Power control device and method for manufacturing a power control device

Abstract

To provide a power control device capable of suppressing a positional deviation of a lead terminal, and a manufacturing method of the power control device.SOLUTION: A power control device 1 has an electronic component EC and a connection unit 10. One of the electronic component EC and the connection unit 10 includes a first lead terminal L1. The other of the electronic component EC and the connection unit 10 includes a second lead terminal L2. One of the first lead terminal L1 and the second lead terminal L2 has a protrusion part. The other of the first lead terminal L1 and the second lead terminal L2 has a recess part. The protrusion part has an inclined plane at a tip end and is configured so as to be inserted into the recess part along the inclined plane from the tip end.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a power control device and a method for manufacturing the power control device.

Background Art

[0002] A large current flows through a power control device for driving an inverter, a motor, etc. The wiring of the power control device through which a large current flows needs to be connected in a method with low loss and high reliability. As a method of connecting wiring, a method of connecting metallic lead terminals such as iron and copper by screwing, welding, etc. is used. The wiring connection method is used not only for inverters and motors but also for charge and discharge devices such as batteries, hot water supply facilities, air conditioning devices, etc. At the time of connection, two or more target lead terminals are brought into contact for connection. For example, Japanese Patent Application Laid-Open No. 2021-185742 (Patent Document 1) describes a power conversion device provided with a positive electrode terminal and a negative electrode terminal as two lead terminals.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a power control device having wiring facilities such as a power module that needs to conduct a large current, electronic components such as capacitors, and a connection unit for connecting them, there is a displacement in the position of the lead terminals when the lead terminals are connected. As a result, the quality, strength, life, and reliability of the connection deteriorate.

[0005] In the power conversion device described in the above publication, due to variations in the dimensions of the lead terminals, displacements of the lead terminals occur due to displacements in the vertical, horizontal, and height positions of the lead terminals relative to each other, the distance between the lead terminals (connection surface), and the insertion angle.

[0006] This disclosure has been made in view of the above-mentioned problems, and its purpose is to provide a power control device and a method for manufacturing a power control device that can suppress misalignment of lead terminals. [Means for solving the problem]

[0007] The power control device of this disclosure comprises an electronic component and a connection unit. One of the electronic component and the connection unit includes a first lead terminal. The other of the electronic component and the connection unit includes a second lead terminal. One of the first lead terminal and the second lead terminal has a protrusion. The other of the first lead terminal and the second lead terminal has a recess. The protrusion has an inclined surface at its tip and is configured to be inserted into the recess along the inclined surface from the tip. The upper end faces of the first lead terminal and the second lead terminal are welded side by side. The welded surfaces formed on the upper end faces of the first and second lead terminals intersect with the contact surfaces of the first and second lead terminals. The convex and concave portions restrict the position of the first and second lead terminals in the direction perpendicular to the welded surface. [Effects of the Invention]

[0008] According to the power control device of this disclosure, the protrusion has an inclined surface at its tip and is configured to be inserted into the recess along the inclined surface from the tip. Therefore, the protrusion is inserted into the recess along the inclined surface. Consequently, misalignment of the lead terminal can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram of the power control device according to Embodiment 1. [Figure 2] This is a schematic perspective view of the power control device according to Embodiment 1. [Figure 3] This is a schematic perspective view of the power module of the power control device according to Embodiment 1. [Figure 4] This is a schematic perspective view of the connection unit of the power control device according to Embodiment 1. [Figure 5] This is an external view diagram of the configuration of the power control device and peripheral equipment used during laser welding. [Figure 6] This is a schematic top view showing the operation of the lead terminal chuck jig when connecting lead terminals. [Figure 7] It is a schematic top view showing the operation of the lead terminal pressing jig. [Figure 8] It is a schematic enlarged perspective view showing the configuration during lead terminal welding. [Figure 9] It is a schematic perspective view showing the lead terminal connection when there is no displacement between the lead terminals. [Figure 10] It is a schematic perspective view showing the lead terminal connection when there is displacement between the lead terminals. [Figure 11] It is a schematic perspective view of the lead terminals of the power control device according to Embodiment 1. [Figure 12] It is a schematic perspective view of the lead terminals provided with three displacement suppression structures of the power control device according to Embodiment 1. [Figure 13] It is a schematic perspective view of a structure for suppressing lead distortion when suppressing displacement of the lead terminals of the power control device according to Embodiment 1. [Figure 14] It is a schematic diagram showing the connection of conventional lead terminals. [Figure 15] It is a schematic top view showing the connection of the lead terminals of the power control device according to Embodiment 1. [Figure 16] It is a schematic side view showing the connection of the lead terminals of the power control device according to Embodiment 1. [Figure 17] It is a schematic perspective view showing a modification example of the lead terminals of the power control device according to Embodiment 1. [Figure 18] It is a schematic diagram showing another modification example of the lead terminals of the power control device according to Embodiment 1. [Figure 19] It is a schematic perspective view showing the state where the lead terminal direction of the connection unit of the power control device according to Embodiment 2 is aligned with the laser irradiation direction. ​​​​​​​It is a schematic perspective view showing the lead terminals of the connection unit of the power control device according to Embodiment 3. [Figure 23] It is a schematic enlarged perspective view showing a state in which the lead terminals of the power control device according to Embodiment 3 are connected in an overlapping manner. [Figure 24] It is a schematic perspective view showing the lead terminals of the power control device according to Embodiment 3 that are connected in an overlapping manner. [Figure 25] It is a schematic perspective view showing how the lead terminals of the power control device according to Embodiment 3 are connected in an overlapping manner. [Figure 26] It is a schematic perspective view showing a state in which the lead terminals of the power control device according to Embodiment 3 are connected in a butting manner. [Figure 27] It is a schematic perspective view showing the lead terminals of the power control device according to Embodiment 3 that are connected in a butting manner. [Figure 28] It is a schematic perspective view showing a modified example of the lead terminals of the power control device according to Embodiment 3 that are connected in a butting manner. [Figure 29] It is a schematic perspective view showing another modified example of the lead terminals of the power control device according to Embodiment 3 that are connected in a butting manner. [Figure 30] It is a schematic side view showing the connection of the lead terminals of the power control device according to Embodiment 4. [Figure 31] It is a schematic perspective view showing the connection of the lead terminals of the power control device according to Embodiment 5. [Figure 32] It is a schematic side view showing the connection of the lead terminals of the power control device according to Embodiment 6.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments will be described with reference to the drawings. In the following, the same or corresponding parts will be denoted by the same reference numerals, and duplicate explanations will not be repeated.

