JPWO2020235047A1 - Semiconductor device - Google Patents

Abstract

The semiconductor chip (8), the conductive base plate (4) connected to the semiconductor chip (8), the insulating outer wall (2) surrounding the semiconductor chip (8), and the outer wall (2) facing the semiconductor chip (8). ), A conductive member (5) provided between the semiconductor chip (8) and the cover plate (3) and connecting the semiconductor chip (8) and the cover plate (3). , An elastic member provided in the recess (5a) of the energizing member (5) and urged to press the electrode of the semiconductor chip (8) via the energizing member (5), and energizing with the cover plate (4). The energization maintaining portion (5d) for maintaining contact with the member (5) is provided, and the energizing member (5) has a shape that is rotationally symmetric with respect to the central axis (5c) of the recess (5a).

Description

The present application relates to semiconductor devices.

A semiconductor chip connected to the base plate by a base plate, a cover plate provided facing the base plate, and a first main electrode, and connected to the cover plate via an electric contact member to which a spring force is applied by the second main electrode. The semiconductor device provided is disclosed (see, for example, Patent Document 1). A spring member is provided on the upper part of this semiconductor chip as a conductive member having an elastic force so that even if a large current flows in the event of an accident, the cover plate and the base plate are short-circuited. ..

Japanese Unexamined Patent Publication No. 2000-223658

In Patent Document 1, when a large current flows at the time of an accident, the cover plate and the base plate can be short-circuited. However, when a large current flows, a large electromagnetic force is generated in the electric contact member connected to the semiconductor chip, the electric contact member is broken, and an arc is generated before a short circuit failure occurs. When an arc is generated, the arc affects the outside of the semiconductor device in addition to the damage inside the semiconductor device due to the arc. In order to suppress the influence of the arc on the outside, it is necessary to provide a special housing structure in the semiconductor device, and there is a problem that it becomes difficult to miniaturize the semiconductor device.

The present application has been made to solve the above-mentioned problems, and an object thereof is to obtain a semiconductor device which suppresses the generation of an arc and realizes miniaturization.

The semiconductor device disclosed in the present application includes a semiconductor chip, a conductive base plate connected to one surface of the semiconductor chip, an insulating outer wall in contact with the base plate and surrounding the semiconductor chip, and the other surface of the semiconductor chip. A conductive cover plate that faces the outer wall and closes the outer wall, an energizing member that is provided between the semiconductor chip and the cover plate and connects the semiconductor chip and the cover plate, and opens on the side of the cover plate. An elastic member provided in a recess of the energizing member and urged to press an electrode on the other surface of the semiconductor chip through the energizing member, and maintaining contact between the cover plate and the energizing member. The energization member is provided with an energization maintenance portion, and the energization member has a shape that is rotationally symmetric with respect to the central axis of the recess.

According to the semiconductor device disclosed in the present application, it is possible to suppress the generation of an arc and realize miniaturization.

It is sectional drawing which shows the structural outline of the semiconductor device which concerns on Embodiment 1. FIG. It is a perspective view which shows the main part of the semiconductor device which concerns on Embodiment 1. FIG. It is a perspective perspective view which shows the structure of the semiconductor device which concerns on Embodiment 1. FIG. It is a perspective view which shows the assembly of the main part of the semiconductor device which concerns on Embodiment 1. FIG. It is a perspective view which shows the assembly of the semiconductor device which concerns on Embodiment 1. FIG. It is a perspective perspective view which shows another structure of the semiconductor device which concerns on Embodiment 1. FIG. It is sectional drawing which shows the other structural outline of the semiconductor device which concerns on Embodiment 1. FIG. It is a perspective view which shows another energizing member of the semiconductor device which concerns on Embodiment 1. FIG. It is sectional drawing which shows the structural outline of the semiconductor device which concerns on Embodiment 2. It is a perspective perspective view which shows the structure of the semiconductor device which concerns on Embodiment 2. 9 is a cross-sectional view taken along the alternate long and short dash line AA of FIG. It is a perspective view which shows the assembly of the main part of the semiconductor device which concerns on Embodiment 2. FIG. It is a perspective view which shows the assembly of the semiconductor device which concerns on Embodiment 2. FIG. FIG. 3 is a perspective perspective view showing another configuration of the semiconductor device according to the second embodiment. It is sectional drawing which shows the other structural outline of the semiconductor device which concerns on Embodiment 2. FIG. 9 is a cross-sectional view showing another configuration in the alternate long and short dash line AA of FIG. It is sectional drawing which shows a part of the unit of the semiconductor device which concerns on Embodiment 3. FIG. It is sectional drawing which shows the core member of the semiconductor device which concerns on Embodiment 3. FIG. It is sectional drawing which shows a part of another unit of the semiconductor device which concerns on Embodiment 3. FIG. It is sectional drawing which shows a part of another unit of the semiconductor device which concerns on Embodiment 3. FIG. It is sectional drawing which shows a part of the unit of the semiconductor device which concerns on Embodiment 4. FIG. It is sectional drawing which shows a part of another unit of the semiconductor device which concerns on Embodiment 4. FIG. It is sectional drawing which shows a part of another semiconductor device which concerns on Embodiment 4. FIG. It is sectional drawing which shows a part of another semiconductor device which concerns on Embodiment 4. FIG.

