JP7237192B2 - Semiconductor device, manufacturing method thereof, and power conversion device - Google Patents

Description

The present invention relates to a semiconductor device, its manufacturing method, and a power converter.

A semiconductor device (power module) used for power control includes a semiconductor chip, an insulating substrate, a bonding layer, and terminals. A conductive circuit pattern is formed on one main surface of the insulating substrate, and a heat radiating material is arranged on the other main surface. A semiconductor element and a terminal are respectively joined to the conductive circuit pattern by a joining layer.

The terminals include an external output terminal for outputting controlled power to the outside. As for the external output terminals, attempts have been made to improve the shape of the external output terminals, the method of holding the external output terminals, and the like, in order to reduce process costs and improve reliability. For example, Patent Literature 1 proposes an external output terminal provided with a protrusion to be placed on an insulating substrate. By allowing the external output terminals to stand on their own with the protrusions, the conventionally required jigs are eliminated, simplifying the bonding process and improving yields.

JP 2018-160618 A

In a semiconductor device, a terminal is bonded to a conductive circuit pattern by a bonding layer interposed between the terminal and the conductive circuit pattern. At this time, it is important to control the distance between the terminal and the conductive circuit pattern, that is, the thickness of the bonding layer in order to ensure the reliability of the bonding portion and to extend the life. This was confirmed by the inventors' evaluation.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and one object thereof is to provide a semiconductor device capable of improving the reliability of the joint portion to extend the life of the device, and another object thereof. Another object of the present invention is to provide a method for manufacturing such a semiconductor device, and a further object is to provide a power conversion device including such a semiconductor device.

A semiconductor device according to the present invention has an insulating substrate, a terminal, and a bonding layer. The insulating substrate has a first main surface and a second main surface facing each other, a conductive circuit pattern is formed on the side of the first main surface, and a heat dissipating material is arranged on the side of the second main surface. The terminals are electrically connected to the conductive circuit pattern. The joining layer joins the terminal and the conductive circuit pattern. A terminal comprises a joint and one or more supports. The bonding body includes a bonding surface that is bonded to the conductive circuit pattern by a bonding layer. One or more supports are connected to the bonding body, and are positioned in a manner in contact with the conductive circuit pattern in a region other than the region where the bonding body is bonded in the conductive circuit pattern, and the bonding layer intervenes. Keep the distance between the contact surface of the body and the conductive circuit pattern. It also has a case in which the insulating substrate is accommodated. The side of the terminal opposite to the side joined to the conductive circuit pattern is held by the case.
Another semiconductor device according to the present invention has an insulating substrate, a terminal, and a bonding layer. The insulating substrate has a first main surface and a second main surface facing each other, a conductive circuit pattern is formed on the side of the first main surface, and a heat dissipating material is arranged on the side of the second main surface. The terminals are electrically connected to the conductive circuit pattern. The joining layer joins the terminal and the conductive circuit pattern. A terminal comprises a joint and one or more supports. The bonding body includes a bonding surface that is bonded to the conductive circuit pattern by a bonding layer. One or more supports are connected to the bonding body, and are positioned in a manner in contact with the conductive circuit pattern in a region other than the region where the bonding body is bonded in the conductive circuit pattern, and the bonding layer intervenes. Keep the distance between the contact surface of the body and the conductive circuit pattern. The joining layer surrounds the support and is formed from a region where the joining body and the conductive circuit pattern are joined to a region where the support is located.
Still another semiconductor device according to the present invention has an insulating substrate, a terminal, and a bonding layer. The insulating substrate has a first main surface and a second main surface facing each other, a conductive circuit pattern is formed on the side of the first main surface, and a heat dissipating material is arranged on the side of the second main surface. The terminals are electrically connected to the conductive circuit pattern. The joining layer joins the terminal and the conductive circuit pattern. A terminal comprises a joint and one or more supports. The bonding body includes a bonding surface that is bonded to the conductive circuit pattern by a bonding layer. One or more supports are connected to the bonding body, and are positioned in a manner in contact with the conductive circuit pattern in a region other than the region where the bonding body is bonded in the conductive circuit pattern, and the bonding layer intervenes. Keep the distance between the contact surface of the body and the conductive circuit pattern. Spaced apart from the bonding layer, there is another bonding layer that bonds the support to the conductive circuit pattern in a manner surrounding the support.

A method of manufacturing a semiconductor device according to the present invention includes the following steps. An insulating substrate is prepared which has a first main surface and a second main surface facing each other, a conductive circuit pattern is formed on the side of the first main surface, and a heat dissipation material is arranged on the side of the second main surface. A terminal having one end and the other end and electrically connected to the conductive circuit pattern is prepared. A bonding layer bonds one end side of the terminal to the conductive circuit pattern. The step of preparing a terminal comprises: a bonded body including a bonding surface bonded to a conductive circuit pattern by a bonding layer; and one or more supports for maintaining a distance between the conductive circuit pattern and the bonding surface of the bonded body in which the bonding layer is interposed. It has a process. The step of bonding one end side of the terminal to the conductive circuit pattern includes bringing the support into contact with the conductive circuit pattern, and maintaining the distance between the bonding surface of the bonded body and the conductive circuit pattern. and a step of disposing a bonding material to be a bonding layer between the conductive circuit pattern and the bonding material, and a step of bonding the bonded body to the conductive circuit pattern via the bonding layer by treating the bonding material. ing.

