Terminal, method for manufacturing terminal, and semiconductor device

Abstract

To increase the strength of a swaged terminal to a rotary torque in a terminal, in a method for manufacturing the terminal, and in a semiconductor device.SOLUTION: A terminal 10 includes: a tabular first terminal component 11 with a through-hole 11a; and a second terminal component 12 with a columnar part 12a inserted in the through-hole 11a. The second terminal component 12 is swaged to the first terminal component 11 in an end (a swaged part 12b) of the columnar part 12a, the columnar part 12a is in contact with the wall surface of the through-hole 11a, and the through-hole 11a has a polygonal cross section perpendicular to the direction D in which the columnar part 12a is inserted.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, a method has been proposed in which a shaft-shaped member is joined to a substrate by crimping (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 03-018444 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in order to manufacture a terminal having a complex shape, such as a shape having a shaft-shaped portion and a plate-shaped portion, it is conceivable to join a plurality of terminal components by crimping.

[0005] However, when the cylindrical portion of one terminal part is inserted into the circular through hole of another terminal part and the tip of this cylindrical portion is crimped to join, if a rotational torque is applied to the terminal part, slippage occurs at the contact surface between the circular through hole and the cylindrical portion, causing the terminal part to rotate.

[0006] An object of the present invention is to provide a terminal, a method for manufacturing a terminal, and a semiconductor device that can increase the strength of the crimped terminal against rotational torque. [Means for solving the problem]

[0007] In one embodiment, the terminal comprises a first terminal part having a through hole and a second terminal part having a columnar portion inserted into the through hole, the second terminal part being crimped to the first terminal part at a tip of the columnar portion, the columnar portion contacting a wall surface of the through hole, and the through hole having a polygonal cross section perpendicular to the insertion direction of the columnar portion.

[0008] In another aspect, a method for manufacturing a terminal includes manufacturing a terminal including a first terminal part having a through hole and a second terminal part having a columnar portion inserted into the through hole, the method including inserting the columnar portion of the second terminal part into the through hole having a polygonal cross section perpendicular to an insertion direction of the columnar portion, and crimping the second terminal part to the first terminal part at a tip of the columnar portion inserted into the through hole, thereby bringing the columnar portion into contact with a wall surface of the through hole.

[0009] In another aspect, a semiconductor device includes a terminal having a first terminal part having a through hole and a second terminal part having a columnar portion inserted into the through hole, a semiconductor element electrically connected to the terminal, and a case for accommodating the semiconductor element, the case being integrally molded with the terminal with a portion of the terminal exposed, the second terminal part being crimped to the first terminal part at a tip of the columnar portion, the columnar portion contacting a wall surface of the through hole, and the through hole having a polygonal cross section perpendicular to the insertion direction of the columnar portion. Effect of the Invention

[0010] According to the above aspect, the strength of the crimped terminal against rotational torque can be increased. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing a semiconductor device according to an embodiment; [Diagram 2] 1A and 1B are a plan view and a cross-sectional view (part 1) for explaining a manufacturing method of a terminal according to one embodiment. [Diagram 3]1A and 1B are a plan view and a cross-sectional view (part 2) for explaining a manufacturing method of a terminal according to one embodiment. [Figure 4] 5A to 5C are diagrams illustrating examples of shapes of through holes of a first terminal component in an embodiment. [Diagram 5] 1 is a table showing the evaluation results of Examples 1 to 4 and Comparative Examples 1 to 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a terminal, a method for manufacturing a 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 appropriately modified and implemented within the scope of the present invention.

[0013] FIG. 1 is a cross-sectional view showing a semiconductor device 1. As shown in FIG.

[0014] An example in which the terminal is used in a semiconductor device will be described below. The semiconductor device 1 shown in Fig. 1 includes a terminal 10, a semiconductor element 20, a case 30, a laminated substrate 40, a metal base 50, a screw 60, a wiring substrate 70, and wires W1 and W2.

[0015] 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 under the metal base 50. In the following explanation, detailed explanations of configurations, functions, operations, assembly methods, etc. that are the same as or similar to those of the known semiconductor device 1 will be omitted.

[0016] The terminal 10 includes a first terminal part 11 and a second terminal part 12 crimped to the first terminal part 11. Crimping refers to joining by crimping, which is a processing method in which a certain force is applied to multiple members to plastically deform parts of the members and join the members together.

[0017] The first terminal component 11 is plate-shaped and has a through hole 11a. The through hole 11a will be described in detail later, but the cross-sectional shape of the through hole 11a is polygonal, and the columnar portion 12a of the second terminal component 12 contacts the wall surface of the through hole 11a (the wall surface inside the first terminal component 11 that constitutes the through hole 11a). The first terminal component 11 is made of a metal material such as a copper material, a copper alloy material, an aluminum alloy material, or an iron alloy material, and is electrically connected to the second conductor plate 42 by a wiring W2. The second conductor plate 42 is electrically connected to the semiconductor element 20 by a wiring W1. Therefore, it can be said that the first terminal component 11 (terminal 10) is electrically connected to the semiconductor element 20. The wirings W1 and W2 are, for example, lead frames or wires. Furthermore, the first terminal component 11 is not limited to a plate shape extending horizontally, but may have other shapes, such as a plate shape having a bent portion bent at 90 degrees, or a shape other than a plate shape.

