Terminal, method for manufacturing terminal, and semiconductor device

Abstract

In a terminal, a method of manufacturing the terminal, and a semiconductor device, the strength of a crimped terminal with respect to a rotational torque is improved. A terminal (10) is provided with: a plate-shaped first terminal member (11) having a through-hole (11a); and a second terminal member (12) having a columnar portion (12a) inserted into the through hole (11a). The second terminal member (12) is crimped to the first terminal member (11) at the tip (crimped portion (12b)) of the columnar portion (12a), the columnar portion (12a) is in contact with the wall surface of the through-hole (11a), and the cross-section of the through-hole (11a) orthogonal to the insertion direction (D) of the columnar portion (12a) is polygonal.

Description

Technical Field

[0001] The present invention relates to a terminal, a method for manufacturing the terminal, and a semiconductor device including the terminal. Background Art

[0002] Conventionally, there has been proposed a method of joining a shaft-shaped member to a substrate by caulking (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 03-018444 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] However, in order to manufacture a terminal having a complicated shape such as the shape of a shaft-shaped portion and a plate-shaped portion, it is conceivable to join a plurality of terminal members by caulking.

[0008] However, if the cylindrical part of one terminal part is inserted into the circular through hole of another terminal part and riveted at the top end of the cylindrical part, when a rotational torque is applied to the terminal part, the sealing surface between the circular through hole and the cylindrical part will slip, causing the terminal part to rotate.

[0009] An object of the present invention is to provide a terminal, a method for manufacturing the terminal, and a semiconductor device capable of improving the strength of a terminal joined by caulking with respect to rotational torque.

[0010] Solutions for solving problems

[0011] In one technical solution, the terminal comprises: a first terminal component having a through hole; and a second terminal component having a columnar portion inserted into the through hole, the second terminal component being riveted to the first terminal component at the top end of the columnar portion, the columnar portion being in contact with the wall surface of the through hole, and the cross-section of the through hole orthogonal to the insertion direction of the columnar portion being a polygon.

[0012] In another technical solution, a terminal manufacturing method manufactures a terminal having a first terminal component and a second terminal component, wherein the first terminal component has a through hole, and the second terminal component has a columnar portion inserted into the through hole, the terminal manufacturing method includes the following steps: inserting the columnar portion of the second terminal component into the through hole having a polygonal cross-section orthogonal to the insertion direction of the columnar portion; and riveting the second terminal component to the first terminal component at the top end of the columnar portion inserted into the through hole, so that the columnar portion contacts the wall surface of the through hole.

[0013] In another technical solution, a semiconductor device comprises: a terminal, which comprises a first terminal component and a second terminal component, the first terminal component having a through hole, and the second terminal component having a columnar portion inserted into the through hole; a semiconductor element, which is electrically connected to the terminal; and a housing, which is integrally formed with the terminal so that the terminal is partially exposed, the housing accommodating the semiconductor element, the second terminal component is riveted to the first terminal component at the top end of the columnar portion, the columnar portion is in contact with the wall of the through hole, and the cross-section of the through hole orthogonal to the insertion direction of the columnar portion is a polygon.

[0014] Effects of the Invention

[0015] According to the above-described technical solution, the strength of the caulking-joined terminal with respect to the rotational torque can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a cross-sectional view showing a semiconductor device according to an embodiment.

[0017] Figure 2 It is a plan view and a cross-sectional view (part 1) for explaining a method for manufacturing a terminal according to an embodiment.

[0018] Figure 3 It is a plan view and a cross-sectional view (part 2) for explaining a method for manufacturing a terminal according to an embodiment.

[0019] Figure 4 It is a diagram showing an example of the shape of the through hole of the first terminal member in one embodiment.

[0020] Figure 5 This is a table showing the evaluation results of Examples 1 to 4 and Comparative Examples 1 to 4.

[0021] Description of Reference Numerals

[0022] 1. Semiconductor device; 10. Terminal; 11. First terminal component; 11a (11a-1 to 11a-8), through hole; 12. Second terminal component; 12a, columnar portion; 12b, riveted joint portion; 12c, internal threaded hole; 12d, recess; 20. Semiconductor element; 30. Housing; 31. Left side wall; 31a, convex portion; 32. Right side wall; 40. Laminated substrate; 41. First conductor plate; 42. Second conductor plate; 43. Third conductor plate; 44. Insulating substrate; 50. Metal base; 60. Screw member; 70. Wiring substrate; D, insertion direction; G1, G2, gap; P1, first pressing member; P1a, pressing surface; P2, second pressing member; P2a, pressing surface; S, bonding material; W1, W2, wiring. DETAILED DESCRIPTION

[0023] Hereinafter, a terminal, a method for manufacturing the terminal, and a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below, and can be implemented with appropriate modifications within the scope of the gist thereof.

[0024] Figure 1 is a cross-sectional view showing the semiconductor device 1 .

[0025] An example in which the terminal is used in a semiconductor device is shown. Figure 1 The semiconductor device 1 shown includes a terminal 10 , a semiconductor element 20 , a housing 30 , a laminate substrate 40 , a metal base 50 , a screw 60 , a wiring substrate 70 , and wirings W1 and W2 .

[0026] As an example, the semiconductor device 1 is applied to a power conversion device such as an inverter device for an industrial or vehicle-mounted motor together with a cooler (not shown) disposed at the bottom of the metal base 50. In the following description, detailed descriptions of the structure, function, operation, assembly method, etc. that are the same as or similar to the known semiconductor device 1 are omitted.

