JP7818921B2 - Electronic Module - Google Patents

Description

The present invention relates to reducing inductance and heat dissipation in electronic modules.

Conventional electronic modules are known to include one or more electronic elements with electrodes, a substrate on which the electronic elements are mounted and on which wiring connected to the electronic elements is formed, and a lead frame that supports and fixes the substrate and electronic elements, electrically connects and wires the electrode patterns for the switch elements to conductive members using aluminum wire, and is connected to the electrodes of the electronic elements.

Patent Document 1 discloses that, in order to reduce parasitic inductance, DC power input/output electrodes are provided at one end of the circuit board using conductor patterns on an insulating substrate, and the DC power input/output electrodes are arranged with multiple positive electrodes and multiple negative electrodes along the edge of one end, with a positive electrode located between two negative electrodes and a negative electrode located between two positive electrodes.

Patent Document 2 discloses that the positive and negative DC terminals connected to one of each pair of upper and lower arms are arranged in mirror symmetry with respect to the positive and negative DC terminals connected to the other of each pair of upper and lower arms, thereby reducing inductance.

Patent Document 3 discloses that the first and second insulating layers are both formed from a ceramic material, which gives them excellent thermal conductivity and reduces the difference in thermal expansion coefficient between the first and second insulating layers. Therefore, the overlapping of the first and second wiring patterns reduces the inductance of the first and second wiring patterns.

Japanese Patent Application Laid-Open No. 2020-53622 JP 2017-11305 A JP 2016-164919 A

However, the wiring from the terminals of electronic modules to the electronic elements has a large parasitic inductance, and there is a need to reduce switching loss, heat generation, and electromagnetic noise, as well as improve the control stability of electronic modules. Furthermore, with conventional electronic modules, there is also a growing demand for improved reliability against thermal stress, such as thermal expansion caused by switching loss, and for device miniaturization. In particular, with the increasing current and faster operation speeds in recent years, it is becoming difficult for conventional electronic modules to meet these demands.

(1) The electronic module according to the present invention comprises one or more electronic elements having electrodes, a substrate on which the electronic elements are mounted and on which wiring connected to the electronic elements is formed, and a lead frame that supports and fixes at least one of the substrate and the electronic elements, and at least a portion of the lead frame is formed above the electronic elements.

(2) In the electronic module according to the present invention, the lead frame has a first lead frame on one side of which a power supply terminal, an output terminal, and a ground terminal are formed, and a second lead frame on the other side of which a plurality of signal terminals are formed, and the first lead frame is connected to the electrode portion of the electronic element.

(3) In the electronic module according to the present invention, when there are multiple electronic elements, the first lead frame is characterized in that the wiring inductance to each of the connection portions of the multiple electronic elements is uniform.

(4) In the electronic module according to the present invention, the electronic element is a switching element or a rectifying element, and at least a portion of the first lead frame is formed so as to cover all or part of the switching element or the rectifying element.

(5) In the electronic module of the present invention, at least a portion of the first lead frame functions as the ground terminal.

(6) In the electronic module according to the present invention, when there are multiple first lead frames, a terminal temperature equalization structure is formed on each of the multiple first lead frames to equalize the temperature of each terminal.

(7) In the electronic module according to the present invention, the terminal temperature equalization structure is characterized in that the area and shape of the lead frame are set so as to equalize the terminal temperature.

(8) In the electronic module according to the present invention, the terminal temperature equalization structure is characterized in that the lead frame has at least a notch or a hole.

(9) In the electronic module according to the present invention, the electronic elements include silicon carbide, gallium nitride, gallium oxide, and diamond semiconductors.

(1) Because the lead frame is formed above the electronic elements, three-dimensional wiring is created inside the electronic module at a position different from the wiring pattern on the substrate. This eliminates the need to form the wiring pattern formed by the lead frame on the substrate, ensuring sufficient wiring area on the substrate, increasing the wiring width and reducing parasitic inductance, and ensuring reliable support for internal components. As a result, the three-dimensional wiring created by the lead frame and the wiring pattern on the substrate, along with its support, ensures sufficient wiring area on the substrate, providing a highly reliable electronic module that is resistant to thermal shrinkage and other factors despite its compact size. The reduction in parasitic inductance also contributes to reduced loss and noise during operation of the electronic elements. Furthermore, the structure using the lead frame and substrate not only contributes to heat dissipation from the electronic elements, but also provides shielding against electromagnetic noise emitted by the electronic elements.

(2) The lead frame has a first lead frame on one side of which a power terminal, an output terminal, and a ground terminal are formed, and a second lead frame on the other side of which multiple signal terminals are formed. Because the first lead frame is connected to the electrodes of the electronic element, three-dimensional wiring different from the wiring pattern on the substrate is formed inside the electronic module. This eliminates the need to form the wiring pattern formed by the first lead frame on the substrate, ensuring sufficient wiring area on the substrate, widening the wiring width and reducing parasitic inductance, and ensuring reliable support for internal components by the first lead frame and second lead frame. As a result, the three-dimensional wiring and support provided by the first lead frame, second lead frame, and substrate significantly reduces the wiring area on the substrate, providing a compact yet highly reliable electronic module that is resistant to thermal shrinkage and other factors. The reduction in parasitic inductance also contributes to reduced loss and noise during operation of the electronic element. Furthermore, the structure formed by the first lead frame, second lead frame, and substrate not only contributes to heat dissipation from the electronic element, but also provides shielding against electromagnetic noise emitted by the electronic element.

(3) By equalizing the wiring inductance of the first lead frame, the electromotive force generated by changes in current flowing through the electronic element to which the first lead frame is connected is equalized, thereby stabilizing the control of the electronic element.

(4) At least a portion of the first lead frame is formed to cover at least all or part of the switching element or rectifying element, thereby reducing the parasitic inductance of the circuit wiring formed within the electronic module. This reduction in parasitic inductance also contributes to reduced loss and noise during operation of the electronic elements. Furthermore, the structure of the first lead frame, formed from a common flat lead frame, not only contributes to heat dissipation from the electronic elements, but also provides shielding against electromagnetic noise emitted by the electronic elements.