[0018] The second terminal part 12 has a cylindrical shaft shape and a columnar part 12a provided at one end (the lower end in FIG. 1). The columnar part 12a is, for example, a columnar part having a smaller diameter than other parts. A crimped joint part 12b that is crimped and plastically deformed is provided at the tip of the columnar part 12a. The second terminal part 12 is crimped to the first terminal part 11 at the crimped joint part 12b. Therefore, the second terminal part 12 may be called a crimped part, and the first terminal part 11 may be called a crimped part.

[0019] As an example, the second terminal component 12 may have a female screw hole 12c at an end (upper end in FIG. 1) opposite to the columnar portion 12a (crimped joint portion 12b). The second terminal component 12 is made of a metal material such as nickel-plated copper, brass, or stainless steel, and is electrically connected to the wiring board 70 by a screw 60 at the female screw hole 12c.

[0020] The shapes of the first terminal part 11 and the second terminal part 12 are not particularly limited. The first terminal part 11 and the second terminal part 12 may be made of the same material. The columnar part 12a of the second terminal part 12 is not limited to a cylindrical part, and may be a polygonal columnar part having a polygonal columnar shape.

[0021] The semiconductor element 20 is bonded onto the first conductive 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, which is a switching element, or an RC (Reverse Conducting)-IGBT element, which is an integrated element of the IGBT element and a diode element such as an 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 may be formed on a semiconductor substrate using a wide band gap semiconductor such as SiC (Silicon Carbide) or GaN (Gallium Nitride), without being limited to a Si substrate. This type of semiconductor element 20 has electrodes (not shown) on the lower surface and the upper surface. The electrode on the upper surface of the semiconductor element 20 is electrically connected to the above-mentioned wiring W1 by a conductive bonding material. In addition, although not shown, the semiconductor element 20 may be electrically connected to main terminals such as output terminals and input terminals (P terminals and N terminals) and control terminals provided in the case 30 directly by wiring not shown, or indirectly via the first conductor plate 41 and the second conductor plate 42.

[0022] The case 30 has a rectangular cylindrical shape having a left side wall 31, a right side wall 32, and front and rear walls (not shown) integrally therewith, and houses the semiconductor element 20. The case 30 is formed using an insulating resin material such as PPS (Poly Phenylene Sulfide) or PA (Poly Amide). The case 30 is adhered to the upper surface of a metal base 50.

[0023] The case 30 (left side wall 31) is integrally molded with the terminal 10 in a state where a part of the terminal 10 (the female screw hole 12c of the second terminal component 12 and / or the joint part of the first terminal component 11 with the wire W2) is exposed. In other words, the terminal 10 is insert molded into the case 30. The crimped part (crimped joint part 12b) between the first terminal component 11 and the second terminal component 12 may be covered with the resin, which is the material of the case 30, or may be partially or entirely exposed. When the crimped part is covered with the resin, the crimped part is fixed by the resin, so that the fastening property between the first terminal component 11 and the second terminal component 12 is improved. A cylindrical protrusion 31a protruding upward so as to support the upper end of the second terminal component 12 is integrally provided at the upper end of the left side wall 31. The semiconductor element 20, the first conductive plate 41, the second conductive plate 42, and the like in the case 30 are sealed with a sealing material (not shown). The sealing material is, for example, an epoxy resin, a silicone gel, or the like.

[0024] The laminated substrate 40 has a first conductive plate 41, a second conductive plate 42, a third conductive plate 43, and an insulating substrate 44. The first conductive plate 41 and the second conductive plate 42 are provided on an upper surface of the insulating substrate 44, and the third conductive plate 43 is provided on a 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.

[0025] The first conductor plate 41 and the second conductor plate 42 are members that function as wiring members in an inverter circuit, and are formed of, for example, a metal plate or a metal foil of copper, aluminum, etc. The first conductor plate 41 and the second conductor plate 42 may be called a conductor layer, a conductive layer, a conductor pattern, a wiring pattern, etc.

[0026] The third conductor plate 43 is a member that functions as a heat conducting member that conducts heat generated in the inverter circuit to the metal base 50, and is formed of, for example, a metal plate or metal foil of copper, aluminum, or the like. The third conductor plate 43 is joined to the metal base 50 by a joining material S such as solder. The third conductor plate 43 may be called a heat dissipation layer, a heat dissipation plate, a conductor pattern, a heat dissipation pattern, or the like.

