Provided is a semiconductor device having excellent heat dissipation at low cost. The semiconductor device includes a heat spreader, a semiconductor element, a metal block, a terminal having a plate shape, and a sealing material. The semiconductor element includes a front surface electrode and is mounted on an upper surface of the heat spreader. The metal block includes a bonding surface bonded to the front surface electrode and a heat dissipating surface connected to the upper surface with interposition of the insulating member. The metal block is provided so as to straddle above one side of the semiconductor element. The first end of the terminal is bonded to the metal block. The second end of the terminal is exposed from the sealing material and formed to be connectable to an external circuit. The sealing material seals the heat spreader, the semiconductor element, the metal block, and the first end.

TECHNICAL FIELD

The present disclosure relates to a semiconductor device and a method of manufacturing a semiconductor device.

BACKGROUND ART

When the semiconductor element performs a switching operation, heat is generated by internal resistance of the semiconductor element. The heat is released to the cooler through a heat spreader or the like. For example, a semiconductor device described in Patent Document 1 forms a heat dissipation path from a semiconductor element to a cooling body through a heat sink block being a metal body bonded to a front surface of the semiconductor element and an upper side heat sink bonded to the heat sink block.

PRIOR ART DOCUMENT

Patent Document

SUMMARY

Problem to be Solved by the Invention

The heat dissipation path formed in the front surface side of the semiconductor element is preferably formed of a component that easily conducts heat and has a large heat capacity. On the other hand, the terminal connected to the front surface electrode of the semiconductor element is preferably a thin plate from the viewpoint of workability and cost. That is, it has been difficult to achieve both high heat dissipation and low production cost.

In order to solve the above problems, the present disclosure provides a semiconductor device having excellent heat dissipation at low cost.

Means to Solve the Problem

A semiconductor device according to the present disclosure includes a heat spreader, a semiconductor element, a metal block, a terminal, and a sealing material. The semiconductor element includes a front surface electrode. The semiconductor element is mounted on an upper surface of the heat spreader. The metal block includes a bonding surface and at least one heat dissipating surface. The bonding surface is bonded to the front surface electrode of the semiconductor element. The at least one heat dissipating surface is connected to the upper surface of the heat spreader with interposition of the insulating member. The metal block extends from the bonding surface to the at least one heat dissipating surface so as to straddle above at least one side of the semiconductor element. The terminal includes a first end and a second end. The first end is bonded to the metal block. The second end is positioned on the opposite side from the first end and is formed to be connectable to an external circuit. The sealing material seals the heat spreader, the semiconductor element, the metal block, and the first end of the terminal. The second end of the terminal is exposed from the sealing material.

Effects of the Invention

According to the present disclosure, a semiconductor device having excellent heat dissipation at low cost is provided.

The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings.

DESCRIPTION OF EMBODIMENTS

First Embodiment

FIG.1is a plan view showing a configuration of a semiconductor device101in a first embodiment.FIG.2is a cross-sectional view showing a configuration of the semiconductor device101.FIG.2shows a cross section taken along line A-A′ shown inFIG.1.

The semiconductor device101includes a heat spreader1, a semiconductor element2, a metal block3, a first main terminal4A, a second main terminal4B, a signal terminal5, a metal wire6, an insulating member7, a sealing material8, and an insulating sheet9.FIG.1shows a state in which the sealing material8covering above the semiconductor element2or the like is seen through. The same applies to the plan views shown below.FIG.2shows a state where the semiconductor device101is mounted on a cooler11with interposition of a heat dissipating grease12. In addition, in the cross-sectional view inFIG.2, hatching of the heat spreader1and the sealing material8is omitted for convenience of description. The same applies to the cross-sectional views below.

The heat spreader1is formed of metal, for example. The heat spreader1holds the semiconductor element2on its upper surface with interposition of a bonding material15. The bonding material15is, for example, solder.

The semiconductor element2is mounted on an upper surface of the heat spreader1. The semiconductor element2is formed of, for example, a semiconductor such as Si, or what is called a wide bandgap semiconductor such as SiC, GaN, or gallium oxide. The semiconductor element2is a power semiconductor element, a control integrated circuit (IC) for controlling the power semiconductor element, or the like. The semiconductor element2is, for example, an insulated gate bipolar transistor (IGBT), a metal oxide semiconductor field effect transistor (MOSFET), a Schottky barrier diode, or the like. Alternatively, the semiconductor element2may be a reverse-conducting IGBT (RC-IGBT) in which an IGBT and a freewheeling diode are formed in one semiconductor substrate.