Hereinafter, the semiconductor device according to the embodiment of the present application will be described with reference to the drawings, but the same or corresponding members and parts will be described with the same reference numerals in the drawings.

Embodiment 1.
FIG. 1 is a cross-sectional view showing an outline of the configuration of the semiconductor device 1, FIG. 2 is a perspective view showing a main part of the semiconductor device 1, and FIG. 3 is a perspective perspective view showing the configuration of the semiconductor device 1. The semiconductor device 1 incorporated in the power conversion device includes a semiconductor chip 8 such as a switching chip which is a power semiconductor inside, and the semiconductor chip 8 is connected by a pressure contact structure.

The semiconductor device 1 includes a semiconductor chip 8, a conductive base plate 4 connected to an electrode pad 8b on one surface of the semiconductor chip, an insulating outer wall 2 in contact with the base plate 4 and surrounding the semiconductor chip 8, and the other of the semiconductor chips 8. A conductive cover plate 3 that faces the electrode pad 8a on the surface of the surface and closes the outer wall 2, an energizing member 5 provided between the semiconductor chip 8 and the cover plate 3, a spring 7 that is an elastic member, and a cover plate 3. It is provided with an energization maintenance unit 5d that maintains contact with the energization member 5. The energizing member 5 connects the semiconductor chip 8 and the cover plate 3. The spring 7 is provided in a recess 5a provided with an energizing member 5 that opens on the side of the cover plate 3, is in contact with the cover plate 3 at one end and in contact with the bottom 5b of the recess 5a at the other end, and is a semiconductor via the energizing member 5. The other surface of the chip 8 is urged to press the electrode pad 8a provided. The energizing member 5 has a shape that is rotationally symmetric with respect to the central axis 5c of the recess 5a, and the outer circumference of the cross section perpendicular to the central axis 5c of the energizing member 5 is circular. The unit 100, which is a main part of the semiconductor device 1, has an internal configuration of the semiconductor device 1 and includes a semiconductor chip 8, an energizing member 5, and a spring 7. The outer wall 2 is made of, for example, a resin.

^{The energizing member 5 has an electric resistivity of 2 × 10 -8} Ω · m or less so that the temperature rise due to large current energization when the semiconductor device 1 fails is equal to or less than the softening point of the material constituting the energizing member 5. Made of metal material. Such metallic materials are, for example, oxygen-free copper or tough pitch copper. The energizing member 5 is manufactured, for example, by cutting. Since the inside of the semiconductor device 1 becomes hot during driving of the semiconductor device 1, plating such as gold or nickel may be applied to the surface of the current-carrying member 5 in order to suppress oxidation of the surface of the current-carrying member 5. The energizing member 5 is provided in a rotationally symmetric shape in order to efficiently withstand the generated electromagnetic force even if an electromagnetic force is generated when a large current is energized. If the shape is rotationally symmetric, when an electromagnetic force is applied, a force is applied so that the energizing member 5 is compressed, so that the force escapes in the circumferential direction and deformation of the energizing member 5 is less likely to occur. If deformation does not occur, the energizing member 5 will not be damaged or broken, so that the arc discharge that may occur in the gap at the time of breaking is suppressed.

