and supplies it to the battery 6.

  Inverter 9 has three phases of arms in which two switching elements are connected in series, and diodes are connected in parallel to each switching element. The midpoint of each arm is connected to the three-phase windings 1u, 1v, 1w of the electric motor 1. Signals representing the voltage values of the input voltage and output voltage of the inverter 9 are input to the drive control unit 3.

  Two switching elements and two diodes included in each arm of inverter 9 are semiconductor elements included in the semiconductor device of the first embodiment. The switching element is, for example, an IGBT, and the diode is, for example, an FWD. The semiconductor device of the first embodiment is used for each arm of the inverter 9 as a power card for supplying and regenerating power.

  The drive control unit 3 is a device that performs drive control of the electric motor 1 by performing drive control of the inverter 9 of the power supply circuit 2.

  The drive control unit 3 generates a voltage command in, for example, a sine wave control mode, an overmodulation control mode, or a rectangular wave control mode, and performs drive control of the electric motor 1 via the inverter 9. The drive control unit 3 is configured by an ECU, for example.

  The HVECU 4 is connected to a throttle position sensor and outputs a torque command value corresponding to the degree to which the vehicle driver steps on the throttle. The torque command value represents the torque required for the electric motor 1. The torque command value output by the HVECU 4 is input to the drive control unit 3.

  The resolver 5 is an example of a rotation speed detection unit that detects the rotation speed of the rotation shaft of the electric motor 1. A signal representing the rotation speed of the electric motor 1 detected by the resolver 5 is input to the drive control unit 3.

  FIG. 2 is an exploded perspective view of the semiconductor device according to the first embodiment. FIG. 3 is a perspective view showing the internal structure of the semiconductor device of the first embodiment. FIG. 4 is a perspective view showing the semiconductor device of the first embodiment. FIG. 5 is a cross-sectional view of the semiconductor device of First Embodiment.

  The semiconductor device 100 according to the first embodiment includes an electrode 110, semiconductor elements 120A and 120B, an electrode 130, an insulating substrate 140, and a sealing resin 150.

  For ease of understanding, the sealing resin 150 is omitted in FIGS. 2 and 3. The difference between FIG. 3 and FIG. 4 is the presence or absence of the sealing resin 150. That is, when the electrode 110, the semiconductor elements 120A and 120B, the electrode 130, and the insulating substrate 140 shown in FIG. 3 are sealed with the sealing resin 150, the semiconductor device 100 shown in FIG. 4 is obtained. FIG. 5 shows a cross section taken along line AA in FIG.

  Here, a mode in which the semiconductor element 120A is an IGBT and the semiconductor element 120B is an FWD will be described. The semiconductor device 100 including the semiconductor elements 120A and 120B is included in the inverter 9 shown in FIG.

  The electrode 110 functions as an electrode for driving the semiconductor elements 120A and 120B, and also functions as a heat radiating plate (heat sink) that radiates heat generated by the semiconductor elements 120A and 120B. The electrode 110 is made of, for example, copper or a copper alloy, and the thickness is, for example, 1.0 mm to 5.0 mm. The electrode 110 is an example of a first metal plate.

  Semiconductor elements 120 </ b> A and 120 </ b> B are connected to the upper surface of the electrode 110. There is an IGBT collector on the lower surface of the semiconductor element 120A. The collector of the semiconductor element 120A is connected to the upper surface of the electrode 110 by solder, for example. Further, an FWD cathode is provided on the lower surface of the semiconductor element 120B. The cathode of the semiconductor element 120B is connected to the upper surface of the electrode 110 by solder, for example.

  As shown in FIG. 2, a bus bar 111 is connected to the electrode 110. The electrode 110 is connected to the electric motor 1 or the smoothing capacitor 7 </ b> B (see FIG. 1) via the bus bar 111.

  The terminals 121A, 121B, 121C, and 121D on the upper surface of the semiconductor element 120A are connected to the control terminals 172A, 172B, 172C, and 172D by bonding wires 171A, 171B, 171C, and 171D, respectively.

  The control terminals 172A to 172D are fixed by a lead frame (not shown), and after being sealed with the sealing resin 150 as shown in FIG. 4, the lead frame is cut off. The control terminals 172A to 172D are insulated from the electrode 110. At least one of the control terminals 172A to 172D is connected to the gate of the IGBT. The control terminals 172A to 172D are used for inputting a control signal for controlling the driving of the semiconductor element 120A.