[0011] Embodiment 1. Referring to FIGS. 1 to 4, the power control device 1 according to Embodiment 1 will be described.

[0012] Figure 1 is a block diagram of a power control device 1 according to Embodiment 1. The power control device 1 is connected to equipment 200 such as a motor that operates by changing a large current. Equipment 200 may be an inverter or the like in addition to a motor. Referring to Figure 1, the power control device 1 is connected to external equipment 200 and a power source 300. Equipment 200 is the motor to be driven. The power source 300 is an external power supply or a battery such as a storage battery. The power control device 1 controls the power supplied from the power source 300 and transmits it to the equipment 200 to be driven in an appropriate state. This causes the equipment 200 to operate. The power control device 1 includes a power module 12 for turning the current on and off, a capacitor and coil (not shown) for converting and stabilizing the switched-on and switched-off current, a connection unit 10 for inputting or outputting current to these components, and a control board 2 for mounting them. Furthermore, the power control device 1 includes a sensor (not shown) that monitors the input / output status and ensures that the desired output is obtained, and a control IC (Integrated Circuit) (not shown) that turns the power module 12 on and off based on the sensor output value.

[0013] Figure 2 is an internal structure diagram of the power control device 1. Referring to Figure 2, the power control device 1 comprises a control board 2, a connection unit 10, a heat sink 11, and a power module 12. In this embodiment, the power control device 1 includes a power module 12 as an example of an electronic component EC. The power control device 1 comprises a housing 1a. In Figure 2, for the sake of explanation, the housing 1a is shown with a dashed line. The control board 2, connection unit 10, heat sink 11, and power module 12 are housed inside the housing 1a.

[0014] Because the power control device 1 generates heat during operation, a heat sink 11 is provided on the bottom of the power control device 1 to dissipate this heat and cool the inside. Although not shown in Figure 2, the outside of the heat sink 11 is a cooling structure connected to the outside of the housing 1a. This cooling structure can dissipate heat by transferring heat from inside the housing 1a to the outside of the housing 1a through air, cooling water, etc. On top of the heat sink 11 are a connection unit 10 for inputting current to an external power source 300 (see Figure 1), and multiple power modules 12 for switching the input current on and off. Also on top of the heat sink 11 are capacitors and coils (not shown) used to convert power. On top of the connection unit 10 and the multiple power modules 12 is a control board 2 that controls the current flowing to the power modules 12 to drive motors and other devices located outside the power control device 1 by switching it on and off. The control board 2 includes a control IC 100 that controls power conversion based on information from sensors and other components located inside the control board 2, a voltage conversion circuit (not shown), and other components (not shown). A description of the configuration of each component is omitted as it is not relevant to the description of this disclosure.

[0015] One of the electronic component EC and the connection unit 10 includes a first lead terminal L1. The other of the electronic component EC and the connection unit 10 includes a second lead terminal L2. Hereinafter, for convenience of explanation, the first lead terminal L1 and the second lead terminal L2 may be referred to as lead terminals. In this embodiment, the power module current terminal 20 is the first lead terminal (L1), and the connection unit current terminal (power module side) 26 is the second lead terminal (L2). Alternatively, the power module current terminal 20 may be the second lead terminal (L2), and the connection unit current terminal (power module side) 26 may be the first lead terminal (L1).

[0016] The power module 12 of the power control device 1 switches the current input from the power source 300 (see Figure 1) on and off and outputs it. Figure 3 is an external view of the power module 12. The power module 12 transmits the power input from the power source 300 (see Figure 1) to another device 200 (see Figure 1). For this reason, the power module 12 has multiple power module current terminals 20. Large currents flow through the power module current terminals 20 to drive devices 200 (see Figure 1), such as motors. The power module current terminals 20 are usually made of a metal such as copper. The power module 12 also has power module signal terminals 21 for inputting signals to control the on / off state of the current. In addition to terminals for controlling the on / off state of the current, the power module signal terminals 21 also have terminals for detecting the amount of current flowing and terminals for transmitting abnormal signals such as voltage. The power module signal terminals 21 are connected to the control IC 100 through the control board 2. The control IC 100 receives feedback based on this information and controls the on / off state of the current in the power module 12.

[0017] Figure 4 is an external view of the connection unit 10. The connection unit 10 is used to input power to the power control device 1 and output the internally converted power to the outside. One end of the connection unit 10 is connected to a power source 300 (see Figure 1) located outside the power control device 1 via the connection unit current terminal (input / output side) 25. The other end of the connection unit 10 has multiple connection unit current terminals (power module side) 26 for connecting to power modules 12 that control the on / off switching of the input power, and is connected to the required number of power modules 12. There is a similar wiring structure for the connection unit 10 on the opposite side of the power modules 12, but since it is the same as the connection unit 10 described above, the explanation is omitted. As shown in Figure 4, the connection unit 10 has multiple terminals on both ends. These terminals are wired inside the connection unit 10. The outer shell of the connection unit 10 is made of a non-conductive material such as resin. Furthermore, in Figure 4, the connection unit current terminal (power module side) 26 has the same width, thickness, and material as the power module current terminal 20 (see Figure 2), but it may have different width, thickness, and material from the power module current terminal 20 (see Figure 2).

[0018] Referring to Figure 5, the connection of the lead terminals of the power control device 1 according to Embodiment 1 will be described.

