ELECTRONIC MODULE

Abstract

An electronic module 100 according to the present invention comprises: a circuit 120; a first terminal 130; a first retaining nut 230 for fastening an external connecting element 250 to the first terminal 130 by means of a screw 260; and a sealing resin 170 that seals the circuit 120 and a portion of the first terminal 130. Assuming that the surface of the electronic module 100 where the first terminal 130 is exposed by the sealing resin 170 is designated as the upper surface 100A, and that the surfaces of the electronic module 100 on one side opposite the surface are designated as the lower surfaces 100B and 100C, the lower surface 100B projects from the lower surface 100C in the area where the first retaining nut is located, and from the lower surface 100C in the area where the circuit is located.According to the electronic module 100 of the present invention, the wiring resistance and inductance can also be reduced when a power cable is attached to the terminal with the union nut.

Description

[Cross-reference]

[0001] This application claims priority over Japanese patent application 2023-074802, filed on April 28, 2023, the entire contents of which are incorporated into the present application by reference. [Technical field]

[0002] The present invention relates to an electronic module. [State of the art]

[0003] Several structures have been proposed so far for attaching a power cable to a connector of a semiconductor module. Fig. Figure 6 is a view showing a prior art electronic module. Patent reference 1 describes an idea relating to a conductor-connection structure for electrically connecting a terminal 911 of a transistor 901 to a wiring structure 914 on a printed circuit board 902. More precisely, the conductor-connection structure consists of: a plate 915 made of an insulating material, which is provided for pressing the conductor 911 of the transistor 901 against it; and a screw 916, which is provided for fastening the plate 915 to the printed circuit board 902, thereby pressing the plate 915 against the printed circuit board 902 with sufficient pressure.

[0004] On the other hand, a structure was also provided that secures an electrical power cable with a union nut. Patent reference 2 discloses an invention relating to a connection structure of a power semiconductor module, which has a resin mount in which a union nut (insertion nut) is embedded. Patent reference 2 describes how an electrical power cable is connected to a power semiconductor module such that a fastening screw engages with a union nut by tightening, with a connecting terminal being inserted between a conductive socket and a head portion of the fastening screw. [State of the art literature][Patent literature] [Patent Literature 1]: JP-U-3-20461 [Patent Literature 2]: WIPO 2016 / 204306 [Brief description of the invention][Technical problem]

[0005] In a case where an external connection (an electrical power cable) is attached to a terminal of an electronic device with a locking nut that prevents the screw from loosening, the locking nut must have a predetermined length in the direction of the screw's fastening. Consequently, the thickness of the electronic device increases. Since the thickness of the electronic device is correspondingly large due to the length of the locking nut, the circuitry is positioned on a lower part of the electronic device to facilitate heat dissipation. However, the distance between the circuitry and the external connection attached to the terminal is increased by an amount corresponding to the increase in the thickness of the electronic device. This has the disadvantage of increasing the conductor resistance and inductance.

[0006] It is therefore an objective of the present invention to provide an electronic module that can reduce the wiring resistance or inductance even in a case where an external connecting element is attached to a terminal with a union nut. [Solution to the problem]

[0007] An electronic module of the present invention comprises a circuit, a first terminal, a first retaining nut for fastening an external connecting element to the first terminal by means of a screw, and a sealing resin that seals the circuit and part of the first terminal. Assuming a surface of the electronic module where the first terminal is exposed by the sealing resin as the upper surface, and a surface of the electronic module on one side opposite the surface as the lower surface, the lower surface projects from the lower surface in the area where the first retaining nut is located, and from the lower surface in the area where the circuit is located. [Advantageous effects of the present invention]

[0008] In the electronic module of the present invention, the lower surface projects beyond the lower surface in the area where the first union nut of the electronic module is located, in the area where the circuitry is located. With such a configuration, sufficient length (height) between the upper and lower surfaces of the electronic module can be ensured in the area where the first union nut is located. This makes it possible to ensure sufficient thread clearance to allow the internal thread formed in the first union nut and the thread formed on a screw to engage, thus preventing the screw from loosening when the external connecting element is fastened to the first terminal.

