JP6567957B2 - Power semiconductor module manufacturing method - Google Patents

Description

  The present invention relates to a power semiconductor module and a manufacturing method thereof.

  Conventionally, a power semiconductor module in which a plurality of power semiconductor elements are combined into one package is known. Due to the recent demand for miniaturization of power semiconductor modules, the connection between the external lead-out terminal and the wiring pattern on the substrate has been performed by ultrasonic welding instead of wire bonding.

  Ultrasonic welding is required to have the same electrical conductivity and heat dissipation as long as wire bonding, long-term connection reliability, and cost reduction. However, the following two points that cause a decrease in connection reliability are particularly problematic. Is being viewed. That is, the causes of the decrease in connection reliability include (1) a decrease in bonding strength due to the generation of voids that are unbonded portions, and (2) breakage or chipping at the ends of the bonding surface of the wiring pattern due to ultrasonic vibration. Is mentioned. And the proposal which tries to solve the subject of these (1) and (2) is known (refer the following patent document 1).

JP 2012-39018 A

  However, in the conventional ultrasonic welding disclosed in Patent Document 1, the terminal joined to the wiring pattern is formed in a convex shape toward the wiring pattern. For this reason, joining is gradually started from the center of the terminal during joining by ultrasonic welding. When the horn of the ultrasonic welder presses the entire terminal, a concentrated load is applied to the outer peripheral part outside the center part of the terminal. A load will be applied. In this case, there is a problem that the wiring pattern and the substrate are easily cracked due to the influence of the concentrated load, and the connection reliability is inferior by inducing a crack, breakage, chipping or the like.

  This invention is made | formed in view of the said situation, and it aims at providing the power semiconductor module which can improve connection reliability, and its manufacturing method.

  A power semiconductor module according to the present invention includes a substrate having a wiring pattern formed on a surface thereof, a power semiconductor element mounted on the substrate and connected to the wiring pattern, and an external connected to the wiring pattern by ultrasonic welding. A power semiconductor module comprising a lead-out terminal, wherein the external lead-out terminal has a board-side connection part connected to the wiring pattern and an external connection part connected to an external device, and the board-side connection The part is made of a plate-like member, and one of the first contact surface with the wiring pattern and the second contact surface with the horn of the ultrasonic welder is formed in a concave shape or a convex shape. It is characterized by that.

  In one Embodiment of this invention, the said board | substrate side connection part consists of rectangular concave shape or rectangular convex shape in the vertical cross-sectional shape.

  In another embodiment of the present invention, the substrate-side connecting portion has a central region thinner than its outer peripheral frame-shaped region when either one of the first and second contact surfaces is concave. It is formed as follows.

  In still another embodiment of the present invention, the substrate-side connecting portion has a central region that is more than the outer peripheral frame-shaped region when either one of the first and second contact surfaces has a rectangular convex shape. Is also formed to be thicker.

  In still another embodiment of the present invention, the substrate-side connecting portion has a plating layer provided on at least the first contact surface side.

  The method for manufacturing a power semiconductor module according to the present invention includes a substrate having a wiring pattern formed on a surface thereof, a power semiconductor element mounted on the substrate and connected to the wiring pattern, and the wiring pattern connected to the wiring pattern by ultrasonic welding. A method of manufacturing a power semiconductor module comprising an external lead-out terminal, comprising: a board-side connection portion made of a plate-like member and connected to the wiring pattern; and an external connection portion connected to an external device. Any one of the first contact surface with the wiring pattern of the board-side connecting portion and the second contact surface with the horn of the ultrasonic welder has a central region thinner than the outer peripheral frame-shaped region. A step of forming the external lead-out terminal formed in a convex shape in which the concave shape or the central region becomes thicker than the outer peripheral frame-shaped region, and the first contact surface is disposed opposite to the wiring pattern. The serial board-side connecting portion, characterized in that a step of connecting to the wiring pattern by ultrasonic welding.

  In one embodiment of the present invention, in the step of forming the external lead-out terminal, a plating layer is formed at least on the first contact surface side of the substrate side connection portion.