[0027] The insulating substrate 44 is not limited to a specific substrate. The insulating substrate 44 may be a ceramic substrate formed of a ceramic material such as aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), or a composite material of aluminum oxide (Al2O3) and zirconium oxide (ZrO2). The insulating substrate 44 may be, for example, a substrate formed of an insulating resin such as an epoxy resin, a substrate formed by impregnating a base material such as glass fiber with an insulating resin, or a substrate formed by coating the surface of a flat metal core with an insulating resin.

[0028] The metal base 50 is a rectangular plate-like member. The metal base 50 functions as a heat-conducting member that conducts heat generated by the semiconductor element 20 to a cooler (not shown), and is formed of a metal plate such as a copper plate or an aluminum plate. The metal base 50 and the cooler are connected via a heat-conducting material such as thermal grease or thermal compound. The metal base 50 may also function as a cooler.

[0029] As described above, the screw 60 is inserted into the female screw hole 12c of the second terminal component 12 to electrically and physically connect the wiring board 70 and the second terminal component 12 (terminal 10).

[0030] The wiring board 70 is disposed above the case 30. The wiring board 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.

[0031] In the above description, the terminal 10 is disposed in the semiconductor device 1 and electrically connected to the semiconductor element 20, but the use of the terminal 10 is not limited to the semiconductor device 1, and the terminal 10 may be used in any device. In addition, the circuit of the semiconductor device 1 described above includes a switching element, a diode element, and the like inside the semiconductor element 20, but the semiconductor device 1 may configure any circuit, such as a single-phase voltage-type half-bridge inverter circuit, a single-phase full-bridge inverter circuit, or a three-phase AC inverter circuit.

[0032] Next, a manufacturing method of the terminal 10 will be described with reference to Fig. 2 and Fig. 3. Fig. 2(a)-(c) and Fig. 3(a)-(c) show plan views on the upper side and cross-sectional views on the lower side. Note that the terminal 10 in the cross-sectional views of Fig. 2 and Fig. 3 is upside down from the terminal 10 in the cross-sectional view of Fig. 1. Also, in Fig. 2 and Fig. 3, the shape of the first terminal part 11 is shown as a square, but as described above, the first terminal part 11 can have any shape.

[0033] First, as shown in FIG. 2(a), the columnar portion 12a of the second terminal component 12 is inserted into the through hole 11a of the first terminal component 11 in an insertion direction D which is the central axial direction of the through hole 11a (the longitudinal direction of the columnar portion 12a).

[0034] Then, as shown in FIG. 2(b), a first pressing member P1 (indicated by a two-dot chain line in the plan view of the upper figure), which is, for example, a square-prism-shaped punch, presses the tip of the columnar portion 12a inserted into the through hole 11a in the direction opposite to the insertion direction D, thereby crimping and joining the second terminal component 12 to the first terminal component 11 (first pressing). Here, it is desirable that the pressing surface P1a of the first pressing member P1 is larger than a cross section of the through hole 11a (or the columnar portion 12a) perpendicular to the insertion direction D. In the example of FIG. 2(b), the cross-sectional shape of the pressing surface P1a and the through hole 11a is square, and the length L2 of one of the four sides of the pressing surface P1a is longer than the length L1 of one of the four sides of the through hole 11a (L2>L1).

[0035] As shown in FIG. 2(c), the tip of the columnar portion 12a of the second terminal component 12 becomes a crimped joint portion 12b that expands larger than the through hole 11a (indicated by a dashed line (hidden line) together with the columnar portion 12a) by pressing with the first pressing member P1. By pressing (crimping) with the first pressing member P1, the columnar portion 12a comes into contact with each wall surface of the through hole 11a and expands within the through hole 11a along each surface, and is in close contact with each surface of the through hole 11a. In addition, the columnar portion 12a enters the corner portion of the through hole 11a like a wedge-shaped protrusion, and the gap G1 between the columnar portion 12a and the corner portion of the through hole 11a becomes smaller. As a result, for example, when a screw 60 is fastened into the female screw hole 12c shown in Fig. 1, even if a rotational torque T is applied to the second terminal part 12 with the first terminal part 11 fixed to the case 30 or the like (counterclockwise in the upper view of Fig. 2(c)), the columnar part 12a gets caught on each surface of the through hole 11a, and the strength of the terminal 10 against the rotational torque T is increased. Note that the crimping joint in this embodiment is not limited to one in which the columnar part 12a is pressed in the direction opposite to the insertion direction D into the through hole 11a, and other methods such as a method of pressing the columnar part 12a from another direction may be used as long as the tip of the columnar part 12a is plastically deformed.

[0036] Incidentally, even after the columnar portion 12a is pressed by the above-mentioned first pressing member P1, a gap G1 may remain between the corner of the through hole 11a and the columnar portion 12a. In order to show the gap G1 (G2) in the cross-sectional view of the lower figure in Fig. 3(a) to (c), the plan view of the upper figure and the cross-sectional view of the lower figure are tilted by 45 degrees from Fig. 2(a) to (c).