[0019] A large current of several amperes or more typically flows through the power control device 1. Therefore, the connection unit current terminals (input / output side) 25 and connection unit current terminals (power module side) 26 of the connection unit 10, as well as the power module current terminals 20 of the power module 12, need to be connected uniformly and stably to minimize power loss due to energization and to prevent variations in the characteristics of individual lead terminals, such as current, as well as product lifespan and quality. Screw fastening, welding, and connectors are often used for such connections. One example of this connection method is laser welding. Figure 5 is an external view of the configuration of the power control device 1 and peripheral equipment during laser welding. During connection, the power control device 1, with multiple power modules 12 and connection units 10 mounted on a heat sink 11, is installed in an appropriate position for the laser output unit 30, usually directly below it. When the lead terminals are connected by the irradiation of the laser LA, both the power module current terminals 20 and the connection unit current terminals (power module side) 26 are clamped by the lead terminal chuck jig 35, pressing the lead terminals together. The lead terminals are then connected in a tight, gapless state. Figure 5 shows the connection state of the current terminal (power module side) 26 of the connection unit and the power module current terminal 20 of the power module 12.

[0020] Refer to Figure 6 to explain the conventional method of connecting lead terminals.

[0021] As shown in Figure 6(a), when the connection unit current terminal (power module side) 26 and the power module current terminal 20 are connected, a view from above shows that, before both ends of the lead terminals are clamped by the lead terminal chuck jig 35, the connection unit current terminal (power module side) 26 and the power module current terminal 20 are not in close contact and there is a gap between them. The lead terminal chuck jig 35 is a component intended to hold down multiple lead terminals. The lead terminal chuck jig 35 includes, for example, two lead terminal chuck arms 37 facing each other and multiple lead terminal pressing jigs 36 attached to the two lead terminal chuck arms 37. Each of the lead terminal pressing jigs 36 is positioned to match one-to-one with each of the lead terminals. As shown in Figure 6(b), when the lead terminal chuck jig 35 narrows the distance between the two lead terminal chuck arms 37 by clamping them, the lead terminal pressing jig 36 contacts the corresponding lead terminal and presses it down. In this way, the corresponding connection unit current terminal (power module side) 26 and the power module current terminal 20 are pressed down from above and below as shown in Figure 6(b), causing the lead terminals to come into close contact with each other. However, in conventional methods, the positions and angles of these lead terminals are not the same, and in the example shown in Figure 6(b), the horizontal position of the lead terminals does not change when they are clamped, and the lateral displacement shown in Figure 6(b) remains even after the lead terminals are connected.

[0022] Referring to Figure 7, the operation of the lead terminal pressing jig 36 according to Embodiment 1 will be described.

[0023] Figure 7 shows how the lead terminal pressing jig 36 clamps the connection unit current terminal (power module side) 26 and the power module current terminal 20. The lead terminal pressing jig 36 has a first pressing jig 40, a second pressing jig 41, and a lead terminal retainer 42. The lead terminal retainer 42 is shaped to match the shape of the lead terminal in order to press the connection unit current terminal (power module side) 26 and make it tightly attached to the power module current terminal 20. In Figure 7(a), the lead terminal retainer 42 has a plate-like structure that matches the surface of the lead terminal. A spring 43 is installed between the first pressing jig 40 and the second pressing jig 41. In this embodiment, the spring 43 is, for example, a coil spring. The spring 43 is positioned inside the first pressing jig 40 and the second pressing jig 41. The spring 43 is configured to push the first pressing jig 40 and the second pressing jig 41 apart with a constant force. The spring 43 only needs to be expanded with a constant force, and other forces such as air compression may also be used.

[0024] As the gap between the lead terminal chuck jigs 35 (see Figure 6) narrows, the lead terminal pressing jig 36 approaches the connection unit current terminal (power module side) 26 and eventually makes contact. In this way, as shown in Figure 7(b), the connection unit current terminal (power module side) 26 comes into close contact with the lead terminal retainer 42. As the gap between the lead terminal chuck jigs 35 (see Figure 6) narrows further, the connection unit current terminal (power module side) 26 is pushed by the lead terminal retainer 42 and approaches the power module current terminal 20. The power module current terminal 20 is also pushed by the corresponding lead terminal pressing jig 36 (not shown), and similarly approaches the connection unit current terminal (power module side) 26, until the lead terminals come into close contact with each other, as shown in Figure 7(c).

[0025] If the spacing between the lead terminal chuck jigs 35 is to be narrowed further, the first pressing jig 40 and the second pressing jig 41, which were spread apart by the spring 43 until contact, will be pushed in with a force stronger than the repulsive force of the spring 43. Consequently, the spring 43 will compress, and the combined length of the first pressing jig 40 and the second pressing jig 41 will decrease. This force of the spring 43 prevents excessive force from being applied to the lead terminals, thus preventing damage, even if the spacing between the lead terminals is different. In this way, even when the spacing between the lead terminals varies, the spring 43's expansion and contraction range absorbs the misalignment of the lead terminals, allowing the lead terminals to be welded in a consistent state.

[0026] Figure 8 summarizes the explanation so far, illustrating the structure that suppresses misalignment when welding lead terminals together. The connection unit 10 and power module 12 are arranged on the heat sink 11. For simplicity of explanation, the number of power modules 12 is shown as two, but normally multiple power modules 12 are arranged side by side. The power module current terminal 20 and the connection unit current terminal (power module side) 26 face each other, and the lead terminal pressing jig 36 of the lead terminal chuck jig 35 clamps them together. When the lead terminal chuck jig 35 narrows the distance between the lead terminal chuck arms 37, the lead terminal pressing jig 36 clamps the two lead terminals, absorbing positional and thickness variations for each combination and connecting the two lead terminals in a uniform state. By connecting the two lead terminals in this state, the quality of the connection part becomes consistent, enabling a highly reliable connection.

[0027] Referring to Figures 9 and 10, we will explain the cases where there is no misalignment between the lead terminals and where there is misalignment between the lead terminals.

