Press-fit terminal and semiconductor device

Abstract

To meet the required performance or improve the ease of assembly in a press-fit terminal and a semiconductor device.SOLUTION: An elastically deforming portion 10, which is press-fitted into a through-hole 111 (an example of an insertion hole), has four corner regions 10a that contact the through-hole 111 on the periphery of a cross section perpendicular to the press-fitting direction D2, and at least one of the corner regions 10a is a peripheral cut surface-shaped portion 11c, 12c. Alternatively, the elastically deforming portion 10 has arc-shaped portions 11e, 12e with a center of curvature on the central side of the through-hole 111 at both ends of the cross section in the deformation direction D1 of the elastically deforming portion 10. Alternatively, the first branch piece 11 and the second branch piece 12 (an example of a pair of branch pieces) have tip-cut surface-shaped portions 11f, 12f (an example of a tip-chamfered portion) at both ends of the tips 11a, 12a of the elastically deforming portion 10 in the deformation direction D1.SELECTED DRAWING: Figure 4B

Description

[Technical Field]

[0001] The present invention relates to a press-fit terminal and a semiconductor device including the press-fit terminal. [Background technology]

[0002] Conventionally, semiconductor devices have circuit boards on which semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) are mounted, and are used in inverter devices, etc. Such semiconductor devices sometimes use press-fit terminals that are press-fit into insertion holes such as through-holes in the board and elastically deform (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-126786 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-219778 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-141857 Summary of the Invention [Problem to be solved by the invention]

[0004] If the edges of a press-fit terminal's cross section perpendicular to the press-fit direction are angular, it will make near-point contact with the inner wall of the insertion hole, or it may not fit into the opening of the insertion hole when pressed in. This can cause the plating on the terminal and insertion hole to be scraped off, increase the insertion load when press-fitting and the extraction load when extracting, or it may not be possible to press the terminal into the insertion hole. On the other hand, if each of the four corners has a rounded (R-shaped) surface, the extraction load will be smaller.

[0005] An object of the present invention is to provide a press-fit terminal and a semiconductor device that can satisfy required performance or that can improve assembly efficiency. [Means for solving the problem]

[0006] In one aspect, the press-fit terminal has an elastically deforming portion that is pressed into an insertion hole, and the elastically deforming portion has four corner regions that contact the insertion hole on the periphery of a cross section perpendicular to the pressing direction, and at least one of the corner regions is a peripheral cut surface shaped portion.

[0007] In another aspect, the press-fit terminal has an elastically deforming portion that is pressed into an insertion hole, and the elastically deforming portion has arc-shaped portions at both ends of the deformation direction of the elastically deforming portion in a cross section perpendicular to the pressing direction, with the center of curvature being on the central side of the insertion hole.

[0008] In another aspect, the press-fit terminal has an elastically deforming portion that is pressed into an insertion hole, and the elastically deforming portion is a pair of branched pieces that branch into two in the press-fit direction, move away from each other, and curve so that their tips approach each other, and the pair of branched pieces have tip-chamfered portions at both ends of the deformation direction of the elastically deforming portion at the tip.

[0009] In another aspect, a semiconductor device includes any one of the press-fit terminals described above and a substrate provided with the insertion hole. [Effects of the Invention]

[0010] According to the above aspect, it is possible to satisfy required performance or improve the ease of assembly. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view showing a semiconductor device according to an embodiment; [Figure 2] 1 is a front view showing a press-fit terminal according to an embodiment of the present invention; [Figure 3A] FIG. 1 is a front view (part 1) for explaining insertion of a board (press-fitting of a press-fit terminal) in one embodiment. [Figure 3B]FIG. 10 is a front view (part 2) illustrating insertion of a board (press-fitting of a press-fit terminal) in one embodiment. [Figure 3C] FIG. 10 is a front view (part 3) illustrating insertion of a board (press-fitting of a press-fit terminal) in one embodiment. [Figure 4A] 10 is a plan view showing the angular shape of an elastically deformable portion in Comparative Example 1. FIG. [Figure 4B] FIG. 10 is a plan view showing a C-shaped corner of an elastically deforming portion in one embodiment. [Figure 4C] FIG. 10 is a plan view showing the corner CR shape of an elastically deforming portion in one embodiment. [Figure 4D] 10 is a plan view showing the rounded corner shape of an elastically deformable portion in Comparative Example 2. FIG. [Figure 4E] FIG. 10 is a plan view showing the arc shape of an elastically deforming portion in one embodiment. [Figure 4F] FIG. 10 is a plan view showing a staggered CR shape of an elastically deforming portion in one embodiment. [Figure 5] FIG. 10 is an explanatory diagram showing an example of a standard for the remaining plating thickness of a through-hole in one embodiment. [Figure 6] 10A and 10B are explanatory diagrams showing examples of standards for plating scraping lengths of press-fit terminals according to an embodiment. [Figure 7] 10A and 10B are explanatory diagrams showing examples of standard insertion loads for press-fit terminals according to an embodiment. [Figure 8] 10A and 10B are explanatory diagrams showing examples of standards for pull-out loads of press-fit terminals according to an embodiment. [Figure 9] 10A and 10B are a plan view and a front view illustrating interference between a first branch piece of a press-fit terminal and a through-hole when the press-fit terminal is eccentric in one embodiment. [Figure 10] 1A and 1B are a plan view and a front view illustrating a configuration for avoiding interference between a first branch piece of a press-fit terminal and a through-hole when the press-fit terminal is eccentric in one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] A press-fit terminal and a semiconductor device according to an embodiment of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiment described below, and can be modified and implemented as appropriate within the scope of the present invention.