A power conversion device according to the present invention includes the above semiconductor device, a main conversion circuit that converts input power and outputs it, and a control circuit that outputs a control signal for controlling the main conversion circuit to the main conversion circuit. It has

According to the semiconductor device of the present invention, the terminal includes the joint body including the joint surface and the one or more support bodies for maintaining the distance between the joint surface and the conductive circuit pattern, so that the joint layer A distance between the bonding body and the conductive circuit pattern corresponding to the thickness of the bonding layer is maintained to achieve the desired thickness of the bonding layer. As a result, the reliability of the junction between the terminal and the conductive circuit pattern is ensured, which contributes to the extension of the life of the semiconductor device.

According to the method of manufacturing a semiconductor device according to the present invention, the supporting body is brought into contact with the conductive circuit pattern, and the bonding surface and the conductive circuit pattern are kept in a state in which the distance between the bonding surface and the conductive circuit pattern of the bonding body is maintained. A bonding material serving as a bonding layer is disposed between the conductive circuit pattern and the bonding material, and the bonding material is bonded to the conductive circuit pattern via the bonding layer. As a result, the thickness of the bonding layer becomes a desired thickness, the reliability of the bonding portion between the terminal and the conductive circuit pattern is ensured, and it is possible to contribute to the extension of the life of the semiconductor device.

According to the power conversion device of the present invention, by including the semiconductor device described above, the reliability of the joint portion between the terminal and the conductive circuit pattern is ensured, which contributes to the extension of the life of the semiconductor device. can.

1 is a cross-sectional view showing a semiconductor device according to a first embodiment; FIG. FIG. 4 is a plan view showing an example of a terminal applied to a semiconductor device in the same embodiment; FIG. 4 is a front view showing an example of a terminal applied to a semiconductor device in the same embodiment; FIG. 4 is a side view showing an example of a terminal applied to a semiconductor device in the same embodiment; 2 is a perspective view showing an example of a terminal applied to a semiconductor device in the same embodiment; FIG. FIG. 4 is a cross-sectional view showing one step of a method for manufacturing a semiconductor device in the same embodiment; FIG. 7 is a cross-sectional view showing a step performed after the step shown in FIG. 6 in the same embodiment; FIG. 8 is a cross-sectional view showing a step performed after the step shown in FIG. 7 in the same embodiment; FIG. 9 is a cross-sectional view showing a step performed after the step shown in FIG. 8 in the same embodiment; FIG. 10 is a cross-sectional view showing a step performed after the step shown in FIG. 9 in the same embodiment; 11 is a cross-sectional view showing a step performed after the step shown in FIG. 10 in the same embodiment; FIG. FIG. 12 is a cross-sectional view showing a step performed after the step shown in FIG. 11 in the same embodiment; 13 is a cross-sectional view showing a step performed after the step shown in FIG. 12 in the same embodiment; FIG. FIG. 4 is a diagram for explaining a heat radiation path of heat generated in a bonding layer in the same embodiment; FIG. 10 is a plan view showing another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 10 is a front view showing another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 10 is a side view showing another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 10 is a plan view showing still another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 10 is a front view showing still another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 11 is a side view showing still another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 11 is a cross-sectional view showing a semiconductor device according to a second embodiment; FIG. 10 is a cross-sectional view showing a semiconductor device according to a modification in the same embodiment; FIG. 11 is a cross-sectional view showing a semiconductor device according to a third embodiment; FIG. 4 is a cross-sectional view showing one step of a method for manufacturing a semiconductor device in the same embodiment; FIG. 10 is a plan view showing another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 10 is a front view showing another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 10 is a side view showing another example of a terminal applied to the semiconductor device in the same embodiment; FIG. 11 is a block diagram of a power conversion device according to Embodiment 4;

Embodiment 1.
A semiconductor device according to the first embodiment will be described. As shown in FIG. 1 , in the semiconductor device 1 , a semiconductor element 15 is mounted on an insulating substrate 5 . Semiconductor element 15 includes a power semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) or a MOSFET (Metal Oxide Semiconductor Field Effect Transistor). Silicon, silicon carbide, gallium nitride, or the like, for example, is applied as the material of semiconductor element 15 . A terminal 21 is connected to the insulating substrate 5 . A terminal 21 outputs current from the semiconductor element 15 .

The insulating substrate 5 includes an insulating substrate body 7 , conductive circuit patterns 9 a , 9 b , 9 c and a heat dissipation material 11 . The insulating substrate 5 has a first main surface and a second main surface facing each other. A conductive circuit pattern 9a, a conductive circuit pattern 9b, and a conductive circuit pattern 9c are arranged on the first main surface side of the substrate body 7 at intervals. A heat dissipation material 11 is arranged on the side of the second main surface of the substrate body 7 .

The substrate main body 7 may be any material as long as it has insulating properties, and is preferably made of a ceramic material such as silicon nitride (SiN) or aluminum nitride (AlN). Also, the substrate main body 7 may be made of an organic material such as resin, for example. The material of the substrate body 7 does not have to be a single material, and may be, for example, a mixed product. Furthermore, the substrate body 7 may have a multilayer structure.

The conductive circuit patterns 9a, 9b, and 9c may be made of a conductive material, preferably a metal material such as copper (Cu) or aluminum (Al). The electrically conductive material need not be a single electrically conductive material, and may be formed from an alloy, for example. Moreover, the conductive circuit patterns 9a, 9b, and 9c may have a multilayer structure.

The back side of the semiconductor element 15 is joined to the conductive circuit pattern 9b by the joining material 13. As shown in FIG. One electrode (not shown) on the surface side of the semiconductor element 15 is electrically connected to the conductive circuit pattern 9a by a conductive wire 19a. Another electrode (not shown) of semiconductor element 15 is electrically connected to conductive circuit pattern 9c by conductive wire 19b. A terminal 21 is joined to the conductive circuit pattern 9c by a joining layer 17. As shown in FIG. The respective potentials of the conductive circuit pattern 9a and the conductive circuit pattern 9c are different from the potential of the conductive circuit pattern 9b.