[0037] In order to reduce the gap G1 between the corner of the through hole 11a and the columnar portion 12a, as shown in Fig. 3(a), for example, a second pressing member P2 which is a square prism-shaped punch (shown by a two-dot chain line in the plan view in the upper figure) may press the caulking joint portion 12b (the tip of the columnar portion 12a inserted into the through hole 11a) toward the through hole 11a (the second pressing). Here, it is desirable that the pressing surface P2a of the second pressing member P2 is smaller than the cross section orthogonal to the insertion direction D of the through hole 11a (or the caulking joint portion 12b). In the example of Fig. 3(a), the cross-sectional shapes of the pressing surface P2a and the through hole 11a are square, and the length L3 of one side of the four sides of the pressing surface P2a is shorter than the length L1 of one side of the four sides of the through hole 11a (L3 < L1). And it is desirable that the center of the pressing surface P2a coincides with the center of the caulking joint portion 12b.

[0038] Also, the pressing surface P2a of the second pressing member P2 is a polygon similar in shape to the polygon of the cross section of the through hole 11a (for example, a square), and the corners of the pressing surface P2a may press the columnar portion 12a (the caulking joint portion 12b) toward the through hole 11a in a direction that coincides with the corners of the through hole 11a within a virtual plane orthogonal to the insertion direction D.

[0039] As a result, as shown in Fig. 3(b), the wedge-shaped protrusion of the columnar portion 12a that enters the corner of the through hole 11a extends, so that the columnar portion 12a can easily enter deep into the corner of the through hole 11a, and the gap G2 between the corner of the through hole 11a and the columnar portion 12a after pressing by the second pressing member P2 becomes smaller and tends to be filled. Then, as shown in Fig. 3(c), the second pressing member P2 is withdrawn from the caulking joint portion 12b, and a concave portion 12d is formed in the caulking joint portion 12b due to the withdrawal of the second pressing member P2.

[0040] Since the gap G2 between the corner of the through hole 11a and the columnar portion 12a becomes smaller after pressing by the second pressing member P2 as described above, even when a rotational torque T is applied to the second terminal component 12, the columnar portion 12a is caught almost entirely across the vicinity of the corners of each surface of the through hole 11a, so that the strength against the rotational torque T of the terminal 10 is further increased.

[0041] Here, as shown in the cross-sectional view of FIG. 3(b), the second pressing member P2 may press the columnar portion 12a while it has entered the through hole 11a. That is, the second pressing member P2 may press the columnar portion 12a (the crimped joint portion 12b) to a position where at least a part of it (such as the pressing surface P2a) reaches the through hole 11a (from the upper surface of the first terminal component 11 downward in the lower diagram of FIG. 3(b)). This reduces the gap G2 between the corner of the through hole 11a and the columnar portion 12a, making it easier to fill it. When the second pressing member P2 enters the through hole 11a in this way, the recess 12d after the second pressing member P2 is extracted is also formed throughout the inside of the through hole 11a. Furthermore, if the length L3 of one side of the pressing surface P2a is too short, it will be difficult for the columnar portion 12a to penetrate deep into the corner of the through hole 11a. Therefore, as an example, it is preferable that the area of ​​the pressing surface P2a be at least half the cross-sectional area of ​​the through hole 11a.

[0042] FIG. 4 is a diagram showing an example of the shape of the through hole 11a of the first terminal component 11. As shown in FIG.

[0043] Examples of the cross-sectional shape of the through hole 11a (shape of a cross section perpendicular to the insertion direction D) include a triangle (for example, an equilateral triangle) like the through hole 11a-1 shown in FIG. 4(a), a pentagon (for example, a regular pentagon) like the through hole 11a-2 shown in FIG. 4(b), a hexagon (for example, a regular hexagon) like the through hole 11a-3 shown in FIG. 4(c), and an octagon (for example, a regular octagon) like the through hole 11a-4 shown in FIG. 4(d). As described above, any shape can be adopted as the cross-sectional shape of the through hole 11a as long as it has a portion that is caught by the columnar portion 12a when a rotational torque T is applied to the second terminal component 12. However, the through hole 11a-1 having a triangular cross-sectional shape shown in FIG. 4(a) is likely to have a smaller joint area with the columnar portion 12a than the through hole 11a having a square cross-sectional shape shown in FIG. 2(a). Therefore, from the viewpoint of increasing the bonding area, it is preferable to use other through holes 11a such as through hole 11a having a rectangular cross-sectional shape rather than through hole 11a-1 having a triangular cross-sectional shape.