[0013] FIG. 1 is a cross-sectional view showing a semiconductor device 100, and FIG. 2 is a front view showing a press-fit terminal 1. As shown in FIG.

[0014] 1 and 2, and FIGS. 3A to 3C, 4A to 4F, 9, and 10 described below, the press-fitting direction D2 of the press-fit terminal 1 is defined as the positive Z direction, and of the X and Y directions that are perpendicular to the Z direction and perpendicular to each other, the deformation direction D1 of the elastically deforming portion 10 of the press-fit terminal 1 is defined as the X direction. In some cases, the X direction may be referred to as the left-right direction, the Y direction as the front-back direction, and the Z direction as the up-down direction. These directions are terms used for convenience of explanation, and the corresponding relationships between the X, Y, and Z directions will change depending on the posture of the press-fit terminal 1 and the semiconductor device 100, etc.

[0015] The semiconductor device 100 shown in FIG. 1 includes a plurality of press-fit terminals 1, a substrate 110, a semiconductor element 120, a case 130, a laminated substrate 140, a metal base 150, and wires 161-163.

[0016] As an example, the semiconductor device 100 is applied to a power conversion device such as an inverter device for an industrial or automotive motor, together with a cooler (not shown) disposed below the metal base 150. In the following explanation, detailed explanations of configurations, functions, operations, assembly methods, etc. that are the same as or similar to those of known press-fit terminals 1 and semiconductor device 100 will be omitted. Note that the press-fit terminal 1 can also be used for purposes other than the semiconductor device 100.

[0017] 2, the press-fit terminal 1 includes an elastically deforming portion 10 and a base portion 20. The press-fit terminal 1 is made of a metal material such as nickel-plated copper, copper alloy, brass, or stainless steel (with Sn plating on the outermost surface).

[0018] The elastically deforming portion 10 has a first branched piece 11 and a second branched piece 12. The first branched piece 11 and the second branched piece 12 are a pair of branched pieces that bifurcate in the press-fitting direction D2 into the through-hole 111, move apart in the deformation direction D1, and curve so that the tips 11a, 12a approach each other. For example, the elastically deforming portion 10 has a plate-like shape with a thickness direction in the Y direction. The elastically deforming portion 10 can also be called a press-fitting portion, or when it has the first branched piece 11 and the second branched piece 12, it can also be called a U-shaped portion, a crab-claw-shaped portion, a crab-scissors-shaped portion, or the like. The elastically deforming portion 10 may not have branches, and may have other shapes, such as a shape in which the tip 11a of the first branched piece 11 and the tip 12a of the second branched piece 12 are integrated and open at the center.

[0019] The base portion 20 is provided integrally with the elastically deforming portion 10 on the negative side of the elastically deforming portion 10 in the Z direction. In the example of Fig. 1, the base portion 20 has an L-shaped plate shape. Note that, like the shape of the elastically deforming portion 10, the shape of the base portion 20 is not particularly limited.

[0020] 1 is disposed above the case 130. The substrate 110 is provided with a through-hole 111 for electrical connection, which is an example of an insertion hole into which the elastically deforming portion 10 is press-fitted. The substrate 110 is an example of a member electrically connected to the press-fit terminal 1.

[0021] The semiconductor element 120 is bonded onto the first conductor plate 141 by a conductive bonding material (not shown) such as solder. The semiconductor element 120 is formed, for example, by an IGBT (Insulated Gate Bipolar Transistor) element, which is a switching element, or an RC (Reverse Conducting)-IGBT element, which integrates the IGBT element with a diode element, such as an FWD (Free Wheeling Diode) element, connected in anti-parallel to the switching element. The switching element and diode element in the semiconductor element 120 are not limited to a Si substrate, and may be formed on a semiconductor substrate using a wide bandgap semiconductor, such as SiC (Silicon Carbide) or GaN (Gallium Nitride). This type of semiconductor element 120 has electrodes (not shown) on its bottom and top surfaces. The electrodes on the top surface of the semiconductor element 120 are electrically connected to the wirings 161 and 163 by a conductive bonding material. 1 via wiring 163, and is connected to the other press-fit terminal 1 via wiring 161, 162 and second conductor plate 142. The press-fit terminal 1 can be used as any terminal, such as a main terminal such as an output terminal or input terminal (P terminal and N terminal), or a control terminal.

[0022] The case 130 has, for example, a rectangular cylindrical shape with a central axis in the Z direction, and houses the semiconductor element 120 and the like. The case 130 is formed using an insulating resin material such as PPS (Poly Phenylene Sulfide) or PA (Poly Amide). The case 130 is adhered to the upper surface of the metal base 150.

[0023] The case 130 is integrally molded with the press-fit terminals 1, with both ends of the press-fit terminals 1 exposed. The semiconductor element 120, first conductive plate 141, second conductive plate 142, etc. inside the case 130 are sealed with a sealing material (not shown). This sealing material is, for example, epoxy resin, silicone gel, etc. A cover may be provided above the sealing material to cover the entire XY plane of the hollow portion of the case 130.

[0024] The laminated substrate 140 has a first conductive plate 141, a second conductive plate 142, a third conductive plate 143, and an insulating substrate 144. The first conductive plate 141 and the second conductive plate 142 are provided on the upper surface of the insulating substrate 144, and the third conductive plate 143 is provided on the lower surface of the insulating substrate 144. The laminated substrate 140 is, for example, a DCB (Direct Copper Bonding) substrate or an AMB (Active Metal Brazing) substrate.

[0025] The first conductor plate 141 and the second conductor plate 142 are members that function as wiring members in the inverter circuit, and are formed of, for example, a metal plate or metal foil made of copper, aluminum, etc. The first conductor plate 141 and the second conductor plate 142 may also be called a conductor layer, a conductive layer, a conductor pattern, a wiring pattern, etc.