  In another embodiment of the present invention, in the step of connecting to the wiring pattern, a tip end surface of the horn formed in a convex shape is brought into contact with a central region of the second contact surface of the board-side connection portion. Then, ultrasonic welding is performed in a state where a load is applied to the central region.

  According to the present invention, the first contact surface with the wiring pattern of the board-side connecting portion of the external lead-out terminal connected to the wiring pattern of the board by ultrasonic welding and the second contact with the horn of the ultrasonic welding machine. Since either one of the contact surfaces is formed in a concave shape or a convex shape, the load during welding and the energy of ultrasonic vibration can be concentrated in the central region of the substrate side connection portion. Since concentrated load on the end portion is prevented, it is possible to prevent cracks, breakage, chipping, etc. of the wiring pattern and the substrate. Thereby, connection reliability can be improved.

1 is an external perspective view showing a power semiconductor module according to a first embodiment of the present invention. It is an equivalent circuit diagram of the same power semiconductor module. It is an external appearance perspective view which shows the external derivation | leading-out terminal part of the power semiconductor module. It is an external appearance perspective view which shows the negative electrode terminal of the external lead-out terminal part. It is R arrow line view of FIG. FIG. 5 is a cross-sectional view taken along line A-A ′ of FIG. 4. It is a flowchart which shows a part of manufacturing process of the power semiconductor module. It is sectional drawing which shows the ultrasonic welding process in the manufacturing process. It is a figure which shows the modification of the contact surface of the board | substrate side connection part in the external lead-out terminal part. It is a figure which shows the other modification of the contact surface of the board | substrate side connection part in the external lead-out terminal part. It is an external appearance perspective view which shows the negative electrode terminal of the external derivation | leading-out terminal part of the power semiconductor module which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the ultrasonic welding process in the manufacturing process of the same power semiconductor module. It is sectional drawing which shows the ultrasonic welding process in the manufacturing process of the power semiconductor module which concerns on the 3rd Embodiment of this invention. It is an external appearance perspective view which shows the negative electrode terminal of the external derivation | leading-out terminal part of the power semiconductor module which concerns on the 4th Embodiment of this invention. It is sectional drawing which shows the ultrasonic welding process in the manufacturing process of the same power semiconductor module.

  Hereinafter, a power semiconductor module and a manufacturing method thereof according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is an external perspective view showing a power semiconductor module 1 according to the first embodiment of the present invention. FIG. 2 is an equivalent circuit diagram of the power semiconductor module 1. 3 is an external perspective view showing the external lead-out terminal portion 10 of the power semiconductor module 1, and FIG. 4 is an external perspective view showing the negative electrode terminal 12 of the external lead-out terminal portion 10. 5 is a view taken along the arrow R in FIG. 4, and FIG. 6 is a cross-sectional view taken along the line AA ′ in FIG.

  As shown in FIG. 1, a power semiconductor module 1 according to a first embodiment of the present invention includes a three-phase inverter circuit that is a U-phase, V-phase, and W-phase power semiconductor element mounted on a base substrate 3, for example. (Not shown) is mounted. The three-phase inverter circuit is connected to a wiring pattern (not shown) formed on the base substrate 3.

  The three-phase inverter circuit and the wiring pattern on the base substrate 3 are not shown in the figure, but a control signal system terminal unit including various terminals such as a gate electrode terminal, a collector potential signal terminal, and an emitter potential signal terminal, which will be described later, And the external lead-out terminal part 10 which consists of the positive electrode terminal 11, the negative electrode terminal 12, and the alternating current terminal 13 as shown in FIG. 1 is connected, respectively.

  The power semiconductor module 1 configured in this manner covers the periphery of the three-phase inverter circuit, the control signal system terminal portion, and the external lead-out terminal portion 10 on the base substrate 3 with the surrounding resin case 2 by, for example, insert molding. Has a structure. In addition, although illustration is abbreviate | omitted, in the power semiconductor module 1 of a completion form (finished product), the heat radiating member is arrange | positioned, for example in the back surface side of the base substrate 3, and the internal area | region of the surrounding resin case 2 is a gel-like. Sealed with resin.