  The bonding wires 171A to 171D are made of, for example, an aluminum alloy or high-purity aluminum. The wire diameters of the bonding wires 171A to 171D are, for example, 50 μm to 500 μm. The control terminals 172A to 172D are made of, for example, copper or a copper alloy. The thickness of the control terminals 172A to 172D is, for example, 0.3 mm to 1.0 mm.

  On the upper surface of the semiconductor element 120A, there is an IGBT emitter 121E in addition to the terminals 121A to 121D. The emitter 121E is connected to the first portion 132 of the electrode 130. The emitter 121E and the first portion 132 are connected by, for example, solder.

  On the upper surface of the semiconductor element 120B, there is an anode 122A of FWD. The second portion 133 of the electrode 130 is connected to the anode 122A. The anode 122A and the second portion 133 are connected by, for example, solder.

  The emitter 121E of the semiconductor element 120A and the anode 122A of the semiconductor element 120B are connected to each other by the electrode 130.

  As shown in FIGS. 2 and 3, the electrode 130 includes a bus bar 131, a first portion 132, and a second portion 133.

  The bus bar 131 is connected to the electric motor 1 or the smoothing capacitor 7B. The first portion 132 is connected to the emitter 121E of the semiconductor element 120A. The second portion 133 is connected to the anode 122A on the upper surface of the semiconductor element 120B. The electrode 130 is made of copper or a copper alloy, for example, like the electrode 110.

The insulating substrate 140 is affixed to the lower surface of the electrode 110 via silicone grease 141 having adhesiveness and thermal conductivity. The insulating substrate 140 is a ceramic substrate such as silicon nitride (SiN), aluminum nitride (AlN), or alumina (Al ₂ O ₃ ).

  The insulating substrate 140 is formed to be larger than the electrode 110 and thinner than the electrode 110 in plan view. The thickness of the insulating substrate 140 is, for example, 0.2 mm to 1.0 mm.

  The lower surface 140 </ b> A of the insulating substrate 140 is exposed from the sealing resin 150. It functions as a heat sink that radiates heat conducted from the semiconductor elements 120 </ b> A and 120 </ b> B to the electrode 110 to the outside of the semiconductor device 100.

  Further, the insulating substrate 140 is attached to the electrode 110 with the silicone grease 141, but the adhesiveness of the silicone grease 141 does not have an adhesive force enough to fix the insulating substrate 140 to the electrode 110. For this reason, the insulating substrate 140 is fixed by the sealing resin 150. In addition, the thickness of the silicone grease 141 should just be 10 micrometers-200 micrometers, for example. Silicone grease 141 is an example of a heat conductive member having fluidity.

  As shown in FIGS. 4 and 5, the sealing resin 150 is a resin that seals the electrode 110, the semiconductor elements 120 </ b> A and 120 </ b> B, the electrode 130, and the insulating substrate 140. The lower surface 140 </ b> A of the insulating substrate 140 is exposed from the sealing resin 150. That is, the sealing resin 150 is not formed on the lower surface 140 </ b> A of the insulating substrate 140. The bus bars 111 and 131 and the control terminals 172A to 172D extend from the sealing resin 150.

  The sealing resin 150 is made of a thermosetting resin. The sealing resin 150 is made of, for example, an epoxy resin, and glass fibers or the like may be mixed therein. For example, the sealing resin 150 is heated to about 80 ° C. to 200 ° C. to be cured, and then cooled.

  The electrode 110, the semiconductor elements 120A and 120B, the electrode 130, and the insulating substrate 140 are sealed with a sealing resin 150. The sealing resin 150 is in close contact with the insulating substrate 140.

  FIG. 6 is a diagram illustrating an equivalent circuit of the semiconductor device 100 according to the first embodiment. The collector of the semiconductor element 120A made of IGBT is connected to the cathode of the semiconductor element 120B made of FWD via the electrode 110, and the emitter of the semiconductor element 120A made of IGBT is made via the electrode 130, It is connected to the anode of the semiconductor element 120B composed of FWD.

  The gate of the semiconductor element 120A formed of IGBT is connected to the drive control unit 30 (see FIG. 1) via at least one set of the bonding wires 171A to 171D and the control terminals 172A to 172D.

