Electronic module

Abstract

To provide an electronic module which allows a power terminal to stably stand on its own and allows stable wet spread of a conductive bonding material between the power terminal and a lead frame.SOLUTION: An electronic module 100 includes a flat power terminal 160, and an internal connection frame 152 supporting the power terminal 160 and electrically connecting electronic elements 120A, 120B and the power terminal 160. The power terminal 160 has: an insertion part 166 extending from the internal connection frame 152 to a board 112, and a wide part 164 extending in the opposite direction to the board 112 from the internal connection frame 152. The insertion part 166 is compressed in a slot 156 of the internal connection frame 152 and has an end contact the board 112. At a boundary part between the insertion part 166 and the wide part 164, a projection 162 projecting from one surface 165A and the other surface 165B of the power terminal 160 in a thickness direction of the power terminal 160 is formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electronic module. [Background technology]

[0002] There is known an electronic module (semiconductor module) that includes a substrate on which a semiconductor chip is mounted, pin terminals connected to wiring patterns on the substrate, and a lead frame that supports the pin terminals and electrically connects the electrodes of the semiconductor chip to the pin terminals (see Patent Document 1 below). The pin terminals are press-fitted into holes formed in the lead frame, and are supported by a flange formed at a midpoint, allowing the pin terminals to stand on their own, while the flange allows solder to spread stably.

[0003] In conventional electronic modules, electrodes are taken out using pin terminals, but it is difficult to make the cross-sectional area of ​​the current path large, making it difficult to pass large currents. Therefore, the use of plate-shaped power terminals has been proposed to reduce inductance and wiring resistance (see Figure 4).

[0004] As shown in Fig. 4, the electronic module 300 includes two semiconductor elements 320A and 320B formed on one surface of an insulating substrate 312. The first terminal 330 is disposed at the front in the front-rear direction of the electronic module 300. The first connection frame 332 is electrically connected to the first terminal 330 and is integrally formed from the same plate material as the first terminal 330. The second connection frame 342 is electrically connected to the second terminal 340. The electronic module 300 further includes a flat third terminal 360 that functions as a power terminal. The third terminal 360 is disposed such that the thickness direction is the front-rear direction, and is elongated in the up-down direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6850938 Summary of the Invention [Problem to be solved by the invention]

[0006] However, since it is difficult to provide a flange on a flat power terminal, there remain issues such as the difficulty of making it stand stably as in the case of pin terminals that form a flange, and the difficulty of ensuring that the solder (conductive bonding material) between the power terminal and the lead frame is able to wet and spread stably.

[0007] Therefore, the present invention has been made in consideration of the above-mentioned problems, and aims to provide an electronic module that can stably support power terminals and can stably wet and spread solder (conductive bonding material) between the power terminals and the lead frame. [Means for solving the problem]

[0008] The electronic module of the present invention comprises a substrate on which electronic elements are mounted, flat power terminals connected to wiring patterns on the substrate, and an internal connection frame that supports the power terminals and electrically connects the electronic elements to the power terminals, the internal connection frame being a flat member with an elongated hole, the power terminals having an insertion portion extending from the internal connection frame toward the substrate and a wide portion extending from the internal connection frame in the opposite direction to the substrate, and are electrically connected to the internal connection frame, with the insertion portion pressed into the elongated hole in the internal connection frame so that the tip portion is in contact with the substrate, and protrusions are formed at the boundary between the insertion portion and the wide portion that protrude from one side and the other side of the power terminal in the thickness direction of the power terminal. [Effects of the Invention]

[0009] According to the electronic module of the present invention, protrusions are formed at the boundary between the insertion portion and the wide portion, protruding from one side and the other side of the power terminal in the thickness direction of the power terminal. This makes it possible to provide an electronic module that allows the power terminal to stand stably and independently, and that allows the solder (conductive bonding material) between the power terminal and the lead frame to wet and spread stably. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing the appearance of an electronic module 100 according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing the structure of a power terminal. [Figure 3] 3A is a cross-sectional view taken along line XX in FIG. 2, and FIG. 3B is a diagram illustrating the wetting and spreading of solder provided near the protrusion of the power terminal. [Figure 4] 1A and 1B are diagrams illustrating an electronic module 300 according to a conventional technique. DETAILED DESCRIPTION OF THE INVENTION

[0011] An electronic module according to an embodiment of the present invention will be described below. The embodiment described below does not limit the scope of the invention. Furthermore, not all of the elements and combinations thereof described in the embodiment are necessarily essential to the present invention.