[0027] The terminal 10 includes a first terminal member 11 and a second terminal member 12 riveted to the first terminal member 11. Riveting means joining by riveting, which is a processing method of applying a certain force to multiple components to cause local plastic deformation of the components to join the components to each other.

[0028] The first terminal member 11 is in the shape of a plate and has a through hole 11a. The cross-sectional shape of the through hole 11a is a polygon, and the columnar portion 12a of the second terminal member 12 contacts the wall surface of the through hole 11a (the wall surface of the through hole 11a inside the first terminal member 11). The through hole 11a will be described in detail later. The first terminal member 11 is a metal material formed of a metal material such as a copper material, a copper alloy material, an aluminum alloy material, an iron alloy material, etc., and is electrically connected to the second conductor plate 42 by wiring W2. The second conductor plate 42 is electrically connected to the semiconductor element 20 by wiring W1. Therefore, it can be said that the first terminal member 11 (terminal 10) is electrically connected to the semiconductor element 20. In addition, the wiring W1 and W2 are, for example, lead frames or leads. In addition, the first terminal member 11 is not limited to a horizontally extended plate shape, and may also be in other shapes such as a plate shape having a bent portion bent at 90 degrees, a shape other than a plate shape, etc.

[0029] The second terminal member 12 is in the shape of a cylindrical shaft and has a columnar portion 12a. The columnar portion 12a is provided at one end of the second terminal member 12 ( Figure 1 The columnar portion 12a is, for example, a cylindrical portion in the shape of a cylinder having a diameter smaller than that of other portions. A riveted joint portion 12b that is plastically deformed by riveting is provided at the top of the columnar portion 12a. The second terminal member 12 is riveted to the first terminal member 11 at the riveted joint portion 12b. Therefore, the second terminal member 12 may also be referred to as a riveted member, and the first terminal member 11 may be referred to as a riveted member.

[0030] As an example, the second terminal member 12 may also have an end portion ( Figure 1 The second terminal member 12 is made of a metal material such as copper, brass, or stainless steel plated with nickel, and is electrically connected to the wiring substrate 70 by means of a screw 60 in the internal threaded hole 12c.

[0031] In addition, there is no particular restriction on the shapes of the first terminal member 11 and the second terminal member 12. In addition, the materials of the first terminal member 11 and the second terminal member 12 may also be the same material. In addition, the columnar portion 12a of the second terminal member 12 is not limited to a cylindrical portion, and may also be a polygonal columnar portion in a polygonal column shape, etc.

[0032] The semiconductor element 20 is bonded to the first conductor plate 41 by a conductive bonding material (not shown) such as solder. The semiconductor element 20 is composed of, for example, an IGBT (Insulated Gate Bipolar Transistor) element as a switching element, an RC (Reverse Conducting)-IGBT element formed by integrating the IGBT element and a diode element such as a FWD (Free Wheeling Diode) element connected in reverse parallel to the switching element. The switching element and the diode element in the semiconductor element 20 are not limited to those formed on a Si substrate, and can also be formed on a semiconductor substrate using a wide bandgap semiconductor such as SiC (silicon carbide) or GaN (gallium nitride). Such a semiconductor element 20 is provided with electrodes not shown on the lower surface and the upper surface. The semiconductor element 20 is electrically connected to the wiring W1 mentioned above by using a conductive bonding material at the electrodes provided on the upper surface. Although not shown, the semiconductor element 20 can also be electrically connected to main terminals such as output terminals and input terminals (P terminals and N terminals), control terminals, etc. provided in the housing 30 directly or indirectly via the first conductor plate 41 and the second conductor plate 42 using wiring not shown.

[0033] The housing 30 is in the shape of a square tube having a left side wall 31, a right side wall 32, and a front wall and a rear wall (not shown) as a whole, and accommodates the semiconductor element 20. The housing 30 is formed of an insulating resin material such as PPS (Poly Phenylene Sulfide) or PA (Poly Amide). The housing 30 is bonded to the upper surface of the metal base 50.

[0034] The housing 30 (left side wall 31) is integrally formed with the terminal 10 in a state where a part of the terminal 10 (the internal thread hole 12c of the second terminal member 12 and / or the part of the first terminal member 11 that is joined to the wiring W2) is exposed. In other words, the terminal 10 is embedded in the housing 30. In addition, the rivet portion (rivet joint portion 12b) between the first terminal member 11 and the second terminal member 12 may be covered with the resin as the material of the housing 30, or may be partially or completely exposed. When covered with the resin, the rivet portion is fixed by the resin, so that the tightness between the first terminal member 11 and the second terminal member 12 is improved. A cylindrical convex portion 31a protruding upward in a manner of supporting the upper end of the second terminal member 12 is integrally provided at the upper end of the left side wall 31. In addition, the semiconductor element 20, the first conductor plate 41, the second conductor plate 42, etc. in the housing 30 are sealed by a sealing material not shown. The sealing material is, for example, epoxy resin, silicone gel, etc.

[0035] The laminated substrate 40 includes a first conductor plate 41, a second conductor plate 42, a third conductor plate 43, and an insulating substrate 44. The first conductor plate 41 and the second conductor plate 42 are provided on the upper surface of the insulating substrate 44, and the third conductor plate 43 is provided on the lower surface of the insulating substrate 44. The laminated substrate 40 is, for example, a DCB (Direct Copper Bonding) substrate or an AMB (Active Metal Brazing) substrate.