(5) Because a portion of the first lead frame functions as a ground terminal, parasitic inductance is reduced, particularly in the circuit wiring of the ground potential portion formed within the electronic module. This reduction in parasitic inductance contributes to reduced loss and noise during operation, particularly in large-current-capacity electronic elements. Furthermore, the structure of the first lead frame formed from a common flat lead frame not only contributes to heat dissipation from large-current-capacity electronic elements, but also has the effect of shielding electromagnetic noise emitted by large-current-capacity electronic elements.

(6) The first lead frame has a terminal temperature equalization structure that limits the amount of thermal conduction of heat generated by the electronic element and equalizes the terminal temperatures of the power supply terminal, output terminal, and ground terminal. Therefore, the first lead frame can limit the amount of thermal conduction of heat generated by the electronic element and equalize the terminal temperatures of the power supply terminal, output terminal, and ground terminal.

(7) It is preferable that the terminal temperature equalization structure be configured so that the area and shape of the lead frame are set to equalize the terminal temperature. This configuration allows for a simple structure that reduces inductance while equalizing the terminal temperatures of the power supply terminal, output terminal, and ground terminal.

(8) When setting the thermal resistance of the terminal temperature equalization structure, the lead frame may have a shape with notches or holes. Furthermore, the thermal resistance may be adjusted by adjusting the surface shape of the lead frame, for example, by making it uneven. This configuration allows for a simple structure to reduce inductance while equalizing the terminal temperatures of the power supply terminal, output terminal, and ground terminal.

(9) Because the electronic elements include silicon carbide, gallium nitride, gallium oxide, and diamond semiconductors, it is possible to provide an electronic module that can accommodate higher circuit currents and faster switching speeds. In other words, it is possible to improve the switching loss, heat generation, and electromagnetic noise caused by parasitic inductance, which are issues when using silicon carbide, gallium nitride, gallium oxide, and diamond semiconductors to increase circuit currents and speed up switching, as well as the resulting control stability and reliability of the electronic module.

1A and 1B are perspective views of an electronic module according to the present invention, in which FIG. 1A is a top perspective view of the electronic module, and FIG. 1B is a perspective view of the electronic module shown in FIG. 1A with the bottom side facing up. 1 shows a cross-sectional structure of an electronic module according to the present invention. 1 is a cross-sectional view showing a first lead frame and a second lead frame of an electronic module according to the present invention. FIG. 2 is a diagram showing the circuit configuration of a control circuit for controlling the power supplied from a power supply to a three-phase motor. 1 is a plan view showing the arrangement of wiring, electronic elements, and connectors on a substrate in an electronic module according to a first embodiment. FIG. 1 illustrates a first embodiment. FIG. 10 illustrates a second embodiment. FIG. 10 is a diagram illustrating a third embodiment. FIG. 10 is a diagram illustrating a fourth embodiment.

The electronic module and lead frame of the present invention will be described below with reference to the drawings. Note that the drawings are schematic diagrams and do not necessarily accurately reflect actual dimensions. The embodiments described below do not limit the invention as claimed. Furthermore, not all of the elements and combinations thereof described in each embodiment are necessarily essential to the solution of the present invention. In each embodiment, the same reference numerals will be used across embodiments for elements with the same basic configuration, features, functions, etc. (including components that are not completely identical in shape, etc.), and repeated description may be omitted.

Figure 1 shows an electronic module 110 for controlling the power supplied from a power source to a three-phase motor. Figure 1(A) is a top perspective view of the electronic module 110 according to the embodiment, and Figure 1(B) is a perspective view of the electronic module 110 with the bottom side of (A) facing up.

As shown in Figures 1(A) and 1(B), the electronic module 110 has a heat dissipation section 114 on the upper surface of the electronic module main body 112. Lead frames are provided on the side surfaces of the electronic module main body 112. A signal lead frame 116 is provided on one side surface, and a W-phase lead frame 118, a power supply lead frame 120, a ground lead frame 122, a V-phase lead frame 124, and a U-phase lead frame 126 are provided on the other side surface. These lead frames are made of a conductive metal, such as copper.

Figure 2 shows the cross-sectional structure of an electronic module 110 according to the present invention. Note that the package and heat dissipation section 114 of the electronic module main body 112 are omitted. The electronic module 110 according to the present invention comprises one or more electronic elements 140 each having an electrode portion 144, a substrate 142 on which the electronic elements 140 are mounted and on which wiring 138 connected to the electronic elements 140 is formed, and a lead frame 128 that supports and fixes at least one of the substrate 142 or the electronic elements 140 and is connected to the electrode portion 144 of the electronic elements 140, with at least a portion of the lead frame being formed above the surface of the substrate 142 on which the electronic elements 140 are mounted. "Above" refers to a position facing the surface of the substrate; for example, if the electronic module 110 in Figure 2 is drawn upside down, it would be "below" the surface of the substrate 142. Either case does not depart from the spirit of the invention.

Figure 2(A) shows an example in which a portion of the lead frame 128 is connected to wiring 138, and Figure 2(B) shows an example in which a portion of the lead frame 128 is connected to an electrode portion 144 of an electronic element 140.

Figure 2 (A) shows an example configuration in which a lead frame 128 supports and fixes a substrate 142. Wiring 138 is formed in a pattern on the substrate 142, and the terminals of an electronic element 140 are connected to the wiring 138, for example by soldering, and the lead frame 128 is connected to the wiring 138. A portion of the lead frame 128 is formed in a position facing the surface of the substrate 142 on which the electronic element 140 is mounted.

Figure 2(B) shows an example configuration in which a lead frame 128 supports and fixes an electronic element 140. The electronic element 140, which has an electrode portion 144, is connected to a substrate 142 via wiring 138, and the lead frame 128 is connected to the electrode portion 144. A portion of the lead frame 128 is formed above the surface of the substrate 142 on which the electronic element 140 is mounted.