[0026] The third conductor plate 143 is a member that functions as a heat conduction member that conducts heat generated in the inverter circuit to the metal base 150, and is formed, for example, from a metal plate or metal foil such as copper or aluminum. The third conductor plate 143 is joined to the metal base 150 by a joining material S such as solder. The third conductor plate 143 may also be called a heat dissipation layer, heat dissipation plate, conductor pattern, heat dissipation pattern, etc.

[0027] The insulating substrate 144 may be a ceramic substrate formed from 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 144 may be, for example, a substrate formed from an insulating resin such as 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 150 is a rectangular plate-shaped member. The metal base 150 functions as a heat-conducting member that conducts heat generated by the semiconductor element 120 to a cooler (not shown), and is formed of a metal plate such as a copper plate or an aluminum plate. The metal base 150 and the cooler are connected via a heat-conducting material such as thermal grease or a thermal compound. The metal base 150 may also function as a cooler.

[0029] The wiring 161 to 163 are, for example, lead frames or wires. The wiring 161 connects the semiconductor element 120 and the second conductor plate 142. The wiring 162 connects the second conductor plate 142 and the base portion 20 of the press-fit terminal 1 on the positive side in the Y direction. The wiring 163 connects the semiconductor element 120 and the base portion 20 of the press-fit terminal 1 on the negative side in the Y direction.

[0030] In the above description, the press-fit terminal 1 is disposed in the semiconductor device 100, but the use of the press-fit terminal 1 is not limited to the semiconductor device 100 and may be used in any device. The circuit of the semiconductor device 100 includes a switching element, a diode element, and the like inside the semiconductor element 120, but the semiconductor device 100 may constitute 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. The above description of the semiconductor device 100 is merely an example, and the semiconductor device 100 may be any device provided with a substrate 110 having a through-hole 111 (an example of an insertion hole) into which the elastically deforming portion 10 of the press-fit terminal 1 is press-fitted.

[0031] Next, the insertion of the substrate 110 (press-fitting of the press-fit terminal 1) will be described with reference to the front views of FIGS. 3A to 3C.

[0032] First, as shown in FIG. 3A, for example, a manufacturing apparatus for semiconductor device 100 positions multiple through-holes 111 in substrate 110 at the positions of multiple press-fit terminals 1, and then moves substrate 110 in the negative Z direction (substrate insertion direction D3). As a result, elastically deforming portion 10 exposed upward from case 130 shown in FIG. 1 above enters cylindrical through-hole 111. Before elastically deforming portion 10, maximum width W0 of elastically deforming portion 10 in deformation direction D1 (X direction) is greater than the inner diameter of through-hole 111. Note that instead of moving substrate 110 in the negative Z direction as described above, press-fit terminal 1 (elastically deforming portion 10) may be press-fit by moving press-fit terminal 1 (case 130) in the positive Z direction.

[0033] Next, as shown in FIG. 3B , when the board 110 is pressed in the board insertion direction D3, both ends of the first branch piece 11 and the second branch piece 12 in the deformation direction D1 contact the inner circumferential wall of the through-hole 111, and the elastically deforming portion 10 elastically deforms so as to be compressed in the deformation direction D1. During this deformation of the elastically deforming portion 10, the tips 11a, 12a of the first branch piece 11 and the second branch piece 12 elastically deform so as to approach each other. Therefore, immediately after the start of elastic deformation, the maximum width W1 of the elastically deforming portion 10 becomes shorter than the maximum width W0 before elastic deformation. Note that, as both ends of the elastically deforming portion 10 in the deformation direction D1 contact the inner circumferential wall of the through-hole 111, excessive force is generated at the contact points of the first branch piece 11 and the second branch piece 12, causing them to be gouged (dig into) and resulting in plating scraping 11b, 12b. Although not shown, the through-hole 111 suffers plating scraping and deformation.

[0034] As shown in FIG. 3C , once the insertion of the board 110 in the board insertion direction D3 is complete, the elastically deforming portion 10 is further compressed in the deformation direction D1, bringing the first branched piece 11 and the second branched piece 12 into contact with each other. In this state, the elastic force of the elastically deforming portion 10 is strong, making it difficult for the elastically deforming portion 10 to be removed even when pulled in the direction opposite the press-fitting direction D2. The maximum width W2 of the elastically deforming portion 10 after press-fitting coincides with the inner diameter of the through-hole 111 and is therefore shorter than the maximum width W1 immediately after the start of elastic deformation. Furthermore, plating scraping 11b, 12b of the first branched piece 11 and the second branched piece 12 increases. The length of this plating scraping 11b, 12b protruding from the through-hole 111 in the deformation direction D1 is the scraping length L. If this scraping length L is long, it can cause problems such as wiring short circuits. In Figure 3C, since the diameter of through hole 111 is standard for press-fit terminal 1, the first branch piece 11 and the second branch piece 12 make surface contact on the flat portion (YZ plane). However, if through hole 111 has the smallest diameter, for example, they will make contact only at the base side (the end on the negative side of the Z direction) of the flat portion, and if through hole 111 has the largest diameter, they will make contact only at the tip side (the end on the positive side of the Z direction) of the flat portion.