[0036] The first conductor plate 41 and the second conductor plate 42 function as wiring members in the inverter circuit and are formed of metal plates or metal foils such as copper and aluminum. The first conductor plate 41 and the second conductor plate 42 may also be referred to as conductor layers, conductive layers, conductor patterns, wiring patterns, etc.

[0037] The third conductor plate 43 is a member that functions as a heat conducting member that conducts heat generated by the inverter circuit to the metal base 50, and is formed of, for example, a metal plate or metal foil such as copper or aluminum. The third conductor plate 43 is joined to the metal base 50 using a joining material S such as solder. The third conductor plate 43 may also be referred to as a heat dissipation layer, a heat dissipation plate, a conductor pattern, a heat dissipation pattern, etc.

[0038] The insulating substrate 44 is not limited to a specific substrate. The insulating substrate 44 may be, for example, a ceramic substrate formed of a ceramic material such as aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), and a composite material of aluminum oxide (Al2O3) and zirconium oxide (ZrO2). The insulating substrate 44 may be, for example, a substrate formed by molding an insulating resin such as epoxy resin, a substrate formed by impregnating a base material such as glass fiber with an insulating resin, a substrate formed by coating the surface of a flat metal core with an insulating resin, etc.

[0039] The metal base 50 is a rectangular plate-shaped member. The metal base 50 is a member that functions as a heat conduction member that conducts the heat generated by the semiconductor element 20 to a cooler (not shown), and is formed of, for example, a metal plate such as a copper plate or an aluminum plate. In addition, the metal base 50 is connected to the cooler via a heat conductive material such as thermal grease or a heat conductive compound. In addition, the metal base 50 may also function as a cooler.

[0040] As described above, the screw 60 is inserted into the internal thread hole 12c of the second terminal member 12, and the wiring substrate 70 and the second terminal member 12 (terminal 10) are electrically and physically connected.

[0041] The wiring substrate 70 is disposed above the housing 30. The wiring substrate 70 is an example of a member electrically connected to the terminal 10. This member may be another member such as a lead frame or an external conductor connected to the semiconductor device 1.

[0042] In the above description, the case where the terminal 10 is arranged on the semiconductor device 1 and electrically connected to the semiconductor element 20 is described as an example, but the use of the terminal 10 is not limited to the semiconductor device 1, and can also be used in any device. In addition, the circuit of the above-mentioned semiconductor device 1 includes a switching element, a diode element, etc. inside the semiconductor element 20, but the semiconductor device 1 only needs to constitute any circuit such as a single-phase voltage type half-bridge inverter circuit, a single-phase full-bridge inverter circuit, a three-phase AC inverter circuit, etc.

[0043] Next, refer to Figure 2 and Figure 3 A method for manufacturing the terminal 10 will be described. Figure 2 (a)~(c) and Figure 3 In (a) to (c), a top view is shown on the upper side, and a cross-sectional view is shown on the lower side. Figure 2 and Figure 3 The terminal 10 in the cross-sectional view is Figure 1 The terminal 10 in the cross-sectional view is turned upside down. Figure 2 and Figure 3 In FIG. 1 , the shape of the first terminal member 11 is shown as a square, but as described above, the first terminal member 11 can be set to any shape.

[0044] First, if Figure 2 As shown in (a), the columnar portion 12a of the second terminal member 12 is inserted into the through hole 11a of the first terminal member 11 in the insertion direction D which is the central axis direction of the through hole 11a (the length direction of the columnar portion 12a).

[0045] Then, if Figure 2 As shown in (b), the first pressing member P1 (illustrated by a double-dashed line in the top view from the upper side), which is a punch in the shape of a quadrangular prism, for example, presses the top end of the columnar portion 12a inserted into the through hole 11a in a direction opposite to the insertion direction D, thereby riveting the second terminal member 12 to the first terminal member 11 (first pressing). Here, it is desired that the pressing surface P1a of the first pressing member P1 is larger than the cross section of the through hole 11a (or the columnar portion 12a) that is orthogonal to the insertion direction D. Figure 2 In the example (b), the cross-sectional shapes of the pressing surface P1a and the through hole 11a are square, and the length L2 of one side of the pressing surface P1a is longer than the length L1 of one side of the through hole 11a (L2>L1).

[0046] like Figure 2As shown in (c), the top end of the columnar portion 12a of the second terminal component 12 becomes a riveted joint portion 12b that is expanded to be larger than the through hole 11a (illustrated in dashed lines (hidden lines) together with the columnar portion 12a) by pressing using the first pressing member P1. By pressing (riveting) the first pressing member P1, the columnar portion 12a contacts the wall surfaces of the through hole 11a and expands within the through hole 11a along the surfaces, fitting closely with the surfaces of the through hole 11a. In addition, the columnar portion 12a enters the corner of the through hole 11a in the form of a wedge-shaped protrusion, and the gap G1 between the columnar portion 12a and the corner of the through hole 11a becomes smaller. Thus, for example, when the screw 60 is tightened to Figure 1 When the internal threaded hole 12c shown in FIG. 1 is formed, even when a rotational torque T (in Figure 2 The columnar portion 12a is also caught on each surface of the through hole 11a, so the strength of the terminal 10 with respect to the rotation torque T is improved. In addition, the riveting connection in this embodiment is not limited to pressing the columnar portion 12a in the direction opposite to the insertion direction D of the through hole 11a, and other methods such as pressing the columnar portion 12a from other directions can also be used, as long as the top of the columnar portion 12a is plastically deformed.