The bonding material 13 may be any conductive material, preferably a metal material such as solder, sintered silver (Ag), or sintered copper (Cu). The conductive material need not be a single conductive material, and may be, for example, an alloy. Also, the bonding material 13 may have a multilayer structure.

Conductive wire 19a is for signal input, for example. Conductive wire 19b is, for example, a current path. Conductive wire 19a and conductive wire 19b are connected to different potentials, for example. In the case of the current path, instead of the conductive wire 19b, for example, a plate-shaped electrode may be used. The plate-shaped electrodes are joined to the semiconductor element 15 and the conductive circuit pattern 9c by soldering, for example.

The heat dissipation material 11 is joined to the base plate 3 by soldering, for example. Heat radiation material 11 and base plate 3 may be integrally formed from the same member, for example. When the heat dissipating material 11 and the base plate 3 are formed from a single member, heat is dissipated without passing through the joint between the heat dissipating material 11 and the base plate 3, compared to the case where the heat dissipating material 11 and the base plate 3 are formed from different members. will take place. Therefore, the heat dissipation material 11 and the base plate 3 formed from a single member are more preferable because the thermal resistance from the semiconductor element 15 to the back surface of the base plate 3 can be reduced.

As shown in FIGS. 1, 2, 3, 4 and 5, the terminal 21 is provided with a joining body 23 and a support 25 on one end side, and an external connection body 27 on the other end side. . Terminal 21 is formed by, for example, punching and bending. The joined body 23 is joined to the conductive circuit pattern 9c by the joining layer 17. As shown in FIG. The terminal 21 is a path for outputting current, and a conductive material is used. A metal material such as copper (Cu) or aluminum (Al) is preferable as the conductive material. The electrically conductive material need not be a single electrically conductive material, and may be formed from an alloy, for example. Also, the terminal 21 may have a multilayer structure.

The bonding layer 17 may be made of any conductive material, preferably a metal material such as solder, sintered silver (Ag), or sintered copper (Cu). The electrically conductive material need not be a single electrically conductive material, and may be formed from an alloy, for example. Also, the bonding layer 17 may have a multilayer structure.

The thinner the bonding layer 17 is, the smaller the electrical resistance of the current path of the current flowing through the terminal 21 is. However, when the bonding layer 17 is, for example, solder, if the bonding layer 17 (solder) becomes too thin, it becomes difficult for the solder to wet and spread in the narrow portion where the bonding layer 17 becomes too thin.

For this reason, it is assumed that the bonding becomes insufficient and cracks develop during operation involving temperature cycles. If the crack progresses in the bonding layer 17, it becomes a factor that lowers the reliability of the semiconductor device. If the thickness of the bonding layer 17 is less than 40 μm, it is assumed that the bonding will be insufficient, so the bonding layer 17 preferably has a thickness of 40 μm or more.

On the other hand, the thicker the bonding layer 17, the less likely cracks will occur. However, the electrical resistance of the current path of the current flowing through the terminal 21 increases. Moreover, it becomes difficult to form a thick bonding layer 17 . When eutectic solder is used as the solder, if the thickness exceeds 2 mm, there is a tendency for insufficient bonding to occur. Therefore, the thickness of the bonding layer 17 is 2 mm or less. is preferred.

The thickness of the bonding layer 17 corresponds to the distance between the bonding surface 23a of the bonded body 23 and the conductive circuit pattern 9c. This thickness (distance) is preferably constant over the entire joint surface 23a. The support 25 is arranged so as to be in contact with the conductive circuit pattern 9c. The distance L (see FIG. 10) between the joint surface 23a and the conductive circuit pattern 9c is maintained while the support 25 is in contact with the conductive circuit pattern 9c. That is, the support 25 has the function of keeping the distance corresponding to the thickness of the bonding layer 17 constant.

In this semiconductor device 1 , the support 25 is arranged with a distance from the bonding layer 17 . Further, the support 25 may be arranged very close to the conductive circuit pattern 9c. As will be described later, the support 25 also functions as part of a heat dissipation path.

The position where the support 25 is arranged is not limited to one position, and it is preferable to provide a plurality of positions in order to make the thickness of the bonding layer 17 more uniform. Moreover, it is preferable to set the position of the support 25 according to the position of the conductive circuit pattern 9 c or the joint 23 . Variations of the support 25 will be described later.

A case 31 is arranged on the base plate 3 so as to surround the insulating substrate 5 on which the semiconductor element 15 and the like are mounted. The inside of the case 31 is filled with an insulating sealing material 33 for sealing the insulating substrate 5 and the like. The case 31 may be made of an insulating material, and preferably made of a resin material such as PPS (Poly Phenylen Sulfide).

The insulating sealing material 33 may be any material as long as it has insulating properties, and is preferably, for example, a resin material such as gel or epoxy. When the insulating sealing material 33 is gel, a lid (not shown) may be attached to the case 31 so that the insulating sealing material 33 cannot be seen from the outside. Like the case 31, the lid may be made of an insulating material, and preferably made of a resin material such as PPS. The semiconductor device 1 according to Embodiment 1 is configured as described above.

Next, an example of a method for manufacturing the semiconductor device 1 described above will be described. As shown in FIG. 6, first, an insulating substrate 5 including an insulating substrate body 7, conductive circuit patterns 9a, 9b, 9c, and a heat dissipation material 11 is prepared.