  The semiconductor element 120 </ b> A of the semiconductor device 100 is turned on / off by a control signal input from the drive control unit 30 to the gate. A current flows through the semiconductor element 120B when the semiconductor element 120A is off.

  Next, a method for manufacturing the semiconductor device 100 according to the first embodiment will be described.

  7 and 8 are diagrams showing manufacturing steps of the semiconductor device 100 of the first embodiment.

  First, the electrode 110, the semiconductor elements 120A and 120B, the electrode 130, the insulating substrate 140, and the control terminals 172A to 172D are aligned. A known jig may be used for alignment.

  In the state shown in FIG. 7, the electrode 110 and the semiconductor elements 120A and 120B, and the semiconductor elements 120A and 120B and the electrode 130 are joined using a solder foil or the like. The solder foil is, for example, solder formed into a sheet by rolling a material such as SnAg solder containing tin and silver or SnCu solder containing tin and copper.

  In addition, the insulating substrate 140 is bonded to the lower surface of the electrode 110 with silicone grease 141. A bus bar 111 is connected to the electrode 110. The terminals 121A to 121D of the semiconductor element 120A and the control terminals 172A to 172D are connected by bonding wires 171A to 171D, respectively.

  The surfaces of the electrodes 110 and 130 may be plated with nickel. Further, a portion of the surface of the electrodes 110 and 130 that contacts the solder foil may be plated with gold in order to improve wettability.

  As shown in FIG. 7, the electrodes 110, the semiconductor elements 120A and 120B, the electrodes 130, and the insulating substrate 140 are connected by melting the solder foil in the aligned state.

  As shown in FIG. 7, the electrode 110, the semiconductor elements 120 </ b> A and 120 </ b> B, the electrode 130, and the insulating substrate 140 that are bonded together are in a solution in which polyamide or polyimide is dissolved in an organic solvent before sealing with the sealing resin 150. By impregnating, the surface is coated with a film such as polyamide or polyimide. This is because the sealing resin 150 can easily adhere to the surfaces of the electrode 110, the semiconductor elements 120A and 120B, the electrode 130, and the insulating substrate 140.

  Next, the electrode 110, the semiconductor elements 120A and 120B, the electrode 130, the insulating substrate 140, the bus bars 111 and 131, and the control terminals 172A to 172D are sealed with a sealing resin 150. Sealing with the sealing resin 150 is performed by performing a thermosetting process on the sealing resin 150.

  In the thermosetting process, the semiconductor elements 120A and 120B, the electrode 130, the insulating substrate 140, the bus bars 111 and 131, and the control terminals 172A to 172D shown in FIG. 8 are placed in heated molds 180A and 180B, and the thermosetting resin is heated. The curing reaction of the thermosetting resin is promoted by pouring into the molds 180A and 180B, applying a supplementary pressure to the thermosetting resin in the molds 180A and 180B and heating. In this way, insert molding is performed.

  At this time, since the resin injection pressure works between the molds 180A and 180B to press the electrode 110 against the mold 180B, the silicone grease 141 between the electrode 110 and the insulating substrate 140 is compressed in the thickness direction. By doing so, it becomes thinner. For this reason, the thermal conductivity between the electrode 110 and the insulating substrate 140 is improved.

  The thermosetting resin is heated at, for example, a temperature of about 80 ° C. to 200 ° C., and then cooled to obtain the sealing resin 150 shown in FIG. The sealing resin 150 seals the electrode 110, the semiconductor elements 120A and 120B, the electrode 130, and the insulating substrate 140. Further, from the sealing resin 150, the lower surface 140A of the insulating substrate 140, the bus bars 111 and 131, and a part of the outside of the control terminals 172A to 172D are exposed.

  According to the semiconductor device 100 of the first embodiment as described above, the electrode 110 and the insulating substrate 140 are merely bonded together by the adhesive force of the silicone grease 141 or the capillary phenomenon. The silicone grease 141 has adhesiveness that does not cause misalignment when the electrodes 110 and the insulating substrate 140 are aligned in the manufacturing process described with reference to FIGS. 7 and 8.

  For this reason, it can suppress that position shift arises in the electrode 110 and the insulated substrate 140 in a manufacture stage.

  Further, the electrode 110 and the insulating substrate 140 are thermally bonded by the silicone grease 141, but are not rigidly bonded by the silicone grease 141. The electrode 110 and the insulating substrate 140 are only temporarily bonded by silicone grease 141, and the insulating substrate 140 is fixed by the sealing resin 150.