[0047] Even after the columnar portion 12a is pressed by the first pressing member P1, a gap G1 may exist between the corner of the through hole 11a and the columnar portion 12a. Figure 3 In (a) to (c), since the gap G1 (G2) is also shown in the lower cross-sectional view, the upper plan view and the lower cross-sectional view are relative to each other. Figure 2 (a) to (c) are shown at an inclination of 45 degrees.

[0048] In order to reduce the gap G1 between the corner of the through hole 11a and the columnar portion 12a, as shown in FIG. Figure 3 As shown in (a), the second pressing member P2 (shown as a two-dot chain line in the top view from the upper side) which is a punch in the shape of a quadrangular prism, for example, preferably presses the rivet joint portion 12b (the top end of the columnar portion 12a inserted into the through hole 11a) toward the through hole 11a (second pressing). Here, it is desirable that the pressing surface P2a of the second pressing member P2 is smaller than the cross section of the through hole 11a (or the rivet joint portion 12b) which is orthogonal to the insertion direction D. Figure 3 In the example (a), the cross-sectional shape of the pressing surface P2a and the through hole 11a is a square, and the length L3 of one of the four sides of the pressing surface P2a is shorter than the length L1 of one of the four sides of the through hole 11a (L3<L1). In addition, it is desired that the center of the pressing surface P2a coincides with the center of the rivet joint portion 12b.

[0049] In addition, the pressing surface P2a of the second pressing member P2 is a polygon (for example, a square) having a shape similar to the polygon of the cross-section of the through hole 11a, and it is preferred to press the columnar portion 12a (riveted joint portion 12b) toward the through hole 11a in a direction where the corners of the pressing surface P2a are aligned with the corners of the through hole 11a within an imaginary plane orthogonal to the insertion direction D.

[0050] Therefore, if Figure 3 As shown in (b), the wedge-shaped protrusion of the columnar portion 12a entering the corner of the through hole 11a is extended, so that the columnar portion 12a can easily enter the deep corner of the through hole 11a, and the gap G2 between the corner of the through hole 11a and the columnar portion 12a after being pressed by the second pressing member P2 becomes smaller and filled. Figure 3 As shown in (c), the second pressing member P2 is pulled out from the caulking joint portion 12b, and the recessed portion 12d is formed in the caulking joint portion 12b due to the pulling out of the second pressing member P2.

[0051] As described above, the gap G2 between the corner of the through hole 11a and the columnar portion 12a after being pressed by the second pressing member P2 becomes smaller, so that even if the rotational torque T is applied to the second terminal component 12, the columnar portion 12a will be stuck on all surfaces of the through hole 11a almost entirely near the corner, thereby further improving the strength of the terminal 10 relative to the rotational torque T.

[0052] Here, if Figure 3 As shown in the cross-sectional view of (b), the second pressing member P2 preferably presses the columnar portion 12a in a state of entering the through hole 11a. That is, the second pressing member P2 presses the columnar portion 12a (the rivet joint portion 12b) until at least a portion of the second pressing member P2 (the pressing surface P2a, etc.) reaches the position of the through hole 11a ( Figure 3 (b) is preferably below the upper surface of the first terminal component 11. As a result, the gap G2 between the corner of the through hole 11a and the columnar portion 12a becomes smaller and is easier to fill. In the case where the second pressing member P2 enters the interior of the through hole 11a like this, the recess 12d is also formed throughout the interior of the through hole 11a after the second pressing member P2 is pulled out. In addition, if the length L3 of one side of the pressing surface P2a is too short, it is difficult for the columnar portion 12a to enter deep into the corner of the through hole 11a. Therefore, as an example, it is preferably to set the area of ​​the pressing surface P2a to more than half of the cross-sectional area of ​​the through hole 11a.

[0053] Figure 4 It is a diagram showing an example of the shape of the through hole 11 a of the first terminal member 11 .

[0054] Examples of the cross-sectional shape of the through hole 11a (the shape of the cross section perpendicular to the insertion direction D) include: Figure 4 A triangle (for example, an equilateral triangle) such as the through hole 11a-1 shown in (a) Figure 4 A pentagon (e.g., a regular pentagon) such as the through hole 11a-2 shown in (b) Figure 4 A hexagonal shape (e.g., a regular hexagonal shape) such as the through hole 11a-3 shown in (c) Figure 4 As shown in (d), the cross-sectional shape of the through hole 11a can be any shape as long as it has a portion that is engaged with the columnar portion 12a when a rotational torque T is applied to the second terminal member 12. However, unlike Figure 2 Compared with the through hole 11a having a quadrilateral cross-sectional shape shown in (a), Figure 4 The area of ​​the through hole 11a-1 with a triangular cross-sectional shape shown in (a) that is joined to the columnar portion 12a tends to become smaller. Therefore, from the viewpoint of increasing the joining area, it is more desirable to use other through holes 11a such as the through hole 11a with a quadrilateral cross-sectional shape rather than the through hole 11a-1 with a triangular cross-sectional shape.