[0012] In the following description, the longitudinal direction of the electronic module 100 will be referred to as the front-rear direction, and the lateral direction will be referred to as the left-right direction, as shown in Fig. 1. The height direction of the electronic module 100 will be referred to as the up-down direction. In the following description, the terms front, rear, left, right, top, and bottom are used for convenience of explanation and do not specify the orientation in which the electronic module 100 is attached when it is used.

[0013] The electronic module 100 is composed of an insulating substrate 112, electronic elements 120A, 120B, a first terminal 130, a second terminal 140, a third terminal 160, a first connection frame (internal connection frame) 132, a second connection frame (internal connection frame) 142, and a third connection frame (internal connection frame) 152.

[0014] The electronic elements 120A and 120B may be, for example, power MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). The electronic elements may be any suitable semiconductor elements other than MOSFETs, such as IGBTs, triacs, and diodes. The electronic elements 120A and 120B may be disposed on one surface of the insulating substrate 112. Each of the electronic elements 120A and 120B is, for example, configured as a semiconductor element, and includes electrodes (not shown) formed on one or both surfaces of the insulating substrate 112. Note that electronic elements other than semiconductor elements (for example, capacitors) may also be used.

[0015] The insulating substrate 112 on which the electronic elements are mounted is a DCB (Direct Copper Bonding) substrate with a metal plate for heat dissipation formed on its lower surface (back surface). Wiring is provided on the insulating substrate 112, and the electronic elements 120A, 120B are mounted on the wiring. The insulating substrate 112 may be a printed circuit board or the like. The insulating substrate 112 is formed in the shape of a rectangular plate, and is preferably disposed in the center of the electronic module 100 in the longitudinal direction, i.e., the front-to-rear direction.

[0016] 1, the first terminal 130 is disposed at the front in the front-rear direction of the electronic module 100. The first terminal 130 is a plate-shaped member made of a conductive flat plate material, for example, a copper plate. The first terminal 130 has a through-hole 131 that passes through the first terminal 130 in the up-down direction. The through-hole 131 has, for example, a circular shape when viewed in the up-down direction.

[0017] The first connection frame 132 is electrically connected to the first terminals 130. The first connection frame 132 is embedded inside a sealing resin (not shown). In the electronic module 100, the first connection frame 132 and the first terminals 130 are formed integrally from the same plate material.

[0018] The first connection frame 132 has through holes (reference numerals omitted) that pass through the first connection frame 132 in the vertical direction. The through holes have a circular shape when viewed in the vertical direction. The upper ends of internal connection terminals (reference numerals omitted) fit into the through holes. The internal connection terminals connect the first connection frame 132 to electrodes (not shown) of the electronic element 120A. The internal connection terminals are fixed to the first connection frame 132 by, for example, press-fitting.

[0019] 1, the second terminal 140 is disposed at the rear of the electronic module 100 in the front-to-rear direction. The second terminal 140 is a plate-shaped member made of a conductive flat plate material, for example, a copper plate. The second terminal 140 has a through-hole 141 that passes through the second terminal 140 in the up-down direction. The through-hole 141 has, for example, a circular shape when viewed in the up-down direction.

[0020] The second connection frame 142 is electrically connected to the second terminals 140. The second connection frame 142 is embedded inside a sealing resin (not shown). In the electronic module 100, the second connection frame 142 and the second terminals 140 are formed integrally from the same plate material.