  Accordingly, heat generated in the semiconductor elements 120A and 120B is transmitted to the insulating substrate 140 through the electrode 110 and the silicone grease 141, and is radiated from the insulating substrate 140 to the outside.

  In addition, although the linear expansion coefficient of the electrode 110 and the insulating substrate 140 is greatly different, as described above, the electrode 110 and the insulating substrate 140 are thermally bonded by the silicone grease 141 but are rigidly bonded. Not.

  For this reason, even if thermal expansion and thermal contraction of the electrode 110 and the insulating substrate 140 occur as the semiconductor device 100 is driven, generation of stress is suppressed between the electrode 110 and the insulating substrate 140, and thus the insulating substrate 140 Can be prevented from being damaged.

  In addition, since the breakage of the insulating substrate 140 can be suppressed in this way, the thickness of the electrode 110 can be increased, and the heat dissipation performance of the semiconductor device 100 can be improved.

  Further, in the semiconductor device 100, since the injection pressure of the resin acts to press the electrode 110 against the mold 180B in the manufacturing stage as described above, the silicone grease 141 between the electrode 110 and the insulating substrate 140 is thick. It can be made thinner by being compressed in the direction. For this reason, the thermal conductivity between the electrode 110 and the insulating substrate 140 can be improved.

  Further, in the step of forming the sealing resin 150, the silicone grease 141 is thinned by pressing the electrode 110 and the insulating substrate 140 by the injection pressure of the resin. The step of pressurizing the electrode 110 and the insulating substrate 140 to thin the silicone grease 141 is not necessary.

  As described above, according to the first embodiment, it is possible to provide the semiconductor device 100 in which breakage of the insulating substrate 140 is suppressed. In the semiconductor device 100 of the first embodiment, since the electrode 110 and the insulating substrate 140 are connected via the thinned silicone grease 141, the heat dissipation effect is also improved.

  In addition, since the insulating substrate 140 is fixed by the sealing resin 150, workability for assembling the semiconductor device 100 to the inverter 9 is improved.

  When the semiconductor device 100 is mounted on a hybrid vehicle, the inverter 9 is exposed to a high temperature each time the electric motor 10 is driven and regenerated. In such a situation, it is very beneficial to use the semiconductor device 100 of the first embodiment with improved cooling performance.

  Note that the thermal conductivity of the silicone grease 141 can be adjusted by the amount of inorganic filler mixed in the silicone grease 141, for example.

  In the above description, the mode in which the gap between the electrode 110 and the insulating substrate 140 is pasted with the silicone grease 141 has been described. However, heat can be conducted from the electrode 110 to the insulating substrate 140, and the electrode 110 and the insulating substrate 140 can be rigidly connected. Any material that is not bonded can be used in place of the silicone grease 141. As such a thing, the paste which mixed metal powder, such as a silver paste, with resin can be used, for example.

  In the above description, the semiconductor device 100 has been described as including two semiconductor elements 120A and 120B. However, the semiconductor device 100 may include only one semiconductor element or may include three or more semiconductor elements.

  Moreover, although the form containing IGBT and FWD was demonstrated above, MOSFET and a bipolar transistor may be included.

  Moreover, although the sealing resin 150 demonstrated the form comprised by an epoxy resin above, the sealing resin 150 may be comprised by PPS (polyphenylene sulfide) resin and PBT (polybutylene terephthalate) resin.

  In the above, the form in which the semiconductor device 100 is used for the inverter 9 of the hybrid vehicle has been described. However, the semiconductor device 100 may be used for an inverter of an EV (Electric Vehicle) vehicle and other types of vehicles. It may be used for other than vehicles.

<Embodiment 2>
FIG. 9 is a diagram showing a cross-sectional structure of the semiconductor device of the second embodiment. 9A and 9B correspond to the cross section shown in FIG. 5 of the semiconductor device 100 of the first embodiment.

  In the following, the same components as those of the semiconductor device 100 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 9A, the semiconductor device 200 of the second embodiment is different from the semiconductor device 100 of the first embodiment in that a groove 111 is formed on the lower surface 110A of the electrode 110.

  The groove 111 is formed along the four sides of the lower surface 110 </ b> A of the electrode 110. The depth of the groove 111 is, for example, about 0.1 mm and the width is about 1 mm.