[0009] On the other hand, the lower surface in the area where the circuit is located is positioned closer to the upper surface of the electronics module compared to the lower surface in the area where the first locking nut is located. This allows the circuit and the first connection to be positioned close together, thereby reducing the wiring resistance and inductance of the electronics module. [Brief description of the drawings] Fig. Figure 1 is a perspective view of an electronic module 100 according to one embodiment. Fig. Figure 2 is an external view of the electronic module 100 according to the embodiment. Fig. 3 is a cross-sectional view along a line AA in Fig. 2(a). Fig. Figure 4 is a view describing an internal structure of the electronic module 100 according to the embodiment. Fig. Figure 5 is a view that describes a state in which external connecting elements 250 are attached to the electronic module 100 by screws 260 according to the embodiment. Fig. Figure 6 is a view showing a state-of-the-art electronics module. [Description of the embodiments]

[0010] An electronic module according to the present invention is described below. The embodiment described below is not intended to limit the invention as defined in the claims. Furthermore, not all elements and combinations of these elements described in the embodiment are necessarily essential for the present invention.

[0011] Fig. Figure 1 is a perspective view of the electronics module 100 according to one embodiment. Fig. Figure 2 is an external view of the electronic module 100 according to the embodiment. Fig. 2(a) is a top view of electronic module 100. Fig. 2(b) is a side view of electronic module 100. Fig. 2(c) is a top view of electronic module 100. Fig. Figure 3 is a cross-sectional view along line AA in Fig. 1. Fig. Figure 4 is a view describing the internal structure of the electronic module 100 according to the embodiment. Fig. Figure 5 is a view that describes a state in which external connecting elements 250 are attached to the electronic module 100 by screws 260 according to the embodiment.

[0012] The following description, as in the Fig. 1 and Fig. As shown in Figure 2, the longitudinal direction of the electronic module 100 is described as a front-back direction, and the transverse direction as a left-right direction. The vertical direction of the electronic module 100 is described as an up-down direction. The terms "front," "back," "left," "right," "up," and "down" in the following description serve to simplify the description and do not indicate the direction in which the electronic module 100 is mounted during use.

[0013] As in the Fig. As shown in Figures 1 to 4, the electronics module 100 is elongated in the front-to-back direction and has an approximately rectangular, parallelepiped body shape that is flat in the top-to-bottom direction. The electronics module 100 includes a circuit 120, a first terminal 130, a second terminal 140, a first wiring 132B, a second wiring 142B, a first union nut 230, a second union nut 240, signal terminals 172, 174, 182, 184, and a sealing resin 170.

[0014] In the following description, “the first connection 130, the second connection 140” can also be referred to as “connections 130, 140” and “the first union nut 230, the second union nut 240” can also be referred to as “union nuts 230, 240”.

[0015] Circuit 120 includes wires and devices. The devices include, for example, power metal oxide semiconductor field-effect transistors (power MOSFETs).

[0016] A printed circuit board 112 is, for example, a direct copper bond board (DCB board) in which the circuit 120 is formed on one side of a ceramic plate and a metal is formed on the other side of the ceramic plate for heat dissipation. The printed circuit board 112 can be a printed circuit board or similar. It is desirable that the printed circuit board 112 be formed in a rectangular, flat plate shape and be arranged on a central section of the electronic module 100 in a front-to-back direction, which forms the longitudinal direction.

[0017] As in the Fig. As shown in Figures 1 to 4, the first terminal 130 is arranged in a front-to-back direction on a front face of the electronic module 100. The first terminal 130 consists of a plate element 132A, which is formed from a flat, electrically conductive plate element such as a copper plate. The first terminal 130 has a through-hole (without a reference numeral) that penetrates the first terminal 130 in a top-to-bottom direction. Viewed from top to bottom, the through-hole has, for example, a circular shape. The shape of the through-hole is not limited to a circular shape but can also be a polygonal shape, such as a hexagon.

[0018] An upper end of the first union nut 230 engages by fitting into the through-hole. In this case, it is desirable that the height of an upper surface of the first union nut 230 be equal to or less than the height of an upper surface of the first terminal 130. If the external connecting element 250 is positioned on the upper surface of the first terminal 130 and fastened to the upper surface of the first terminal 130 by screws 260, such a configuration ensures a reliable electrical connection between the first terminal 130 and the external connecting element 250 (see Fig. 5).