In FIG. 2, the lead frame 128 is disposed opposite the electronic element 140, resulting in a three-dimensional wiring structure inside the package of the electronic module main body 112 that is different from the pattern wiring 138 formed on the surface of the substrate 142. This eliminates the need to form the wiring pattern formed by the lead frame 128 on the substrate 142, ensuring sufficient wiring area on the substrate 142 and allowing for wider wiring widths, thereby reducing parasitic inductance. Furthermore, the lead frame 128 reliably supports the electronic element 140 mounted on the substrate 142 inside the electronic module main body 112.

As a result, the three-dimensional wiring and support provided by the lead frame 128 and substrate 142 allows for a significant reduction in the wiring area on the substrate 142, making it possible to provide a highly reliable electronic module 110 that is small but resistant to thermal shrinkage and other factors. The reduction in parasitic inductance also contributes to reduced loss and noise during operation of the electronic element 140. Furthermore, the structure formed by the lead frame 128 and substrate 142 not only contributes to heat dissipation from the electronic element 140, but also has the effect of blocking electromagnetic noise emitted by the electronic element 140.

In the electronic module 110 according to the present invention, the electronic element 140 includes silicon carbide, gallium nitride, gallium oxide, and diamond semiconductors. This makes it possible to provide an electronic module 110 that can accommodate higher currents and faster switching speeds in circuits. In other words, it is possible to improve the switching loss, heat generation, and electromagnetic noise caused by parasitic inductance, which are issues when using silicon carbide, gallium nitride, gallium oxide, and diamond semiconductors to increase circuit currents and speed up switching, as well as the resulting control stability and reliability of the electronic module.

In the electronic module 110, as shown in FIG. 1, the lead frame 128 has a first lead frame 130 on one side of which a power terminal (power lead frame 120), output terminals (W-phase lead frame 118, V-phase lead frame 124, U-phase lead frame 126), and ground terminal (ground lead frame 122) are formed, and a second lead frame 132 on the other side of which multiple signal terminals (signal lead frame 116) are formed, and the first lead frame 130 is connected to the electrode portion 144 of the electronic element 140.

Figure 3 shows the cross-sectional structure of the first lead frame 130 and second lead frame 132 of the electronic module 110 according to the present invention. The first lead frame 130 has a power terminal (power lead frame 120), output terminals (W-phase lead frame 118, V-phase lead frame 124, U-phase lead frame 126), and a ground terminal (ground lead frame 122). The second lead frame 132 has multiple signal terminals (signal lead frame 116). The first lead frame 130 is connected to the electrode portion 144 of the electronic element 140.

As a result, the wiring pattern wired inside the electronic module main body 112 formed by the first lead frame 130 does not need to be formed on the substrate 142, allowing for the wiring area of the substrate 142 to be secured and the wiring width to be increased. This reduces parasitic inductance. Furthermore, the first lead frame 130 and the second lead frame 132 reliably support the electronic element 140 mounted internally on the substrate 142.

Through the three-dimensional wiring and support provided by the first lead frame 130, second lead frame 132, and substrate 142, the wiring area on the substrate 142 can be significantly reduced, providing a highly reliable electronic module 110 that is small yet resistant to thermal contraction. The reduction in parasitic inductance also contributes to reduced loss and noise during operation of the electronic element 140. Furthermore, the structure consisting of the first lead frame 130, second lead frame 132, and substrate 142 not only contributes to heat dissipation from the electronic element 140, but also has the effect of blocking electromagnetic noise emitted by the electronic element 140.

(First embodiment)
A first embodiment of an electronic module 110 for controlling the power supplied to a three-phase motor from a power supply shown in FIG. 1 will now be described.

Figure 4 shows the circuit configuration of a control circuit for controlling the power supplied from a power supply to a three-phase motor. The control circuit has U-phase, V-phase, and W-phase regions, and converts DC power input from a DC power supply (not shown) connected to the power supply terminal VCC and ground terminal GND into three-phase AC power and outputs it from the output terminals (U, V, W).

The U-phase region is arranged with the U-phase first switch element Q1, first connector CL1, central wiring section 13U, U-phase second switch element Q4, second connector CL4, source wiring section 15U, shunt resistor R1, ground wiring section 10U, third connector CL7, U-phase third switch element Q7, output wiring section 14U, fourth connector CL10, fifth connector CL13, and sixth connector CL16. In the U-phase region, the power supply terminal VCC is electrically connected to the ground terminal GND via the power supply wiring section 12, first connector CL1, U-phase first switch element Q1, central wiring section 13U, U-phase second switch element Q4, second connector CL4, source wiring section 15U, shunt resistor R1, and ground wiring section 10U. Furthermore, the power supply terminal VCC is electrically connected to the motor terminal U via the central wiring section 13U, the third connector CL7, the U-phase third switch element Q7, and the output wiring section 14U, forming a control circuit for power supplied from the motor terminal U to the three-phase motor.

The V-phase region is arranged with the V-phase first switch element Q2, first connector CL2, central wiring section 13V, V-phase second switch element Q5, second connector CL5, source wiring section 15V, shunt resistor R2, ground wiring section 10V, third connector CL8, V-phase third switch element Q8, output wiring section 14V, fourth connector CL11, fifth connector CL14, and sixth connector CL17. In the V-phase region, the power supply terminal VCC is electrically connected to the ground terminal GND via the power supply wiring section 12, first connector CL2, V-phase first switch element Q2, central wiring section 13V, V-phase second switch element Q5, second connector CL5, source wiring section 15V, shunt resistor R2, and ground wiring section 10V. In addition, the power supply terminal VCC is electrically connected to the motor terminal V via the central wiring section 13V, the third connector CL8, the V-phase third switch element Q8, and the output wiring section 14V, forming a control circuit for power supplied from the motor terminal V to the three-phase motor.