  The groove 111 moves toward the outer periphery of the electrode 110 when the electrode 110 and the insulating substrate 140 are pressurized by the resin injection pressure in the step of forming the sealing resin 150 of the semiconductor device 200. It is formed in order to receive the surplus of the silicone grease 141.

  A surplus of the silicone grease 141 that is pushed outward by pressure between the electrode 110 and the insulating substrate 140 is accumulated in the groove 141.

  For this reason, it can suppress that the excess part of the silicone grease 141 protrudes outside the electrode 110 by planar view.

  Further, as shown in FIG. 9B, recesses 112 may be formed along the four sides of the lower surface 110A of the electrode 110 instead of the groove 111 shown in FIG. 9A.

  The recess 112 is formed along the end of the lower surface 110 </ b> A of the electrode 110.

  Even in the case of having such a recess 112, as in the case of having the groove 111, the surplus of the silicone grease 141 that is pushed outward between the electrode 110 and the insulating substrate 140 by pressure is accumulated in the recess 112. .

  For this reason, it can suppress that the excess part of the silicone grease 141 protrudes outside the electrode 110 by planar view.

  In addition, although the groove part 111 or the recessed part 112 demonstrated the form formed over the perimeter of the four sides of the lower surface 110A of the electrode 110 in the above, the groove part 111 or the recessed part 112 was formed in a part of four sides of the lower surface 110A of the electrode 110. It may be formed. For example, you may form along two opposite sides among four sides.

  Moreover, the groove part 111 or the recessed part 112 may be formed continuously, and one place or multiple places may be interrupted. Furthermore, the groove 111 may be formed in a double manner, the groove 111 and the recess 112 may be combined on the same side, or the groove 111 and the recess 112 may be arranged for each side.

<Embodiment 3>
FIG. 10 is a diagram showing a cross-sectional structure of the semiconductor device of the third embodiment. The cross section shown in FIG. 10 corresponds to the cross section shown in the semiconductor device 200 of the second embodiment (FIG. 9A).

  The semiconductor device 300 of the third embodiment has a configuration in which the lower surface 140A of the insulating substrate 140 of the semiconductor device 200 of the second embodiment is covered with a metal film 360. Since other configurations are the same as those of the semiconductor device 200 of the second embodiment shown in FIG. 9A, the same components as those of the semiconductor device 200 of the second embodiment are denoted by the same reference numerals below. The description is omitted.

  A metal film 360 used as a protective film for the insulating substrate 140 is formed on the lower surface 140 </ b> A of the insulating substrate 140 of the semiconductor device 300.

  The metal film 360 is, for example, a copper foil or an aluminum foil, and is brazed to the lower surface 140A of the insulating substrate 140.

  In FIG. 10, the metal film 360 is formed only on one surface of the insulating substrate 140, but it may be formed on both surfaces.

  FIG. 11 is a diagram illustrating a part of the manufacturing process of the semiconductor device 300 according to the third embodiment.

  As shown in FIG. 11A, after forming the sealing resin 150 of the semiconductor device 300 using the molds 180A and 180B (see FIG. 8), a part of the sealing resin 150 is the lower surface of the metal film 360. 360A may be covered.

  In such a case, the sealing resin 150 in a portion below the lower surface 360A of the metal film 360 is cut off by cutting or shot blasting using a tooth tool or the like.

  As shown by a broken line in FIG. 11B, when the portion of the sealing resin 150 below the lower surface 360A of the metal film 360 is scraped, the metal film 360 is exposed from the sealing resin 150.

  Thus, when the lower part of the sealing resin 150 is scraped off, if the metal film 360 is not formed, the insulating substrate 140 made of ceramic or the like may be damaged. On the contrary, the tooth tool may be damaged.

  However, if the metal film 360 is formed, even if the lower portion of the sealing resin 150 is scraped off, the lower surface 360A of the metal film 360 is scraped off together with the lower portion of the sealing resin 150 and is not damaged.

  Therefore, according to the third embodiment, after the sealing resin 150 is formed, the semiconductor device 300 is manufactured without damaging the insulating substrate 140 even when the lower portion of the sealing resin 150 is scraped off. be able to.

  Further, when the lower portion of the sealing resin 150 is scraped in this way, the lower surface 360A of the metal film 360 is also scraped, so that the surfaces of the sealing resin 150 and the metal film 360 can be aligned on the lower surface of the semiconductor device 300.