The semiconductor element2in the first embodiment is an IGBT.FIG.3is a plan view showing a configuration of the semiconductor element2. The semiconductor element2is in a chip state and has a rectangular planar shape. The semiconductor element2includes a front surface electrode2A, a control electrode2B, and a termination region2C, on a front surface thereof. A cell region (not shown) in which a plurality of IGBT cells are arrayed is provided inside the termination region2C. The front surface electrode2A is an electrode pad that functions as an emitter of the IGBT. The control electrode2B includes a gate pad, an emitter sense pad, a temperature sense pad, and the like. The gate pad functions as a gate of the IGBT. Since being connected to the signal terminal5through the metal wire6, the control electrode2B is also referred to as a signal wire pad. The termination region2C is provided around the cell region, that is, at the outer peripheral portion of the chip. The termination region2C includes a guard ring being a structure for holding a withstand voltage of the semiconductor element2. The semiconductor element2includes a back surface electrode (not shown) on a back surface thereof. The back surface electrode functions as a collector of the IGBT. The back surface electrode is bonded to the upper surface of the heat spreader1with interposition of the bonding material15. Here, the back surface electrode is bonded to a die pad region (not shown) provided on the upper surface of the heat spreader1.

The metal block3includes a bonding surface3A and a heat dissipating surface3B. The bonding surface3A and the heat dissipating surface3B are positioned on the lower surface of the metal block3. The bonding surface3A is bonded to the front surface electrode2A of the semiconductor element2with interposition of the bonding material16. The bonding material16is, for example, solder. The heat dissipating surface3B is connected to an upper surface of the heat spreader1with interposition of the insulating member7. More specifically, the heat dissipating surface3B is in contact with the upper surface of the insulating member7, and the lower surface of the insulating member7is in contact with the upper surface of the heat spreader1. The metal block3extends from the bonding portion between the bonding surface3A and the front surface electrode2A of the semiconductor element2to the outside of the semiconductor element2beyond one side (the right side inFIG.1) of the semiconductor element2, and is bent downward. That is, the metal block3in the first embodiment has an L-shaped cross-sectional shape and is provided so as to straddle above one side of the semiconductor element2.

Preferably, the metal block3is formed of a material having a high thermal conductivity, and has a large heat capacity. The metal block3is preferably formed of, for example, copper or an alloy containing copper. Copper or an alloy containing copper has good bonding property to solder. The metal block3formed of copper or an alloy containing copper is excellent in assembling property. The metal block3is preferably formed of a material having a linear expansion coefficient of 7 ppm/° C. or more and 12 ppm/° C. or less. The thickness of the metal block3is preferably, for example, about 2 mm.

The metal block3includes a through hole3C in the bonding surface3A. The through hole3C penetrates between the upper surface and the lower surface of the metal block3. The through hole3C is provided approximately at the center of the bonding surface3A. In other words, in a plan view, the through hole3C is provided approximately at the center of the bonding portion between the bonding surface3A and the front surface electrode2A of the semiconductor element2.

The insulating member7secures a necessary withstand voltage with respect to a voltage applied between the emitter and the collector. The thickness of the insulating member7is preferably small so that heat is efficiently transferred from the metal block3to the heat spreader1. That is, the insulating member7is preferably thin as long as a withstand voltage is secured.

The first main terminal4A has a plate shape. The first main terminal4A includes one end and the other end positioned on the opposite side from the one end. The one end of the first main terminal4A is bonded to the upper surface of the metal block3with interposition of a bonding material17. The bonding material17is, for example, solder. The other end of the first main terminal4A is led out to the outside of the sealing material8. The other end of the first main terminal4A is formed to be connectable to an external circuit. The first main terminal4A is an emitter connected to the front surface electrode2A of the semiconductor element2with interposition of the metal block3. The first main terminal4A has a bent portion between the one end and the other end.