[0055] In addition, as the cross-sectional shape of the through hole 11a, in addition to Figure 2 , Figure 3 In addition to such quadrilaterals, we can also list Figure 4 The through hole 11a-5 shown in (e) is a seven-pointed star, Figure 4 The through hole 11a-6 shown in (f) is a pentagonal star, as shown in Figure 4 The through hole 11a-7 shown in (g) is a shape obtained by cutting off the portion of the pentagonal star except the corner portion along a curve forming a single imaginary circle, Figure 4 The through hole 11a-8 shown in (h) is a shape obtained by cutting out the part of the five-pointed star except the corner in a straight line. In the through holes 11a-5 to 11a-8 having these star-shaped cross-sectional shapes, the anchoring effect is stronger when the columnar part 12a enters the corner. In addition, Figure 4 (g) and Figure 4 The dotted line portion in (h) is just an imaginary line used to represent the corners of the pentagram.

[0056] Next, refer to Figure 5 The evaluation results of Examples 1 to 4 and Comparative Examples 1 to 4 are shown in Table 1.

[0057] In Examples 1 to 4 and Comparative Examples 1 to 4, the diameter of the columnar portion 12a of the second terminal member 12 (the length of one side in Comparative Examples 3 and 4) is 1.5 mm, the diameter of the portion of the second terminal member 12 other than the columnar portion 12a is 5 mm, and the length of the columnar portion 12a before pressing is 2.8 mm. Pressing is performed in such a manner that the diameter of the caulking portion 12b after pressing becomes 2.4 mm and the length of the caulking portion 12b (the portion extending from the through hole 11a) after pressing becomes 0.7 mm. In addition, the thickness of the first terminal member 11 is 0.8 mm, and the width of the first terminal member 11 in the width direction is 5 mm. That is, caulking is performed under the condition that the length of one side of the through hole 11a of the first terminal member 11 (the diameter in Comparative Examples 1 to 4) is greater than the diameter of the columnar portion 12a and less than the diameter of the caulking portion 12b. At this time, the second terminal member 12 is rotated, and the rotation torque T (destructive torque) is measured until the second terminal member 12 after riveting is separated from the first terminal member 11. In addition, for Examples 1 to 4 and Comparative Examples 1 to 4, each destructive torque (standardized torque) is calculated when the destructive torque 0.2 [N·m] of Comparative Example 1 described later is set to 1 (standardized with the destructive torque value of Comparative Example 1).

[0058] First, Example 1 is as described above with reference to Figure 2 and Figure 3 The example in which the cross-sectional shape of the through hole 11a is a quadrilateral (square), the columnar portion 12a is a cylindrical shape, and the second pressing member P2 (pressing surface P1a is a quadrilateral (square)) is used to press the second time is described. Moreover, in Example 1, the second pressing member P2 is pressed in a direction in which the corner of the pressing surface P2a of the second pressing member P2 is consistent with the corner of the cross section of the through hole 11a. The breaking torque of Example 1 is 0.3 [N·m], and the normalized torque is 1.5. That is, compared with Comparative Example 1, which is one of the previous examples, the breaking torque (fastening force) is increased by 50%.

[0059] Next, Example 2 is the same as Example 1 except that the second pressing member P2 is pressed in a direction that the corner of the pressing surface P2a of the second pressing member P2 is offset by 45 degrees from the corner of the cross section of the through hole 11a. The breaking torque of Example 2 is 0.26 [N·m], and the normalized torque is 1.3. Compared with Comparative Example 1, it is improved by 30%, but the normalized torque of Example 2 is less than the normalized torque of Example 1, so it can be said that it is desirable to have the corner of the pressing surface P2a of the second pressing member P2 and the corner of the cross section of the through hole 11a be consistent with each other as in Example 1.

[0060] Next, Example 3 is the same as Example 1 except that the cross-sectional shape of the through hole 11a and the pressing surface P2a of the second pressing member P2 are not quadrilateral (square) but pentagon (regular pentagon). The breaking torque of Example 3 is 0.27 [N·m], and the normalized torque is 1.35. If the number of sides of the through hole 11a is made larger than the number of sides of the through hole 11a of Example 1 whose cross-sectional shape is quadrilateral, as in the through hole 11a of Example 3 whose cross-sectional shape is pentagon, it can be said that even if the pressing force of the second pressing member P2 is small, the columnar portion 12a can be easily expanded to the corner of the through hole 11a when being flattened, but the amount of bite of the columnar portion 12a into the corner of the through hole 11a becomes smaller. If the number of sides of the through hole 11a is increased, it is considered that the breaking torque is reduced because the amount of the columnar portion 12a that bites into the corner of the through hole 11a is reduced and the cross-sectional shape of the through hole 11a is close to a perfect circle. However, as long as the cross-sectional shape of the through hole 11a is a polygon, the columnar portion 12a will expand by plastic deformation toward the corner of the polygon, so the breaking torque (fastening force) is improved compared with Comparative Example 1.

[0061] Next, Example 4 is the same as Example 1 except that the second pressing by the second pressing member P2 is omitted. The breaking torque of Example 4 is 0.22 [N·m] and the normalized torque is 1.1. In Example 4, compared with Example 1 in which the second pressing is applied, it can be said that the gap between the columnar portion 12a and the corner of the through hole 11a becomes smaller after the first pressing using the first pressing member P1. Figure 2 The gap G1 shown in (c) is larger than that after the second pressing using the second pressing member P2. Figure 3 The gap G2 shown in (c) is large. Therefore, it can be said that the columnar portion 12a does not fully enter the corner of the through hole 11a, and the destructive torque becomes smaller. In addition, since the gap G1 after the first press is larger than the gap G2 after the second press, it can be said that the axial tensile strength of the second terminal component 12 is relatively low. However, even if the second press of the second pressing member P2 is omitted as in Example 4, the standardized torque is 1.1, and the destructive torque increases by 10% compared with Comparative Example 1 in which the cross-sectional shape of the through hole is circular, and the destructive torque increases by 37.5% compared with Comparative Example 3 described later, so the effectiveness of the cross-sectional shape of the through hole 11a being a polygon can be confirmed. From the results of the above Examples 1 to 4, it can be seen that the cross-sectional shape of the through hole 11a is preferably a polygon such as a quadrilateral or a pentagon.