[0035] 4A (Comparative Example 1 with an angular shape), when four corner regions 10a located on the periphery of the cross section of elastically deforming portion 10 perpendicular to press-fitting direction D2 (positive side of the Z direction) and in contact with through-hole 111 are angular, elastically deforming portion 10 is press-fit into through-hole 111 while in contact with through-hole 111 in a state close to point contact with elastically deforming portion 10, the scraping length L of plating scrapes 11b and 12b described above becomes long. Here, the four corner regions 10a located on the periphery of the cross section of the elastically deforming portion 10 perpendicular to the press-fitting direction D2 and in contact with the through-hole 111 are portions in contact with the inner circumferential wall of the through-hole 111, and are the four corner regions 10a at an end on the positive side in the X direction (deformation direction D1) and in the positive side in the Y direction (direction perpendicular to the X direction in the cross section), an end on the positive side in the X direction and in the negative side in the Y direction, an end on the negative side in the X direction and in the positive side in the Y direction, and an end on the negative side in the X direction and in the negative side in the Y direction. In the example of FIG. 4A , since the elastically deforming portion 10 includes the first branch piece 11 and the second branch piece 12, two of the four corner regions 10a are formed in the first branch piece 11 and two are formed in the second branch piece 12. In addition, the four corner regions 10a can also be said to be regions connecting the side of the press-fit terminal 1 in the X direction (deformation direction D1 of the elastically deforming portion 10 (or the press-fit terminal 1)) and the side in the Y direction (direction perpendicular to the X direction) in a cross section perpendicular to the press-fit direction D2. In other words, the four corner regions 10a can be said to be the four corner regions of a rectangular region (or approximately rectangular region) formed by the first branch piece 11, the second branch piece 12, and the region sandwiched between them in a cross section perpendicular to the press-fit direction D2.

[0036] As shown in FIG. 4B (corner C-shape), peripheral cut-surface shaped portions 11c, 12c may be provided at four corner regions 10a (see FIG. 4A) on the periphery of the elastically deforming portion 10 (first branch piece 11 and second branch piece 12). These peripheral cut-surface shaped portions 11c, 12c may be provided, for example, over the entire elastically deforming portion 10 in the press-fitting direction D2. However, it is sufficient that the peripheral cut-surface shaped portions 11c, 12c are provided on at least a portion of the elastically deforming portion 10 that can come into contact with the through-hole 111 (a portion that has a larger diameter than the through-hole 111 before press-fitting). The elastically deforming portion 10 having the peripheral cut-surface shaped portions 11c, 12c may be formed by a subsequent chamfering process, or may be formed by any molding method, pressing method, or the like.

[0037] 4C (CR-corner shape), of the four corner regions 10a (see FIG. 4A) on the periphery of the elastically deforming portion 10 (first branch piece 11 and second branch piece 12), peripheral cut surface-shaped portions 11c, 12c may be provided in the corner region 10a on the positive side in the Y direction, and peripheral round surface-shaped portions 11d, 12d may be provided in the corner region 10a on the negative side in the Y direction. These peripheral cut surface-shaped portions 11c, 12c and peripheral round surface-shaped portions 11d, 12d may be provided, for example, over the entire elastically deforming portion 10 in the press-fitting direction D2, but may only be provided in at least a part of the elastically deforming portion 10 that can come into contact with the through-hole 111 (a part that has a larger diameter than the through-hole 111 before press-fitting).

[0038] As shown in Figure 4D (comparison example 2 with rounded corners), when rounded peripheral surface shaped portions 11d, 12d are provided in all four corner regions 10a (see Figure 4A) on the periphery of the elastically deforming portion 10 (first branch piece 11 and second branch piece 12), the remaining plating thickness [μm] of the through hole 111 shown in Figure 5 does not become extremely thick, but the pull-out load [N] when pulling out the press-fit terminal 1 shown in Figure 8 from the board 110 becomes close to the lower limit standard of 40 [N], as will be described in detail later.

[0039] As shown in FIG. 4E (arc shape), arc-shaped portions 11e and 12e may be provided at both ends of the elastically deforming portion 10 (first branch piece 11 and second branch piece 12) in the deformation direction D1, with the center of curvature being on the central side of the through-hole 111. These arc-shaped portions 11e and 12e may have a radius of curvature that is the same as or close to the radius of the through-hole 111. The arc-shaped portions 11e and 12e may be provided, for example, over the entire elastically deforming portion 10 in the press-fitting direction D2, but may only be provided on at least a part of the elastically deforming portion 10 that can come into contact with the through-hole 111. The arc-shaped portions 11e and 12e may also be referred to as a surface hole (inner peripheral wall of the through-hole 111) fitting shape.

[0040] The centers of curvature of arc-shaped portions 11e and 12e are located near the center of through-hole 111 when press-fit terminal 1 is inserted into through-hole 111 and maximum width W2 of elastically deforming portion 10 coincides with the inner diameter of through-hole 111. Before press-fit terminal 1 is inserted into through-hole 111, when elastically deforming portion 10 has maximum width W1, the centers of curvature of arc-shaped portions 11e and 12e are located at positions spaced apart by maximum width W1 - maximum width W2.

[0041] If the radius of curvature of arc-shaped portions 11e, 12e is less than the radius of through-hole 111, each arc-shaped portion 11e, 12e will contact through-hole 111 at one point in the center. If the radius of curvature of arc-shaped portions 11e, 12e is greater than the radius of through-hole 111, each arc-shaped portion 11e, 12e will contact through-hole 111 at two points, at the ends of each arc-shaped portion. If the ratio of the radius of curvature of arc-shaped portions 11e, 12e to the radius of through-hole 111 is greater than 100%, in terms of the points of contact with through-hole 111, the pull-out load will increase, the insertion load will increase, the length of terminal plating scraping will increase, and the remaining through-hole plating will decrease. Similarly, if the ratio is less than 100%, in terms of the points of contact with through-hole 111, the pull-out load will decrease, the insertion load will decrease, the length of terminal plating scraping will decrease, and the remaining through-hole plating will increase.