  Note that even if the insulating substrate 140 and the metal film 360 repeat thermal expansion and thermal contraction with the operation of the semiconductor device 300, the metal film 360 is thinner than the insulating substrate 140. Accordingly, the metal film 360 expands and contracts. The thickness of the metal film 360 may be 0.5 mm, for example.

  In addition, when the insulating substrate 140 is covered with the metal film 360, even when a foreign object is caught when the metal film 360 of the semiconductor device 300 is attached to a cooler or the like, the metal film 360 is deformed and the pressure due to the contamination is added. Dispersion can suppress damage to the insulating substrate 140.

<Embodiment 4>
FIG. 12 is an exploded perspective view of the semiconductor device of the fourth embodiment. FIG. 13 is a perspective view showing the internal structure of the semiconductor device of the fourth embodiment.

  The semiconductor device 400 according to the fourth embodiment has a configuration in which an insulating substrate is also provided above the semiconductor elements 120A and 120B of the semiconductor device 100 according to the first embodiment. Since other configurations are the same as those of the semiconductor device 100 of the first embodiment, the same components as those of the semiconductor device 100 of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The semiconductor device 400 includes an electrode 110, semiconductor elements 120A and 120B, spacers 420A and 420B, an electrode 430, and insulating substrates 140 and 440. 12 and 13, the sealing resin is omitted.

  A semiconductor device 400 according to the fourth embodiment includes an electrode 430 that functions as a heat sink (heat sink) instead of the electrode 130 of the semiconductor device 100 according to the first embodiment, and an insulating substrate 440 is attached to the upper surface of the electrode 430. Have Note that spacers 420A and 420B are inserted between the electrode 430 and the semiconductor elements 120A and 120B in order to prevent interference between the bonding wires 171A, 171B, 171C and 171D and the electrode 430 mainly.

  The spacers 420A and 420B are made of copper or a copper alloy. The spacer 420A joins the emitter 121E of the IGBT and the electrode 430. The spacer 420B joins the anode 122A of the FWD and the electrode 430. The height of the spacers 420A and 420B may be a height that can prevent the bonding wires 171A, 171B, 171C, and 171D from interfering with the electrode 430.

  The electrode 430 is an example of a second metal plate. The electrode 430 has a configuration similar to that of the electrode 110 and functions as an electrode for the semiconductor elements 120A and 120B and also functions as a heat sink (heat sink) for the semiconductor elements 120A and 120B. The heat generated by the semiconductor elements 120A and 120B is transferred to the electrode 430 through the spacers 420A and 420B.

  The semiconductor elements 120A and 120B, the spacers 420A and 420B, and the electrode 430 are joined by solder. A bus bar 431 is connected to the electrode 430. The bus bar 431 is the same as the bus bar 131 of the first embodiment.

The insulating substrate 440 is an example of a second insulating substrate. The insulating substrate 440 is bonded to the upper surface of the electrode 430 with silicone grease. Similar to the insulating substrate 140, the insulating substrate 440 is a ceramic substrate such as silicon nitride (SiN), aluminum nitride (AlN), or alumina (Al ₂ O ₃ ).

  The insulating substrate 440 is larger than the electrode 430 and thinner than the electrode 430 in plan view. The thickness of the insulating substrate 440 is, for example, 0.2 mm to 1.0 mm.

  The insulating substrate 440 is thermally bonded to the electrode 430 and radiates heat transferred from the semiconductor elements 120A and 120B through the spacers 420A and 420B and the electrode 430. The upper surface 440A of the insulating substrate 440 is exposed from a sealing resin described later.

  FIG. 14 is a diagram showing a cross-sectional structure of the semiconductor device of the fourth embodiment. The cross section shown in FIG. 14 is a cross section taken along line BB in FIG.

  As shown in FIG. 14, a spacer 420 </ b> B and an electrode 430 are connected on the semiconductor device 120 </ b> B, and an insulating substrate 440 is pasted on the electrode 430 via silicone grease 441.

  The electrode 430 and the insulating substrate 440 are thermally bonded by the silicone grease 441, but are not rigidly bonded by the silicone grease 441. The insulating substrate 440 is fixed with a sealing resin 450.

  For this reason, the heat generated in the semiconductor elements 120A and 120B is transmitted to the insulating substrate 440 through the electrode 430 and the silicone grease 441, and is radiated from the insulating substrate 440 to the outside.