  The surrounding resin case 2 of the power semiconductor module 1 is covered with a cover (not shown). An IGBT chip, a diode chip, etc., which will be described later, constituting the three-phase inverter circuit, and the control signal system terminal unit and the external lead-out terminal unit 10 are connected to the inside of the module by bonding wires (not shown) such as a ribbon wire or a thick wire. It is connected.

  A base substrate 3 of the power semiconductor module 1 shown in FIG. 1 is formed in, for example, a rectangular plate shape, and U-phase elements, V-phase elements, and W-phase elements of a three-phase inverter circuit are arranged along the longitudinal direction of the base substrate 3. Has been. A control signal system terminal portion and an external lead-out terminal portion 10 are provided for each of the U-phase, V-phase, and W-phase elements.

  The three-phase inverter circuit on the base substrate 3 is not shown in FIG. 1, but may be constituted by a chip represented by an equivalent circuit as shown in FIG. This three-phase inverter circuit includes an IGBT series circuit and a parallel freewheel diode, and is composed of elements of each phase of U-phase PU, V-phase PV, and W-phase PW.

  As shown in FIG. 2, the power semiconductor module 1 includes, for example, a positive terminal P1 (11) constituting a part of the upper arm PUU of the U-phase PU of the three-phase inverter circuit and a part of the lower arm PUL. A negative terminal N1 (12) is provided. Further, an AC terminal U (13) constituting a part of the U-phase PU, a gate electrode terminal GUU constituting a part of the upper arm PUU, and a gate electrode terminal GUL constituting a part of the lower arm PUL are provided. It has been. In the U-phase PU, the positive terminal P1 (11), the negative terminal N1 (12), and the AC terminal U (13) constitute the external lead-out terminal portion 10.

  The IGBT chip QUU of the upper arm PUU and the IGBT chip QUL of the lower arm PUL are connected in series. The free wheel diode FWDUU of the upper arm PUU is connected in parallel to the IGBT chip QUAU. Furthermore, the free wheel diode FWDUL of the lower arm PUL is connected in parallel to the IGBT chip QUL.

  Although not shown, the power semiconductor module 1 includes a collector potential signal terminal for extracting the collector potential of the IGBT chips QUAU and QUIL, an emitter potential signal terminal for extracting the emitter potential, and a temperature detection for the IGBT chip. A power supply terminal for supplying current to the thermistor is also provided. The collector potential signal terminal, the emitter potential signal terminal, and the gate electrode terminals GUU and GUL constitute a control signal system terminal portion.

  Similarly, the power semiconductor module 1 includes a positive terminal P2 (11) constituting a part of the upper arm PVU of the V-phase PV of the three-phase inverter circuit and a negative terminal N2 (12 constituting a part of the lower arm PVL). ) And are provided. Further, an AC terminal V (13) that constitutes a part of the V-phase PV, a gate electrode terminal GVU that constitutes a part of the upper arm PVU, and a gate electrode terminal GVL that constitutes a part of the lower arm PVL are provided. It has been. In the V phase PV, the positive terminal P2 (11), the negative terminal N2 (12), and the AC terminal V (13) constitute the external lead-out terminal portion 10.

  The IGBT chip QVU of the upper arm PVU and the IGBT chip QVL of the lower arm PVL are connected in series. The free wheel diode FWDVU of the upper arm PVU and the free wheel diode FWDVL of the lower arm PVL are connected in parallel to the IGBT chips QVU and QVL, respectively.

  Further, the power semiconductor module 1 includes a positive terminal P3 (11) constituting a part of the upper arm PWU of the W-phase PW of the three-phase inverter circuit and a negative terminal N3 (12) constituting a part of the lower arm PWL. And are provided. Furthermore, an AC terminal W (13) constituting a part of the W-phase PW, a gate electrode terminal GWU constituting a part of the upper arm PWU, and a gate electrode terminal GWL constituting a part of the lower arm PWL are provided. It has been. In the W phase PW, the positive terminal P3 (11), the negative terminal N3 (12), and the AC terminal W (13) constitute the external lead-out terminal portion 10.

  The IGBT chip QWU of the upper arm PWU and the IGBT chip QWL of the lower arm PWL are connected in series. The freewheel diode FWDWU of the upper arm PWU and the freewheel diode FWDWL of the lower arm PWL are connected in parallel to the IGBT chips QWU and QWL, respectively.