[0028] Figure 9 shows the case where there is no misalignment of the lead terminals of the power module current terminal 20 and the connection unit current terminal (power module side) 26. As shown in Figure 9(a), when there is no misalignment of the original lead terminals, the power module current terminal 20 and the connection unit current terminal (power module side) 26 are pressed straight by the lead terminal pressing jig 36. As a result, as shown in Figure 9(b), the lead terminals can be in close contact without any misalignment in length, width, height, or rotational direction. When the laser output unit 30 (see Figure 5) irradiates the top of the lead terminals with a laser, the metal of each lead terminal melts and welds together. When all lead terminals are connected in this state, the quality of the connection of all lead terminals is the same except for differences in placement from the laser output unit 30 (see Figure 5).

[0029] Next, Figure 10 shows the case where there is a misalignment between the power module current terminal 20 and the connection unit current terminal (power module side) 26. Figure 10(a) shows the state where the connection unit current terminal (power module side) 26 is misaligned to the left relative to the power module current terminal 20. Figure 10(b) shows the state where the height of the connection unit current terminal (power module side) 26 is lower relative to the power module current terminal 20. Figure 10(c) shows the state where the connection unit current terminal (power module side) 26 is rotated relative to the power module current terminal 20. In this state, the angles of the welded surfaces at the top of the lead terminals are different for the power module current terminal 20 and the connection unit current terminal (power module side) 26. When the connection unit 10 (see Figure 5) and the power module 12 (see Figure 5) are connected together, due to variations in the position and angle of individual lead terminals, the surface conditions when the lead terminals are joined together will be a mixture of different types, as shown in Figures 10(a), 10(b), and 10(c). If a laser is irradiated from the laser output unit 30 (see Figure 5) to connect the lead terminals in this state, the melting area and melting results during welding will differ, resulting in differences in connection strength, lifespan until deterioration, and appearance quality during inspection.

[0030] Referring to Figure 11, the structure of the lead terminals of the power control device 1 according to Embodiment 1 will be described in more detail.

[0031] One of the first lead terminal L1 and the second lead terminal L2 has a protrusion 51. The other of the first lead terminal L1 and the second lead terminal L2 has a recess 50. In this embodiment, the connection unit current terminal (power module side) 26 has a protrusion 51, and the power module current terminal 20 has a recess 50.

[0032] As shown in Figure 11(a), the power module current terminal 20 and the connection unit current terminal (power module side) 26 are provided with a pair of concave and concave structures: a positioning hole (recess) 50 and a positioning projection (convex part) 51. In Figure 11(a), the power module current terminal 20 is provided with a positioning hole (recess) 50. There are no restrictions on the combination of the positioning hole (recess) 50 and the positioning projection (convex part) 51 with the lead terminal, and the power module current terminal 20 may also be provided with a positioning projection (convex part).

[0033] Figure 11(a) shows that there is one positioning hole (recess) 50 and one positioning projection (protrusion) 51. The protrusion 51 has an inclined surface IS at its tip. The side surface of the tip of the protrusion 51 is sloped. The inclined surface IS is curved or straight. The tip of the positioning projection (protrusion) 51 is conical, triangular pyramidal, spherical, etc. The protrusion 51 is configured to be inserted into the recess 50 along the inclined surface IS from its tip. The positioning hole (recess) 50 has a shape corresponding to the positioning projection (protrusion) 51. When the positioning projection (protrusion) 51 is inserted into the positioning hole (recess) 50, the positioning hole (recess) 50 is completely closed. This structure is shown in Figure 11(b). Figure 11(b) includes a projection view. As shown in Figure 11(c), there is no limit to the number of recesses in the positioning hole (recess) 50 and the positioning projection (protrusion) 51. For example, three positioning holes (recesses) 50 and three positioning protrusions (protrusions) 51 may be provided.

[0034] Referring to Figure 12, the connection between the power module current terminal 20 and the connection unit current terminal (power module side) 26 will be explained. When the lead terminals are placed facing each other, the recess 50 and the protrusion 51 (concave and convex parts) interlock. If there is no misalignment between the lead terminals, the concave and convex parts interlock from the front as shown in Figure 12(a) and are in close contact as shown in Figure 12(d). On the other hand, if there is a horizontal or rotational misalignment between the lead terminals, the concave and convex parts will be arranged as shown in Figures 12(b) and 12(c). For example, in the state shown in Figure 12(b), the lead terminals are pressed by the lead terminal pressing jig 36 (see Figure 8), and the tip of one of the multiple positioning protrusions (protrusions) 51, for example, the tip of positioning protrusion (protrusion) 51 (51a), contacts the corresponding positioning hole (recess) 50 (50a). The tip of the positioning projection (protrusion) 51 (51a) is an inclined surface IS, that is, a streamlined shape with an inclination. As it is pressed by the lead terminal pressing jig 36 (see Figure 8), the power module current terminal 20 shifts in the direction of the lead terminal along the inclined surface IS of the protrusion 51, suppressing misalignment of the lead terminal so that it overlaps with the connection unit current terminal (power module side) 26, and suppressing horizontal and rotational misalignment. Eventually, the positioning projections (protrusions) 51 (51b, 51c) also come into contact with the corresponding positioning holes (recesses) 50 (50b, 50c), and as they are pressed, misalignment is suppressed. Finally, the three protrusions and recesses are pressed together, and as shown in Figure 12(d), the protrusions and recesses are in close contact without any misalignment. Similarly, in Figure 12(c), which shows rotational misalignment in the opposite direction to Figure 12(b), misalignment can be suppressed, and the protrusions and recesses can be in close contact without any misalignment as shown in Figure 12(d). In this case, by changing the thickness of the lead terminal, the strength of the side on which you want to change the angle of the lead terminal is weakened, allowing you to pre-determine which terminals you want to suppress misalignment from.