[0042] The radius of curvature of the arc-shaped portions 11e and 12e is preferably 80% to 150% of the radius of the through-hole 111. This is the range in which the thickness of the press-fit terminal 1 in the Y direction is 50% of that of the through-hole 111, and when the press-fit terminal 1 is inserted into the through-hole 111, a gap of 5% or less is formed. As described above, if the radius of curvature of the arc-shaped portions 11e and 12e is less than the radius of the through-hole 111, each arc-shaped portion 11e and 12e will contact the through-hole 111 at one point in the center, and this gap will be at both ends of each arc-shaped portion 11e and 12e. If the radius of curvature of the arc-shaped portions 11e and 12e is greater than the radius of the through-hole 111, each arc-shaped portion 11e and 12e will contact the through-hole 111 at two points, at the ends, and this gap will be at the center of each arc-shaped portion 11e and 12e. If the relationship between the thickness of the press-fit terminal 1 and the diameter of the through-hole 111 is different, the ratio of the radius of curvature of the arc-shaped portions 11e and 12e to the radius of the through-hole 111 can be adjusted appropriately so that the gap is 5% or less when the press-fit terminal 1 is inserted into the through-hole 111.

[0043] As shown in FIG. 4F (staggered CR shape), among the four corner regions 10a (see FIG. 4A) on the periphery of the elastically deforming portion 10 (first branch piece 11 and second branch piece 12), a peripheral cut surface shaped portion 11c may be provided in the corner region 10a on the positive side in the Y direction of the elastically deforming portion 10 of the first branch piece 11, a peripheral rounded surface shaped portion 11d may be provided in the corner region 10a on the negative side in the Y direction, and a peripheral rounded surface shaped portion 12d may be provided in the corner region 10a on the positive side in the Y direction of the second branch piece 12, and a peripheral cut surface shaped portion 12c may be provided in the corner region 10a on the negative side in the Y direction. In this case, it can be said that two peripheral cut surface shaped portions 11c, 12c are provided diagonally opposite one of the four corner regions 10a, and two peripheral rounded surface shaped portions 11d, 12d are provided diagonally opposite the other of the four corner regions 10a.

[0044] At least one of the four peripheral corner regions 10a of the elastically deformable portion 10 having the above-mentioned peripheral cut surface shaped portions 11c, 12c may have an angular shape, for example, at a right angle, but it is preferable that all of the corner regions 10a have a shape that is not angular (a shape that is chamfered by the peripheral cut surface shaped portions 11c, 12c or the peripheral round surface shaped portions 11d, 12d).

[0045] As shown in Fig. 5, the remaining plating thickness [μm] of through-hole 111 after press-fitting press-fit terminal 1 is measured, for example, by cross-sectional observation, and the minimum standard is generally set at 8 μm. While the remaining plating thickness [μm] for the angular shape (Comparative Example 1) shown in Fig. 4A is approximately 5 μm (shown by the black circle), which is below the minimum standard, the remaining plating thickness [μm] for the C-corner shape shown in Fig. 4B (approximately 10 μm), the CR-corner shape shown in Fig. 4C (approximately 12 μm), the R-corner shape (Comparative Example 2) shown in Fig. 4D (approximately 15 μm), and the arc-shaped shape shown in Fig. 4E (approximately 20 μm) exceeds the minimum standard. Furthermore, the arc-shaped elastically deformed portion 10 shown in Fig. 4E has an extremely thick remaining plating thickness [μm] of approximately 20 μm, making it particularly effective in terms of increasing the remaining plating thickness. 6 to 8 described later, the description of the elastically deforming portion 10 having a staggered CR shape shown in FIG. 4F will be omitted.

[0046] As shown in Fig. 6, the length L (see Fig. 3C) of plating scraping 11b, 12b of press-fit terminal 1 (elastically deforming portion 10) after press-fitting is, for example, the longest length of plating scraping 11b, 12b, and has an upper standard limit of 650 μm. While the scraping length L (μm) for the angular shape (Comparative Example 1) shown in Fig. 4A is approximately 780 μm (shown by a black circle), which exceeds the upper standard limit, the scraping length L (μm) for the C-corner shape shown in Fig. 4B (approximately 630 μm), the CR-corner shape shown in Fig. 4C (approximately 600 μm), the R-corner shape (Comparative Example 2) shown in Fig. 4D (approximately 550 μm), and the arc shape shown in Fig. 4E (approximately 500 μm) is below the upper standard limit. Furthermore, the arc-shaped elastically deforming portion 10 shown in FIG. 4E has the shortest scraped length L [μm] of approximately 550 [μm], and is therefore particularly effective in terms of shortening the scraped length L.

[0047] As shown in Fig. 7, the insertion load [N] required to insert (press-fit) the press-fit terminal 1 (elastically deformable portion 10) into the through-hole 111 is, for example, the load per press-fit terminal 1, and the upper limit standard is 110 [N] and the lower limit standard is 40 [N]. While the insertion load [N] for the rectangular shape (Comparative Example 1) shown in Fig. 4A is approximately 100 [N] (shown by the hatched circle), which falls between the upper and lower limits, it is close to the upper limit and the margin is small. In contrast, the differences between the upper and lower limits for the C-corner shape shown in Fig. 4B (approximately 90 [N]), the CR-corner shape shown in Fig. 4C (approximately 85 [N]), the R-corner shape (Comparative Example 2) shown in Fig. 4D (approximately 75 [N]), and the arc shape shown in Fig. 4E (approximately 70 [N]) are relatively large. In particular, the arc-shaped elastically deforming portion 10 shown in FIG. 4E has a sufficient difference between the upper and lower limits of the specification, and the insertion load [N] is small at approximately 70 [N], so it can be said to be effective from the viewpoint of the insertion load.