[0019] The lower surface of the first terminal 130 and the first union nut 230 are embedded in the sealing resin 170. Conversely, the upper surface of the first terminal 130 is exposed to the outside of the sealing resin 170. By positioning the external connecting element 250 on the upper surface of the first terminal 130, which is exposed by the sealing resin 170, and by fastening the external connecting element 250 to the upper surface of the first terminal 130 with a screw 260, the electrical connection between the first terminal 130 and the external connecting element 250 can be established.

[0020] The first union nut 230 will be described later.

[0021] The first wiring 132B is electrically connected to the first terminal 130. The first wiring 132B is embedded in the sealing resin 170.

[0022] In the electronics module 100, the first wiring 132B is formed integrally with the first connection 130 using the same plate element 132. This means that a portion of the plate element 132, which is embedded in the sealing resin 170, corresponds to the first wiring 132B.

[0023] The first wiring 132B has a through-hole (without reference numeral) that vertically penetrates the first wiring 132B. Viewed from top to bottom, the through-hole is circular. An upper end section of an internal connecting electrode 134 engages by fitting into the through-hole. The first wiring 132B and an electrode (without reference numeral) of the circuit 120 are connected to each other by the internal connecting electrode 134. The internal connecting electrode 134 is attached to the first wiring 132B, for example, by a press fit.

[0024] As in the Fig. As shown in Figures 1 to 4, the second terminal 140 is located on the rear side of the electronic module 100, oriented front-to-back. The second terminal 140 consists of a plate element 142A, which is formed from a flat, electrically conductive plate such as a copper plate. The second terminal 140 has a through-hole (without a reference numeral) that penetrates the second terminal 140 in a top-to-bottom direction. Viewed from top to bottom, the through-hole has, for example, a circular shape. The shape of the through-hole is not limited to a circular shape but can also be a polygonal shape, such as a hexagon.

[0025] An upper end of the second union nut 240 engages by fitting into the through-hole. In this case, it is desirable that the height of an upper surface of the second union nut 240 be equal to or less than the height of an upper surface of the second terminal 140. If the outer connecting element 250 is positioned on the upper surface of the second terminal 140 and fastened to the upper surface of the second terminal 140 by a screw 260, such a configuration ensures a reliable electrical connection between the second terminal 140 and the outer connecting element 250 (see Fig. 5).

[0026] The lower surface of the second terminal 140 and the second union nut 240 are embedded in the sealing resin 170. The upper surface of the second terminal 140, on the other hand, is exposed to the outside of the sealing resin 170. By positioning the external connecting element 250 on the upper surface of the second terminal 140, which is exposed by the sealing resin 170, and by fastening the external connecting element 250 to the upper surface of the second terminal 140 by means of the screw 260, the electrical connection between the second terminal 140 and the external connecting element 250 can be established.

[0027] The second union nut 240 will be described later.

[0028] The second wiring 142B is electrically connected to the second terminal 140. The second wiring 142B is embedded in the sealing resin 170.

[0029] In the electronics module 100, the second wiring 142B is formed integrally with the second connection 140 using the same plate element 142. This means that a portion of the plate element 142, which is embedded in the sealing resin 170, corresponds to the second wiring 142B.

[0030] The second wiring 142B has four through-holes (without reference numerals) that penetrate the second wiring 142B in a top-to-bottom direction. The through-holes are circular when viewed from top to bottom. An upper end section of an internal connecting electrode 144 engages by fitting into each of the four through-holes. The second wiring 142B and electrodes (not shown in the drawing) of the circuit 120 are connected to each other by four internal connecting electrodes 144. The internal connecting electrodes 144 are attached to the second wiring 142B, for example, by a press fit. The number of through-holes and the number of internal connecting electrodes 144 mentioned above can be set to any number from one to more, without being limited to four, provided that the required current flow is permitted.