[0035] When misalignment of lead terminals is suppressed, the angle and position of the lead terminals are controlled so that they align. This can cause twisting, bending, or deflection at locations other than the tip of the lead terminal. To prevent these from occurring in unexpected locations, a structure is provided in the lead terminal portion to absorb the shape changes of the lead terminal when misalignment is suppressed. The lead terminal shown in Figure 13 is the power module current terminal 20 of the power module 12. In Figure 13(a), a movable part 28 is provided in which the thickness and shape of the lead terminal are changed to facilitate suppression of misalignment when aligning the tip of the lead terminal. As shown in Figure 13(b), if the original lead terminal has a structure that bends at a right angle midway, a structure is added to a part of it that is easily deformable in the direction to be suppressed. For example, as shown in Figure 13(c), the lead terminal has a cylindrical movable part 28. Alternatively, as shown in Figure 13(d), the lead terminal has a movable part 28 whose plate thickness direction is changed in advance. This makes it easier to respond when a force to suppress misalignment of the lead terminal is applied in the plate thickness direction. A cylindrical shape like that shown in Figure 13(c) can accommodate positional displacement in any direction, including diagonal. A shape like that shown in Figure 13(d) makes it easier to suppress horizontal positional displacement.

[0036] Refer to Figure 14 to explain the conventional connection of lead terminals. When the distance between lead terminals is narrowed to ensure close contact during connection, initially, the power module current terminal 20 and the connection unit current terminal (power module side) 26, as shown in Figure 14(a), flex and move closer together to achieve close contact, as shown in Figure 14(b). In this case, since the lead terminals do not have positioning holes (recesses) 50 and positioning protrusions (protrusions) 51, misalignment of the lead terminals is not sufficiently suppressed and remains as is.

[0037] Next, with reference to Figure 15, we will explain the case where a positioning hole (recess) 50 and a positioning projection (protrusion) 51 are provided on the lead terminal. In this case, the lead terminal is pressed down while suppressing misalignment. As shown in Figure 15(a), the lead terminals are separated from each other before being pressed down. This state is a view of the lead terminals from above, and there is a horizontal misalignment between the lead terminals. Figure 16(a) is a view from the side.

[0038] When the lead terminal pressing jig 36 presses down on the lead terminals, the distance between the lead terminals decreases, and the inclined surface IS at the tip of the positioning projection (protrusion) 51 comes into contact with the inclined surface inside the positioning hole (recess) 50, as shown in Figure 15(b). In this state, the center positions of the lead terminals are offset. Because the tip of the positioning projection (protrusion) 51 is offset from the center line of the positioning hole (recess) 50, the inclined surface IS of the positioning projection (protrusion) 51 is pressed against the inclined surface of the positioning hole (recess) 50, and the position of the positioning projection (protrusion) 51 is suppressed along the inclined surface IS. In this case, the connection unit current terminal (power module side) 26 is shifted upward relative to the power module current terminal 20, as shown in Figure 15(b).

[0039] Furthermore, when the lead terminal pressing jig 36 pushes the lead terminal in, the positioning projection (convex portion) 51 is completely pushed in and enters the positioning hole (recessed portion) 50, as shown in Figure 15(c). This means that the misalignment is eliminated as the lead terminal enters from the front. As shown in Figure 13, if the lead terminal has a structure that absorbs the strain of the lead terminal when misalignment is suppressed, deformation occurs in the direction that suppresses misalignment at that part of the structure, and this deformation also absorbs the strain of the lead terminal.

[0040] This will be explained from the side using Figure 16. Figure 16(a) shows the side view of Figure 15(a), and shows the state before the lead terminal pressing jig 36 presses the lead terminals. In this state, there is a height misalignment between the lead terminals. As the lead terminal pressing jig 36 presses the lead terminals, the inclined surface IS of the positioning projection (convex part) 51 in Figure 16(b) is completely pressed in and embedded in the positioning hole (recess) 50, as shown in Figure 16(c). At this time, the power module current terminal 20 and the connection unit current terminal (power module side) 26 undergo deformation sufficient to absorb the misalignment of the lead terminals as the misalignment of the lead terminals is suppressed. As a result, the lead terminals are in close contact with each other, and the upper ends to be connected are uniformly in close contact without any misalignment for all of the lead terminals. When the laser is irradiated by the laser output unit 30 (see Figure 5) and the lead terminals are connected, a stable quality connection without variation is obtained.

[0041] The shapes of the positioning hole (recess) 50 and the positioning projection (protrusion) 51 are such that they match when fitted together, but they are not limited to a specific shape. An example of the recess and protrusion is shown in Figure 17. In Figure 17(a), the positioning hole (recess) 50 is provided by cutting out a part of the power module current terminal 20. The positioning projection (protrusion) 51 is provided by providing a projection on the connection unit current terminal (power module side) 26. In the positioning projection (protrusion) 51, the part from the center upwards of the protrusion 51 may be inclined trapezoidal shape, as shown in Figure 17(b). The tip of the protrusion 51 is not limited to a trapezoid; it can be conical, parallelogram, or other shapes. When the lead terminals are pressed together, the positioning projection (protrusion) 51 fits into the cutout of the positioning hole (recess) 50, as shown in Figure 17(a). At this time, the inclined surface IS of the positioning projection (protrusion) 51 grips the power module current terminal 20, and positional deviations in height, horizontal, and rotational directions are suppressed.

[0042] As shown in Figures 18(a) and 18(b), the base portion of the uneven surface may also be configured in a rectangular shape. Figure 18(a) is a schematic perspective view showing the uneven surface of the lead terminal. Figure 18(b) is a schematic front view, top view, and right side view showing the uneven surface of the lead terminal. Furthermore, as shown in Figure 18(c), multiple different shapes may be provided for the uneven surface. By combining a convex portion 51 with an inclined surface IS and a shape that easily improves the misalignment direction with a concave portion 50, the vertical, horizontal, and height misalignment of the lead terminals, as well as the rotational misalignment of the lead terminals, are suppressed.

[0043] Next, a method for manufacturing the power control device 1 according to Embodiment 1 will be described.

[0044] In this embodiment, the control method for the power control device 1 comprises a preparation step and an insertion step. In the preparation step, the electronic component EC and the connection unit 10 are prepared. The electronic component EC and the connection unit 10 include a first lead terminal L1 on one side and a second lead terminal L2 on the other side. One of the first lead terminal L1 and the second lead terminal L2 has a protrusion 51, and the other of the first lead terminal L1 and the second lead terminal L2 has a recess 50.