The energizing member 5 is provided with a flexible bent portion as the energizing maintaining portion 5d, and the elasticity of the bent portion keeps the energizing member 5 and the cover plate 3 in constant contact with each other. Further, the flexible bent portion of the energizing member 5 may always be pressed against the cover plate 3 by the spring 5g provided on the energizing member 5. The pressing of the semiconductor chip 8 of the spring 7 prevents the formation of a gap between the energizing member 5 and the cover plate 3, and the energization between the cover plate 3 and the base plate 4 is maintained. The installation location of the spring 5g is not limited to two locations, and the installation locations may be further increased.

The lower end surface 5e, which is the contact point of the energizing member 5 with the electrode pad 8a, is manufactured with a dimensional shape in which the lower end surface 5e does not protrude from the electrode pad 8a. If the lower end surface 5e protrudes from the electrode pad 8a, an electrical defect such as an air discharge may occur in the operation of the semiconductor chip 8, and the semiconductor chip 8 may be damaged.

The semiconductor chip 8 is, for example, a diode chip or a switching chip. The semiconductor device 1 may include only one of them, or may include both of them. The semiconductor chip 8 to be installed may be provided with one or a plurality of the same type. The switching chip may be, for example, an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), or a combination of a plurality of types thereof. It doesn't matter. Inside the power conversion device, the semiconductor device 1 is held by receiving a pressure contact force from the cover plate 3 and the base plate 4. This pressure contact force compresses the spring 7 and presses the energizing member 5 against the semiconductor chip 8, so that good electrical contact between the semiconductor chip 8 and the energizing member 5 is maintained.

Since the cover plate 3 and the base plate 4 are connected to other semiconductor devices or other circuits outside the semiconductor device 1, they are made of a metal having a small electric resistance such as nickel-plated copper.

The spring 7 is, for example, a disc spring and is made of phosphor bronze. The shape having elasticity is not limited to the shape of the disc spring, and the material is not limited. As another example, the shape of a leaf spring may be used. The reason for providing the spring 7 will be described below. The power conversion device incorporating the semiconductor device 1 is assumed to convert electric power having a voltage higher than the rated voltage of the semiconductor device 1, and a plurality of semiconductor devices 1 are connected in series for use. If even one of the semiconductor devices 1 connected in series fails and the space between the cover plate 3 and the base plate 4 of the semiconductor device 1 is electrically opened, the power conversion device does not operate correctly. In the power conversion device, one or a plurality of semiconductor devices 1 are connected in series in advance in order to ensure redundancy, and when the semiconductor device 1 fails, the cover plate 3 and the base plate 4 are short-circuited by short-circuiting. The operation of the power conversion device continues only with the remaining semiconductor device 1 connected in series. In order to short-circuit between the cover plate 3 and the base plate 4, it is necessary to maintain electrical contact via the semiconductor chip 8 when the semiconductor chip 8 fails. However, if the semiconductor chip 8 and the energizing member 5 are mechanically detached at the time of failure, electrical contact cannot be maintained. A spring 7 is provided to press the semiconductor chip 8 with the energizing member 5 in order to maintain electrical contact. By pressing the energizing member 5, the electrical contact between the energizing member 5 and the semiconductor chip 8 is maintained.

The assembly of the semiconductor device 1 will be described. FIG. 4 is a perspective view showing the assembly of a main part of the semiconductor device 1 according to the first embodiment, and FIG. 5 is a perspective view showing the assembly of the semiconductor device 1 according to the first embodiment. As shown in FIG. 4, the unit 100 is installed by inserting the spring 7 into the recess 5a, and is assembled by bringing the lower end surface 5e of the energizing member 5 into contact with the electrode pad 8a. As shown in FIG. 5, the semiconductor device 1 is assembled by connecting the base plate 4 and the electrode pad 8b, attaching the outer wall 2 to the base plate 4, and closing the opening of the outer wall 2 with the cover plate 3.

The number of units 100 included in the semiconductor device 1 may be one or a plurality. FIG. 6 is a perspective perspective view showing another configuration of the semiconductor device 1 according to the first embodiment. In FIG. 6, the semiconductor device 1 includes four units 100. The number of units 100 included in the semiconductor device 1 is not limited to four, and any number of units 100 can be included according to the specifications of the semiconductor device 1.