  Also in the V-phase PV and W-phase PW, the collector potential signal terminal for extracting the collector potential of the IGBT chips QVU, QVL, QWU, and QWL, the emitter potential signal terminal for extracting the emitter potential, and the temperature detection of the IGBT chip Power supply terminals for supplying current to the thermistor are also provided. The collector potential signal terminal, the emitter potential signal terminal, and the gate electrode terminals GVU, GVL, GWU, and GWL constitute V-phase PV and W-phase PW control signal system terminal sections, respectively.

  As shown in FIG. 3, the external lead-out terminal portion 10 includes a positive electrode terminal 11, a negative electrode terminal 12, and an AC terminal 13 that are combined and arranged in an insulated state. Since the positive electrode terminal 11, the negative electrode terminal 12, and the AC terminal 13 have substantially the same structure and configuration except for the shape, the negative electrode terminal 12 will be described below as an example.

  As shown in FIG. 4, the negative electrode terminal 12 is formed by punching / bending a metal base material 21 (see FIG. 6) such as copper or aluminum. The negative electrode terminal 12 has a crank shape when viewed from above, and an external connection portion 14 connected to an external device such as a cable is formed on one end side. Further, the negative electrode terminal 12 has a substrate side connection portion 15 connected to the wiring pattern of the base substrate 3 by ultrasonic welding on the other end side, and connects the external connection portion 14 and the substrate side connection portion 15. It has the terminal main-body part 16 to connect.

  The external connection portion 14 is formed in a plate shape and includes a screw insertion hole 14a provided at the center thereof. The terminal main body 16 is formed so as to have a main surface 16 a at a position lower than the main surface 14 b of the external connection portion 14. The thickness t1 of the external connection portion 14 and the terminal main body portion 16 is set to 1.5 mm, for example. The board-side connection portion 15 is also formed in a plate shape, and is formed such that its main surface 15b is positioned lower than the main surface 16a of the terminal body portion 16. The main surface 15b is a flat surface having no irregularities and constitutes a second contact surface with a horn 80 of an ultrasonic welding machine to be described later.

  The board-side connecting portion 15 is formed in a rectangular shape having, for example, a width of about 9 mm, a length of about 6 mm, and a thickness t2 of, for example, 0.8 mm, and as shown in FIG. 5, the back surface opposite to the main surface 15b. Constitutes the first contact surface 15a with the wiring pattern. The contact surface 15a is formed in a concave shape, for example. The first contact surface 15a is configured to include, for example, a rectangular central region 17 and an outer peripheral frame-shaped region 18 on the outer side when viewed in the direction of arrow R (plan view), and the central region 17 is an outer peripheral frame-shaped region. By being formed so as to be thinner than 18, the vertical cross-sectional shape is formed into a U-shaped rectangular concave shape.

  As shown in FIG. 6, the substrate-side connecting portion 15 can include, for example, a plating layer 22 provided on at least the first contact surface 15 a side. The plating layer 22 is made of nickel or the like having a thickness of about 2 to 6 μm. And the plating layer 22 comprises the 1st contact surface 15a provided with the thin center area | region 17 and the outer periphery frame-shaped area | region 18 with the metal base material 21 of the negative electrode terminal 12. FIG.

  The positive electrode terminal 11, the negative electrode terminal 12, and the AC terminal 13 of the external lead-out terminal portion 10 each include a substrate-side connection portion 15 having the first contact surface 15a configured as described above. For this reason, during ultrasonic welding with the wiring pattern of the base substrate 3, it is possible to concentrate the energy of the ultrasonic vibration by applying a load to the central region 17 while starting the joining from the outer peripheral frame region 18. it can. This prevents a concentrated load from being applied to the end portion of the board-side connecting portion 15 on the first contact surface 15a side, and the substrate pattern cracks or breaks due to the concentrated load on the wiring pattern or the base substrate 3 below the end portion. , Chipping and the like can be prevented.

  Next, a part of manufacturing process of the power semiconductor module 1 configured as described above will be described with reference to a flowchart of FIG. FIG. 7 is a flowchart showing a part of the manufacturing process of the power semiconductor module 1. FIG. 8 is a cross-sectional view showing an ultrasonic welding process in this manufacturing process.