[0048] As shown in Fig. 8, the pull-out load [N] required to pull the press-fit terminal 1 (elastically deformable portion 10) from the through-hole 111 is, for example, the load per press-fit terminal 1, and the lower limit standard is set at 40 [N]. This insertion load [N] exceeds the lower limit standard for the angular shape (Comparative Example 1) shown in Fig. 4A (approximately 75 [N]), the C-shaped corner shape (approximately 65 [N]) shown in Fig. 4B, the CR-shaped corner shape (approximately 62 [N]) shown in Fig. 4C, the R-shaped corner shape (Comparative Example 2) (approximately 60 [N]) shown in Fig. 4D, and the arc-shaped corner shape (approximately 52 [N]) shown in Fig. 4E. The arc-shaped elastically deformable portion 10 shown in Fig. 4E has the smallest insertion load [N] at approximately 52 [μm], and therefore is inferior to the other shapes in terms of increasing the insertion load [N].

[0049] 5, the scraping length L [μm] ...

[0050] 9, the press-fit terminal 1 may become eccentric with respect to the through-hole 111 due to factors such as the assembly accuracy of the semiconductor device 100 and the processing accuracy and tolerances of each part. Such eccentricity may occur even when a manufacturing device is used to align the positions of the multiple through-holes 111 in the substrate 110 with the positions of the multiple press-fit terminals 1 before press-fitting the press-fit terminals 1. In the example of FIG. 9, the press-fit terminal 1 is eccentric to the negative side in the X direction with respect to the through-hole 111. In this case, particularly when the width in the deformation direction D1 of the tips 11a, 12a of the elastically deforming portion 10 (first branch piece 11 and second branch piece 12) (total width including the width Wa of the first branch piece 11, the width of the second branch piece 12, and the width of the gap between the first branch piece 11 and the second branch piece 12) is long enough to approach the inner diameter of the through hole 111 (when the design margin is small), the tip 11a (width Wa) of the first branch piece 11 may come into contact with the lower end (opening portion) of the through hole 111, making it impossible to press-fit the press-fit terminal 1.

[0051] 10, it is preferable that the first branched piece 11 and the second branched piece 12 have tip cut surface shaped portions 11f, 12f at both ends of the tips 11a, 12a in the deformation direction D1 of the elastically deforming portion 10. This narrows the area (press-fitting start surface) of the tips 11a, 12a and positions them closer to the center in the Y direction, making it less likely that the tips 11a, 12a of the first branched piece 11 and the second branched piece 12 will come into contact with the lower end (opening portion) of the through-hole 111.

[0052] The tip-cut surface-shaped portions 11f, 12f are preferably provided in at least one (preferably all four) of the four corner regions 10a of the elastically deforming portion 10 at the tips 11a, 12a, i.e., the four corner regions 10a (the corner regions 10a on the positive side of the Y direction and the corner regions 10a on the negative side of the Y direction) located on the periphery of a cross section of the elastically deforming portion 10 perpendicular to the press-fitting direction D2 and in contact with the through-hole 111, so as to form an inclined surface having a triangular shape in a plan view. As a result, the width Wb in the deformation direction D1 at both ends of the tips 11a, 12a in the Y direction is sufficiently smaller than the width Wa (see FIG. 9) of the tips 11a, 12a at a portion where the tip-cut surface-shaped portions 11f, 12f are not provided. The tip-cut surface-shaped portions 11f, 12f are preferably provided at both ends of the tips 11a, 12a in the Y direction so that the width Wb in the deformation direction D1 decreases toward the positive side of the Z direction.

[0053] A total of four cut-tip surface shaped portions 11f, 12f may be provided at the corner regions 10a on the positive side in the Y direction and the negative side in the Y direction of the tips 11a, 12a of the first branched piece 11 and the second branched piece 12. However, two cut-tip surface shaped portions 11f, 12f may be provided, one each on the first branched piece 11 and the second branched piece 12, so as to extend over the entire Y direction. Here, the cut-tip surface shaped portions 11f, 12f are an example of a chamfered tip portion. This chamfered tip portion may be a rounded tip portion that has a rounded shape in a plan view or a front view.

[0054] Further, below the tip cut surface shaped portions 11f, 12f, the above-mentioned peripheral cut surface shaped portions 11c, 12c, peripheral round surface shaped portions 11d, 12d, arc shaped portions 11e, 12e, etc. may be provided.

[0055] In the first aspect of the present embodiment described above, press-fit terminal 1 includes elastically deforming portion 10 that is press-fit into through-hole 111, which is an example of an insertion hole. As shown in FIGS. 4B, 4C, and 4F, elastically deforming portion 10 has four corner regions 10a that contact through-hole 111 around its periphery in a cross section perpendicular to press-fitting direction D2, and at least one corner region 10a has peripherally cut surface-shaped portions 11c and 12c around its periphery. In a second aspect, as shown in FIG. 4E, elastically deforming portion 10 includes arc-shaped portions 11e and 12e with a center of curvature on the central side of through-hole 111 at both ends of elastically deforming portion 10 in deformation direction D1 in a cross section perpendicular to press-fitting direction D2. Semiconductor device 100 shown in FIG. 1 includes press-fit terminal 1 according to the first or second aspect described above and substrate 110 having through-hole 111, which is an example of an insertion hole. For example, corner region 10a is a region connecting the side of press-fit terminal 1 (elastically deforming portion 10) in deformation direction D1 and the side in a direction perpendicular to deformation direction D1 in a cross section perpendicular to press-fit direction D2.