[0031] The electronic module 100 can have a third connection 160. The third connection 160 is any constituent element. As in Fig. As shown in Figures 1 to 4, the third terminal 160 is formed from a flat plate element with electrical conductivity, such as a copper plate. The third terminal 160 is arranged such that the direction of the plate thickness forms the front-back direction and is formed in an elongated shape, with the top-bottom direction defined as the longitudinal direction. The third terminal 160 has a section exposed by the sealing resin 170 (hereinafter referred to as the "upper section") and a section covered by the sealing resin 170 (hereinafter referred to as the "lower section").

[0032] A through-hole (without reference numeral) penetrating the third terminal 160 in a front-to-back direction is formed in an upper section of the third terminal 160. In this configuration, an external connector (not shown in the drawing) can be fastened to the third terminal 160 by means of a screw (not shown in the drawing) and a nut (not shown in the drawing). Furthermore, one end of a cap nut (not shown in the drawing) can engage by fitting it into the through-hole. With this configuration, it is possible to reliably establish an electrical connection between the third terminal 160 and the external connector when the external connector is fastened to the third terminal 160 by the screw.

[0033] A lower section of the third terminal 160 is connected to an electrode (not shown in the drawing) of the circuit 120.

[0034] The electronic module 100 can have a third wiring connection 152. The third wiring connection 152 is any constituent element. The third wiring connection 152 is electrically connected to the third terminal 160. The third wiring connection 152 can be arranged on the same plane as the first wiring connection 132B and the second wiring connection 142B.

[0035] The third wire 152 has a through-hole (without reference numeral) that penetrates the third wire 152 in a top-to-bottom direction. Viewed vertically, the through-hole has a circular shape. An upper end section of an internal connecting electrode 154 engages by fitting into the through-hole. The third wire 152 and an electrode (not shown in the drawing) of the circuit 120 are connected to each other. The internal connecting electrode 154 is attached to the third wire 152, for example, by an interference fit.

[0036] Electronic module 100 has signal connections 172, 174, 182, 184. These signal connections can be any constituent elements. As in Fig. As shown in Figure 4, each of the signal terminals 172, 174, 182, 184 has: a pin terminal (without reference numeral) that is column-shaped, for example in a circular column form; and a support element (without reference numeral) that is in the form of a flat plate. The support element is a flat, plate-shaped element with electrical conductivity, which is produced by stamping a copper plate.

[0037] The signal terminals 172, 174, 182, 184 are arranged so that they protrude upwards from the sealing resin 170. Each of the signal terminals 172, 174, 182, 184 has a section exposed by the sealing resin 170 and a section covered by the sealing resin 170. The sections of the signal terminals 172, 174, 182, 184 covered by the sealing resin 170 are electrically connected to the electrodes of the circuit 120. The sections of the signal terminals 172, 174, 182, 184 exposed by the sealing resin 170 can be connected to external connecting elements, which are not shown in the drawing.

[0038] As in Fig. As shown in Figure 3, each of the union nuts 230 and 240 is a nut where one side is closed, so that a threaded hole does not penetrate the nut. The union nuts 230 and 240 are designed such that one side of the nut described above is closed. If the circuit 120, the first wiring 132B, and the second wiring 142B of the electronic module 100 are sealed with the sealing resin 170, the union nuts 230 and 240 can be used without any restriction, provided that the sealing resin 170 does not flow from the closed side of the nut into the threaded hole. The designation of the union nuts 230 and 240 is also significant. The union nuts 230, 240 are essentially nuts that are commercially available under the names cap nuts, blind nuts, decorative nuts and the like.

[0039] The shape of a section of the two union nuts 230, 240, which engages with the first port 130 or the second port 140 by means of a fitting, is not limited, provided that the two union nuts 230, 240 engage with the through-hole formed in the first port 130 or the second port 140. The shape of the section can be, in addition to a circular shape, as shown in the Fig. Figures 1 to 3 show a polygon shape, such as a hexagon.

[0040] The sealing resin 170 seals the circuit 120, the lower surface of the first terminal 130, the lower surface of the second terminal 140, the first wiring 132B, the second wiring 142B, the first union nut 230, and the second union nut 240. However, a portion of the device (the printed circuit board 112) on which the circuit 120 is mounted may be exposed by the sealing resin 170. The sealing resin 170 is made from a thermosetting compound produced by adding a silicon dioxide filler and the like to an epoxy resin, which forms a major component of the thermosetting resin. The sealing resin 170 protects the circuit 120 from environmental influences such as heat, light, moisture, and the like.