Next, as shown in FIG. 7, the semiconductor element 15 is bonded to the conductive circuit pattern 9b by the bonding material 13. Next, as shown in FIG. A bonding material 13, such as solder, is placed on the conductive circuit pattern 9b. A jig (not shown) is used to place the semiconductor element 15 on the solder. The insulating substrate 5 is put into a high-temperature furnace such as a reflow furnace, and the solder is melted in the high-temperature furnace. By solidifying the molten solder as the bonding material 13 , the semiconductor element 15 is bonded to the conductive circuit pattern 9 b by the bonding material 13 .

At this time, a film may be appropriately formed on the surface of the conductive circuit pattern 9b by plating or the like depending on the material of the bonding material 13 . In addition, when a silver (Ag) sintered body or a copper (Cu) sintered body is used as the material of the bonding material 13, appropriate pressure is applied to the surface of the semiconductor element 15 during bonding to assist bonding. You may make it

Next, as shown in FIG. 8, the semiconductor element 15 and the conductive circuit pattern 9a are electrically connected by conductive wires 19a using a wire bonding apparatus (not shown). The semiconductor element 15 and the conductive circuit pattern 9c are electrically connected by the conductive wire 19b. Conductive wire 19a is bonded, for example, to a gate electrode or sense (neither shown) of semiconductor device 15 . Conductive wire 19b is joined to an electrode (not shown) of semiconductor element 15 through which a current is output. In addition to the conductive wire 19b, for example, a frame may be joined to the electrode from which current is output.

Next, as shown in FIG. 9, the insulating substrate 5 with the semiconductor element 15 mounted thereon is bonded to the base plate 3 . A joining material (not shown) such as solder is placed on the base plate 3 . An insulating substrate 5 is placed on the bonding material using, for example, a jig (not shown). The base plate 3 is put into a high-temperature furnace such as a reflow furnace, and the solder is melted in the high-temperature furnace. The insulating substrate 5 is joined to the base plate 3 by solidifying the melted solder.

At this time, a film may be appropriately formed on the surface of the base plate 3 by plating or the like depending on the bonding material. Note that this step is not necessary when the base plate 3 is bonded to the insulating substrate 5 in advance. This is the case, for example, when the heat radiating material 11 of the insulating substrate 5 and the base plate 3 are directly bonded by metal bonding under high temperature and high pressure conditions.

Next, a step of electrically connecting the conductive circuit patterns 9a, 9b, and 9c to the outside is performed. As a connection mode, a terminal may be used, and direct bonding may be used in which the terminal and the conductive circuit pattern are bonded by a bonding layer. Alternatively, indirect bonding may be used in which the terminal and the conductive circuit pattern are bonded via a wire.

Here, in particular, the process of extracting the output current of the semiconductor element 15 from the terminal to the outside by direct bonding will be described. The terminal 21 includes a joint body 23, a support body 25 and an external connection body 27 (see FIG. 10).

As shown in FIG. 10, a bonding layer material 16 such as eutectic solder is placed on the conductive circuit pattern 9c. Next, terminals 21 are arranged on the conductive circuit pattern 9c. At this time, the terminal 21 is arranged so that the bonding layer material 16 is sandwiched between the terminal bonded body 23 and the conductive circuit pattern 9c.

The thickness of the bonding layer material 16, that is, the distance L between the bonded body 23 and the conductive circuit pattern 9c is preferably constant over the entire bonding surface 23a. Therefore, the terminal 21 is provided with a support 25 that defines the distance L between the joined body 23 and the conductive circuit pattern 9c. When joining the joined body 23 to the conductive circuit pattern 9c, it is preferable to use a jig (not shown) for holding and fixing the terminal 21 .

In order to make the distance L between the joint 23 and the conductive circuit pattern 9c uniform within the joint surface 23a, it is preferable to use a terminal having a plurality of supports. Variations of terminals will be described later.

Next, with the terminals 21 fixed, the insulating substrate 5 and the like are placed in a high-temperature processing apparatus such as a nitrogen oven for a desired period of time. The eutectic solder is melted in the high temperature processing equipment and re-solidified as the bonding layer 17 . Thereby, as shown in FIG. 11, the joined body 23 of the terminal 21 is joined to the conductive circuit pattern 9c by the joining layer 17. Next, as shown in FIG. When the output current is output from the back side of the semiconductor element 15, the joined body 23 of the terminal 21 may be joined to the conductive circuit pattern 9b by the same method.

Next, as shown in FIG. 12, the case 31 is adhered to the base plate 3 using an adhesive such as silicone resin. At this time, the entire contact surface (bonding surface) between the case 31 and the base plate 3 is coated with a silicone resin so that the insulating sealing material filled in the case 31 in a later process does not leak out of the case 31. keep it Thereafter, high temperature treatment is performed as appropriate to cure the adhesive such as silicone resin, and the base plate 3 and the case 31 are joined together.

Next, as shown in FIG. 13, the case 31 is filled with an insulating sealing material 33 for insulating sealing. For example, an insulating sealing material 33 such as gel or epoxy resin is filled so that no air bubbles remain. Thereafter, high temperature treatment is performed as appropriate to harden the insulating sealing material 33 . After that, if necessary, a lid (not shown) covering the insulating sealing material 33 may be attached. For example, a lid such as PPS may be adhered to the case 31 using silicone resin. Moreover, if necessary, the shape of the external connection body 27 of the terminal 21 may be changed by, for example, bending the external connection body 27 of the terminal 21 according to the connection specification with the outside. Thus, the semiconductor device 1 shown in FIG. 1 is completed.