[0056] 4A , elastically deforming portion 10 is located on the periphery of a cross section perpendicular to press-fitting direction D2, and if four corner regions 10a in contact with through-hole 111 are angular, elastically deforming portion 10 will come into contact with the inner peripheral wall of through-hole 111 in a manner similar to point contact. In contrast, in the first and second aspects of the present embodiment, peripheral cut-surface-shaped portions 11c, 12c and arc-shaped portions 11e, 12e are provided, thereby mitigating stress concentration at the contact portions, and elastically deforming portion 10 comes into contact with through-hole 111 and is supported by repulsion over the entire wider contact portion. This makes it possible to prevent scraping of the plating on elastically deforming portion 10 or through-hole 111, and to prevent excessive insertion loads during press-fitting and extraction loads during extraction of elastically deforming portion 10. 4D , in which only rounded-edge surface-shaped portions 11d, 12d are provided at the four corner regions 10a of elastically deforming portion 10, this is not particularly effective in terms of, for example, the remaining plating thickness [μm] of through-hole 111 shown in FIG. 5 , the length L [μm] of plating scraping 11b, 12b of press-fit terminal 1 (elastically deforming portion 10) shown in FIG. 6 , and the insertion load [N] shown in FIG. 7 , but by selectively employing cut-edge surface-shaped portions 11c, 12c or arc-shaped portions 11e, 12e, press-fit terminal 1 can be designed and manufactured to meet required performance. Furthermore, the maximum width W0 of press-fit terminal 1 and the inner diameter of through-hole 111 can be set within a wide range, the design margin relative to performance standards (specifications) can be increased, the assembly defect rate can be reduced, and manufacturing costs can be reduced. Furthermore, since products such as the press-fit terminal 1 and the semiconductor device 100 that meet various standards and have sufficient specifications can be shipped to customers, it is possible to expect effects such as improved customer satisfaction, improved reliability, and reduced customer complaints.

[0057] 10, the elastically deforming portion 10 is a pair of branched pieces (first branched piece 11 and second branched piece 12) that are bifurcated in the press-fitting direction D2, are spaced apart from each other, and are curved so that the tips 11a, 12a approach each other. The first branched piece 11 and the second branched piece 12 have cut-edge surface-shaped portions 11f, 12f (an example of a chamfered tip portion) at both ends of the tips 11a, 12a of the elastically deforming portion 10 in the deformation direction D1. The semiconductor device 100 shown in FIG. 1 includes the press-fit terminal 1 of the third aspect and a substrate 110 having a through-hole 111, which is an example of an insertion hole. The semiconductor device 100 also includes the press-fit terminal 1 of the third aspect and a substrate 110 having a through-hole 111, which is an example of an insertion hole.

[0058] As a result, even if eccentricity occurs between the press-fit terminal 1 (elastically deforming portion 10) and the through-hole 111, when the elastically deforming portion 10 is press-fitted into the through-hole 111, the tips 11a, 12a of the first branch piece 11 and the second branch piece 12 are more likely to fit into the opening of the through-hole 111. This improves assembly efficiency.

[0059] In addition, in this embodiment, as shown in Figures 4C and 4F, the elastically deforming portion 10 is located on the periphery of a cross section perpendicular to the press-fit direction D2, and the four corner regions 10a in contact with the through hole 111 include one or more corner regions 10a that are peripheral cut surface-shaped portions 11c, 12c and one or more corner regions 10a that are peripheral round surface-shaped portions 11d, 12d.

[0060] By employing an elastically deformable portion 10 having such a shape, it is possible to design and manufacture the press-fit terminal 1 in a manner that is more in line with the required performance.

[0061] In addition, in this embodiment, as shown in FIG. 4F, two peripheral cut surface shaped portions 11c, 12c are provided so as to face each other in one diagonal direction among the four corner regions 10a, and two peripheral round surface shaped portions 11d, 12d are provided so as to face each other in the other diagonal direction among the four corner regions 10a.

[0062] This makes it possible to suppress variations in contact between the elastically deforming portion 10 and the through hole 111 when pressed in, compared to an embodiment in which peripheral cut surface-shaped portions 11c, 12c are provided on the positive Y-direction side of the elastically deforming portion 10 and peripheral round surface-shaped portions 11d, 12d are provided on the negative Y-direction side of the elastically deforming portion 10, as shown in Figure 4C.

[0063] Furthermore, in this embodiment, in the first and second viewpoints described above, as in the third viewpoint described above, the elastically deforming portion 10 may be a pair of branched pieces that are bifurcated in the press-fitting direction D2 and spaced apart from each other, and whose tips 11a, 12a are curved so as to approach each other.

[0064] The separation of the tips 11a, 12a of the first branch piece 11 and the second branch piece 12 in this manner facilitates elastic deformation of the elastically deforming portion 10, thereby increasing the maximum width W0 of the elastically deforming portion 10. Therefore, as described above, the provision of the peripheral cut surface-shaped portions 11c, 12c and the arc-shaped portions 11e, 12e effectively prevents the plating of the elastically deforming portion 10 and the through-hole 111 from being scraped off, and prevents the insertion load when the elastically deforming portion 10 is press-fitted or the withdrawal load when the elastically deforming portion 10 is pulled out from becoming too large.

[0065] In addition, in a third aspect of this embodiment, as shown in FIG. 10, the tip chamfer shapes provided at both ends of the elastically deforming portion 10 at the tips 11a, 12a in the deformation direction D1 are tip cut surface shaped portions 11f, 12f provided in at least one of the four corner regions 10a.

[0066] This makes it easier for the tips 11a, 12a of the first branch piece 11 and the second branch piece 12 to fit into the opening of the through-hole 111 than in an embodiment where the tip chamfer shape is a tip round surface shape portion.