The second main terminal4B has a plate shape. The second main terminal4B includes one end and the other end positioned on the opposite side from the one end. The one end of the second main terminal4B is bonded to the upper surface of the heat spreader1with interposition of a bonding material (bonding material18shown inFIG.14). The bonding material18is, for example, solder. The other end of the second main terminal4B is led out to the outside of the sealing material8. The other end of the second main terminal4B is formed to be connectable to an external circuit. The second main terminal4B is a collector connected to the back surface electrode of the semiconductor element2with interposition of the heat spreader1. The second main terminal4B has a bent portion between the one end and the other end.

The signal terminal5has a plate shape. The signal terminal5includes one end and the other end positioned on the opposite side from the one end. The one end of the signal terminal5is bonded to the control electrode2B through the metal wire6. The metal wire6is, for example, an aluminum wire. The other end of the signal terminal5is led out to the outside of the sealing material8. The other end of the signal terminal5is formed to be connectable to an external circuit. The signal terminal5has a bent portion between the one end and the other end.

The first main terminal4A, the second main terminal4B, and the signal terminal are preferably formed of, for example, copper or an alloy containing copper. The first main terminal4A, the second main terminal4B, and the signal terminal5are thinner than the metal block3. The thicknesses of the first main terminal4A, the second main terminal4B, and the signal terminal5are preferably, for example, 1 mm or less. Since the first main terminal4A, the second main terminal4B, and the signal terminal5are thinner than the metal block3, cutting or bending is easy in the manufacturing step of the semiconductor device101.

The insulating sheet9is attached to a lower surface of the heat spreader1. The insulating sheet9has a configuration in which an insulating layer9A and a copper foil9B are integrated. The thickness of the insulating layer9A is about 0.2 mm. The thickness of the copper foil9B is about 0.1 mm.

The sealing material8seals the heat spreader1, the semiconductor element2, the metal block3, the one end of the first main terminal4A, the one end of the second main terminal4B, the metal wire6, the one end of the signal terminal5, and the upper surface side of the insulating sheet9. The lower surface of the copper foil9B of the insulating sheet9, the other end of the first main terminal4A, the other end of the second main terminal4B, and the other end of the signal terminal5are exposed from the sealing material8. The sealing material8is, for example, a mold resin. In the IGBT for power control, a high voltage is applied between the emitter and the collector. The withstand voltage of the IGBT is secured by the mold resin and the guard ring of the termination region2C.

The cooler11is attached to the semiconductor device101with interposition of the heat dissipating grease12. The heat dissipating grease12fills a minute space that can be generated between the copper foil9B of the insulating sheet9and the cooler11. The heat dissipating grease12makes heat transfer between the insulating sheet9and the cooler11easier. The cooler11releases heat generated in the semiconductor element2to the outside.

Next, a method of manufacturing the semiconductor device101in the first embodiment will be described.FIG.4is a flowchart showing a method of manufacturing the semiconductor device101.

In step S1, the semiconductor element2is mounted on the upper surface of the heat spreader1with interposition of the bonding material15.

In step S2, the metal block3is placed at a predetermined position with respect to the semiconductor element2and the heat spreader1. At this time, the position of the bonding surface3A of the metal block3is adjusted to above the front surface electrode2A of the semiconductor element2. More specifically, in a plan view, the position of the through hole3C of the metal block3is adjusted to the vicinity of the center of the front surface electrode2A of the semiconductor element2. The position of the heat dissipating surface3B of the metal block3is adjusted to above the insulating member7provided on the upper surface of the heat spreader1. The insulating member7may be provided at a predetermined position on the upper surface of the heat spreader1in advance, or may be inserted into between the metal block3and the heat spreader1in step S2. Similarly, the lead frame in which the first main terminal4A, the second main terminal4B, and the signal terminal5are integrated is placed at a predetermined position with respect to the metal block3and the heat spreader1. A jig is used to position each component. When the positional relationship between the metal block3and the semiconductor element2is temporarily fixed by the jig, a gap is formed between the bonding surface3A of the metal block3and the front surface electrode2A of the semiconductor element2.

After each component is positioned, each bonding place in the heat spreader1, the semiconductor element2, the metal block3, and the lead frame is bonded by a bonding material. That is, the metal block3is bonded to the semiconductor element2by the bonding material16, the first main terminal4A is bonded to the metal block3by the bonding material17, and the second main terminal4B is bonded to the heat spreader1by the bonding material18. In the bonding step between the metal block3and the semiconductor element2, the melted bonding material16is supplied from the through hole3C. The bonding material16spreads in a gap between the bonding surface3A and the front surface electrode2A. The bonding material16is, for example, solder. Accordingly, the metal block3is fixed so as to straddle above one side of the semiconductor element2.