[0041] Fig. Figure 5 is a view showing a state in which the external connecting elements 250 are attached to the electronic module 100 with the screws 260.

[0042] As in Fig. As shown in Figure 5, the electronic module 100 is mounted on a heat sink 300, which has a projecting section. An external connecting element 250 is arranged on an upper surface of the first terminal 130 and is fastened to the upper surface of the first terminal 130 by a screw 260. An external connecting element 250 is arranged on an upper surface of the second terminal 140 and is fastened to the upper surface of the second terminal 140 by a screw 260. Preferably, a downward force is exerted on the two external connecting elements 250, and the electronic module 100 is pressed against the heat sink 300 with a certain force.

[0043] Assuming a surface of the electronic module 100 where the first terminal 130 and the second terminal 140 are exposed by the sealing resin 170, as the upper surface 100A, and surfaces opposite the upper surface 100A as the lower surfaces 100B, 100C, the lower surfaces 100C are as shown in the Fig. 1, Fig. 2 and Fig. Figure 5 shows that, in the areas where the first union nut 230 and the second union nut 240 are located, the lower surfaces 100C project downwards from the lower surface 100B in the area where the circuit 120 is located. This means that the electronic module 100 is configured such that the lower surfaces 100C project downwards from the lower surface 100B in the area where the circuit 120 is located in the areas where the union nuts 230 and 240 are located.

[0044] More precisely, the height of the areas where the union nuts 230, 240 of the electronic module 100 are located is greater than the height of the area where the circuit 120 is located. That is, the length between the upper surface 100A and the lower surface 100C of the electronic module 100 in the area where the union nuts 230, 240 are located is greater than the length between the upper surface 100A and the lower surface 100B of the electronic module 100 in the area where the circuit 120 is located.

[0045] In such a configuration, it is possible to ensure sufficient length between the upper surface 100A and the lower surface 100C of the electronic module 100 in the areas where the union nuts 230, 240 are located. This ensures a thread clearance long enough to allow the threads formed in the union nuts 230, 240 and the threads formed on the screws 260 to mesh. When the external connecting elements 250 are fastened to the terminals 130, 140 with the screws 260, loosening of the screws 260 can be prevented.

[0046] On the other hand, the lower surface 100B, in the area where the circuit 120 is located, is positioned close to the upper surface 100A of the electronic module, compared to the lower surfaces 100C in the area where the union nuts 230 and 240 are located. With this configuration, the circuit 120 can be positioned near the terminals 130 and 140. This reduces the wiring resistance and inductance of the electronic module.

[0047] In electronic module 100, the circuit 120 can be located near the lower surface 100B. With such a configuration, the heat generated by the circuit 120 can be properly dissipated from the lower surface 100B of the electronic module 100. As shown in Fig. As shown in Figure 5, in particular by forming the heat sink 300 in a shape adapted to the shape of the lower surfaces 100B, 100C of the electronic module 100, the heat generated by the circuit 120 can be effectively radiated from the lower surface 100B.

[0048] As in Fig. As shown in Figure 3, the first wiring 132B is arranged along the upper surface 100A of the electronics module 100. Furthermore, the circuit 120 is arranged along the lower surface 100B of the electronics module 100.

[0049] The length between the first wiring 132B and the circuit 120 can be set to any length greater than or equal to a length (insulation gap) that allows the insulation between the first wiring 132B and the circuit 120 to be maintained. By setting the length between the first wiring 132B and the circuit 120 to a length greater than or equal to the insulation gap, it is possible to prevent a short-circuit current from flowing through the sealing resin 170 between the first wiring 132B and the circuit 120.

[0050] Furthermore, the circuit 120 in the electronic module 100 is arranged along the lower surface 100B of the electronic module 100, so that the heat generated by the circuit 120 can be effectively radiated from the lower surface 100B.

[0051] Part of the element on which the circuit 120 is arranged (the printed circuit board 112) may be exposed on the lower surface of the electronic module 100. In the case of the Fig. Of the two main surfaces belonging to the circuit board 112 shown in Figure 5, the main surface on which the circuit 120 is not arranged is located on the lower surface of the electronic module 100.