The W-phase region is arranged with the W-phase first switch element Q3, first connector CL3, central wiring section 13W, W-phase second switch element Q6, second connector CL6, source wiring section 15W, shunt resistor R3, ground wiring section 10W, third connector CL9, W-phase third switch element Q9, output wiring section 14W, fourth connector CL12, fifth connector CL15, and sixth connector CL18. In the W-phase region, the power supply terminal VCC is electrically connected to the ground terminal GND via the power supply wiring section 12, first connector CL3, W-phase first switch element Q3, central wiring section 13W, W-phase second switch element Q6, second connector CL6, source wiring section 15W, shunt resistor R3, and ground wiring section 10W. The power supply terminal VCC is also connected to the motor terminal W via the central wiring section 13W, the third connector CL9, the W-phase third switch element Q9, and the output wiring section 14W, forming a control circuit for power supplied from the motor terminal W to the three-phase motor.

The multiple signal terminals 30 include first gate signal terminals GTU, GTV, GTW, center signal terminals STU, STV, STW, second gate signal terminals GBU, GBV, GBW, third gate signal terminals GTU1, GTV1, GTW1, power supply signal terminal VLNKS, first and second thermistor terminals RTP, RTN, first current detection terminals CP1, CP2, CP3, and second current detection terminals CN1, CN2, CN3.

Of the multiple signal terminals 30, the first gate signal terminals GTU, GTV, GTW are connected to the three first gate wiring portions 16U, 16V, 16W, respectively. The central signal terminals STU, STV, STW are connected to the central wiring portions 1U, 13V, 13W, respectively. The second gate signal terminals GBU, GBV, GBW are connected to the second gate wiring portions 17U, 17V, 17W, respectively. The third gate signal terminals GTU1, GTV1, GTW1 are connected to the third gate wiring portions 18U, 18V, 18W, respectively. The power supply signal terminal VLNKS is connected to the power supply wiring portion 12. The first and second thermistor terminals RTP, RTN are connected to the first and second thermistor wiring portions LT1, LT2, respectively. The first current detection terminals CP1, CP2, and CP3 are connected to the first current detection wiring portions LC1U, LC1V, and LC1W, respectively. The second current detection terminals CN1, CN2, and CN3 are connected to the second current detection wiring portions LC2U, LC2V, and LC2W, respectively.

Figure 5 is a plan view showing the arrangement of wiring 138, electronic elements 140, and connectors on a substrate 142 in the electronic module 110 according to the first embodiment. This plan view shows the state without connection via the lead frame 128 of the control circuit shown in Figure 4. Note that the substrate 142 is indicated by the symbol X, and the electronic elements 140 are indicated by the symbols of individual specific elements, such as the switch element Q1. Similarly, the wiring 138 is indicated by a wiring portion and connector, and is indicated by an individual symbol.

Substrate X is rectangular, with two opposing long sides (hereinafter referred to as the first side X1 and the second side X2) and two opposing short sides (hereinafter referred to as the third side X3 and the fourth side X4). One surface (hereinafter referred to as the surface S) of substrate X has multiple wiring sections formed by attaching metal plates, and the other surface (back surface) of substrate X has a heat dissipation metal plate attached. Specifically, on the surface S of substrate X, a rectangular power supply wiring section 12 is provided on the second side X2 side, extending along the second side X2 from near the third side X3 to near the fourth side X4. Between the first gate wiring section 16V and the output wiring section 14W (described later), power supply wiring section 12 extends to the first side X1, with its end having an L-shaped portion extending along the first side X1 toward the fourth side X4.

On the surface S of the substrate X, a U-phase region in which a circuit for controlling the power supplied to the three-phase motor via the motor terminal U is configured, a V-phase region in which a circuit for controlling the power supplied to the three-phase motor via the motor terminal V is configured, and a W-phase region in which a circuit for controlling the power supplied to the three-phase motor via the motor terminal W is configured are formed side by side in this order from the third side X3 toward the fourth side X4.

On the surface S of the substrate X, three central wiring portions 13U, 13V, and 13W, three first gate wiring portions 16U, 16V, and 16W, and three output wiring portions 14U, 14V, and 14W are provided on the first side X1 side adjacent to the power supply wiring portion 12. The central wiring portion 13U extends from the second side X2 to the first side X1 side, with its end portion extending toward the third side X3, forming an L-shape, and is provided adjacent to the third side X3. The central wiring portions 13V and 13W each extend from the second side X2 to the first side X1 side, with its end portion extending toward the fourth side X4, also forming an L-shape. The central wiring portion 13W is provided adjacent to the fourth side X4. The central wiring portion 13V is provided in a position approximately in the center of the long side of the substrate X.

Each of the three first gate wiring portions 16U, 16V, and 16W has a rectangular shape extending from the second side X2 to the first side X1. The first gate wiring portion 16U is located adjacent to the third side X3 and the central wiring portion 13U, and is arranged so that the overall shape when combined with the L-shaped central wiring portion 13U is rectangular. The first gate wiring portion 16W is located adjacent to the fourth side X4 and the central wiring portion 13W, and is arranged so that the overall shape when combined with the L-shaped central wiring portion 13W is rectangular. The first gate wiring portion 16V is located adjacent to the central wiring portion 13V, and is arranged so that the overall shape when combined with the L-shaped central wiring portion 13V is rectangular.

Each of the three output wiring sections 14U, 14V, and 14W has a rectangular shape extending from the second side X2 to the first side X1. The two output wiring sections 14U and 14V are located adjacent to each other between the two central wiring sections 13U and 13V. The output wiring section 14U is located adjacent to the central wiring section 13U, and the output wiring section 14V is located adjacent to the central wiring section 13V. The output wiring section 14W is located adjacent to the central wiring section 13W between the two central wiring sections 13V and 13W.

On the surface S of the substrate X, three second gate wiring portions 17U, 17V, 17W, three source wiring portions 15U, 15V, 15W, three third gate wiring portions 18U, 18V, 18W, and three ground wiring portions 10U, 10V, 10W are provided at positions on the first side X1 adjacent to the central wiring portions 13U, 13V, 13W and the output wiring portions 14U, 14V, 14W. The second gate wiring portion 17U is provided at a position adjacent to the third side X3 and extends from the central wiring portion 13U toward the first side X1 along the third side X3, with its end portion extending along the first side X1 toward the fourth side X4, forming an L-shape. Second gate wiring portion 17W is located adjacent to fourth side X4 and extends from central wiring portion 13W toward first side X1 along fourth side X4, with its end portion extending along first side X1 toward third side X3, forming an L-shape. Second gate wiring portion 17V is located adjacent to central wiring portion 13V and has a rectangular shape extending from central wiring portion 13V toward first side X1.