[0021] The electronic module 100 includes a third terminal (hereinafter referred to as "power terminal") 160 that functions as a power terminal. As shown in FIG. 1, the power terminal 160 is formed of a conductive flat plate material, for example, a copper plate. The power terminal 160 is disposed so that the thickness direction is in the left-right direction, and the power terminal 160 has an elongated shape with the longitudinal direction in the up-down direction. Details of the power terminal 160 will be described later.

[0022] The electronic module 100 includes a third connection frame 152. The third connection frame 152 is electrically connected to the power terminals 160. The third connection frame 152 may be disposed on the same plane as the first connection frame 132 and the second connection frame 142 (in FIG. 1, they are on the same plane).

[0023] The third connection frame 152 has through holes (reference numerals omitted) that pass through the third connection frame 152 in the vertical direction. The through holes have a circular shape when viewed in the vertical direction. The upper ends of internal connection terminals 154 fit into the through holes. The internal connection terminals 154 connect the third connection frame 152 to electrodes (not shown) of the electronic element 120A. The internal connection terminals 154 are fixed to the third connection frame 152 by, for example, press-fitting.

[0024] (Power terminal structure) The structure of the power terminal 160 will be described below with reference to FIG. 2. The power terminal 160 has an insertion portion 166 extending downward from the third connection frame 152 toward the insulating substrate 112, and a wide portion 164 extending upward from the third connection frame 152 in the opposite direction from the insulating substrate 112. The power terminal 160 is electrically connected to the third connection frame 152, and the insertion portion 166 is press-fit into an elongated hole 156 (see FIGS. 1 and 3) in the third connection frame 152 so that its tip portion contacts the insulating substrate 112. At the boundary between the insertion portion 166 and the wide portion 164, protrusions (convex portions) 162 are formed that protrude from one surface 165A and the other surface 165B of the power terminal 160 in the thickness direction of the power terminal 160. The elongated hole 156 and the insertion portion 166 have an elongated shape in cross section with the longitudinal direction as viewed from the top-bottom direction.

[0025] As shown in FIG. 3(a), a first protrusion 162a is formed on one surface 165A of the power terminal 160, and a second protrusion 163a is formed on the other surface 165B. The first protrusion 162a and the second protrusion 163a are formed with a predetermined distance between them and protruding in opposite directions. The first protrusion 162a is formed by punching out the other surface 165B of the insertion portion 166, and a first punched-out portion (recess) 162b is formed. The second protrusion 163a is formed by punching out the one surface 165A of the insertion portion 166, and a second punched-out portion (recess) 163b is formed.

[0026] Furthermore, it is preferable that the protruding heights of first protruding portion 162a and second protruding portion 163a are the same, and that A≦B / 2 be satisfied, where A is the protruding height and B is the plate thickness of power terminal 160. The reason that A≦B / 2 is preferable is that if the protruding portion height A and the plate thickness B of power terminal 160 satisfy the condition A>B / 2, the strength of first protruding portion 162a and second protruding portion 163a may be weakened. Note that height A refers to the length from the surface of power terminal 160 to the top of the protruding portion (see FIG. 3(a)).

[0027] Therefore, according to the above-described configuration, the first protrusion 162a and the second protrusion 163a are protruded perpendicularly and in opposite directions relative to the surface of the power terminal 160, so that the power terminal 160 can be supported by the first protrusion 162a and the second protrusion 163a, and the power terminal 160 can stand stably and independently.

[0028] 3(b), solder BM, which is a conductive bonding material, is provided between the inner circumferential surface of the slot 156 and the insertion portion 166. The power terminal 160 and the third connection frame 152 are electrically connected via this solder BM. This solder BM is formed by, for example, printing or dispensing solder BM on the upper surface of the third connection frame 152 corresponding to the insertion portion 166. When this solder BM is heated, it flows into the gap between the insertion portion 166 and the inner circumferential surface of the slot 156 and solidifies. The flow of this solder BM is guided from the first protrusion 162a and the second protrusion 163a. ​​Therefore, by forming the first protrusion 162a and the second protrusion 163a, the solder between the power terminal 160 and the third connection frame (lead frame) 152 can be stably wetted and spread.