[0045] In the insertion process, the protrusion 51 is inserted into the recess 50. The protrusion 51 has an inclined surface IS at its tip and is inserted into the recess 50 along the inclined surface IS from the tip.

[0046] Next, the effects and advantages of Embodiment 1 will be described.

[0047] According to the power control device 1 of Embodiment 1, the protrusion 51 has an inclined surface IS at its tip and is configured to be inserted into the recess 50 along the inclined surface IS from the tip. Therefore, the protrusion 51 is inserted into the recess 50 along the inclined surface IS. Consequently, misalignment of the lead terminal can be suppressed.

[0048] According to the manufacturing method of the power control device 1 in Embodiment 1, the protrusion 51 is inserted into the recess 50 along the inclined surface IS from its tip. Therefore, misalignment of the lead terminals can be suppressed.

[0049] Laser welding is used to ensure high productivity when connecting lead terminals. However, in laser welding, misalignment of the lead terminals can cause changes in the molten state of the lead terminals during laser irradiation, leading to welding defects and a decrease in welding quality. If lead terminals are used in this condition, it can result in increased power loss, heat generation, and a reduced lifespan. In this embodiment, misalignment of the lead terminals can be suppressed, so when laser welding is used to connect the lead terminals, variations in the welding state can be suppressed. Therefore, welding defects and a decrease in welding quality of lead terminals can be suppressed.

[0050] Embodiment 2. Embodiment 2 has the same configuration, operation, and effects as Embodiment 1 unless otherwise specified. Therefore, the same reference numerals are used for components identical to those in Embodiment 1, and the descriptions are not repeated.

[0051] Figure 5 already shows the configuration when connecting lead terminals, especially when using a laser. In this case, the lead terminals are facing the same direction (upward in Figure 5). As viewed from the laser output unit 30, the angles of the tip surfaces of each lead terminal are different. Therefore, the absorption rate of the energy applied to the lead terminals during connection from the laser output unit 30 differs for each lead terminal. This results in variations in the connection quality of the lead terminals.

[0052] In this embodiment, as shown in Figure 19, the connection unit current terminal (power module side) 26 of the connection unit 10 is positioned to face the laser output unit 30. The direction in which this lead terminal faces can be determined in advance from the positional relationship between the connection unit 10 and the laser output unit 30. On the other hand, since multiple power modules 12 are installed on the heat sink 11, versatility is required. Therefore, it is not efficient to individually process the direction in which the power module current terminal 20 faces and prepare multiple types. For this reason, the direction of the power module current terminal 20 can be directed towards the laser output unit 30, which is the direction in which the connection unit current terminal (power module side) 26 faces, and is suitable for laser connection. This makes it possible to improve the connection quality of the lead terminals by standardizing the state of the lead terminals during connection.

[0053] The manufacturing method for the power control device 1 according to Embodiment 2 further includes a laser irradiation step. In the laser irradiation step, the first lead terminal L1 and the second lead terminal L2 are irradiated with a laser while the convex portion 51 is inserted into the concave portion 50. The first lead terminal L1 and the second lead terminal L2 are arranged along the direction in which the laser is irradiated.

[0054] Next, the effects and advantages of Embodiment 2 will be described.

[0055] According to the manufacturing method of the power control device 1 of Embodiment 2, the first lead terminal L1 and the second lead terminal L2 are arranged along the direction in which the laser is irradiated. Therefore, by making the state of the lead terminals uniform during connection, the connection quality of the lead terminals can be improved.

[0056] Furthermore, the connection state can be made uniform across multiple lead terminals. This allows for uniform connection strength, appearance, and surface condition. Additionally, by improving the losses during operation of the power control device 1, heat generation can be reduced, thereby uniformizing damage caused by thermal expansion and contraction. This improves the lifespan of the power control device 1.

[0057] Embodiment 3. Embodiment 3 has the same configuration, operation, and effect as Embodiment 1 unless otherwise specified. Therefore, the same reference numerals are used for components identical to those in Embodiment 1, and the descriptions are not repeated.

[0058] In this embodiment, as shown in Figure 20, the electronic component EC is arranged on an arc-shaped member EL. Specifically, the power module 12 is arranged on an arc-shaped heat sink 11. Member EL is not limited to the power module 12, but can also be a housing or other structure on which the electronic component EC is mounted. The inclined surface of this heat sink 11 is based on the outer shape of an arc with the laser output section 30 as the center of the circle. Therefore, by concentrating the direction of the power module current terminals 20 in a certain direction during connection, variations during connection can be suppressed, and the connection quality of the lead terminals can be improved.

[0059] The control method for the power control device 1 according to Embodiment 3 further includes a placement step. In the placement step, the electronic component EC is placed on the arc-shaped heat sink 11. By placing the electronic component EC on the arc-shaped heat sink 11, the first lead terminal L1 and the second lead terminal L2 are positioned along the direction in which the laser is irradiated.

[0060] Next, the effects and advantages of Embodiment 3 will be described.

[0061] According to the manufacturing method of the power control device 1 of Embodiment 3, the electronic component EC is arranged on the arc-shaped heat sink 11, so that the first lead terminal L1 and the second lead terminal L2 are arranged in the direction in which the laser is irradiated. Therefore, by making the state of the lead terminals uniform during connection, the connection quality of the lead terminals can be improved.

[0062] Embodiment 4. Embodiment 4 has the same configuration, operation, and effect as Embodiment 1 unless otherwise specified. Therefore, the same reference numerals are used for components identical to those in Embodiment 1, and their descriptions are not repeated.

[0063] When connecting the connection unit 10 and the power module 12, it is more efficient to shorten the wiring distance as much as possible in order to reduce the loss due to current flow and thereby lower the Ls (stray inductance). In this embodiment, the lead terminals of the connection unit 10 and the power module 12 are straight and not bent into an L shape as shown in Figure 16. Figure 21 shows the power module 12 with the lead terminals not bent. Note that in Figure 21, the protrusions are not shown for the sake of explanation. Figure 22 shows the connection unit 10 with the lead terminals not bent.