  As shown in FIG. 7, the power semiconductor module 1 includes a terminal forming process (step S100), an ultrasonic welding process (step S102), and an enclosing resin case forming process (step S104) in the entire manufacturing process. After going through the process, it is finally manufactured as a finished product. Below, each said process is demonstrated. Note that the base substrate 3, the three-phase inverter circuit, various terminals constituting the control signal system terminal portion, and the like are separately prepared and prepared.

  First, each terminal 11-13 which comprises the external derivation | leading-out terminal part 10 is formed (step S100). Each terminal 11-13 forms the plating layer 22 in the single side | surface side of the metal base material 21, for example, and forms the external connection part 14, the board | substrate side connection part 15, and the terminal main-body part 16 by stamping / bending. Then, by pressing the board-side connecting portion 15, it is thinner than the external connecting portion 14 and the terminal main body portion 16 as a whole, and the central region 17 on the first contact surface 15 a side is an outer peripheral frame-like region. The board-side connecting portion 15 is formed to be thinner than 18 and the main surface 15b is flat.

  Next, after mounting a three-phase inverter circuit on the base substrate 3 and performing wire bonding or the like, the wiring pattern of the base substrate 3 placed on the anvil 81 as shown in FIG. 4, the board-side connecting portion 15 is arranged so that the first contact surface 15 a faces the wiring pattern 4. Then, the planar tip surface 82 of the horn 80 of the ultrasonic welding machine (not shown) is brought into contact with the main surface 15 b of the board-side connecting portion 15. In the first embodiment, the tip surface 82 of the horn 80 is configured to have a larger area than the first contact surface 15 a including the central region 17 and the outer peripheral frame region 18.

  Thereafter, pressure is applied while pressing the horn 80 in the direction indicated by arrow B in the figure, and ultrasonic welding is performed by vibrating in the direction indicated by arrow C in the figure (step S102). At this time, metal atoms are bonded to each other at the interface between the plating layer 22 and the metal base material 21 and the wiring pattern 4 in the outer peripheral frame region 18 of the first contact surface 15a. At the same time, the load of the horn 80 and the energy of ultrasonic vibration are concentrated in the central region 17 so that the plated layer 22 and the metal base material 21 in the central region 17 and the wiring pattern 4 come into contact with each other, and atomic bonds between the metals at the interface occur. Made.

  As a result, as shown in FIG. 8B, the first contact surface 15a of the board-side connecting portion 15 is not subjected to a concentrated load on the end portion of the substrate-side connecting portion 15 on the first contact surface 15a side. A strong bonding layer 23 is formed over the entire interface between the wiring pattern 4 and the wiring pattern 4. Accordingly, it is possible to prevent the crack, breakage, chipping, or the like below the end portion on the contact surface 15a side of the board side connection portion 15 connected to the wiring pattern 4 and to improve the connection reliability.

  When the terminals 11 to 13 of the external lead-out terminal section 10 are connected to the wiring pattern 4 of the base board 3 in this way, the base board 3 to which the three-phase inverter circuit, the control signal system terminal section, and the external lead-out terminal section 10 are connected and screw insertion. Each component such as a bolt for screwing inserted through the hole 14a is set in a cavity of a predetermined mold.

  Then, a resin material such as PPS resin or PBT resin is injected into the cavity of the mold, and the surrounding resin case 2 is formed by insert molding (step S104). Thereafter, the molded product is taken out from the cavity of the mold, and the power semiconductor module 1 is manufactured through completion inspection and the like.

  As described above, according to the power semiconductor module 1 of the first embodiment, the central region 17 in which the first contact surface 15a of the substrate-side connecting portion 15 with the wiring pattern 4 of the base substrate 3 is concave. And an outer peripheral frame-shaped region 18. For this reason, during welding, the outer peripheral frame-like region 18 that is the end portion side of the first contact surface 15a is reliably joined to the wiring pattern 4, and a load is applied to the central region 17 in a concentrated manner to generate ultrasonic vibrations. It is possible to perform welding by concentrating the energy. Therefore, it is possible to prevent a load from being applied to the end of the board-side connecting portion 15 on the first contact surface 15a side, and to prevent the base substrate 3 below the end from being cracked, damaged, chipped, etc. Can be increased.