In step S3, the metal wire6is ultrasonically bonded to the signal terminal5and the control electrode2B. This step is what is called a wire bonding step.

In step S4, the heat spreader1, the semiconductor element2, the metal block3, the one end of the first main terminal4A, the one end of the second main terminal4B, the metal wire6, the one end of the signal terminal5, and the upper surface side of the insulating sheet9are set in the cavity of the molding mold. Resin pellets are set in a pot. The molten resin is extruded from the pot into the heated mold by the plunger. The resin passes through the runner and flows into the cavity through the injection gate of the mold. Thereafter, the resin is cured, and the heat spreader1, the semiconductor element2, the metal block3, the one end of the first main terminal4A, the one end of the second main terminal4B, the metal wire6, the one end of the signal terminal5, and the upper surface side of the insulating sheet9are sealed. The resin corresponds to the sealing material8.

In step S5, unnecessary resin cured at the injection gate portion is cut off, and a package is formed. Furthermore, coupling portions of the lead frame are cut, and the first main terminal4A, the second main terminal4B, and the signal terminal5are separated from each other. Each of the first main terminal4A, the second main terminal4B, and the signal terminal5is subjected to bending into a predetermined shape. Thus, the semiconductor device101is completed.

Next, the operation of the semiconductor device101in the first embodiment will be described. Each of the other end of the first main terminal4A and the other end of the second main terminal4B is connected to a bus bar (not shown).

When a voltage is applied from the signal terminal5to between the gate and the emitter of the IGBT through the gate pad, the IGBT is driven. That is, the current flows from the bus bar on the collector side to the second main terminal4B, the heat spreader1, the semiconductor element2, the metal block3, the first main terminal4A, and the bus bar on the emitter side in order. At that time, heat is generated by the internal resistance of the semiconductor element2. The semiconductor device101in the first embodiment not only releases the heat from the back surface of the semiconductor element2to the cooler11with interposition of the heat spreader1, the insulating sheet9, and the heat dissipating grease12, but also releases the heat from the front surface of the semiconductor element2to the cooler11with interposition of the metal block3, the insulating member7, the heat spreader1, the insulating sheet9, and the heat dissipating grease12.

Since the metal block3has a function of transferring heat and a function of storing heat, the metal block3is preferably formed of a material having high thermal conductivity, and the heat capacity of the metal block3is preferably large. Therefore, the metal block3is preferably thick. On the other hand, since being subjected to cutting or bending in the manufacturing step of the semiconductor device101, the first main terminal4A is preferably thinner than the metal block3. When the metal block3and the first main terminal4A constitute an integrated component, the integrated component has a thicker portion and a thinner portion. That is, since the component has a special and complicated shape, the production cost increases. On the other hand, when the semiconductor device does not include the metal block3, heat generated in the semiconductor element2is also released through the first main terminal4A having a thin plate shape, but a sufficient heat dissipation effect cannot be expected.

The metal block3and the first main terminal4A in the first embodiment are components separate from each other. The semiconductor device101includes a metal block3thicker than the first main terminal4A in order to increase heat capacity, and includes a first main terminal4A thinner than the metal block3in order to improve workability. Therefore, both high heat dissipation and low production costs are achieved.

An electric motor car such as an electric vehicle or a hybrid vehicle is provided with an inverter circuit. The inverter circuit that drives the three-phase motor has a configuration in which six semiconductor devices101are combined. The inverter circuit controls the rotation speed and the like of the three-phase motor by pulse width modulation (PWM) control. The motor may be temporarily locked, such as when the electric motor car climbs on a curb. At this time, a large current flows through the semiconductor element2. Although the time during which the large current flows is a short time of about 1 second or less, the amount of heat generated in the semiconductor element2is large.

In the semiconductor device101in the first embodiment, the heat is not only released from the back surface of the semiconductor element2to the cooler11with interposition of the heat spreader1, the insulating sheet9, and the heat dissipating grease12, but also released from the front surface of the semiconductor element2to the cooler11with interposition of the metal block3, the insulating member7, the heat spreader1, the insulating sheet9, and the heat dissipating grease12. Therefore, high heat dissipation is achieved.