The number of the semiconductor chips 8 included in the semiconductor device 1 may be one or a plurality. FIG. 7 is a cross-sectional view showing another outline of the configuration of the semiconductor device 1 according to the first embodiment. In FIG. 7, the semiconductor chip 8 includes both a diode chip 81 and a switching chip 82. The diode chip 81 is in contact with the energizing member 51 at the electrode pad 81a. The switching chip 82 is in contact with the energizing member 52 at the emitter electrode pad 82a. The switching chip 82 is provided with a gate electrode pad 82b on the same side as the emitter electrode pad 82a, and is connected to one end of the gate wiring 10. The other end of the gate wiring 10 is connected to the gate signal board 9 provided on the cover plate 3. The gate signal substrate 9 protrudes from between the outer wall 2 and the cover plate 3 to the outside of the semiconductor device 1, and the gate signal substrate 9 is connected to an external device.

The operation of the semiconductor device 1 will be described. In order to maintain high reliability of the power conversion device, the semiconductor device 1 is provided with a function of continuing the operation of the power conversion device in which the semiconductor device 1 is incorporated even if the semiconductor chip 8 fails. The details will be described below. The failure of the semiconductor chip 8 occurs, for example, when the timing of transition from the OFF state to the ON state in one of the plurality of switching chips 82 deviates from the transition timing of the other switching chips 82. When the transition timing is deviated, the current that should be evenly divided into the plurality of switching chips 82 that are normally connected in parallel flows to one chip that is deviated from the timing. In that case, the electric charge stored in the capacitors connected in parallel flows into the switching chip 82 whose timing is different, and a large current momentarily flows to the switching chip 82.

Conventionally, when a large current exceeding the rating flows through the energizing member and the switching chip, heat corresponding to the resistance component of the energizing member is generated in the energizing member, the temperature of the energizing member rises, and the energizing member may soften. there were. At the same time, the energizing member may be deformed by a large electromagnetic force generated on the energizing member, and the energizing member may be damaged. In particular, when the energizing member is damaged and the wire is broken, a gap is generated at the broken portion. Since there is a potential difference in the generated gap, an arc discharge occurs in the gap. When an arc discharge occurs, the gas filling the inside of the semiconductor device 1 is heated, the internal pressure of the semiconductor device 1 rises, and then the internal pressure exceeds the durability of the outer wall 2 of the semiconductor device 1 and damages the outer wall 2. There is a possibility of causing it. When the degree of increase in the internal pressure is significant, the semiconductor device 1 is damaged, and the damage may lead to damage to other parts inside the power conversion device. When the damage of the semiconductor device 1 is not suppressed, it is necessary to separately provide a special housing structure or the like for protecting other parts inside the power conversion device around the semiconductor device 1.

In the present application, since the energizing member 5 having a rotationally symmetric shape is provided, deformation of the energizing member 52 due to electromagnetic force is prevented and arc discharge is suppressed. Preventing the deformation of the energizing member 52 due to the electromagnetic force and suppressing the generation of the arc prevents the semiconductor device 1 from being damaged, and the semiconductor device 1 has high reliability. Further, since it is possible to prevent the semiconductor device 1 from being damaged by suppressing the generation of an arc, it is not necessary to provide a special housing structure. In addition to the miniaturization of the semiconductor device 1, the semiconductor inside the power conversion device The space required for installing the device 1 can be reduced.

Another configuration example of the energizing member 5 will be described. FIG. 8 is a perspective view showing another energizing member 5 of the semiconductor device 1 according to the first embodiment. In FIG. 2, the outer circumference of the cross section perpendicular to the central axis 5c of the energizing member 5 is circular, but in the energizing member 5 shown in FIG. 8, the outer circumference of the cross section perpendicular to the central axis 5c of the energizing member 5 is polygonal. In FIG. 8, the outer circumference of the quadrangle is shown, but the present invention is not limited to this, and a hexagon may be used as long as the shape is rotationally symmetric with respect to the central axis 5c. By making the outer circumference of the cross section perpendicular to the central axis 5c of the energizing member 5 polygonal, the energizing member 5 does not have a curved surface, so that the energizing member 5 can be easily manufactured by cutting.