[0064] As shown in Figure 23, the first lead terminal L1 and the second lead terminal L2 are configured to extend linearly in the first direction. The first direction is the direction in which the first lead terminal L1 and the second lead terminal L2 extend linearly. When the connection unit 10 and the power module 12 are combined, some of the lead terminals overlap, and the connection unit current terminal (power module side) 26 of the connection unit 10 and the power module current terminal 20 of the power module 12 partially overlap.

[0065] As shown in Figure 24, a positioning hole (recess) 50 is provided in the connection unit current terminal (power module side) 26 at the overlapping portion of the lead terminals, and a positioning projection (protrusion) 51 is provided in the power module current terminal 20. When connected, the lead terminals are pressed together from above and below by the lead terminal pressing jig 36. Alternatively, the strength of the lower lead terminal may be increased so that the upper lead terminal is only pressed down from above. Or, the lower lead terminal may be supported by an insulating base, heat sink, etc., so that the upper lead terminal is only pressed down from above.

[0066] As shown in Figure 25, the protrusion 51 is configured to be inserted into the recess 50 in a second direction intersecting the first direction. The second direction is the direction in which the lead terminals overlap. The second direction may also be perpendicular to the first direction. Even if the lead terminals are misaligned in the vertical and horizontal directions as shown in Figure 25(a) before they are pressed down, as the lead terminal pressing jig 36 presses the lead terminals down, the positioning hole (recess) 50 and the positioning projection (protrusion) 51 engage as shown in Figure 25(b). By utilizing the inclined portions of the multiple positioning projections (protrusions) 51 and the force pressing down on the connection unit current terminal (power module side) 26, misalignment of the lead terminals is suppressed. As a result, as shown in Figure 25(c), the lead terminals are finally brought into close contact and connected with suppressed misalignment of the lead terminals.

[0067] As shown in Figure 26, the overlapping portion of the lead terminals can be eliminated, and the connection unit current terminal (power module side) 26 and the power module current terminal 20 can be connected by abutting their tips together. As shown in Figure 27, the protrusion 51 is configured to be inserted into the recess 50 in the first direction. As shown in Figure 27(a), a positioning projection (protrusion) 51 is provided. As shown in Figure 27(b), a positioning hole (recess) 50 is provided at the tip of the lead terminal. This makes it possible to suppress rotation and horizontal displacement of the lead terminal.

[0068] Modified examples of the positioning hole (recess) 50 and positioning projection (protrusion) 51 are shown in Figures 28 and 29. In the modified lead terminals shown in Figures 28(a) and 28(b), the protrusion 51 is configured in a triangular pyramidal shape. The recess 50 has a triangular pyramidal space to match the protrusion 51. In the modified lead terminal shown in Figure 28(c), three recesses 50 and three protrusions 51 are provided. In another modified lead terminal shown in Figure 29, the protrusion 51 is configured in a trapezoidal shape in plan view. The recess 50 has a trapezoidal space to match the protrusion 51 in plan view. In this case, two recesses 50 and two protrusions 51 are provided. By connecting the lead terminals with reduced misalignment, the connection quality of the lead terminals can be made uniform.

[0069] Next, the effects and advantages of Embodiment 4 will be described.

[0070] In the power control device 1 according to Embodiment 4, the first lead terminal L1 and the second lead terminal L2 are configured to extend linearly in the first direction. This reduces losses due to current flow, thereby enabling a low Ls (stray inductance).

[0071] As shown in Figure 25, the protrusion 51 is configured to be inserted into the recess 50 in a second direction intersecting the first direction. This makes it possible to suppress misalignment of the lead terminals by inserting the protrusion 51 into the recess 50 with the lead terminals overlapping.

[0072] As shown in Figure 26, the protrusion 51 is configured to be inserted into the recess 50 in a first direction. This makes it possible to suppress misalignment of the lead terminals by inserting the protrusion 51 into the recess 50 with the lead terminals facing each other.

[0073] Embodiment 5. Embodiment 5 has the same configuration, operation, and effect as Embodiment 1 unless otherwise specified. Therefore, the same reference numerals are used for components identical to those in Embodiment 1, and the descriptions are not repeated.

[0074] As shown in Figure 30, in this embodiment, one of the first lead terminal L1 and the second lead terminal L2 includes a fixing claw 99. The other of the first lead terminal L1 and the second lead terminal L2 is fixed by the fixing claw 99 with a protrusion 51 inserted into a recess 50. As shown in Figure 30(a), a fixing claw 99 with a return structure is provided on one side of the lead terminal, for example, the connection unit current terminal (power module side) 26. As shown in Figure 30(b), when the lead terminal pressing jig 36 pushes the power module current terminal 20 inside the fixing claw 99, the fixing claw 99 can maintain the tight contact of the lead terminal even when the lead terminal pressing jig 36 releases its pressure.

[0075] As shown in Figure 31, in a modified version of this embodiment, a groove 110 is provided on the outer surface of the convex portion 51. The concave portion 50 includes a projection 111 that protrudes from its inner surface. The projection 111 is configured to fit into the groove 110 when the convex portion 51 is inserted into the concave portion 50.

[0076] As shown in Figure 31(a), a projection 111 is provided in the middle of the positioning hole (recess) 50. A groove 110 is provided in the middle of the positioning projection (protrusion) 51. When opposing lead terminals are pressed together by the lead terminal pressing jig 36, the positioning hole (recess) 50 and the positioning projection (protrusion) 51 are pressed together while suppressing misalignment of the lead terminals in the vertical, horizontal, height, and rotational directions. As shown in Figure 31(b), the groove 110 and the projection 111 interlock with each other inside the positioning hole (recess) 50.

[0077] Next, the effects of Embodiment 5 will be described.

[0078] According to the power control device 1 of Embodiment 5, the other end of the first lead terminal L1 and the second lead terminal L2 is fixed by a fixing claw 99 with the protrusion 51 inserted into the recess 50. Therefore, even if the lead terminal pressing jig 36 releases its pressure, the fixing claw 99 can maintain the tight contact state of the lead terminals.