  In the power semiconductor module 1 of the above-described embodiment, a three-phase inverter circuit is employed as the power semiconductor element. However, since this three-phase inverter circuit is merely an example, another circuit may be employed. . Moreover, the board | substrate side connection part 15 of each terminal 11-13 may be provided with the following 1st contact surfaces 15a, for example. FIG. 9 is a view showing a modification of the first contact surface 15 a of the board-side connecting portion 15 in the external lead-out terminal portion 10. FIG. 10 is a view showing another modification of the first contact surface 15 a of the board-side connecting portion 15 in the external lead-out terminal portion 10. 9A and 10A show the front of the first contact surface 15a, and FIGS. 9B and 10B show the cross section of the board-side connecting portion 15. FIG.

  As shown in FIGS. 9A and 9B, the first contact surface 15a of the modified example may have a concave central region 17 having a circular and curved cross-sectional shape and an outer peripheral frame region 18 thereof. Further, as shown in FIGS. 10A and 10B, the first abutting surface 15a of another modified example has a rectangular central region 17 with a deepest cross-sectional shape and a peripheral frame thereof. It may have a shaped region 18. In addition, in each, the main surface 15b is comprised by planar shape. Even if comprised in this way, since the load and the energy of ultrasonic vibration can be concentrated and welded to the center area | region 17 as mentioned above, connection reliability can be improved.

  Further, in the first embodiment, the board-side connecting portion 15 is provided with a central region 17 and an outer peripheral frame-like region 18 on the first contact surface 15a side, and the main surface 15b is a flat rectangular concave shape. Although formed, the central region 17 on the first contact surface 15 a side may be formed in a rectangular convex shape by forming it thicker than the outer peripheral frame region 18. Even in this case, it is possible to achieve the same effects as described above.

[Second Embodiment]
FIG. 11 is an external perspective view showing the negative electrode terminal 12 of the external lead-out terminal portion 10 of the power semiconductor module 1 according to the second embodiment of the present invention. FIG. 12 is a cross-sectional view showing an ultrasonic welding process in the manufacturing process of the power semiconductor module 1. Note that FIG. 12 shows a state before welding including the cross-section portion along the line BB ′ in the board-side connection portion 15A of FIG. 11, and the illustration of the wiring pattern is omitted. In the following description including FIG. 11 and FIG. 12, the same reference numerals are assigned to the same components as those in the first embodiment, and therefore, a duplicate description is omitted below.

  As shown in FIG. 11, in the second embodiment, the substrate-side connection portion 15 </ b> A of the negative electrode terminal 12, which is cited as an example of the terminal of the external lead-out terminal portion 10, has a planar first contact surface 15 a. The main area 15 is formed so that the central area 17 is thinner than the outer peripheral frame-shaped area 18. In this respect, the configuration of the first contact surface 15a and the main surface 15b is different from the substrate-side connection portion 15 of the first embodiment in which the configurations are upside down.

  As shown in FIG. 12, the plated layer 22 is formed on the first contact surface 15 a side, and the central region 17 on the main surface 15 b side is formed with an area larger than the tip surface 82 of the horn 80. Even when the board-side connecting portion 15A configured as described above is used, the center of the main surface 15b is eliminated while eliminating the concentrated load on the end portion on the first contact surface 15a side during ultrasonic welding using the horn 80. The tip surface 82 of the horn 80 can be reliably brought into contact with the region 17, and a load can be concentrated on the central region 17 to concentrate the energy of ultrasonic vibration to perform welding. Thereby, there can exist an effect similar to 1st Embodiment.

[Third Embodiment]
FIG. 13: is sectional drawing which shows the ultrasonic welding process in the manufacturing process of the power semiconductor module 1 which concerns on the 3rd Embodiment of this invention. FIG. 13 shows the state before welding with the wiring pattern omitted, as in FIG. As shown in FIG. 13, in the third embodiment, the tip shape of the horn 80 is formed to have a protruding portion 80a protruding in a convex shape. A tip surface 82 of the horn 80 is provided at the tip of the protruding portion 80a. This is different from the first and second embodiments in which the tip shape of the horn 80 is a flat tip surface 82.