As described above, in the semiconductor device 1 according to the first embodiment, the energizing member 5 is provided in a shape that is rotationally symmetric with respect to the central axis 5c of the recess 5a to prevent deformation of the energizing member 5 due to electromagnetic force and generate an arc. Since the suppression is performed, damage to the semiconductor device 1 due to the arc is prevented, so that the semiconductor device 1 does not need to be provided with a special housing structure, and the semiconductor device 1 can be miniaturized. Further, since the energizing member 5 can be provided in a shape that is rotationally symmetric with respect to the central axis 5c of the recess 5a to reduce the thickness of the energizing member 5 for withstanding the electromagnetic force, the energizing member 5 and the semiconductor device 1 can be thinned. Can be miniaturized. Further, when the outer circumference of the cross section perpendicular to the central axis 5c of the energizing member 5 is circular, the current is completely symmetrical in the direction of the central axis 5c and the load due to the electromagnetic force is not concentrated, so that the energizing member withstands the electromagnetic force. The thickness of 5 can be reduced. Further, since the spring 7 presses the semiconductor chip 8, even if the semiconductor chip 8 is damaged, the cover plate 3 and the base plate 4 can be reliably short-circuited. Further, the energization maintenance unit 5d can maintain the energization between the cover plate 3 and the base plate 4 even when the spring 7 presses the semiconductor chip 8.

Embodiment 2.
The semiconductor device 1 according to the second embodiment will be described. 9 is a cross-sectional view showing an outline of the configuration of the semiconductor device 1, FIG. 10 is a perspective perspective view showing the configuration of the semiconductor device 1, and FIG. 11 is a cross-sectional view taken along the alternate long and short dash line AA of FIG. The semiconductor device 1 according to the second embodiment has a configuration in which a core member 6 for pressing a semiconductor chip 8 is provided, and an energization auxiliary member 5f is closely fixed to the core member 6.

The energizing member 5 includes a core member 6 and an energizing auxiliary member 5f. The core member 6 surrounds the recess 5a and presses the electrode pad 8a provided on the other surface of the semiconductor chip 8. The energization auxiliary member 5f surrounds the core member 6 and is fixed to the core member 6. The core member 6 is a metal having a Young's modulus higher than that of the energization auxiliary member 5f, and is, for example, stainless steel. The spring 7 is installed in the recess 5a surrounded by the core member 6. The spring 7 that is compressed and comes into contact with the cover plate 3 presses the semiconductor chip 8 via the core member 6.

The energization auxiliary member 5f is divided into a plurality of parts. As shown in FIG. 11, the plurality of energization assisting members 5f are provided on the side surface of the core member 6 so as to be rotationally symmetric with respect to the central axis 5c of the recess 5a. All the surfaces facing the core member 6 of the energization assist member 5f are in close contact with and fixed to the core member 6. The energization auxiliary member 5f is a metal material having a smaller electrical resistivity than the core member 6, and is, for example, oxygen-free copper or tough pitch copper. As shown in FIG. 9, the cover plate 3 and the semiconductor chip 8 are connected to each other via the energization auxiliary member 5f and the core member 6. The energization assisting member 5f is provided with a bending portion which is an energizing maintenance portion 5d at a contact point with the cover plate 3, and when the cover plate 3 and the base plate 4 are pressurized with a predetermined pressure contact force, the energization assisting member 5f and the cover plate 3 are energized. The member 5f is reliably contacted, and an energization path is formed between the cover plate 3 and the semiconductor chip 8. Since the bent portion serves as the energization maintaining portion 5d, a spring 5 g may be provided as in the first embodiment. The connection between the energization assisting member 5f and the core member 6 is performed, for example, by fitting, fixing with screws, and fixing via a conductive adhesive, but is not limited thereto.

As shown in FIG. 11, since the plurality of energization assisting members 5f are arranged rotationally symmetrically with respect to the central axis 5c, the direction in which the electromagnetic force is applied to the energizing assisting member 5f during energization is in the direction toward the central axis 5c. Become. All the energization assisting members 5f are in contact with the core member 6 on the side of the central axis 5c, and an electromagnetic force is generated in the direction toward the core member 6. Since the core member 6 of the energization assisting member 5f is a mechanical support, deformation of the energizing assisting member 5f due to electromagnetic force can be prevented. Although FIG. 11 shows the core member 6 having the shape of an octagonal prism, the present invention is not limited to this, and any other prism shape may be used as long as the shape is rotationally symmetric with respect to the central axis 5c.