[0029] (Effects of the Electronic Module 100 According to the Embodiment) The electronic module 100 according to the embodiment includes an insulating substrate 112 on which electronic elements 120A and 120B are mounted, flat-plate-shaped power terminals 160 connected to the wiring pattern on the insulating substrate 112, and an internal connection frame 152 that supports the power terminals 160 and electrically connects the electronic elements 120A and 120B to the power terminals 160. The internal connection frame 152 is a flat-plate-shaped member having elongated holes 156. The power terminals 160 are inserted into the insulating substrate 112 and extend in a direction from the internal connection frame 152 toward the insulating substrate 112. The power terminal 160 has an insertion portion 166 and a wide portion 164 extending from the internal connection frame 152 in the opposite direction to the insulating substrate 112, and is electrically connected to the internal connection frame 152. The insertion portion 166 is press-fitted into the elongated hole 156 of the internal connection frame 152 so that its tip portion contacts the insulating substrate 112. A first protrusion 162a and a second protrusion 163a protruding in the thickness direction of the power terminal 160 from one surface 165A and the other surface 165B of the power terminal 160 are formed at the boundary between the insertion portion 166 and the wide portion 164. Therefore, the first protrusion 162a and the second protrusion 163a can support the power terminal 160, allowing the power terminal 160 to stably stand on its own and allowing the solder BM to stably wet and spread between the power terminal 160 and the internal connection frame 152.

[0030] Furthermore, according to the electronic module of the embodiment, at least one protrusion 162 is formed on one surface 165A and at least one protrusion 162 is formed on the other surface 165B, so that the power terminal 160 can be reliably and stably supported.

[0031] Furthermore, according to the electronic module of the embodiment, when the protruding height of the protruding portion 162 is A and the plate thickness of the power terminal 160 is B, A≦B / 2 is satisfied, so that the strength of the protruding portion 162 can be maintained at a certain level or higher.

[0032] (Variation) In the above example, one protrusion is formed on one surface and one on the other surface, but two or more may be formed on one surface and two or more on the other surface. In this case, it is preferable that the spacing between the protrusions on one surface is equal to the spacing between the protrusions on the other surface. With this configuration, the number of protrusions is large, which reliably improves the self-standing property.

[0033] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. [Explanation of symbols]

[0034] 100...electronic module, 112...insulating substrate, 120A, 120B...electronic element (semiconductor element), 132...first connection frame (internal connection frame), 142...second connection frame (internal connection frame), 152...third connection frame (internal connection frame), 156...long hole, 160...third terminal (power terminal), 162...protrusion (convex portion), 162a...first protrusion, 163a...second protrusion, 164...wide portion, 165A...one surface (power terminal surface), 165B...other surface (power terminal surface), 166...insertion portion, BM...solder (conductive bonding material)

Claims

1. a substrate on which electronic elements are mounted; a flat power terminal connected to the wiring pattern on the board; an internal connection frame that supports the power terminals and electrically connects the electronic element and the power terminals; the internal connection frame is a flat plate-like member having a hole, the power terminal has an insertion portion extending from the internal connection frame toward the board and a wide portion extending from the internal connection frame in a direction opposite to the board, and is electrically connected to the internal connection frame; the insertion portion is press-fitted into the elongated hole of the internal connection frame so that its tip portion contacts the board; and protrusions are formed at the boundary between the insertion portion and the wide portion, protruding from one surface and the other surface of the power terminal in the thickness direction of the power terminal.

1. An electronic module comprising:

2. At least one protrusion is formed on the one surface and at least one protrusion is formed on the other surface.

2. The electronic module of claim 1.

3. When the protruding height of the protruding portion is A and the plate thickness of the power terminal is B, A≦B / 2 is satisfied.

3. An electronic module according to claim 1 or 2.

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