The two source wiring portions 15U, 15W are rectangular and extend from the second side X2 to the first side X1. The source wiring portion 15U is located adjacent to the central wiring portion 13U and the second gate wiring portion 17U. The source wiring portion 15W is located adjacent to the central wiring portion 13W and the second gate wiring portion 17W. The source wiring portion 15V is located adjacent to the central wiring portion 13V and the second gate wiring portion 17V, extends from the central wiring portion 13V side to the first side X1, and has a generally L-shaped configuration in which the width on the central wiring portion 13V side is larger than the width on the first side X1 side.

The third gate wiring portion 18U is located adjacent to the output wiring portion 14U and extends from the fourth side X4 to the third side X3 along the output wiring portion 14U, with its end extending along the first side X1 along the source wiring portion 15U, forming a generally L-shaped configuration. The end of the third gate wiring portion 18U on the third side X3 side (the corner of the L-shape) has a notch to avoid the central wiring portion 13U. The third gate wiring portion 18V is located adjacent to the output wiring portion 14V and extends from the third side X3 to the fourth side X4 along the output wiring portion 14V, with its end extending along the first side X1 along the source wiring portion 15V, forming a generally L-shaped configuration.

A notch is provided at the end of the third gate wiring portion 18V on the fourth side X4 side (corner of the L-shape) so as to avoid the central wiring portion 13V. The third gate wiring portion 18W is located adjacent to the output wiring portion 14W and extends from the third side X3 side to the fourth side X4 side along the output wiring portion 14W, with its end extending along the source wiring portion 15V to the first side X1 side, forming a roughly L-shape. A notch is provided at the end of the third gate wiring portion 18W on the fourth side X4 side (corner of the L-shape) so as to avoid the central wiring portion 13W.

Ground wiring section 10U (first ground wiring section) is located adjacent to third gate wiring section 18U and has a generally rectangular shape extending from the third gate wiring section 18U side toward first side X1. The width of ground wiring section 10U on the third gate wiring section 18U side is slightly larger than the width on the first side X1 side. Ground wiring section 10V (second ground wiring section) is located adjacent to third gate wiring section 18V and ground wiring section 10U and has a generally rectangular shape extending from the third gate wiring section 18V side toward first side X1 along ground wiring section 10U. The width of ground wiring section 10V on the third gate wiring section 18V side is slightly larger than the width on the first side X1 side. Ground wiring section 10W (third ground wiring section) is located adjacent to third gate wiring section 18W and has a rectangular shape extending from the third gate wiring section 18W side toward first side X1.

On the surface S of the substrate X, three first current detection wiring portions LC1U, LC1V, and LC1W, three second current detection wiring portions LC2U, LC2V, and LC2W, one first thermistor wiring portion LT1, and one second thermistor wiring portion LT2 are provided on the first side X1 side. The first and second thermistor wiring portions LT1 and LT2 are provided side by side in a direction along the first side X1, between the second gate wiring portion 17V and the first side X1. The first and second thermistor wiring portions LT1 and LT2 extend from the second gate wiring portion 17V toward the first side X1, and are bent diagonally in a crank shape at their midpoints.

The first current detection wiring section LC1U is located adjacent to the source wiring section 15U and extends from the second side X2 to the first side X1 along the source wiring section 15U, with its end extending to the third side X3, forming an L-shape. The end of the first current detection wiring section LC1U on the second side X2 is connected to the source wiring section 15U below the shunt resistor R1. The first current detection wiring section LC1V is located adjacent to the source wiring section 15V and extends from the second side X2 to the first side X1 along the source wiring section 15V, with its end extending to the fourth side X4, forming an L-shape.

The end of the first current detection wiring section LC1V on the second side X2 is connected to the source wiring section 15V below the shunt resistor R2. The first current detection wiring section LC1W is located adjacent to the source wiring section 15W and extends along the source wiring section 15W from the second side X2 to the first side X1, with its end extending to the third side X3, forming an L-shape. The end of the first current detection wiring section LC1W on the second side X2 is connected to the source wiring section 15V below the shunt resistor R3.

The second current detection wiring section LC2U is located adjacent to the ground wiring section 10U and extends from the second side X2 to the first side X1 along the ground wiring section 10U, with its end extending toward the fourth side X4, forming an L-shape. The end of the second current detection wiring section LC2U on the second side X2 is connected to the ground wiring section 10U below the shunt resistor R1. The second current detection wiring section LC2V is located adjacent to the ground wiring section 10V and extends from the second side X2 to the first side X1 along the ground wiring section 10V, with its end extending toward the third side X3, forming an L-shape. The end of the second current detection wiring section LC2V on the second side X2 is connected to the ground wiring section 10U below the shunt resistor R2.

The second current detection wiring section LC2W is located adjacent to the ground wiring section 10W and extends along the ground wiring section 10W from the second side X2 to the first side X1, with its end extending toward the third side X3, forming an L-shape. The end of the second current detection wiring section LC2W on the second side X2 is connected to the ground wiring section 10W below the shunt resistor R3.

The connectors are made by bending a plate-shaped conductive material. The three first connectors CL1-CL3, three second connectors CL4-CL6, three third connectors CL7-CL9, three fourth connectors CL10-CL12, three fifth connectors CL13-CL15, and three sixth connectors CL16-CL18 each have a first connection portion that connects to an electrode on the top surface of each switch element, a second connection portion that connects to a wiring portion on surface S, and a linking portion that connects the first and second connection portions. These linking portions have a roughly U-shaped arch shape in cross section to prevent short-circuiting between the two wiring portions connected by the connector. The three first connectors CL1-CL3, the three second connectors CL4-CL6, and the three third connectors CL7-CL9 connect the source electrodes of each switch element to the wiring on surface S, and all have the same shape.