[0044] In addition, the cross-sectional shape of the through-hole 11a may be a square shape as shown in Figs. 2 and 3, a heptagonal star shape as shown in Fig. 4(e) of the through-hole 11a-5, a pentagonal star shape as shown in Fig. 4(f) of the through-hole 11a-6, a shape in which the part of the pentagonal star shape except for the corners is cut out by a curved line forming a single imaginary circle as shown in Fig. 4(g) of the through-hole 11a-7, and a shape in which the part of the pentagonal star shape except for the corners is cut out by a straight line as shown in Fig. 4(h). In the through-holes 11a-5 to 11a-8 having these star-shaped cross-sectional shapes, the anchor effect is strong when the columnar part 12a enters the corner. Note that the dotted lines in Figs. 4(g) and (h) are merely imaginary lines to represent the corners of the pentagonal star shape.

[0045] Next, the evaluation results of Examples 1 to 4 and Comparative Examples 1 to 4 will be described with reference to the table of FIG.

[0046] In Examples 1 to 4 and Comparative Examples 1 to 4, the second terminal component 12 had a diameter of the columnar portion 12a (length of one side in Comparative Examples 3 and 4) of 1.5 mm, a diameter of the portion of the second terminal component 12 excluding the columnar portion 12a of 5 mm, and a length of the columnar portion 12a before pressing of 2.8 mm. Pressing was performed so that the diameter of the crimped joint portion 12b after pressing was 2.4 mm, and the length of the crimped joint portion 12b (portion extending from the through hole 11a) after pressing was 0.7 mm. The first terminal component 11 had a thickness of 0.8 mm and a width in the short side direction of the first terminal component 11 was 5 mm. In other words, crimping was performed under the condition that the length of one side of the through hole 11a of the first terminal component 11 (diameter in Comparative Examples 1 to 4) was larger than the diameter of the columnar portion 12a and smaller than the diameter of the crimped joint portion 12b. At that time, the second terminal part 12 was rotated to measure the rotation torque T (breaking torque) until the second terminal part 12 and the first terminal part 11 after crimping were separated. Then, for Examples 1 to 4 and Comparative Examples 1 to 4, the breaking torques (normalized torques) were calculated when the breaking torque of Comparative Example 1, which will be described later, 0.2 [N m], was set to 1 (normalized by the breaking torque value of Comparative Example 1).

[0047] First, as described above with reference to Figs. 2 and 3, Example 1 is an example in which the cross-sectional shape of the through hole 11a is quadrilateral (square), the columnar portion 12a is cylindrical, and the second pressing is performed using the second pressing member P2 (the pressing surface P1a is quadrilateral (square)). In Example 1, pressing is performed by the second pressing member P2 in such a manner that the corners of the pressing surface P2a of the second pressing member P2 are aligned with the corners of the cross-section of the through hole 11a. The breaking torque of Example 1 was 0.3 [N·m], and the normalized torque was 1.5. In other words, the breaking torque (fastening force) was improved by 50% compared to Comparative Example 1, which is one of the conventional examples.

[0048] Next, Example 2 is similar to Example 1, except that pressing by the second pressing member P2 is performed with the corners of the pressing surface P2a of the second pressing member P2 and the corners of the cross section of the through hole 11a shifted by 45 degrees. The breaking torque of Example 2 was 0.26 [N·m], and the normalized torque was 1.3. Although this is 30% improved compared to Comparative Example 1, since the normalized torque of Example 2 is smaller than that of Example 1, it can be said that it is preferable that the corners of the pressing surface P2a of the second pressing member P2 are oriented to coincide with the corners of the cross section of the through hole 11a, as in Example 1.

[0049] Next, Example 3 is similar to 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 pentagonal (regular pentagonal) instead of quadrilateral (square). The breaking torque of Example 3 was 0.27 [N·m], and the normalized torque was 1.35. If the number of corners of the through hole 11a is greater than that of the through hole 11a of Example 1, which has a quadrilateral cross-sectional shape, as in the case of the through hole 11a of Example 3, which has a pentagonal cross-sectional shape, it can be said that the columnar portion 12a is likely to expand to the corners of the through hole 11a when crushed even if the pressing force of the second pressing member P2 is small, but the biting of the columnar portion 12a into the corners of the through hole 11a is small. It is considered that the breaking torque is reduced by increasing the number of corners of the through hole 11a, because the biting of the columnar portion 12a into the corners of the through hole 11a is reduced and the cross-sectional shape of the through hole 11a approaches a perfect circle. However, if the cross-sectional shape of the through hole 11a is polygonal, the columnar portions 12a will plastically deform and expand at the corners of the polygon, so that the breaking torque (fastening force) is improved compared to Comparative Example 1.