In summary, the semiconductor device101in the first embodiment includes the heat spreader1, the semiconductor element2, the metal block3, the first main terminal4A, and the sealing material8. The semiconductor element2includes the front surface electrode2A. The semiconductor element2is mounted on the upper surface of the heat spreader1. The metal block3includes the bonding surface3A and at least one heat dissipating surface3B. The bonding surface3A is bonded to the front surface electrode2A of the semiconductor element2. The at least one heat dissipating surface3B is connected to the upper surface of the heat spreader1with interposition of the insulating member7. The metal block3extends from the bonding surface3A to the at least one heat dissipating surface3B so as to straddle above at least one side of the semiconductor element2. The first main terminal4A includes a first end and a second end. The first end is bonded to the metal block3. The second end is positioned on the opposite side from the first end and is formed to be connectable to an external circuit. The sealing material8seals the heat spreader1, the semiconductor element2, the metal block3, and the first end of the first main terminal4A. The second end of the first main terminal4A is exposed from the sealing material8.

This semiconductor device101achieves both high heat dissipation and low production cost. The semiconductor device101is used for an inverter circuit that controls a motor of an electric vehicle, a train, or the like, or a converter circuit for regeneration.

In addition, the metal block3in the first embodiment includes a through hole3C in the bonding surface3A. When the metal block3is formed of copper or an alloy containing copper, and the semiconductor element2is formed of Si, a difference between the linear expansion coefficient of the metal block3and the linear expansion coefficient of the semiconductor element2is large. When the reflow step is applied to the bonding between the metal block3and the semiconductor element2, stress associated with temperature change is large. The thickness of the solder changes before and after the reflow step regardless of whether the bonding material16is plate-shaped solder or cream-shaped solder. In the first embodiment, molten solder is supplied from the through hole3C of the metal block3. Therefore, the thickness of the bonding material16matches the width of the gap, and is controlled to a constant value. Therefore, the semiconductor device101having high reliability is implemented.

Furthermore, when the metal block3is formed of a material having a linear expansion coefficient of 7 ppm/° C. or more and 12 ppm/° C. or less, stress on the chip at the time of heating in a bonding step or the like is reduced. Therefore, the reliability of the semiconductor device101is improved.

When the semiconductor element2is formed of SiC having a high thermal conductivity, heat dissipation is improved, so that the size of the semiconductor element2can be reduced.

Second Embodiment

A semiconductor device and a method of manufacturing the semiconductor device in a second embodiment will be described. In the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and the detailed description thereof will be omitted.

FIG.5is a plan view showing a configuration of a semiconductor device102in the second embodiment.FIG.6is a cross-sectional view showing a configuration of the semiconductor device102.FIG.6shows a cross section taken along line B-W shown inFIG.5.

The metal block3includes a plurality of heat dissipating surfaces3B. The plurality of heat dissipating surfaces3B are positioned on the lower surface of the metal block3. Here, the metal block3includes a first heat dissipating surface31B and a second heat dissipating surface32B. Each of the first heat dissipating surface31B and the second heat dissipating surface32B is connected to an upper surface of the heat spreader1with interposition of the insulating member7. The bonding surface3A of the metal block3is positioned between the first heat dissipating surface31B and the second heat dissipating surface32B.

The metal block3extends from the bonding portion between the bonding surface3A and the front surface electrode2A of the semiconductor element2to the outside of the semiconductor element2beyond a first side (the upper side inFIG.5) of the semiconductor element2, and is bent downward. A lower surface of the downward bent portion is the first heat dissipating surface31B. The metal block3extends from the bonding portion to the outside of the semiconductor element2beyond a second side (the lower side inFIG.5) opposite to the first side of the semiconductor element2, and is bent downward. A lower surface of the bent portion is the second heat dissipating surface32B. The metal block3in the second embodiment has a U-shaped cross-sectional shape and is provided so as to straddle above two sides of the semiconductor element2.

The insulating member7is an insulating resin film formed on an upper surface of the heat spreader1. The insulating resin film is formed in a region excluding a die pad region to which the back surface electrode of the semiconductor element2is bonded and a terminal bonding region (not shown) to which the second main terminal4B is bonded.