The assembly of the semiconductor device 1 will be described. FIG. 12 is a perspective view showing the assembly of the unit 100 which is a main part of the semiconductor device 1 according to the second embodiment, and FIG. 13 is a perspective view showing the assembly of the semiconductor device 1 according to the second embodiment. As shown in FIG. 12, the unit 100 is installed by inserting a spring 7 into the recess 5a, fixing the energization assisting member 5f to the side surface 6a of the core member 6, and connecting the lower end surface 6b of the core member 6 and the electrode pad 8a. Assembled in contact. As shown in FIG. 13, the semiconductor device 1 is assembled by connecting the base plate 4 and the electrode pad 8b, attaching the outer wall 2 to the base plate 4, and closing the opening of the outer wall 2 with the cover plate 3.

The number of units 100 included in the semiconductor device 1 may be one or a plurality. FIG. 14 is a perspective perspective view showing another configuration of the semiconductor device 1 according to the second embodiment. In FIG. 14, the semiconductor device 1 includes four units 100. The number of units 100 included in the semiconductor device 1 is not limited to four, and any number of units 100 can be included according to the specifications of the semiconductor device 1.

The number of the semiconductor chips 8 included in the semiconductor device 1 may be one or a plurality. FIG. 15 is a cross-sectional view showing another outline of the configuration of the semiconductor device 1 according to the second embodiment. In FIG. 15, the semiconductor chip 8 includes both a diode chip 81 and a switching chip 82. The diode chip 81 is in contact with the core member 61 at the electrode pad 81a. The switching chip 82 is in contact with the core member 62 at the emitter electrode pad 82a. The switching chip 82 is provided with a gate electrode pad 82b on the same side as the emitter electrode pad 82a, and is connected to one end of the gate wiring 10. The other end of the gate wiring 10 is connected to the gate signal board 9 provided on the cover plate 3. The gate signal substrate 9 protrudes from between the outer wall 2 and the cover plate 3 to the outside of the semiconductor device 1, and the gate signal substrate 9 is connected to an external device.

In the above, the configuration is such that a plurality of energization assisting members 5f are provided, but the present invention is not limited to this, and as shown in the cross-sectional view of the unit 100 of FIG. 16, one of the cylindrical shapes is formed on the side surface 6a of the cylindrical core member 6. The configuration may be such that the two energization assisting members 5f are fitted and fixed. Compared with the case where a plurality of energization assisting members 5f are provided, the number of fixing points of the energizing assisting member 5f and the core member 6 is reduced, so that the manufacturing process is simplified.

As described above, in the semiconductor device 1 according to the second embodiment, the energization assisting member 5f is fixed to the core member 6 having a Young's modulus higher than that of the energizing assisting member 5f, and the core member 6 mechanically supports the energizing assisting member 5f. Therefore, it is possible to prevent the deformation of the energization assisting member 5f due to the electromagnetic force. Further, it is possible to prevent deformation of the energizing member 5 due to the pressure contact force received from the cover plate 3 and the base plate 4. Further, since the core member 6 prevents the energization assisting member 5f from being deformed, the thickness of the energizing assisting member 5f can be reduced, and the energizing assisting member 5f and the semiconductor device 1 can be miniaturized. Further, since the energization assisting member 5f is provided with a metal material having an electric resistivity smaller than that of the core member 6 and the cross-sectional area of the energizing assisting member 5f required at the time of energization can be reduced, the energizing assisting member 5f and the semiconductor device 1 can be made smaller. Can be transformed into.

Embodiment 3.
The semiconductor device 1 according to the third embodiment will be described. FIG. 17 is a cross-sectional view showing a part of the unit 100 of the semiconductor device 1, and FIG. 18 is a cross-sectional view showing the core member 6 of the semiconductor device 1. The semiconductor device 1 according to the third embodiment has a configuration in which, in addition to the configuration of the semiconductor device 1 shown in the second embodiment, a groove 6c for fixing the energization assisting member 5f is provided on the side surface 6a of the core member 6. There is.