[0052] In such a configuration, it is possible to bring the circuit board 112 and the heat sink 300 into direct contact with each other when mounting the electronic module 100 onto the heat sink 300. As a result, the heat generated in the circuit 120 can be quickly and effectively radiated via the circuit board 112 to the heat sink 300.

[0053] In the embodiment described above, the case was described in which the device contained in circuit 120 is a power MOSFET. However, the present invention is not limited to such a case. The circuit can be formed by other semiconductor devices such as an IGBT, a thyristor, a diode, and the like. Furthermore, a material such as silicon, SiC, or GaN can be used as the material for the device. Additionally, the device can be a device other than a semiconductor device, such as a capacitor or an inductor.

[0054] The electronic module 100 according to the present invention comprises: the first terminal 130; the first union nut 230, by means of which the external connecting element 250 is fastened to the first terminal 130 by the screw 260; and the sealing resin 170, which seals the circuit 120 and a portion of the first terminal 130. Assuming the surface of the electronic module 100 where the first terminal 130 is exposed by the sealing resin is the upper surface 100A, and the surfaces of the electronic module opposite the upper surface 100A are the lower surfaces 100B and 100C, the lower surface 100C projects further in the area where the first union nut 230 is located than the lower surface 100B in the area where the circuit 120 is located.

[0055] The electronic module 100 according to the present invention is configured such that the lower surface 100C, in the area where the first union nut 230 is located, projects beyond the lower surface 100B in the area where the circuit 120 is located. With this configuration, sufficient length (height) between the upper surface 100A and the lower surface 100C of the electronic module 100 can be ensured in the area where the first union nut 230 is located. Accordingly, it is possible to ensure a thread clearance long enough to allow the thread formed in the first union nut 230 and the thread formed on the screw 260 to engage. Thus, when the external connecting element 250 is attached to the first terminal 130, loosening of the screw 260 can be prevented.

[0056] On the other hand, the lower surface 100B, on which the circuit 120 is arranged, is closer to the upper surface 100A of the electronic module than the lower surfaces 100C in the areas where the first union nuts 230 are located. Accordingly, the circuit 120 can be arranged at a location near the first terminal 130. This reduces the wiring resistance and inductance of the electronic module. [List of reference symbols] 100 electronic devices 112 Circuit board 120 circuit 130 first connection 132 plate elements 132B first wiring 134 internal connecting electrode 140 second connection 142 plate elements 144 internal connecting electrode 142B second wiring 160 third connection 170 Sealing resin 172, 174, 182, 184 Signal connection 230 first union nut 240 second union nut 250 external connecting element 260 screw QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-074802

[0001] JP-U-3-20461

[0004]

Claims

[1] Electronic module comprising: a circuit; a first connection; a first union nut for attaching an external connecting element to the first connection by means of a screw; and a sealing resin that seals the circuit and part of the first connection, wherein assuming a surface of the electronic module where the first connection is exposed by the sealing resin as the upper surface and a surface of the electronic module on one side opposite the surface as the lower surface, the lower surface in an area where the first union nut is located protrudes from the lower surface in an area where the circuit is located. [2] Electronic module according to claim 1, further comprising a first wiring which is electrically connected to the first terminal and is arranged in the sealing resin, wherein the first wiring is arranged along an upper surface of the electronic module; and The circuit is arranged along a lower surface of the electronic module. [3] Electronic module according to claim 1 or 2, wherein part of an element on which the circuit is arranged is exposed on the lower surface of the electronic module. [4] Electronic module according to claim 1, wherein the height of a region in which the first cap nut is arranged is higher than the height of a region in which the circuit is arranged. [5] Electronic module according to claim 1, further comprising: a second terminal; and a second union nut for attaching an external connecting element to the second terminal by means of a screw; wherein the electronic module extends in a longitudinal direction, a lower surface of the electronic module in an area where the second retaining nut is located, protrudes from a lower surface of the electronic module in an area where the circuit is located, and the first union nut is arranged longitudinally on one end section of the electronic module and the second union nut is arranged longitudinally on another end section of the electronic module.

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