The method of manufacturing the semiconductor device102in the second embodiment is similar to the method of manufacturing the semiconductor device in the first embodiment. However, in step S1, a heat spreader1coated with the insulating resin film in advance in a region excluding the die pad region and the terminal bonding region is prepared. The semiconductor element2is mounted on the die pad region of the heat spreader1. At this time, since the die pad region is surrounded by the insulating resin film, the solder does not flow out to the periphery of the die pad region. In step S2, the bonding surface3A of the metal block3is bonded to the front surface electrode2A of the semiconductor element2, and the first heat dissipating surface31B and the second heat dissipating surface32B are connected to the heat spreader1with interposition of the insulating resin film.

In this semiconductor device102, since the metal block3has the plurality of heat dissipating surfaces3B, heat dissipation is improved. For example, the chip temperature distribution of the IGBT is leveled.

Since the heat dissipating surface3B of the metal block3is close to the upper surface of the heat spreader1with interposition of the thin insulating resin film, favorable heat dissipation is obtained. Furthermore, since the thickness of the insulating resin film has high uniformity, uniform heat dissipation is achieved on each heat dissipating surface3B. Since it is not necessary to insert the insulating member7as in the first embodiment, productivity is improved.

In the second embodiment, an example of the semiconductor device102in which the metal block3extends to the outside of the two sides of the semiconductor element2has been shown. The metal block3may extend to the outside of the three sides of the semiconductor element2. By providing three heat dissipating surfaces3B, heat dissipation is further improved.

Third Embodiment

A semiconductor device and a method of manufacturing the semiconductor device in a third embodiment will be described. In the third embodiment, the same components as those of the first or second embodiment are denoted by the same reference numerals, and the detailed description thereof will be omitted.

FIG.7is a plan view showing a configuration of a semiconductor device103in the third embodiment.FIG.8is a cross-sectional view showing a configuration of the semiconductor device103.FIG.8shows a cross section taken along line C-C′ shown inFIG.7.

The metal block3includes a recessed portion3D. The recessed portion3D is provided on the lower surface of the metal block3. The recessed portion3D is recessed in the direction from the lower surface to the upper surface of the metal block3with respect to the bonding surface3A.

The recessed portion3D is provided outside a bonding portion where the bonding surface3A and the front surface electrode2A of the semiconductor element2are bonded. The recessed portion3D in the third embodiment is a groove provided above the termination region2C of the semiconductor element2, that is, above the guard ring. The extending direction of the groove corresponds to the extending direction of the guard ring.

The method of manufacturing the semiconductor device103is similar to the method of manufacturing the semiconductor device in the first embodiment. In step S4, when the resin is injected into the mold, the groove of the metal block3improves the fluidity of the resin above the guard ring. Therefore, the generation of air bubbles is suppressed, and the insulation property is improved. This semiconductor device103prevents a decrease in the withstand voltage of the guard ring.

Fourth Embodiment

A semiconductor device and a method of manufacturing the semiconductor device in a fourth embodiment will be described. In the fourth embodiment, the same components as those of any one of the first to third embodiments are denoted by the same reference numerals, and the detailed description thereof will be omitted.

FIG.9is a plan view showing a configuration of a semiconductor device104in the fourth embodiment.FIG.10is a cross-sectional view showing a configuration of the semiconductor device104.FIG.10shows a cross section taken along line D-D′ shown inFIG.9.

As in the third embodiment, the metal block3includes a groove provided above the guard ring as the recessed portion3D. The metal block3in the fourth embodiment includes a hole3E penetrating between the bottom portion of the groove and the upper surface of the metal block3.

The method of manufacturing the semiconductor device104is similar to the method of manufacturing the semiconductor device in the first embodiment. In step S4, when the resin is injected into the mold, air bubbles easily escape from the hole3E. This semiconductor device104prevents a decrease in the withstand voltage of the guard ring.

Fifth Embodiment

A semiconductor device and a method of manufacturing the semiconductor device in a fifth embodiment will be described. In the fifth embodiment, the same components as those of any one of the first to fourth embodiments are denoted by the same reference numerals, and the detailed description thereof will be omitted.

FIG.11is a plan view showing a configuration of a semiconductor device105in the fifth embodiment.FIG.12is a cross-sectional view showing a configuration of the semiconductor device105.FIG.12shows a cross section taken along line E-E′ shown inFIG.11.

The insulating member7between the upper surface of the heat spreader1and the heat dissipating surface3B of the metal block3is a sealing material8. That is, the insulating member7is formed of a molding resin. In order to improve heat dissipation from the metal block3to the heat spreader1, it is preferable that the molding resin between the heat dissipating surface3B and the heat spreader1is thin as long as a necessary withstand voltage is secured.