[0050] Next, Example 4 is similar to 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 to Example 1 in which the second pressing is applied, the gap between the columnar portion 12a and the corner of the through hole 11a is the gap G1 shown in FIG. 2(c) after the first pressing using the first pressing member P1, which is larger than the gap G2 shown in FIG. 3(c) after the second pressing using the second pressing member P2. Therefore, it can be said that the columnar portion 12a does not sufficiently enter the corner of the through hole 11a, and the breaking torque is small. In addition, since the gap G1 after the first pressing is larger than the gap G2 after the second pressing, it can be said that the tensile strength in the axial direction of the second terminal component 12 is relatively low. However, even when the second pressing by the second pressing member P2 is omitted as in Example 4, the normalized torque is 1.1, and the breaking torque is 10% larger than in Comparative Example 1 in which the cross-sectional shape of the through hole is circular, and 37.5% larger than in Comparative Example 3 described later, confirming the effectiveness of the polygonal cross-sectional shape of through hole 11a. From the results of Examples 1 to 4 above, it can be seen that a polygonal cross-sectional shape such as a square or pentagon is preferable for the cross-sectional shape of through hole 11a.

[0051] Next, in Comparative Example 1, the cross-sectional shape of the through hole is circular, which is different from that in Example 1, 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, the breaking torque is considered to be relatively small compared to Example 1 because columnar portion 12a does not bite into the corners of the through hole, and because the through hole is circular and there is no surface to receive the rotation of columnar portion 12a.

[0052] 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 change was confirmed in the breaking torque or tensile strength compared to Comparative Example 1. This is considered to be because, even when the second pressing is performed, the cross-sectional shape of the through hole is circular, so that the columnar portion 12a does not enter the corner of the through hole and the columnar portion 12a does not get caught on the side surface (inner peripheral surface) of the through hole.

[0053] Comparative Example 3 is similar to Comparative Example 1 except that the columnar portion 12a is a square columnar portion. The breaking torque of Comparative Example 3 was 0.16 [N·m], and the normalized torque was 0.8. In Comparative Example 3, a gap is generated between the through hole having a circular cross section and the columnar portion 12a having a square columnar portion, and the contact area is small, so that the breaking torque and tensile strength are considered to be inferior to Comparative Example 1. In addition, the corners of the square columnar portion bite into the circular through hole, so that cracks are likely to occur. In other words, it can be seen that the breaking torque is not improved when the cross-sectional shape of the through hole and the cross section perpendicular to the insertion direction D of the columnar portion 12a are reversed to those of Example 4.

[0054] Comparative Example 4 is similar to Comparative Example 3, except that the second pressing member P2 with a pressing surface P2a having a square shape is used. In Comparative Example 4, the corners of the columnar portion 12a and the corners of the pressing surface P2a are shifted by 45 degrees so as to fill the gap in Comparative Example 3. The breaking torque of Comparative Example 4 was 0.18 [N·m], and the normalized torque was 0.9. In Comparative Example 4, the gap between the through hole having a circular cross section and the columnar portion 12a, which is a square columnar portion, can be made smaller than in Comparative Example 3, but the gap remains, so that it is considered that the breaking torque is smaller than that of Comparative Example 1.

[0055] The terminal 10 according to the present embodiment described above includes a first terminal component 11 having a through hole 11a, and a second terminal component 12 having a columnar portion 12a inserted into the through hole 11a. The second terminal component 12 is crimped to the first terminal component 11 at a tip (crimped joint portion 12b) of the columnar portion 12a, the columnar portion 12a contacts the wall surface of the through hole 11a, and the through hole 11a has a polygonal cross section perpendicular to the insertion direction D of the columnar portion 12a.

[0056] Furthermore, the manufacturing method of the terminal 10 according to this embodiment is a method for manufacturing a terminal 10 including a first terminal part 11 having a through hole 11a and a second terminal part 12 having a columnar portion 12a inserted into the through hole 11a, and includes inserting the columnar portion 12a of the second terminal part 12 into the through hole 11a having a polygonal cross section perpendicular to the insertion direction D of the columnar portion 12a (insertion process shown in FIG. 2(a)), and crimping the second terminal part 12 to the first terminal part 11 at the tip (crimped joint portion 12b) of the columnar portion 12a inserted into the through hole 11a, thereby bringing the columnar portion 12a into contact with the wall surface of the through hole 11a (increasing the contact area) (pressing process (crimping joint process) shown in FIGS. 2(b) and (c)).

[0057] Furthermore, the semiconductor device 1 according to this embodiment includes the above-mentioned terminal 10, a semiconductor element 20 electrically connected to the terminal 10, and a case 30 that is integrally molded with the terminal 10 with a portion of the terminal 10 (for example, the female screw hole 12c of the second terminal component 12 and / or the joint portion with the wiring W2 of the first terminal component 11) exposed, and that houses the semiconductor element 20.