The first connection portions of these connectors have a width corresponding to the width of the source electrode, and the second connection portions are narrower than the first connection portions. The three fourth connection portions CL10 to CL12, the three fifth connection portions CL13 to CL15, and the three sixth connection portions CL16 to CL18 connect the gate electrodes of each switch element to the wiring portion on surface S, and all have the same shape. The first connection portions of these connectors have a width corresponding to the width of the gate electrode, and the second connection portions are wider than the first connection portions.

The U-phase first switch element Q1, V-phase first switch element Q1, and W-phase first switch element Q1 are each disposed on the power supply wiring section 12. The U-phase first switch element Q1 is located near the third side X3 on the power supply wiring section 12. The V-phase first switch element Q2 is located approximately in the center of the power supply wiring section 12 in the direction along the second side X2. The W-phase first switch element Q3 is located near the fourth side X4 on the power supply wiring section 12. The U-phase first switch element Q1, V-phase first switch element Q1, and W-phase first switch element Q1 each have a source electrode and a gate electrode formed side by side on the front surface of each switch element, and a drain electrode formed on the back surface. The gate electrode of the U-phase first switch element Q1 is located on the third side X3 side, and the drain electrode is connected to the power supply wiring section 12.

The source electrode of the U-phase first switch element Q1 is connected to the central wiring portion 13U via the first connector CL1, and the gate electrode of the U-phase first switch element Q1 is connected to the first gate wiring portion 16U via the fourth connector CL10. The V-phase first switch element Q2 is arranged so that its gate electrode faces the fourth side X4, and its drain electrode is connected to the power supply wiring portion 12.

The source electrode of the V-phase first switch element Q2 is connected to the central wiring portion 13V via the first connector CL2, and the gate electrode of the V-phase first switch element Q2 is connected to the first gate wiring portion 16V via the fourth connector CL11. The W-phase first switch element Q3 is arranged so that its gate electrode is positioned on the fourth side X4 side and its drain electrode is connected to the power supply wiring portion 12. The source electrode of the W-phase first switch element Q3 is connected to the central wiring portion 13W via the first connector CL3, and the gate electrode of the W-phase first switch element Q3 is connected to the first gate wiring portion 16W via the fourth connector CL12.

The U-phase second switch element Q4, the V-phase second switch element Q4, and the W-phase second switch element Q6 are respectively disposed on the first side X1 of the central wiring portions 13U, 13V, and 13W. The U-phase second switch element Q4, the V-phase second switch element Q4, and the W-phase second switch element Q6 each have a source electrode and a gate electrode formed side by side on the front surface of the switch element, and a drain electrode formed on the back surface. The U-phase second switch element Q4 is disposed such that its gate electrode is disposed on the third side X3 and its drain electrode is connected to the central wiring portion 13U. The source electrode of the U-phase second switch element Q4 is connected to the source wiring portion 15U via the second connector CL4, and the gate electrode of the U-phase second switch element Q4 is connected to the second gate wiring portion 17U via the fifth connector CL13. The V-phase second switch element Q5 is disposed such that its gate electrode faces the fourth side X4 and its drain electrode is connected to the central wiring portion 13V.

The source electrode of the W-phase second switch element Q5 is connected to the source wiring portion 15V via the second connector CL5, and the gate electrode of the W-phase second switch element Q5 is connected to the second gate wiring portion 17V via the fifth connector CL14. The W-phase second switch element Q6 is arranged so that its gate electrode is disposed on the fourth side X4 side and its drain electrode is connected to the central wiring portion 13W. The source electrode of the W-phase second switch element Q6 is connected to the source wiring portion 15W via the second connector CL6, and the gate electrode of the W-phase second switch element Q6 is connected to the second gate wiring portion 17W via the fifth connector CL15.

The U-phase third switch element Q7, the V-phase third switch element Q8, and the W-phase third switch element Q9 are located approximately in the center of the output wiring sections 14U, 14V, and 14W, respectively. The U-phase third switch element Q7, the V-phase third switch element Q8, and the W-phase third switch element Q9 each have a source electrode and a gate electrode formed side by side on the front surface of the switch element, and a drain electrode formed on the back surface. The U-phase third switch element Q7 is disposed so that its gate electrode faces the first side X1, and its drain electrode is connected to the output wiring section 14U. The source electrode of the U-phase third switch element Q7 is connected to the central wiring section 13U via the third connector CL7, and its gate electrode is connected to the third gate wiring section 18U via the sixth connector CL16. The V-phase third switch element Q8 is disposed so that its gate electrode faces the first side X1, and its drain electrode is connected to the output wiring section 14V.

The source electrode of the V-phase third switch element Q8 is connected to the central wiring portion 13V via the third connector CL8, and the gate electrode of the V-phase third switch element Q8 is connected to the third gate wiring portion 18V via the sixth connector CL17. The W-phase third switch element Q9 is arranged so that its gate electrode faces the first side X1 and its drain electrode is connected to the output wiring portion 14W. The source electrode of the W-phase third switch element Q9 is connected to the central wiring portion 13W via the third connector CL9, and the gate electrode of the W-phase third switch element Q9 is connected to the third gate wiring portion 18W via the sixth connector CL18.

The three shunt resistors R1 to R3 are respectively provided on the first side X1 of the source wiring sections 15U, 15V, 15W and the ground wiring sections 10U, 10V, 10W, straddling the source wiring sections 15U, 15V, 15W and the ground wiring sections 10U, 10V, 10W. Shunt resistor R1 is provided straddling the source wiring section 15U to connect it to the ground wiring section 10U. Shunt resistor R2 is provided straddling the source wiring section 15V to connect it to the ground wiring section 10V. Shunt resistor R3 is provided straddling the source wiring section 15W to connect it to the ground wiring section 10W.

The thermistor RT is arranged across the end of the first thermistor wiring portion LT1 on the second side X2 and the end of the second thermistor wiring portion LT2 on the second side X2.

The power supply terminal VCC, the three motor terminals U, V, and W, and the ground terminal GND are arranged so that the external connection portions of each terminal, which are connected to a substrate other than the substrate X, are aligned along the second side X2 at positions outside the second side X2. Starting from the third side X3, the motor terminal U, motor terminal V, ground terminal GND, power supply terminal VCC, and motor terminal W are arranged in this order.