In the semiconductor device 1 described above, the reliability of the semiconductor device 1 is improved because the bonding layer 17 that bonds the terminal bonding body 23 to the conductive circuit pattern 9c is formed to have a constant thickness. can be done. This will be explained.

The thinner the bonding layer 17 is, the smaller the electrical resistance of the current path of the current flowing through the terminal 21 is. However, when the bonding layer 17 is, for example, solder, if the bonding layer 17 (solder) becomes too thin, it becomes difficult for the solder to wet and spread in the narrow portion where the bonding layer 17 becomes too thin.

For this reason, it is assumed that the bonding becomes insufficient and cracks develop during operation involving temperature cycles. If the crack progresses in the bonding layer 17, it becomes a factor that lowers the reliability of the semiconductor device. If the thickness of the bonding layer 17 is less than 40 μm, it is assumed that the bonding will be insufficient, so the bonding layer 17 preferably has a thickness of 40 μm or more.

On the other hand, the thicker the bonding layer 17, the less likely cracks will occur. However, the electrical resistance of the current path of the current flowing through the terminal 21 increases. Moreover, it becomes difficult to form a thick bonding layer 17 . When eutectic solder is used as the solder, if the thickness exceeds 2 mm, there is a tendency for insufficient bonding to occur. Therefore, the thickness of the bonding layer 17 is 2 mm or less. is preferred.

The support 25 of the terminal 21 is arranged so as to be in contact with the surface of the conductive circuit pattern 9c, thereby maintaining the distance between the joint 23 and the conductive circuit pattern 9c corresponding to the thickness of the bonding layer 17. have a function. By setting the thickness of the bonding layer 17 to a desired thickness, the reliability of the bonding portion between the terminal 21 (bonding body 23) and the conductive circuit pattern 9c is ensured, contributing to the extension of the life of the semiconductor device. be able to.

Further, in the semiconductor device 1 described above, the support 25 also functions as a heat dissipation path. As shown in FIG. 14, the heat generated in the bonding layer 17 is dissipated through three paths including the first heat dissipation path P1, the second heat dissipation path P2, and the third heat dissipation path P3.

The first heat radiation path P<b>1 is a heat radiation path that flows from the bonding layer 17 to the base plate 3 after passing through the portion of the conductive circuit pattern 9 c located directly below the bonding layer 17 . The second heat radiation path P2 is a heat radiation path that flows from the bonding layer 17 through the bonded body 23 and then to the external connection body 27 side.

The third heat dissipation path P3 flows from the bonding layer 17 through the bonding body 23, flows through the support 25, flows from the support 25 through the portion of the conductive circuit pattern 9c located directly below the support 25, and flows through the base. It is a heat radiation path that flows to the plate 3 . The support 25 can contribute to the heat dissipation of the bonding layer 17 as a part of the third heat dissipation path P3.

By adding the third heat dissipation path P3 as a heat dissipation path, the temperature of the bonding layer 17 can be effectively lowered. By lowering the temperature of the bonding layer 17, the thermal stress generated in the bonding layer 17 and the like is relaxed, and deformation of the peripheral portion of the bonding layer 17 can be suppressed. As a result, it is possible to contribute to the extension of the life of the semiconductor device 1 .

(Terminal variations)
Variations of the terminals 21 applied to the semiconductor device 1 will be described. In the semiconductor device 1 described above, the terminals 21 shown in FIGS. 2 to 5 have been described as an example, but the present invention is not limited to this. As shown in FIGS. 15, 16 and 17, for example, terminals 21 are attached to joints 23 as shown in FIGS. A terminal 21 having a support 25 attached at a position different from that of the support 25 of the terminal 21 shown in FIG. 5 may be applied.

Moreover, the number of supports 25 is not limited to one, and a terminal 21 having a plurality of supports 25 may be applied. As shown in FIGS. 18, 19 and 20, a terminal comprising three supports 25, for example supports 25a, 25b as a first part of the support and a support 25c as a second part of the support. 21 may be applied.

In this case, when the terminal 21 is joined to the conductive circuit pattern 9c, the distance between the joined body 23 and the conductive circuit pattern 9c (see FIG. 10) is made more uniform over the entire joining surface of the joined body 23. can be made As a result, the terminal 21 (bonded body 23) can be bonded to the conductive circuit pattern 9c by the bonding layer 17 having a more uniform thickness within the bonding surface 23a. As a result, the reliability of the joint portion is further improved, which can contribute to the extension of the life of the semiconductor device 1 . Moreover, when joining the terminal 21 to the conductive circuit pattern 9c, there is no need for a jig for holding the terminal 21, which can contribute to an improvement in productivity.

Embodiment 2.
A semiconductor device according to the second embodiment will be described. As shown in FIG. 21, in the semiconductor device 1, the bonding layer 17 is formed in a manner surrounding the support 25, extending from the region bonding the bond 23 to the conductive circuit pattern 9c to the region where the support 25 is located. there is Since the configuration other than this is the same as the configuration of the semiconductor device 1 shown in FIG. 1 and the like, the same reference numerals are given to the same members, and the description thereof will not be repeated unless necessary.

The support 25 is arranged at a position separated by a distance D from the part where the bonding body 23 is bonded to the conductive circuit pattern 9c by the bonding layer 17 . When the bonding layer 17 is formed so as to surround the support 25, it is assumed that solder (a part of the bonding layer 17) flows into the gap between the support 25 and the conductive circuit pattern 9c.

The gap between the support 25 and the conductive circuit pattern 9c is much narrower than the distance between the joined body 23 and the conductive circuit pattern 9c. In addition, this distance is sufficiently narrow even when compared to the distance at which a joint layer is formed by general solder.