  In addition, the electrode 430 and the insulating substrate 440 have greatly different linear expansion coefficients, but the electrode 430 and the insulating substrate 440 are thermally bonded by the silicone grease 441 as described above, but are rigidly bonded. Not.

  For this reason, even if thermal expansion and thermal contraction of the electrode 430 and the insulating substrate 440 occur when the semiconductor device 400 is driven, generation of stress is suppressed between the electrode 430 and the insulating substrate 440. Can be prevented from being damaged.

  Further, since the breakage of the insulating substrate 440 can be suppressed as described above, the thickness of the electrode 430 can be increased, and the heat dissipation performance of the semiconductor device 400 can be improved.

  Further, in the semiconductor device 400, since the injection pressure of the resin works to press the electrode 430 against the molds 180A and 180B (see FIG. 8) in the manufacturing stage as described above, the gap between the electrode 430 and the insulating substrate 440 is increased. A certain silicone grease 441 can be made thinner by being compressed in the thickness direction. For this reason, the thermal conductivity between the electrode 430 and the insulating substrate 440 can be improved.

  Further, in the step of forming the sealing resin 450, the silicone grease 441 is thinned by pressing the electrode 430 and the insulating substrate 440 by the injection pressure of the resin. The step of pressurizing the electrode 430 and the insulating substrate 440 to thin the silicone grease 441 is not necessary.

  As described above, according to the fourth embodiment, it is possible to provide the semiconductor device 400 in which the breakage of the insulating substrates 140 and 440 is suppressed.

  The semiconductor device 400 of the fourth embodiment has a higher heat dissipation effect than the semiconductor device 100 of the first embodiment because heat generated in the semiconductor elements 120A and 120B is radiated from both the insulating substrates 140 and 440.

  In the semiconductor device 400 of the fourth embodiment, since the electrode 430 and the insulating substrate 440 are connected via the thinned silicone grease 441, the heat dissipation effect is also improved.

  In the above description, the mode in which the silicone grease 441 is attached between the electrode 430 and the insulating substrate 440 has been described. Any material that is not bonded can be used in place of the silicone grease 441. As such a thing, the paste which mixed metal powder, such as a silver paste, with resin can be used, for example.

  Further, the lower surface 140A of the insulating substrate 140 may be covered with the metal film 360, and the upper surface 440A of the insulating substrate 440 may be covered with the same metal film. This metal film is an example of a second metal film.

  Further, a groove or a recess similar to the groove 111 or the recess 112 described in Embodiment 2 may be formed on the upper surface of the electrode 430.

  The semiconductor device according to the exemplary embodiment of the present invention has been described above. However, the present invention is not limited to the specifically disclosed embodiment, and does not depart from the scope of the claims. Various modifications and changes are possible.

100, 200, 300, 400 Semiconductor device 110, 130, 430 Electrode 111 Groove portion 112 Recess portion 120A, 120B Semiconductor element 140, 440 Insulating substrate 141, 441 Silicone grease 150, 450 Sealing resin 360 Metal film 420A, 420B Spacer

Claims (5)

A first metal plate;
A semiconductor element mounted on one surface of the first metal plate;
A first insulating substrate disposed on the other surface of the first metal plate;
A sealing resin for sealing the first metal plate, the semiconductor element, and the first insulating substrate;
A semiconductor device in which a fluid heat conductive member is applied or formed between the first metal plate and the first insulating substrate.   The semiconductor device according to claim 1, wherein a concave portion or a groove portion is formed on a surface of the first metal plate that contacts the first insulating substrate along an outer periphery of the surface.   3. The semiconductor device according to claim 1, wherein a first metal film is disposed on a surface of the first insulating substrate opposite to a surface in contact with the first metal plate. A spacer connected to a surface opposite to the surface connected to the first metal plate of the semiconductor element;
A second metal plate connected to a surface opposite to the surface connected to the first metal plate of the semiconductor element via the spacer;
A second insulating substrate disposed on a surface opposite to the surface connected to the spacer of the second metal plate,
The spacer, the second metal plate, and the second insulating substrate are sealed with the sealing resin, and fluid heat conduction is performed between the second metal plate and the second insulating substrate. The semiconductor device according to claim 1, wherein the member is applied or formed.   5. The semiconductor device according to claim 4, wherein a second metal film is disposed on a surface of the second insulating substrate opposite to a surface in contact with the second metal plate.

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