As shown in FIG. 18, the core member 6 is provided with a groove 6c along the direction of the central axis 5c on each of the octagonal side surfaces 6a. The groove 6c is formed, for example, by cutting. As shown in FIG. 17, the energization assist member 5f is fitted and fixed in each groove 6c. The connection between the energizing auxiliary member 5f and the groove 6c may be fixed by a screw or fixed by a conductive adhesive in addition to the fitting.

The reason for providing the groove 6c will be described. When a current flows through a plurality of energization assisting members 5f, an electromagnetic force is generated in a direction in which adjacent energization assisting members 5f are attracted to each other. If an electromagnetic force of the same magnitude is applied to the plurality of energization assisting members 5f, the energizing assisting member 5f will not be deformed and will not break. However, if there is a variation in the current flowing through each of the energization assisting members 5f due to a slight misalignment of the energization assisting member 5f or the like, the electromagnetic force toward the adjacent energizing assisting member 5f is different. Deformation toward either side will occur. Once the deformation occurs, the electromagnetic force in the direction toward the energizing auxiliary member 5f that is closer to the distance becomes larger, and a larger deformation occurs. The large deformation leads to the breakage of the energization auxiliary member 5f and the generation of an arc. Preventing the deformation of the energization assisting member 5f due to the electromagnetic force and suppressing the generation of the arc prevents the semiconductor device 1 from being damaged, and the semiconductor device 1 has high reliability. A groove 6c is provided in order to suppress the misalignment of the energization assisting member 5f that causes deformation of the energizing assisting member 5f.

Another configuration example of the energization auxiliary member 5f will be described. FIG. 17 shows the energization assisting member 5f having a cross-sectional shape that matches the size of the groove 6c, but the present invention is not limited to this, and as shown in FIG. 19 or FIG. 20, the energizing assisting member 5f has a cross section larger than that of the groove 6c. It may have a shape or a small cross-sectional shape. The size of the cross-sectional shape of the energization assisting member 5f is determined by, for example, the magnitude of the current energized in the energizing assisting member 5f.

As described above, in the semiconductor device 1 according to the third embodiment, since the groove 6c for fixing the energization assisting member 5f is provided on the side surface 6a of the core member 6, the energization that causes the deformation of the energization assisting member 5f and the generation of an arc is generated. The misalignment of the auxiliary member 5f can be suppressed.

Embodiment 4.
The semiconductor device 1 according to the fourth embodiment will be described. FIG. 21 is a cross-sectional view showing a part of the unit 100 of the semiconductor device 1. The semiconductor device 1 according to the fourth embodiment has a configuration in which the cross-sectional shape of the energization auxiliary member 5f is different from that of the semiconductor device 1 shown in the third embodiment.

The shape of the cross section perpendicular to the central axis 5c of the energization assisting member 5f is a square shape in which the corner portion 5h has a curvature. The corner portion 5h is formed by, for example, R processing. The energization assisting member 5f is in contact with a surface at the bottom of the groove 6c and is in contact with a point on the two side surfaces of the groove 6c, and the energization assisting member 5f and the groove 6c are in contact with each other at three points, so that the positional deviation of the energizing assisting member 5f is suppressed. , The energization auxiliary member 5f is stably connected to the groove 6c.

The reason for providing a square shape having a curvature on the corner portion 5h will be described. It is known that when a current flows through a conductor, the current density increases on the surface of the conductor and decreases toward the inside away from the surface, which is the skin effect. The distance at which the current becomes 1 / e of the current flowing on the surface of the conductor is called the skin depth, and is defined by the electrical resistivity and dielectric constant of the conductor. For example, in the case of copper wire, the depth of the skin is about 1 mm for an alternating current of 4 to 5 kHz. The cross section without corners is the most effective shape for the skin effect because the current is not concentrated on the corners, and it has a high heat generation density suppressing effect with a small cross-sectional area.

Another configuration example of the energization auxiliary member 5f will be described. As shown in FIG. 22, the configuration in which the energization assist member 5f has a curvature at the corner portion 5h may be circular. The energization assisting member 5f is in contact with a point at the bottom of the groove 6c and is also in contact with a point on the two side surfaces of the groove 6c. , The energization auxiliary member 5f is stably connected to the groove 6c. The circular energization auxiliary member 5f is, for example, an electric wire.