The method of manufacturing the semiconductor device105is similar to the method of manufacturing the semiconductor device in the first embodiment. However, in step S2, the metal block3and the like are bonded in a state where a gap is formed between the upper surface of the heat spreader1and the heat dissipating surface3B of the metal block3. That is, after completion of step S2, the insulating member7is not present between the upper surface of the heat spreader1and the heat dissipating surface3B of the metal block3. In step S4, resin is flowed into the gap between the heat dissipating surface3B of the metal block3and the upper surface of the heat spreader1, and the insulating member7is formed.

The molding resin injected into the gap between the heat dissipating surface3B of the metal block3and the upper surface of the heat spreader1achieves both an insulating function between the metal block3and the heat spreader1and a heat dissipation function from the metal block3to the heat spreader1. Since the insulating member7shown in the first embodiment and the insulating resin film shown in the second embodiment are unnecessary, cost reduction is achieved.

Sixth Embodiment

A semiconductor device and a method of manufacturing the semiconductor device in a sixth embodiment will be described. In the sixth embodiment, the same components as those of any one of the first to fifth embodiments are denoted by the same reference numerals, and the detailed description thereof will be omitted.

FIG.13is a plan view showing a configuration of a semiconductor device106in the sixth embodiment.FIG.14is a cross-sectional view showing a configuration of the semiconductor device106.FIG.14shows a cross section taken along line F-F′ shown inFIG.13. The method of manufacturing the semiconductor device106is similar to the method of manufacturing the semiconductor device in the first embodiment. In step S5, the resin is injected from the two injection gates8A.FIGS.13and14show the semiconductor device106in a state before the resin cured in the injection gates8A is cut off.

The metal block3has inclined surfaces3F at end portions of the heat dissipating surface3B.

In step S4of the method of manufacturing the semiconductor device106, the injection gates8A for injecting the resin are provided in the lateral direction of the gap between the heat dissipating surface3B of the metal block3and the upper surface of the heat spreader1. The height of the injection gates8A approximately matches the height of the upper surface of the heat spreader1. The resin is filled into the cavity of the mold through the injection gates8A.

In order to efficiently transfer heat from the heat dissipating surface3B of the metal block3to the heat spreader1, it is preferable that the gap between the heat dissipating surface3B and the upper surface of the heat spreader1is narrow. However, since the resin has viscosity, it is difficult to fill a narrow space. When the gap is too narrow, the gap is not filled with the resin, and the collector and the emitter of the IGBT are short-circuited. In the sixth embodiment, the injection gates8A are provided at substantially the same height as the upper surface of the heat spreader1. The resin injected from the injection gates8A flows along the upper surface of the heat spreader1, is further guided by the inclined surface3F of the metal block3, and the gap is efficiently filled with the resin. As a result, the semiconductor device106that achieves both securing of insulation property and improvement in heat dissipation is implemented. Even when the metal block3includes a curved surface instead of the inclined surface3F, a similar effect is produced.

Seventh Embodiment

A semiconductor device and a method of manufacturing the semiconductor device in a seventh embodiment will be described. In the seventh embodiment, the same components as those of any one of the first to sixth embodiments are denoted by the same reference numerals, and the detailed description thereof will be omitted.

FIG.15is a plan view showing a configuration of a semiconductor device107in the seventh embodiment.FIG.16is a cross-sectional view showing a configuration of the semiconductor device107.FIG.16shows a cross section taken along line G-G′ shown inFIG.15. As in the sixth embodiment,FIG.15shows the semiconductor device107in a state before the resin cured in the injection gates8A is cut off.

The metal block3includes a plurality of narrow grooves3G on the heat dissipating surface3B. The extending direction of the stripe-shaped narrow groove3G is a direction from the injection gate8A toward the gap between the heat dissipating surface3B of the metal block3and the upper surface of the heat spreader1. In other words, the injection gate8A is provided at a destination where the narrow groove3G extends. Since the resin injected from the injection gate8A is filled along the stripe-shaped narrow groove3G, the filling property is further improved.

In the present disclosure, each embodiment can be freely combined, and each embodiment can be appropriately modified or omitted.

EXPLANATION OF REFERENCE SIGNS