The power supply terminal VCC has an external connection portion located outside the sealing member A, a base portion connected to the external connection portion, and an internal connection portion provided at the tip portion extending from the base portion. The internal connection portion of the power supply terminal VCC is connected to the power supply wiring portion 12 at a position to the side of the first switch element Q2 mounted on the power supply wiring portion 12. The external connection portion of the power supply terminal VCC extends from the internal connection portion in the direction of the second side X2 and is located at a position protruding outside the sealing member A.

Motor terminal U is connected to output wiring section 14U. Motor terminal V is connected to output wiring section 14V. Motor terminal W is connected to output wiring section 14W.

The multiple signal terminals 30 include three first gate signal terminals GTU, GTV, and GTW, three central signal terminals STU, STV, and STW, three second gate signal terminals GBU, GBV, and GBW, three third gate signal terminals GTU1, GTV1, and GTW1, a power supply signal terminal VLNKS, first and second thermistor terminals RTP and RTN, three first current detection terminals CP1, CP2, and CP3, and three second current detection terminals CN1, CN2, and CN3. The multiple signal terminals 30 are arranged so that the external connection portions of each terminal, which are connected to a substrate or the like other than the substrate X, are aligned along the first side X1 at positions outside the first side X1.

The first lead frame 130 is connected one-to-one to external connection parts (not shown) located outside the sealing member through each wiring part (connection part) in Figure 5, based on the correspondence shown in Figure 4. The first lead frame 130 of the ground terminal GND connects the external connection parts (not shown) located outside the sealing member to the internal ground wiring parts 10U, 10V, and 10W.

When there are multiple electronic elements 140, the first lead frame 130 preferably equalizes the wiring inductance to each of the connection points of the multiple electronic elements 140. The electronic elements 140 are at least switching elements or rectifying elements, and at least a portion of the first lead frame is formed to cover all or part of at least the switching elements or rectifying elements. It is also preferable that at least a portion of the first lead frame 130 functions as a ground terminal. Furthermore, it is preferable that terminals through which high voltages and large currents flow in response to control signals are arranged together on the first lead frame 130. Therefore, by equalizing the wiring inductance to each of the connection points of the multiple electronic elements 140, i.e., the inductance of each lead frame, the electromotive force generated by changes in the flowing current is equalized, thereby stabilizing the control of the electronic elements 140 and reducing noise.

The inductance Ls of the lead frame is calculated by the following formula, where L is the length of each lead frame, W is the width, and H is the thickness.

This calculation formula makes it possible to design the first lead frame 130 so that each inductance is equal.

Figure 6 shows the first embodiment. Figure 6(A) is a plan view, and Figure 6(B) is a cross-sectional view. A lead frame is provided on a substrate 142 on which an electronic element 140 is mounted via wiring 138 and connectors. The first lead frame 130 includes a W-phase lead frame 118, a power lead frame 120, a ground lead frame 122, a V-phase lead frame 124, and a U-phase lead frame 126, and the impedance of each lead frame is equalized. Since the ground lead frame 122 requires wiring to three locations on the substrate 142, the ground lead frame 122 is branched into three branches: ground branch lead frame 123U, ground branch lead frame 123V, and ground branch lead frame 123W. The second lead frame 132 is the lead frame for the signal terminal portion 134.

As shown in Figure 6(B), each lead frame located on the substrate 142 is formed three-dimensionally on the surface of the substrate 142 on which the electronic element 140 is mounted.

Second Embodiment
7A and 7B are diagrams showing a second embodiment. Fig. 7A is a plan view, and Fig. 7B is a cross-sectional view. The difference from the first embodiment is that the grounding branch lead frame 123U, the grounding branch lead frame 123V, and the grounding branch lead frame 123W are provided in spatial positions different from the other lead frames. The rest is the same as the first example.

By arranging grounding branch lead frame 123U, grounding branch lead frame 123V, and grounding branch lead frame 123W in a different spatial position from the other lead frames, they can be formed three-dimensionally in multiple layers at opposing positions on the surface of substrate 142 on which electronic element 140 is mounted. This makes it possible to arrange lead frames even when they overlap at opposing positions on the surface of substrate 142, thereby reducing impedance.

(Third embodiment)
8A and 8B are diagrams showing a third embodiment. Fig. 8A is a plan view, and Fig. 8B is a cross-sectional view. The difference from the second embodiment is that a common ground lead frame 123C is provided on the ground branch lead frame 123U, the ground branch lead frame 123V, and the ground branch lead frame 123W. The rest is the same as the second embodiment.

By providing the common grounding lead frame 123C, when there are multiple first lead frames 130, a terminal temperature equalization structure is formed that equalizes the terminal temperatures of each of the multiple first lead frames 130. The common grounding lead frame 123C is a flat lead frame that covers the surface of the substrate, and covers all or at least part of the switching elements and rectifying elements, as well as the other first lead frames 130, resulting in a structure that equalizes the terminal temperatures.

In the electronic module 110 according to the third embodiment, the inductance of the first lead frame 130 is equalized, and the electromotive force generated by changes in current flowing through the electronic element 140 to which the first lead frame 130 is connected is equalized, thereby stabilizing the control of the electronic element. At least a portion of the first lead frame 130 is formed to cover all or at least a portion of the switching element and rectifying element, thereby particularly reducing the parasitic inductance of the circuit wiring formed within the electronic module 110. Reducing parasitic inductance also contributes to reducing losses and noise during operation of the electronic element.

Furthermore, because the grounding common lead frame 123C is formed from a flat plate, it not only contributes to heat dissipation from the electronic element 140, but also has the effect of blocking electromagnetic noise emitted from the electronic element 140. The grounding common lead frame 123C particularly reduces the parasitic inductance of the circuit wiring in the ground potential portion formed within the electronic module 110. Reducing parasitic inductance also contributes to reducing losses and noise during operation, particularly for electronic elements with large current capacities. Furthermore, the structure of the grounding common lead frame 123C, which is formed from a common flat lead frame, not only contributes to heat dissipation from electronic elements with large current capacities, but also has the effect of blocking electromagnetic noise emitted from electronic elements with large current capacities.