As described above, in the semiconductor device 1 according to the fourth embodiment, since the cross-sectional shape of the energization auxiliary member 5f is a square shape having a curvature at the corner portion 5h, the current does not concentrate on the corner portion 5h and the cross-sectional area is small. It is possible to have a high heat generation density suppressing effect. Further, since the energization assisting member 5f is in contact with the groove 6c at three points, the misalignment of the energizing assisting member 5f can be suppressed. Further, the energization assist member 5f can be stably connected to the groove 6c.

As shown in FIG. 23, the energization maintenance portion may be a convex portion 5i provided on the surface of the energization auxiliary member 5f facing the cover plate 3 and fitted with the concave portion 3a provided in the cover plate 3. Even if a gap is formed between the energization assisting member 5f and the cover plate 3 by pressing the semiconductor chip 8 of the spring 7 when the semiconductor chip 8 fails, contact is maintained on the mutual side surfaces of the concave portion 3a and the convex portion 5i. Therefore, the energization between the cover plate 3 and the base plate 4 is maintained. As shown in FIG. 24, the shape of the recess 3a may be a through hole 3b. Further, the cover plate 3 may be provided with a convex portion, and the energization assist member 5f may be provided with a concave portion or a through hole. By forming the energization maintenance portion with a fitting structure, the number of parts can be reduced because 5 g of the spring is not required.

The present application also describes various exemplary embodiments and examples, although the various features, embodiments, and functions described in one or more embodiments are those of a particular embodiment. It is not limited to application, but can be applied to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Semiconductor device, 2 Outer wall, 3 Cover plate, 3a recess, 3b through hole, 4 base plate, 5 energizing member, 5a recess, 5b bottom, 5c central shaft, 5d energizing maintenance part, 5e lower end surface, 5f energizing auxiliary member, 5g Spring, 5h square part, 5i convex part, 6 core member, 6a side surface, 6b lower end surface, 6c groove, 7 spring, 8 semiconductor chip, 8a electrode pad, 8b electrode pad, 9 gate signal board, 10 gate wiring, 100 unit

Claims (9)

Semiconductor chip,
A conductive base plate connected to one surface of the semiconductor chip,
An insulating outer wall that is in contact with the base plate and surrounds the semiconductor chip,
A conductive cover plate that faces the other surface of the semiconductor chip and closes the outer wall.
An energizing member provided between the semiconductor chip and the cover plate and connecting the semiconductor chip and the cover plate.
An elastic member provided in a recess of the energizing member that opens on the side of the cover plate and urged to press an electrode on the other surface of the semiconductor chip via the energizing member.
And an energization maintenance unit that maintains contact between the cover plate and the energizing member.
A semiconductor device characterized in that the energizing member has a shape that is rotationally symmetric with respect to the central axis of the recess. The semiconductor device according to claim 1, wherein the outer periphery of the cross section perpendicular to the central axis of the energizing member is circular. The semiconductor device according to claim 1, wherein the outer periphery of the cross section perpendicular to the central axis of the energizing member is polygonal. The energizing member includes a core member that surrounds the recess and presses an electrode provided on the other surface of the semiconductor chip, and an energization assisting member that surrounds the core member and is fixed to the core member.
The semiconductor device according to any one of claims 1 to 3, wherein the core member is a metal having a Young's modulus higher than that of the energization assist member. The semiconductor device according to claim 4, wherein the energization assist member is divided into a plurality of parts. The semiconductor device according to claim 5, wherein all the surfaces of the energization assisting member facing the core member are in close contact with and fixed to the core member. The core member has a groove on the side surface along the direction of the central axis.
The semiconductor device according to claim 5 or 6, wherein the energization assist member is fitted and fixed to the groove. The seventh aspect of claim 7, wherein the shape of the cross section perpendicular to the central axis of the energization assisting member is a square shape having a curved corner portion, and the energizing assisting member is in contact with the groove at three or more places. Semiconductor equipment. Claims 1 to 8 are characterized in that the energization maintaining portion is a concave portion provided on a surface of the energizing member facing the cover plate and fitted with a concave portion or a through hole provided in the cover plate. The semiconductor device according to any one of the above.

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