Solder is less likely to wet and spread in narrow gaps. For this reason, it is assumed that cracks develop from the portion of the solder that has flowed into the gap during operation involving temperature cycles. Therefore, it is necessary to set the distance D in consideration of the length over which the crack propagates.

On the other hand, if the distance D is too long, it becomes difficult to ensure the desired thickness of the bonding layer 17 due to warping of the terminal 21 or dimensional error of the case 31 . Therefore, it is preferable to set the distance D within 10 mm.

In the semiconductor device 1 described above, similarly to the semiconductor device 1 described above, the thickness of the bonding layer 17 becomes a desired thickness, thereby reducing the bonding portion between the terminal 21 (bonding body 23) and the conductive circuit pattern 9c. Reliability is ensured, and it is possible to contribute to prolonging the life of the semiconductor device.

Further, by adding the third heat dissipation path P3 to the first heat dissipation path P1 and the second heat dissipation path P2 as a heat dissipation path for heat generated in the bonding layer 17, the temperature rise of the bonding layer 17 can be reliably suppressed, and the semiconductor It can contribute to the extension of the life of the device 1 .

(Modification)
A semiconductor device according to a modification will be described. As shown in FIG. 22, the support 25 of the terminal 21 is spaced apart from the bonding layer 17 . The support 25 is bonded to the conductive circuit pattern 9c by a bonding layer 18 different from the bonding layer 17. As shown in FIG. Since the configuration other than this is the same as the configuration of the semiconductor device 1 shown in FIG. 1 and the like, the same reference numerals are given to the same members, and the description thereof will not be repeated unless necessary.

The bonding material of the bonding layer 18 may be the same bonding material as the bonding material of the bonding layer 17, or may be a different bonding material. For simplification of the manufacturing process, the bonding material of the bonding layer 18 is preferably the same bonding material as the bonding material of the bonding layer 17 .

Since the bonding layer 18 is formed on the support 25, the bonding area between the support and the conductive circuit pattern 9c is increased. As a result, more heat can flow to the base plate 3 via the support 25, and the heat dissipation of the bonding layer 17 can be performed more effectively. That is, heat dissipation through the third heat dissipation path P3 (see FIG. 14) can be promoted. resulting in. A rise in the temperature of the bonding layer 17 can be reliably suppressed, which can contribute to the extension of the life of the semiconductor device 1 .

Embodiment 3.
A semiconductor device according to the third embodiment will be described. As shown in FIG. 23, in semiconductor device 1, terminal 21 is fixed to case 31 in advance. Terminal 21 is attached to case 31 so as to include a portion embedded in case 31 . Terminal 21 includes junction 23 , support 25 and extension 29 . The extending portion 29 extends from the case 31 toward the joined body 23 (extending direction Y2). At least one support 25 is arranged on the extension 29 . Since the configuration other than this is the same as the configuration of the semiconductor device 1 shown in FIG. 1 and the like, the same reference numerals are given to the same members, and the description thereof will not be repeated unless necessary.

In the semiconductor device 1 described above, the terminals 21 are fixed to the case 31 in advance. Therefore, the heat treatment for joining the joined body 23 of the terminal 21 to the conductive circuit pattern 9c must be performed at a temperature lower than the heat-resistant temperature of the case 31 . As shown in FIG. 24, when the bonding layer material 16 that becomes the bonding layer 17 is dissolved, the bonding layer material 16 is paste solder, for example. When the bonding layer material 16 is sintered, the bonding layer material 16 is, for example, a conductive paste material.

In the semiconductor device 1 described above, similarly to the semiconductor device 1 described above, the thickness of the bonding layer 17 is set to a desired thickness by the supporting body 25, so that the terminal 21 (bonding body 23) and the conductive circuit pattern 9c are connected. This can ensure the reliability of the bonding portion of the semiconductor device, thereby contributing to the extension of the life of the semiconductor device.

Further, by adding the third heat dissipation path P3 to the first heat dissipation path P1 and the second heat dissipation path P2 as a heat dissipation path for heat generated in the bonding layer 17, the temperature rise of the bonding layer 17 can be reliably suppressed, and the semiconductor It can contribute to the extension of the life of the device 1 .

Furthermore, since the terminal 21 is fixed to the case 31 in advance, the inclination of the terminal 21 in the direction intersecting with the extending direction Y2 is suppressed. Therefore, a jig for fixing the terminal 21 becomes unnecessary when joining the terminal 21 to the conductive circuit pattern 9c.

Further, in the step of fixing the case 31 to the base plate 3, the adhesive is cured by heat treatment, so this step can be performed simultaneously with the heat treatment performed in the step of bonding the terminal 21 to the conductive circuit pattern 9c. .

In addition, in the semiconductor device 1 described above, the case where one supporting member 25 is arranged on the terminal 21 has been described. The number of supports 25 is not limited to one, and a terminal 21 having a plurality of supports 25 may be applied. As shown in FIGS. 25, 26 and 27, for example, along the extending direction Y2, two supports, a support 25a as a first support part and a support 25b as a second support part, are provided. A terminal 21 with a body 25 may also be applied.

By suppressing the inclination of the joined body 23 in the direction intersecting with the extending direction Y2, the inclination of the joined body 23 in the extending direction Y2 is suppressed. The distance between 23 and the conductive circuit pattern 9c can be made constant. As a result, the terminal 21 (bonded body 23) can be bonded to the conductive circuit pattern 9c by the bonding layer 17 having a desired thickness. As a result, the reliability of the joint portion is further improved, which can contribute to the extension of the life of the semiconductor device 1 .