[0062] Next, the cross-sectional shape of the through hole of Comparative Example 1 is different from that of Example 1, which is circular, and the second pressing is omitted. As described above, the breaking torque of Comparative Example 1 is 0.2 [N·m], and the normalized torque is 1. In Comparative Example 1, it is considered that the breaking torque is relatively small compared with Example 1 because there is no bite of the columnar portion 12a into the corner of the through hole and the through hole is circular and there is no surface to bear the rotation of the columnar portion 12a.

[0063] Next, Comparative Example 2 is the same as Comparative Example 1 except that a second pressing is performed. During the second pressing in Comparative Example 2, the pressing surface P2a of the second pressing member P2 is changed to a circular shape. The breaking torque of Comparative Example 2 is 0.2 [N·m], and the normalized torque is 1. In Comparative Example 2, a second pressing is performed in addition to Comparative Example 1, but no changes are confirmed in the breaking torque and tensile strength compared with Comparative Example 1. It is believed that this is because, even if a second pressing is performed, since the cross-sectional shape of the through hole is circular, the columnar portion 12a does not enter the corner of the through hole, and the columnar portion 12a will not get stuck on the side (inner circumference) of the through hole.

[0064] Comparative Example 3 is the same as Comparative Example 1 except that the columnar portion 12a is a quadrangular columnar portion. The breaking torque of Comparative Example 3 is 0.16 [N·m] and the normalized torque is 0.8. In Comparative Example 3, it is believed that since a gap is formed between the through hole having a circular cross-sectional shape and the columnar portion 12a which is a quadrangular columnar portion, and the contact area becomes small, the breaking torque and tensile strength are inferior to those of Comparative Example 1. In addition, the corners of the quadrangular columnar portion bite into the circular through hole, so cracks are easily generated. That is, it can be seen that when the cross-sectional shape of the through hole and the cross section of the columnar portion 12a orthogonal to the insertion direction D are opposite to those of Example 4, the breaking torque will not be improved.

[0065] Comparative Example 4 is the same as Comparative Example 3 except that the second pressing member P2 having a quadrilateral pressing surface P2a is used. In addition, in Comparative Example 4, the corners of the columnar portion 12a and the corners of the pressing surface P2a are set to be offset by 45 degrees in order to fill the gap in Comparative Example 3. The breaking torque of Comparative Example 4 is 0.18 [N·m], and the normalized torque is 0.9. In Comparative Example 4, it is believed that the gap between the through hole having a circular cross-sectional shape and the columnar portion 12a as a quadrangular columnar portion can be reduced compared to Comparative Example 3, but since the gap remains, the breaking torque is smaller than the breaking torque of Comparative Example 1.

[0066] The terminal 10 of the present embodiment described above comprises: a first terminal member 11 having a through hole 11a; and a second terminal member 12 having a columnar portion 12a inserted into the through hole 11a. The second terminal member 12 is riveted to the first terminal member 11 at the top end (riveted portion 12b) of the columnar portion 12a, the columnar portion 12a contacts the wall surface of the through hole 11a, and the cross section of the through hole 11a perpendicular to the insertion direction D of the columnar portion 12a is a polygon.

[0067] In addition, the manufacturing method of the terminal 10 of the present embodiment manufactures the terminal 10 having a first terminal member 11 and a second terminal member 12, wherein the first terminal member 11 has a through hole 11a, and the second terminal member 12 has a columnar portion 12a inserted into the through hole 11a, and the manufacturing method of the terminal 10 includes the following steps: inserting the columnar portion 12a of the second terminal member 12 into the through hole 11a ( Figure 2 and riveting the second terminal member 12 to the first terminal member 11 at the top end (riveting portion 12b) of the columnar portion 12a inserted into the through hole 11a, thereby making the columnar portion 12a contact with the wall surface of the through hole 11a (increasing the contact area) ( Figure 2 The pressing step (riveting joining step) shown in (b) and (c) of FIG.

[0068] In addition, the semiconductor device 1 of the present embodiment includes: the above-mentioned terminal 10; a semiconductor element 20, which is electrically connected to the terminal 10; and a shell 30, which is integrally formed with the terminal 10 in a state in which a part of the terminal 10 (for example, the internal threaded hole 12c of the second terminal component 12 and / or the part of the first terminal component 11 that is engaged with the wiring W2) is exposed, and the shell 30 accommodates the semiconductor element 20.