[0079] In a modified version of the power control device 1 according to Embodiment 5, the projection 111 is configured to fit into the groove 110 when the convex portion 51 is inserted into the recess 50. This prevents the projection 111 from coming out of the groove 110, thus preventing the convex portion 51 from loosening and coming out after being pushed into the recess 50. Furthermore, it becomes possible to stably bring the lead terminals into close contact and connect them without the need for pressing them down with the lead terminal pressing jig 36 during connection.

[0080] Embodiment 6. Embodiment 6 has the same configuration, operation, and effect as Embodiment 1 unless otherwise specified. Therefore, the same reference numerals are used for components identical to those in Embodiment 1, and the descriptions are not repeated.

[0081] In this embodiment, after connecting the lead terminals, the positioning holes (recesses) 50 and positioning protrusions (protrusions) 51 are not left inside the lead terminals. As shown in Figure 32(a), when connecting, for example in the case of laser welding, the positioning holes (recesses) 50 and positioning protrusions (protrusions) 51 are contained within the welding range (welding depth) MR that is welded by the laser. As a result, the recessed and protruding parts melt during welding. As a result, as shown in Figure 32(b), the recessed and protruding parts become a single welded state, making it possible to connect the lead terminals without any positioning recessed or protruding parts remaining inside the lead terminals after connection.

[0082] The control method for the power control device 1 according to Embodiment 6 further includes a laser irradiation step. In the laser irradiation step, the first lead terminal L1 and the second lead terminal L2 are irradiated with a laser while the protrusion 51 is inserted into the recess 50. The protrusion 51 and the recess 50 are melted by the laser irradiation.

[0083] Next, the effects and advantages of Embodiment 6 will be described.

[0084] According to the manufacturing method of the power control device 1 in Embodiment 6, the protrusions 51 and recesses 50 are melted by irradiation with a laser. This improves the connection quality of the lead terminals.

[0085] The above embodiments can be combined as appropriate.

[0086] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of Symbols]

[0087] 1 Power control device, 2 Control board, 10 Connection unit, 11 Heat sink, 12 Power module, 20 Power module current terminal, 21 Power module signal terminal, 28 Movable part, 30 Laser output unit, 35 Lead terminal chuck jig, 36 Lead terminal pressing jig, 37 Lead terminal chuck arm, 50 Recess, 51 Protrusion, 99 Fixing claw, 110 Groove, 111 Projection, 200 Equipment, 300 Power source, EC Electronic component, EL Member, IS Inclined surface, L1 First lead terminal, L2 Second lead terminal.

Claims

1. Electronic components and, Equipped with a connection unit, One of the electronic component and the connection unit includes a first lead terminal. The other of the aforementioned electronic component and the aforementioned connection unit includes a second lead terminal. One of the first lead terminal and the second lead terminal has a protrusion, The other of the first lead terminal and the second lead terminal has a recess. The aforementioned protrusion has an inclined surface at its tip and is configured to be inserted into the recess along the inclined surface from the tip. The upper end faces of the first lead terminal and the upper end faces of the second lead terminal are welded side by side. The welded surfaces formed on the upper end surface of the first lead terminal and the upper end surface of the second lead terminal intersect with the contact surfaces of the first lead terminal and the second lead terminal, The convex portion and the concave portion are power control devices that restrict the positions of the first lead terminal and the second lead terminal in a direction perpendicular to the welding surface.

2. The first lead terminal and the second lead terminal are configured to extend linearly in the first direction. The power control device according to claim 1, wherein the convex portion is configured to be inserted into the recess in a second direction intersecting the first direction.

3. The first lead terminal and the second lead terminal are configured to extend linearly in the first direction. The power control device according to claim 1, wherein the convex portion is configured to be inserted into the recess in the first direction.

4. One of the first lead terminal and the second lead terminal includes a fixing claw. The power control device according to claim 1, wherein the other of the first lead terminal and the second lead terminal is fixed by the fixing claw with the protrusion inserted into the recess.

5. A groove is provided on the outer surface of the aforementioned protrusion. The recess includes a projection that protrudes from the inner surface, The power control device according to claim 1, wherein the projection is configured to fit into the groove when the convex portion is inserted into the concave portion.

6. The power control device according to claim 1, wherein there are multiple protrusions and recesses.

7. The recess has a shape that matches the protrusion when fitted together, The power control device according to claim 1, wherein the tip of the protrusion contacts the innermost part of the recess.

8. A step of preparing an electronic component and a connection unit, wherein one end includes a first lead terminal and the other end includes a second lead terminal, and one of the first and second lead terminals has a convex portion and the other end has a concave portion, The aforementioned protrusion has an inclined surface at its tip, and is inserted into the recess along the inclined surface from the tip; The process includes welding the upper end faces of the first lead terminal and the second lead terminal side by side. The welded surfaces formed on the upper end surface of the first lead terminal and the upper end surface of the second lead terminal intersect with the contact surfaces of the first lead terminal and the second lead terminal, A method for manufacturing a power control device, wherein the convex portion and the concave portion restrict the position of the first lead terminal and the second lead terminal in a direction perpendicular to the welding surface.

9. The process further comprises irradiating the first lead terminal and the second lead terminal with a laser while the convex portion is inserted into the concave portion, The method for manufacturing a power control device according to claim 8, wherein the first lead terminal and the second lead terminal are arranged along the direction in which the laser is irradiated.

10. The process further includes arranging the electronic component on an arc-shaped member, The method for manufacturing a power control device according to claim 9, wherein the electronic components are arranged on the arc-shaped member, and the first lead terminal and the second lead terminal are arranged in the direction in which the laser is irradiated.

11. The process further comprises irradiating the first lead terminal and the second lead terminal with a laser while the convex portion is inserted into the concave portion, The method for manufacturing a power control device according to claim 8, wherein the protrusions and recesses are melted by irradiation with the laser.

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