[0058] In the terminal 10, the manufacturing method for the terminal 10, and the semiconductor device 1, the cross-sectional shape of the through hole 11a of the first terminal component 11 is polygonal. As a result, the columnar portion 12a of the second terminal component 12 expands in the through hole 11a along each surface of the through hole 11a and adheres closely to each surface of the through hole 11a. In addition, the columnar portion 12a enters the corner of the through hole 11a like 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 has an anchor effect. Even if a rotational torque T is applied to the terminal 10 (for example, the second terminal component 12), the columnar portion 12a is caught on each surface of the through hole 11a, and frictional resistance between the columnar portion 12a and the through hole 11a also acts, making it difficult for the first terminal component 11 and the second terminal component 12 to come off. Therefore, according to this embodiment, the strength (fastening force) of the crimped terminal 10 against the rotational torque T can be increased. Therefore, the performance of the terminal 10 and the semiconductor device 1 can be improved, and customer satisfaction can be increased. Also, compared to a method of increasing the strength against the rotational torque T by increasing the crushing amount (the amount of deformation due to pressing) of the tip of the columnar part 12a, it is possible to avoid the occurrence of cracks around the through hole 11a. Also, in the semiconductor device 1, the terminal 10 is insert-molded into the case 30, so that the case 30 can hold the terminal 10 when the rotational torque T is applied to the terminal 10, and therefore the first terminal part 11 and the second terminal part 12 are more unlikely to come off.

[0059] In the present embodiment, the columnar portion 12a of the second terminal part 12 is a cylindrical portion. Therefore, compared to the case where the columnar portion 12a is a polygonal column, the strength of the terminal 10 against the rotational torque T can be increased with a simple configuration in which one end of the second terminal part 12 is processed into the columnar portion 12a.

[0060] In the present embodiment, the second terminal part 12 may have a female screw hole 12c at the end opposite to the columnar part 12a. This makes it difficult for the first terminal part 11 and the second terminal part 12 to come off from each other, as described above, even if a rotational torque T is applied to the second terminal part 12 when the screw 60 is fastened into the female screw hole 12c.

[0061] In the manufacturing method of the terminal 10 according to the present embodiment, the crimping step includes pressing the columnar portion 12a with a first pressing member P1 having a pressing surface P1a larger than the cross section of the through hole 11a (first pressing step), and then pressing the columnar portion 12a (crimped portion 12b) toward the through hole 11a with a second pressing member P2 having a pressing surface P2a smaller than the cross section of the through hole 11a (second pressing step). This allows the columnar portion 12a to be more easily inserted into 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 a rotational torque T is applied to the terminal 10 (second terminal part 12), the first terminal part 11 and the second terminal part 12 are more unlikely to come off from each other. Also, by increasing the contact area between the columnar part 12a and each wall surface of the through hole 11a, the tensile strength of the second terminal part 12 in the axial direction (the direction opposite to the insertion direction D of the columnar part 12a) can be increased.

[0062] In the manufacturing method of the terminal 10 according to the present embodiment, the pressing surface P2a of the second pressing member P2 is a polygon having a similar shape to the polygon of the cross section of the through hole 11a, and in pressing the columnar portion 12a toward the through hole 11a by the second pressing member P2 (second pressing step), the columnar portion 12a (crimped joint portion 12b) is pressed toward the through hole 11a by the second pressing member P2 having a corner of the pressing surface P2a of the second pressing member P2 aligned with the corner of the cross section of the through hole 11a. This makes it easier for the columnar portion 12a to expand toward the corner of the pressing surface P2a, so that it is easier for the columnar portion 12a to enter the corner of the through hole 11a having a similar shape to the pressing surface P2a. Therefore, even if a rotational torque T is applied to the terminal 10 (second terminal part 12), the first terminal part 11 and the second terminal part 12 are more unlikely to come off from each other. Furthermore, by increasing the contact area between the columnar portion 12a and each surface of the through hole 11a, the tensile strength of the second terminal component 12 in the axial direction can be further increased.

[0063] In the manufacturing method of the terminal 10 according to the present embodiment, in pressing the columnar portion 12a (the crimped joint portion 12b) toward the through hole 11a by the second pressing member P2 (second pressing step), the second pressing member P2 is inserted into the through hole 11a. As a result, the tip (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 (second terminal part 12), the first terminal part 11 and the second terminal part 12 are more unlikely to come off from each other. Furthermore, the contact area between the columnar portion 12a and each surface of the through hole 11a is increased, so that the tensile strength of the second terminal part 12 in the axial direction can be further increased.

[0064] The invention as described in the claims of the original application is set forth below.

[0065] <Appendix 1> a first terminal component having a through hole; a second terminal component having a columnar portion inserted into the through hole, the second terminal component is joined to the first terminal component by crimping at a tip of the columnar portion, the columnar portion being in contact with a wall surface of the through hole, The through hole has a polygonal cross section perpendicular to the insertion direction of the columnar portion. A terminal characterized by:

[0066] <Appendix 2> The columnar portion of the second terminal component is a cylindrical portion. 2. The terminal according to claim 1 .