(Fourth embodiment)
9A and 9B are diagrams showing a fourth embodiment. Fig. 9A is a plan view, and Fig. 9B is a cross-sectional view. The difference from the third embodiment is that a notch 146 and a hole 148 are provided in the grounding common lead frame 123C. The rest is the same as the third example.

By providing at least the notch 146 or the hole 148 in the common grounding lead frame 123C, the lead frame becomes a terminal temperature equalization structure. There may be multiple notches 146 and holes 148. Because the common grounding lead frame 123C has the notch 146 or the hole 148, the terminal temperature equalization structure can reduce inductance with a simple structure while equalizing the terminal temperatures of the power supply terminal, output terminal, and ground terminal.

The terminal temperature equalization structure is a configuration in which the area and shape of the lead frame are set so that the terminal temperature is equalized. When setting the area and shape of the lead frame, thermal resistance is set so that the terminal temperature is equalized. This thermal resistance setting can be adjusted by adjusting the surface shape of the lead frame in addition to the notches and holes mentioned above. With this configuration, it is possible to reduce inductance with a simple structure while equalizing the terminal temperatures of the power supply terminals, output terminals, and ground terminals.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and applications are possible without departing from the spirit and scope of the present invention.

30 Multiple signal terminals 110 Electronic module 112 Electronic module main body 114 Heat dissipation portion 116 Signal lead frame 118 W-phase lead frame 120 Power supply lead frame 122 Ground lead frame 123U Ground branch lead frame 123V Ground branch lead frame 123W Ground branch lead frame 123C Ground common lead frame 124 V-phase lead frame 126 U-phase lead frame 128 Lead frame 130 First lead frame 132 Second lead frame 134 Signal terminal portion 136 Connector 138 Wiring 140 Electronic element 142 Substrate 144 Electrode portion 146 Notch portion 148 Hole portion

Claims (4)

1. An electronic module for controlling power supplied to a three-phase motor from a power source, comprising:
a control circuit in which a first switching element, a second switching element, a third switching element, a fourth switching element, a fifth switching element, and a sixth switching element are mounted on a substrate including a common power supply region, a first ground region, a second ground region, a third ground region, a first output region, a second output region, and a third output region;
a first lead frame electrically connected to the common power supply region;
a second lead frame electrically connected to the first output region;
a third lead frame electrically connected to the second output region;
a fourth lead frame electrically connected to the third output region;
a fifth lead frame electrically connected to the first ground region, the second ground region, and the third ground region;
the first lead frame is directly connected to the common power supply region by three-dimensional wiring;
the second lead frame is directly connected to the first output region by three-dimensional wiring;
the third lead frame is directly connected to the second output region by three-dimensional wiring,
the fourth lead frame is directly connected to the third output region by three-dimensional wiring,
the fifth lead frame is directly connected to the first ground area, the second ground area, and the third ground area by three-dimensional wiring;
Furthermore, the fifth lead frame has a structure in which a base end is connected and a tip end is branched into three, and the three tip end portions are connected to the first ground region, the second ground region, and the third ground region,
Furthermore, the fifth lead frame is characterized in that it has a portion extending from the base end to the tip end that is located at the same spatial height as the first lead frame, the second lead frame, the third lead frame, and the fourth lead frame. 1. An electronic module for controlling power supplied to a three-phase motor from a power source, comprising:
a control circuit in which a first switching element, a second switching element, a third switching element, a fourth switching element, a fifth switching element, and a sixth switching element are mounted on a substrate including a common power supply region, a first ground region, a second ground region, a third ground region, a first output region, a second output region, and a third output region;
a first lead frame electrically connected to the common power supply region;
a second lead frame electrically connected to the first output region;
a third lead frame electrically connected to the second output region;
a fourth lead frame electrically connected to the third output region;
a fifth lead frame electrically connected to the first ground region, the second ground region, and the third ground region;
the first lead frame is directly connected to the common power supply region by three-dimensional wiring;
the second lead frame is directly connected to the first output region by three-dimensional wiring;
the third lead frame is directly connected to the second output region by three-dimensional wiring,
the fourth lead frame is directly connected to the third output region by three-dimensional wiring,
the fifth lead frame is directly connected to the first ground area, the second ground area, and the third ground area by three-dimensional wiring;
Furthermore, the fifth lead frame has a structure in which a base end is connected and a tip end is branched into three, and the three tip end portions are connected to the first ground region, the second ground region, and the third ground region,
Furthermore, the fifth lead frame has a portion extending from the base end to the tip end that is located at a spatial position above the first lead frame, the second lead frame, the third lead frame, and the fourth lead frame. 1. An electronic module for controlling power supplied to a three-phase motor from a power source, comprising:
a control circuit in which a first switching element, a second switching element, a third switching element, a fourth switching element, a fifth switching element, and a sixth switching element are mounted on a substrate including a common power supply region, a first ground region, a second ground region, a third ground region, a first output region, a second output region, and a third output region;
a first lead frame electrically connected to the common power supply region;
a second lead frame electrically connected to the first output region;
a third lead frame electrically connected to the second output region;
a fourth lead frame electrically connected to the third output region;
a fifth lead frame electrically connected to the first ground region, the second ground region, and the third ground region;
the first lead frame is directly connected to the common power supply region by three-dimensional wiring;
the second lead frame is directly connected to the first output region by three-dimensional wiring;
the third lead frame is directly connected to the second output region by three-dimensional wiring,
the fourth lead frame is directly connected to the third output region by three-dimensional wiring,
the fifth lead frame is directly connected to the first ground area, the second ground area, and the third ground area by three-dimensional wiring;
The electronic module further comprises a common grounding lead frame portion configured as a wide rectangle so as to cover the first switching element, the second switching element, the third switching element, the fourth switching element, the fifth switching element, and the sixth switching element. 4. The electronic module of claim 3,
An electronic module characterized in that a notch or a hole is provided in the common ground lead frame portion.