[0069] In these terminals 10, methods for manufacturing the terminals 10, and semiconductor devices 1, the cross-sectional shape of the through hole 11a of the first terminal component 11 is a polygon. As a result, the columnar portion 12a of the second terminal component 12 expands in the through hole 11a along the surfaces of the through hole 11a and fits closely with the surfaces of the through hole 11a. In addition, the columnar portion 12a enters the corner of the through hole 11a in the form of a wedge-shaped protrusion, so that the columnar portion 12a is firmly fixed to the through hole 11a, and the wedge-shaped protrusion of the columnar portion 12a exerts an anchoring effect. Moreover, even if a rotational torque T is applied to the terminal 10 (for example, the second terminal component 12), the columnar portion 12a will be stuck on the surfaces of the through hole 11a, and the friction resistance between the columnar portion 12a and the through hole 11a also plays a role, making it difficult for the first terminal component 11 and the second terminal component 12 to separate. Therefore, according to the present embodiment, the strength (fastening force) of the riveted terminal 10 with respect to the rotational torque T can be improved. Therefore, the performance of the terminal 10 and the semiconductor device 1 can be improved, and customer satisfaction can be improved. In addition, compared with the method of increasing the amount of flattening (the amount of deformation by pressing) at the top of the columnar portion 12a to increase the strength with respect to the rotational torque T, it is possible to avoid the generation of cracks around the through hole 11a. In addition, in the semiconductor device 1, by embedding the terminal 10 in the housing 30, the housing 30 can hold the terminal 10 when the rotational torque T is applied to the terminal 10, so that the first terminal component 11 and the second terminal component 12 are more difficult to separate.

[0070] In addition, in the present embodiment, the columnar portion 12a of the second terminal member 12 is a cylindrical portion. Therefore, compared with the case where the columnar portion 12a is a polygonal column, the strength of the terminal 10 relative to the rotational torque T can be improved by a simple structure in which one end of the second terminal member 12 is processed into a cylindrical columnar portion 12a.

[0071] In addition, in the present embodiment, the second terminal component 12 may also have an internal threaded hole 12c at the end on the side opposite to the columnar portion 12a. Thus, even if a rotational torque T is applied to the second terminal component 12 when the screw member 60 is fastened to the internal threaded hole 12c, as described above, the first terminal component 11 and the second terminal component 12 are not easy to disengage.

[0072] In addition, in the manufacturing method of the terminal 10 of the present embodiment, the riveting joint (riveting joint process) includes: using the first pressing member P1 having a pressing surface P1a larger than the cross-section of the through hole 11a to press the columnar portion 12a (first pressing process); thereafter, using the second pressing member P2 having a pressing surface P2a smaller than the cross-section of the through hole 11a, the columnar portion 12a (riveting joint portion 12b) is pressed toward the through hole 11a (second pressing process). As a result, it is easy to make the columnar portion 12a further enter the corner of the through hole 11a, so that the gap G2 between the columnar portion 12a and the corner of the through hole 11a after the second pressing by the second pressing member P2 can be made smaller than the gap G1 after the first pressing by the first pressing member P1. Therefore, even if the rotation torque T is applied to the terminal 10 (the second terminal member 12), it is possible to make the first terminal member 11 and the second terminal member 12 less likely to separate. Furthermore, by increasing the contact area between the columnar portion 12a and each wall surface of the through hole 11a, the tensile strength of the second terminal member 12 in the axial direction (the direction opposite to the insertion direction D of the columnar portion 12a) can also be improved.

[0073] In addition, in the manufacturing method of the terminal 10 of the present embodiment, the pressing surface P2a of the second pressing member P2 is a polygon with a shape similar to the polygon of the cross section of the through hole 11a. When the columnar portion 12a is pressed toward the through hole 11a by the second pressing member P2 (the second pressing process), the columnar portion 12a (the riveted joint portion 12b) is pressed toward the through hole 11a by the second pressing member P2 with the corner of the pressing surface P2a of the second pressing member P2 being consistent with the corner of the cross section of the through hole 11a. As a result, the columnar portion 12a is easily expanded toward the corner side of the pressing surface P2a, and thus it is further easy to enter the corner of the through hole 11a with a shape similar to the pressing surface P2a. Therefore, even if the rotation torque T is applied to the terminal 10 (the second terminal component 12), it is possible to make the first terminal component 11 and the second terminal component 12 further difficult to separate. Furthermore, by increasing the contact area between the columnar portion 12 a and the surfaces of the through hole 11 a , the tensile strength of the second terminal member 12 in the axial direction can be further increased.

[0074] In addition, in the manufacturing method of the terminal 10 of the present embodiment, in the process (second pressing process) of pressing the columnar portion 12a (riveted joint portion 12b) toward the through hole 11a using the second pressing member P2, the second pressing member P2 is made to enter the interior of the through hole 11a. As a result, the top end (pressing surface P2a) of the second pressing member P2 enters the through hole 11a while pressing the columnar portion 12a into the corner of the through hole 11a. Therefore, even if a rotational torque T is applied to the terminal 10 (the second terminal component 12), the first terminal component 11 and the second terminal component 12 can be made more difficult to separate. Moreover, by increasing the contact area between the columnar portion 12a and each surface of the through hole 11a, the axial tensile strength of the second terminal component 12 can be further improved.

[0075] Hereinafter, the invention described in the claims at the time of filing the present application will be appended.

[0076] <Additional Note 1>

[0077] A terminal, characterized in that:

[0078] The terminal has:

[0079] a first terminal member having a through hole; and

[0080] a second terminal member having a columnar portion inserted into the through hole,

[0081] The second terminal member is riveted to the first terminal member at the top end of the columnar portion, and the columnar portion is in contact with the wall surface of the through hole.

[0082] The through hole has a polygonal cross section perpendicular to the insertion direction of the columnar portion.

[0083] <Note 2>

[0084] The terminal according to Supplement 1 is characterized in that

[0085] The columnar portion of the second terminal member is a cylindrical portion.