  When the horn 80 configured in this manner is used, the tip surface 82 of the projecting portion 80a abuts around the center in the range of the central region 17 on the main surface 15b side during ultrasonic welding, so that it is more concentrated. It is possible to carry out welding by applying a load and energy of ultrasonic vibration to. Thereby, the concentrated load on the end portion on the first contact surface 15a side can be eliminated, and the substrate can be more effectively prevented from being broken, damaged, chipped, and the connection reliability can be improved.

[Fourth Embodiment]
FIG. 14 is an external perspective view showing the negative electrode terminal 12 of the external lead-out terminal portion 10 of the power semiconductor module 1 according to the fourth embodiment of the present invention. FIG. 15 is a cross-sectional view showing an ultrasonic welding process in the manufacturing process of the power semiconductor module 1. Note that FIG. 15 shows a state before welding including a cross section taken along the line CC ′ in the board-side connection portion 15B of FIG. 14, and illustration of a wiring pattern is omitted. In the following description including FIG. 14 and FIG. 15, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 14, in the fourth embodiment, the substrate-side connection portion 15B of the negative electrode terminal 12 cited as an example of the terminal of the external lead-out terminal portion 10 is formed with the planar first contact surface 15a. The main surface 15 b is formed so that the central region 17 is thicker than the outer peripheral frame region 18. This is different from the substrate-side connecting portion 15A of the second and third embodiments in which the central region 17 is formed so as to be thinner than the outer peripheral frame-shaped region 18. The horn 80 of the ultrasonic welder is the same as that of the third embodiment.

  As shown in FIG. 15, the plating layer 22 is formed on the first contact surface 15 a side, and the central region 17 on the main surface 15 b side is formed with a smaller area than the tip surface 82 of the protrusion 80 a of the horn 80. ing. Even when the board-side connecting portion 15B configured as described above is used, the ultrasonic welding using the horn 80 is performed by applying the load and the energy of ultrasonic vibration to the central region 17 in a concentrated manner, and performing the first welding. Concentrated loads on the end portion on the contact surface 15a side can be prevented. Thereby, there can exist an effect similar to embodiment mentioned above.

  As mentioned above, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Power semiconductor module 2 Surrounding resin case 3 Base board 4 Wiring pattern 10 External lead-out terminal part 11 Positive electrode terminal 12 Negative electrode terminal 13 AC terminal 14 External connection part 14a Screw insertion hole 15 Board | substrate side connection part 15a Contact surface 16 Terminal body part 17 Central region 18 Peripheral frame-shaped region 21 Metal base material 22 Plating layer 23 Bonding layer

Claims (3)

A power semiconductor module comprising: a substrate on which a wiring pattern is formed; a power semiconductor element mounted on the substrate and connected to the wiring pattern; and an external lead terminal connected to the wiring pattern by ultrasonic welding A manufacturing method of
A board-side connection portion made of a plate-like member and connected to the wiring pattern; and an external connection portion connected to an external device; and a first contact surface of the board-side connection portion with the wiring pattern; Either one of the second contact surfaces with the horn of the ultrasonic welder is formed in a concave shape in which the central region is thinner than the outer peripheral frame-shaped region or a convex shape in which the central region is thicker than the outer peripheral frame-shaped region. Forming the external lead-out terminal,
A method of manufacturing a power semiconductor module, comprising: a step of opposingly arranging the first contact surface on the wiring pattern and connecting the substrate side connection portion to the wiring pattern by ultrasonic welding. 2. The method of manufacturing a power semiconductor module according to claim 1, wherein in the step of forming the external lead-out terminal, a plating layer is formed at least on the first contact surface side of the substrate-side connection portion. In the step of connecting to the wiring pattern, the front end surface of the horn formed in a convex shape is brought into contact with the central region of the second contact surface of the board-side connecting portion, and a load is applied to the central region The method of manufacturing a power semiconductor module according to claim 1, wherein ultrasonic welding is performed.

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