Moreover, in the semiconductor device 1 according to each of the above-described embodiments, a mode in which the heat dissipation material 11 is bonded to the base plate 3 has been described. The semiconductor device 1 may be a semiconductor device in which the base plate 3 is not provided and the heat dissipation material 11 functions as a base plate.

Embodiment 4.
Here, a power conversion device to which the semiconductor devices described in the first to third embodiments are applied will be described. Although the present disclosure is not limited to a specific power converter, a case where the present disclosure is applied to a three-phase inverter will be described below as a fourth embodiment.

FIG. 28 is a block diagram showing the configuration of a power conversion system to which the power converter according to this embodiment is applied. The power conversion system shown in FIG. 28 includes a power supply 100, a power conversion device 200, and a load 300. FIG. The power supply 100 is a DC power supply and supplies DC power to the power converter 200 . The power supply 100 can be composed of various things, for example, it can be composed of a DC system, a solar battery, and a storage battery. Alternatively, it may be composed of a rectifier circuit or an AC/DC converter connected to an AC system. Also, power supply 100 may be configured by a DC/DC converter that converts DC power output from a DC system into predetermined power.

Power conversion device 200 is a three-phase inverter connected between power supply 100 and load 300 , converts DC power supplied from power supply 100 into AC power, and supplies AC power to load 300 . As shown in FIG. 28, the power conversion device 200 includes a main conversion circuit 201 that converts DC power into AC power and outputs it, and a control circuit 203 that outputs a control signal for controlling the main conversion circuit 201 to the main conversion circuit 201. and

The load 300 is a three-phase electric motor driven by AC power supplied from the power converter 200 . Note that the load 300 is not limited to a specific application, but is an electric motor mounted on various electrical equipment, such as a hybrid vehicle, an electric vehicle, a railroad vehicle, an elevator, or an electric motor for an air conditioner.

Details of the power converter 200 will be described below. The main conversion circuit 201 includes a switching element and a freewheeling diode (not shown). By switching the switching element, the DC power supplied from the power supply 100 is converted into AC power and supplied to the load 300 . Although there are various specific circuit configurations of the main conversion circuit 201, the main conversion circuit 201 according to the present embodiment is a two-level three-phase full bridge circuit, with six switching elements and It can consist of six freewheeling diodes in anti-parallel.

At least one of the switching elements and the freewheeling diodes of the main conversion circuit 201 is a switching element or a freewheeling diode included in the semiconductor device 202 corresponding to the semiconductor device 1 according to at least one of the first to third embodiments described above. . The six switching elements constitute upper and lower arms connected in series for every two switching elements, and each upper and lower arm constitutes each phase (U phase, V phase, W phase) of the full bridge circuit. Output terminals of the upper and lower arms, that is, three output terminals of the main conversion circuit 201 are connected to the load 300 .

Further, the main conversion circuit 201 includes a drive circuit (not shown) for driving each switching element. may be provided. The drive circuit generates a drive signal for driving the switching element of the main conversion circuit 201 and supplies it to the control electrode of the switching element of the main conversion circuit 201 . Specifically, in accordance with a control signal from the control circuit 203, which will be described later, a drive signal for turning on the switching element and a drive signal for turning off the switching element are output to the control electrode of each switching element. When maintaining the switching element in the ON state, the driving signal is a voltage signal (ON signal) equal to or higher than the threshold voltage of the switching element, and when maintaining the switching element in the OFF state, the driving signal is a voltage equal to or less than the threshold voltage of the switching element. signal (off signal).

Control circuit 203 controls the switching elements of main conversion circuit 201 so that desired power is supplied to load 300 . Specifically, based on the power to be supplied to the load 300, the time (on time) during which each switching element of the main conversion circuit 201 should be in the ON state is calculated. For example, the main conversion circuit 201 can be controlled by PWM control that modulates the ON time of the switching element according to the voltage to be output. Then, a control command (control signal) to the drive circuit provided in the main conversion circuit 201 so that an ON signal is output to the switching element that should be in the ON state at each time point, and an OFF signal is output to the switching element that should be in the OFF state. to output The drive circuit outputs an ON signal or an OFF signal as a drive signal to the control electrode of each switching element according to this control signal.

In the power conversion device according to the present embodiment, since the semiconductor device according to the first to third embodiments is applied as the semiconductor device 202 constituting the main conversion circuit 201, the reliability of the junction is improved and the life is extended. can do.

In the present embodiment, an example in which the present disclosure is applied to a two-level three-phase inverter has been described, but the present disclosure is not limited to this, and can be applied to various power converters. In this embodiment, a two-level power conversion device is used, but a three-level or multi-level power conversion device may be used. Disclosure may apply. In addition, the present disclosure can be applied to a DC/DC converter or an AC/DC converter when power is supplied to a DC load or the like.

In addition, the power conversion device to which the present disclosure is applied is not limited to the case where the above-described load is an electric motor. It can also be used, and furthermore, it can be used as a power conditioner for a photovoltaic power generation system, an electric storage system, or the like.

Note that the semiconductor devices and the like described in each embodiment can be combined in various ways as necessary.

The embodiment disclosed this time is an example and is not limited to this. The present invention is defined by the scope of the claims rather than the scope described above, and is intended to include all changes within the meaning and scope equivalent to the scope of the claims.

INDUSTRIAL APPLICABILITY The present invention is effectively used for a semiconductor device equipped with a power semiconductor element and a power conversion device to which the semiconductor device is applied.