[0086] <Addendum 3>

[0087] The terminal according to Supplement 1 or 2 is characterized in that:

[0088] The second terminal member has an internal thread hole at an end portion on the opposite side to the columnar portion.

[0089] <Note 4>

[0090] A method for manufacturing a terminal, comprising manufacturing a terminal having a first terminal member and a second terminal member, wherein the first terminal member has a through hole, and the second terminal member has a columnar portion inserted into the through hole, wherein:

[0091] The manufacturing method of the terminal comprises the following steps:

[0092] inserting the columnar portion of the second terminal member into the through hole having a polygonal cross section perpendicular to the insertion direction of the columnar portion; and

[0093] The second terminal member and the first terminal member are caulked and joined at the tip of the columnar portion inserted into the through hole so that the columnar portion comes into contact with the wall surface of the through hole.

[0094] <Addendum 5>

[0095] The method for manufacturing a terminal according to Supplement 4 is characterized in that:

[0096] The riveting joint includes the following steps:

[0097] pressing the columnar portion using a first pressing member having a pressing surface larger than the cross-section of the through hole; and

[0098] Then, the columnar portion is pressed toward the through hole by a second pressing member having a pressing surface smaller than the cross section of the through hole.

[0099] <Addendum 6>

[0100] The method for manufacturing a terminal according to Supplementary Note 5 is characterized in that:

[0101] The pressing surface of the second pressing member is a polygon having a shape similar to the polygon of the cross section of the through hole,

[0102] In the step of pressing the columnar portion toward the through hole using the second pressing member, the columnar portion is pressed toward the through hole using the second pressing member with the corner of the pressing surface of the second pressing member aligning with the corner of the cross section of the through hole.

[0103] <Addendum 7>

[0104] The method for manufacturing a terminal according to Supplement 5 or 6 is characterized in that:

[0105] In the step of pressing the columnar portion toward the through hole by the second pressing member, the second pressing member is inserted into the through hole.

[0106] <Addendum 8>

[0107] A semiconductor device, characterized in that

[0108] The semiconductor device comprises:

[0109] A terminal comprising a first terminal member and a second terminal member, wherein the first terminal member has a through hole, and the second terminal member has a columnar portion inserted into the through hole;

[0110] a semiconductor element electrically connected to the terminal; and

[0111] a housing formed integrally with the terminal so that the terminal is partially exposed, the housing housing the semiconductor element,

[0112] The second terminal member is riveted to the first terminal member at the top end of the columnar portion, and the columnar portion is in contact with the wall surface of the through hole.

[0113] The through hole has a polygonal cross section perpendicular to the insertion direction of the columnar portion.

[0114] Industrial Applicability

[0115] As described above, the present invention can improve the strength of the caulking-joined terminal against the rotation torque in the terminal, the method for manufacturing the terminal, and the semiconductor device, and is therefore particularly useful in semiconductor device and the like in which a part of the terminal member is fastened.

Claims

1. A terminal, characterized in that: The terminal has: a first terminal member having a through hole; and a second terminal member having a columnar portion inserted into the through hole, The second terminal member is riveted to the first terminal member at the top end of the columnar portion, and the columnar portion is in contact with the wall surface of the through hole. The through hole has a polygonal cross section perpendicular to the insertion direction of the columnar portion.

2. The terminal according to claim 1, characterized in that: The columnar portion of the second terminal member is a cylindrical portion.

3. The terminal according to claim 1 or 2, characterized in that: The second terminal member has an internal thread hole at an end portion on the opposite side to the columnar portion.

4. A method for manufacturing a terminal, comprising manufacturing a terminal having a first terminal member and a second terminal member, wherein the first terminal member has a through hole, and the second terminal member has a columnar portion inserted into the through hole, wherein: The manufacturing method of the terminal comprises the following steps: inserting the columnar portion of the second terminal member into the through hole having a polygonal cross section perpendicular to the insertion direction of the columnar portion; as well as The second terminal member and the first terminal member are caulked and joined at the tip of the columnar portion inserted into the through hole so that the columnar portion comes into contact with the wall surface of the through hole.

5. The method for manufacturing a terminal according to claim 4, characterized in that: The riveting joint includes the following steps: pressing the columnar portion using a first pressing member having a pressing surface larger than the cross section of the through hole; as well as Then, the columnar portion is pressed toward the through hole by a second pressing member having a pressing surface smaller than the cross section of the through hole.

6. The method for manufacturing a terminal according to claim 5, characterized in that: The pressing surface of the second pressing member is a polygon having a shape similar to the polygon of the cross section of the through hole, In the step of pressing the columnar portion toward the through hole using the second pressing member, the columnar portion is pressed toward the through hole using the second pressing member with the corner of the pressing surface of the second pressing member aligning with the corner of the cross section of the through hole.

7. The method for manufacturing a terminal according to claim 5 or 6, characterized in that: In the step of pressing the columnar portion toward the through hole by the second pressing member, the second pressing member is inserted into the through hole.

8. A semiconductor device, characterized in that: The semiconductor device comprises: A terminal comprising a first terminal member and a second terminal member, wherein the first terminal member has a through hole, and the second terminal member has a columnar portion inserted into the through hole; a semiconductor element electrically connected to the terminal; as well as a housing formed integrally with the terminal so that the terminal is partially exposed, the housing housing the semiconductor element, The second terminal member is riveted to the first terminal member at the top end of the columnar portion, and the columnar portion is in contact with the wall surface of the through hole. The through hole has a polygonal cross section perpendicular to the insertion direction of the columnar portion.

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