[0067] <Appendix 3> The second terminal component has a female screw hole at an end opposite to the columnar portion. 3. The terminal according to claim 1 or 2,

[0068] <Appendix 4> A method for manufacturing a terminal including a first terminal part having a through hole and a second terminal part having a columnar portion inserted into the through hole, comprising: inserting the columnar portion of the second terminal component into the through hole having a polygonal cross section perpendicular to an insertion direction of the columnar portion; the second terminal part is crimped to the first terminal part at a tip of the columnar part inserted into the through hole, thereby bringing the columnar part into contact with a wall surface of the through hole; A method for manufacturing a terminal comprising the steps of:

[0069] <Appendix 5> The crimping step includes the steps of: pressing the columnar portion with a first pressing member having a pressing surface larger than the cross section of the through hole; Then, pressing the columnar portion toward the through hole with a second pressing member having a pressing surface smaller than the cross section of the through hole. 5. A method for manufacturing a terminal according to claim 4.

[0070] <Appendix 6> the pressing surface of the second pressing member is a polygon having a similar shape to the polygon of the cross section of the through hole, In the case where the columnar portion is pressed toward the through hole by the second pressing member, the columnar portion is pressed toward the through hole by the second pressing member oriented such that a corner of the pressing surface of the second pressing member coincides with a corner of the cross section of the through hole. 6. A method for manufacturing a terminal according to claim 5.

[0071] <Appendix 7> By pressing the columnar portion toward the through hole with the second pressing member, the second pressing member is caused to enter the inside of the through hole. 7. A method for manufacturing a terminal according to claim 5 or 6.

[0072] <Appendix 8> a terminal including a first terminal part having a through hole and a second terminal part having a columnar portion inserted into the through hole; a semiconductor element electrically connected to the terminal; a case that is integrally formed with the terminals with a portion of the terminals exposed and that houses the semiconductor element; the second terminal component is joined to the first terminal component by crimping at a tip of the columnar portion, the columnar portion being in contact with a wall surface of the through hole, The through hole has a polygonal cross section perpendicular to the insertion direction of the columnar portion. A semiconductor device comprising: [Industrial Applicability]

[0073] As described above, the present invention is capable of increasing the strength of a crimped terminal against rotational torque in a terminal, a terminal manufacturing method, and a semiconductor device, and is therefore particularly useful in semiconductor element devices in which some terminal components are fastened. [Explanation of symbols]

[0074] 1 Semiconductor device 10 Terminals 11 First terminal part 11a(11a-1~11a-8) Through hole 12 Second terminal part 12a Columnar part 12b Crimp joint 12c female thread hole 12d Recess 20 Semiconductor elements 30 cases 31 Left side wall 31a Convex part 32 Right side wall 40 Multilayer Board 41 First conductor plate 42 Second conductor plate 43 Third conductor plate 44 Insulating Substrate 50 Metal Base 60 Screws 70 Wiring board 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

Claims

1. a first terminal component having a through hole; a second terminal component having a columnar portion inserted into the through hole, The second terminal part is joined to the first terminal part by crimping at a tip of the columnar portion, and the columnar portion is in contact with a wall surface of the through hole, The through hole has a polygonal cross section perpendicular to the insertion direction of the columnar portion. A terminal characterized by:

2. The columnar portion of the second terminal component is a cylindrical portion.

2. The terminal according to claim 1 .

3. The second terminal component has a female screw hole at an end opposite to the columnar portion.

3. The terminal according to claim 1 or 2.

4. A method for manufacturing a terminal including a first terminal part having a through hole and a second terminal part having a columnar portion inserted into the through hole, the method comprising the steps of: inserting the columnar portion of the second terminal component into the through hole having a polygonal cross section perpendicular to an insertion direction of the columnar portion; the second terminal part is crimped to the first terminal part at a tip of the columnar part inserted into the through hole, thereby bringing the columnar part into contact with a wall surface of the through hole; A method for manufacturing a terminal comprising the steps of:

5. The crimping step includes the steps of: pressing the columnar portion with a first pressing member having a pressing surface larger than the cross section of the through hole; and then pressing the columnar portion toward the through hole with a second pressing member having a pressing surface smaller than the cross section of the through hole.

5. The method for manufacturing a terminal according to claim 4.

6. the pressing surface of the second pressing member is a polygon similar in shape to the polygon of the cross section of the through hole, In the case where the columnar portion is pressed toward the through hole by the second pressing member, the columnar portion is pressed toward the through hole by the second pressing member oriented such that a corner of the pressing surface of the second pressing member coincides with a corner of the cross section of the through hole.

6. The method for manufacturing a terminal according to claim 5.

7. By pressing the columnar portion toward the through hole with the second pressing member, the second pressing member is caused to enter the inside of the through hole.

7. The method for manufacturing a terminal according to claim 5 or 6.

8. a terminal including a first terminal part having a through hole and a second terminal part having a columnar portion inserted into the through hole; a semiconductor element electrically connected to the terminal; a case that is integrally formed with the terminals with a portion of the terminals exposed and that houses the semiconductor element; The second terminal part is joined to the first terminal part by crimping at a tip of the columnar portion, and the columnar portion is in contact with a wall surface of the through hole, The through hole has a polygonal cross section perpendicular to the insertion direction of the columnar portion. A semiconductor device comprising:

Images