Reference Signs List 1 semiconductor device 3 base plate 5 insulating substrate 7 substrate body 9a, 9b, 9c conductive circuit pattern 11 heat dissipation material 13 bonding material 15 semiconductor element 16 bonding layer material 17, 18 bonding layer 19a , 19b conductive wire, 21 terminal, 23 junction, 23a junction surface, 25, 25a, 25b, 25c support, 27 external connector, 29 extension, 31 case, 33 insulating sealing material, P1, P2, P3 Path, 100 power source, 200 power conversion device, 201 main conversion circuit, 202 semiconductor device, 203 control circuit, 300 load.

Claims (14)

an insulating substrate having a first main surface and a second main surface facing each other, a conductive circuit pattern formed on the first main surface side, and a heat dissipation material disposed on the second main surface side;
a terminal electrically connected to the conductive circuit pattern;
a bonding layer for bonding the terminal and the conductive circuit pattern;
The terminal is
a bonded body including a bonding surface bonded to the conductive circuit pattern by the bonding layer;
The joined body connected to the joined body and positioned in a manner in contact with the conductive circuit pattern in a region other than the region where the joined body is joined in the conductive circuit pattern, and the joining layer intervening. one or more supports that maintain a distance between the joint surface and the conductive circuit pattern;
Having a case in which the insulating substrate is accommodated,
A semiconductor device according to claim 1, wherein a side of the terminal opposite to a side joined to the conductive circuit pattern is held by the case . 2. The semiconductor device according to claim 1 , wherein said support includes a support first portion arranged on a side closer to said case with respect to said joined body. 3. The semiconductor device according to claim 1 , wherein said support includes a support second portion arranged on a side away from said case with respect to said joined body. the terminal includes an extending portion extending from the side on which the case is located toward the joined body and connected to the joined body;
4. The semiconductor device according to claim 1 , wherein two or more of said supports are arranged along said extension. 5. The semiconductor device according to claim 1 , wherein said terminal is fixed to said case. an insulating substrate having a first main surface and a second main surface facing each other, a conductive circuit pattern formed on the first main surface side, and a heat dissipation material disposed on the second main surface side;
a terminal electrically connected to the conductive circuit pattern;
a bonding layer that bonds the terminal and the conductive circuit pattern;
has
The terminal is
a bonded body including a bonding surface bonded to the conductive circuit pattern by the bonding layer;
The joined body connected to the joined body and positioned in a manner in contact with the conductive circuit pattern in a region other than the region where the joined body is joined in the conductive circuit pattern, and the joining layer intervening. one or more supports that maintain a distance between the bonding surface and the conductive circuit pattern;
with
The semiconductor device according to claim 1, wherein the bonding layer surrounds the support and is formed from a region where the bonding and the conductive circuit pattern are bonded to a region where the support is located. an insulating substrate having a first main surface and a second main surface facing each other, a conductive circuit pattern formed on the first main surface side, and a heat dissipation material disposed on the second main surface side;
a terminal electrically connected to the conductive circuit pattern;
a bonding layer that bonds the terminal and the conductive circuit pattern;
has
The terminal is
a bonded body including a bonding surface bonded to the conductive circuit pattern by the bonding layer;
The joined body connected to the joined body and positioned in a manner in contact with the conductive circuit pattern in a region other than the region where the joined body is joined in the conductive circuit pattern, and the joining layer intervening. one or more supports that maintain a distance between the bonding surface and the conductive circuit pattern;
with
A semiconductor device comprising another bonding layer spaced apart from the bonding layer and bonding the support to the conductive circuit pattern in a manner surrounding the support. 8. The semiconductor device according to claim 1, wherein said distance between said bonding surface and said conductive circuit pattern is 40 μm or more and 2 mm or less. 9. The semiconductor device according to claim 8 , wherein said distance between said bonding surface and said conductive circuit pattern is kept constant within said bonding surface. Having a base plate on which the insulating substrate is mounted,
10. The semiconductor device according to claim 1, wherein said heat radiating material and said base plate in said insulating substrate are directly bonded. An insulating substrate is prepared which has a first main surface and a second main surface facing each other, a conductive circuit pattern is formed on the side of the first main surface, and a heat dissipating material is arranged on the side of the second main surface. process and
preparing a terminal having one end side and the other end side and electrically connected to the conductive circuit pattern;
bonding the one end side of the terminal to the conductive circuit pattern with a bonding layer;
The step of preparing the terminal includes:
a bonded body including a bonding surface bonded to the conductive circuit pattern by the bonding layer;
In addition to being connected to the bonded body, in the conductive circuit pattern, it is positioned in a manner in contact with the conductive circuit pattern in a region other than the region where the bonded body is bonded, and the bonding layer intervenes. A step of preparing the terminal including one or more supports that maintain a distance between the joint surface of the joint and the conductive circuit pattern;
The step of joining the one end side of the terminal to the conductive circuit pattern includes:
between the joint surface and the conductive circuit pattern in a state in which the support is brought into contact with the conductive circuit pattern and the distance between the joint surface and the conductive circuit pattern of the joint body is maintained; a step of arranging a bonding material that will be the bonding layer;
and bonding the bonded body to the conductive circuit pattern through the bonding layer by treating the bonding material. placing the insulating substrate on a base plate;
placing a case on the base plate;
12. The method of manufacturing a semiconductor device according to claim 11 , further comprising the step of filling said case with a sealing material for sealing said insulating substrate to which said terminals are joined. In the step of joining the one end side of the terminal to the conductive circuit pattern,
solder is used as the bonding material,
13. The method of manufacturing a semiconductor device according to claim 11 , wherein heat treatment is performed as said treatment. A main conversion circuit that has the semiconductor device according to any one of claims 1 to 10 and converts input power and outputs it;
and a control circuit that outputs a control signal for controlling the main conversion circuit to the main conversion circuit.

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