[0067] The inventions described in the claims of the present application as originally filed are as follows:

[0068] <Appendix 1> An elastically deformable portion is press-fitted into the insertion hole, The elastically deformable portion has four corner regions that contact the insertion hole on the periphery of a cross section perpendicular to the press-fitting direction, and at least one of the corner regions is a peripheral cut surface portion. A press-fit terminal characterized by:

[0069] <Appendix 2> The four corner regions include one or more corner regions that are the peripheral cut surface shaped portion and one or more corner regions that are the peripheral round surface shaped portion. 2. The press-fit terminal according to claim 1,

[0070] <Appendix 3> two of the peripheral cut surface shaped portions are provided so as to face each other in a diagonal direction of one of the four corner regions, The rounded peripheral surface portion is provided in two of the four corner regions so as to face the other corner region in a diagonal direction. 3. The press-fit terminal according to claim 2.

[0071] <Appendix 4> An elastically deformable portion is press-fitted into the insertion hole, The elastically deforming portion has arc-shaped portions with a center of curvature on the center side of the insertion hole at both ends of the elastically deforming portion in the deformation direction in a cross section perpendicular to the press-fitting direction. A press-fit terminal characterized by:

[0072] <Appendix 5> The elastically deformable portion is a pair of branched pieces that are bifurcated in the press-fitting direction, are spaced apart from each other, and are curved so that their tips approach each other. 5. The press-fit terminal according to any one of claims 1 to 4.

[0073] <Appendix 6> An elastically deformable portion is press-fitted into the insertion hole, the elastically deformable portion is a pair of branched pieces that are bifurcated in the press-fitting direction, are spaced apart from each other, and are curved so that their tips approach each other, The pair of branch pieces have chamfered tip portions at both ends in the deformation direction of the elastically deforming portion at the tip. A press-fit terminal characterized by:

[0074] <Appendix 7> the elastically deformable portion has four corner regions in contact with the insertion hole on the periphery of a cross section perpendicular to the press-fitting direction, The tip chamfered portion is a tip cut surface portion provided in at least one of the four corner regions. 7. The press-fit terminal according to claim 6,

[0075] <Appendix 8> A press-fit terminal according to appendix 1, 4 or 6; a substrate provided with the insertion hole; A semiconductor device comprising:

[0076] <Appendix 9> 2. The press-fit terminal according to claim 1, wherein the corner region is a region that connects a side of the press-fit terminal in a deformation direction with a side in a direction perpendicular to the deformation direction in a cross-sectional view perpendicular to the press-fit direction. [Industrial Applicability]

[0077] As described above, the present invention has the effect of satisfying required performance or improving assembly efficiency, and is useful for semiconductor devices such as power semiconductor devices. [Explanation of symbols]

[0078] 1 Press-fit terminal 10 Elastically deformable part 10a corner area 11 First branch piece 11a tip 11b Plating scrape 11c Peripheral cut surface shape part 11d Rounded edge part 11e Arc-shaped part 11f Tip cut surface shape part (tip chamfer shape part) 12 Second branch piece 12a tip 12b Plating scrape 12c Edge cut surface shape part 12d Rounded edge part 12e Arc-shaped part 12f Tip cut surface shape part (tip chamfer shape part) 20 Base part 100 Semiconductor device 110 Substrate 111 through hole 120 Semiconductor elements 130 cases 140 Laminated Board 141 First conductor plate 142 Second conductor plate 143 Third conductor plate 144 Insulating substrate 150 metal base 161~163 Wiring D1 Deformation direction D2 Press-fit direction D3 Board insertion direction L: Shaved length S Bonding material W0,W1,W2 Maximum width Wa, Wb width

Claims

1. An elastically deformable portion is press-fitted into the insertion hole, the elastically deformable portion has four corner regions in contact with the insertion hole on a periphery of a cross section perpendicular to the press-fitting direction, At least one of the corner regions is a peripheral cut surface shaped portion. A press-fit terminal characterized by:

2. The four corner regions include one or more corner regions that are the peripheral cut surface shaped portion and one or more corner regions that are the peripheral round surface shaped portion.

2. The press-fit terminal according to claim 1.

3. two of the peripheral cut surface shaped portions are provided so as to face each other in a diagonal direction of one of the four corner regions, The rounded peripheral surface portion is provided in two of the four corner regions so as to face the other corner region in a diagonal direction.

3. The press-fit terminal according to claim 2.

4. An elastically deformable portion is press-fitted into the insertion hole, The elastically deforming portion has arc-shaped portions with a center of curvature on the center side of the insertion hole at both ends of the elastically deforming portion in the deformation direction in a cross section perpendicular to the press-fitting direction. A press-fit terminal characterized by:

5. The elastically deformable portion is a pair of branched pieces that are bifurcated in the press-fitting direction, are spaced apart from each other, and are curved so that their tips approach each other.

5. The press-fit terminal according to claim 1, wherein the press-fit terminal is made of a material selected from the group consisting of acrylic and acrylic.

6. An elastically deformable portion is press-fitted into the insertion hole, the elastically deformable portion is a pair of branched pieces that are bifurcated in the press-fitting direction, are spaced apart from each other, and are curved so that their tips approach each other, The pair of branch pieces have chamfered tip portions at both ends in the deformation direction of the elastically deforming portion at the tip. A press-fit terminal characterized by:

7. the elastically deformable portion has four corner regions in contact with the insertion hole on a periphery of a cross section perpendicular to the press-fitting direction, The chamfered tip portion is a cut surface portion provided in at least one of the four corner regions.

7. The press-fit terminal according to claim 6.

8. The press-fit terminal according to claim 1, 4 or 6; a substrate provided with the insertion hole; A semiconductor device comprising:

9. The press-fit terminal according to claim 1 , wherein the corner region is a region connecting a side of the press-fit terminal in a deformation direction and a side in a direction perpendicular to the deformation direction in a cross section perpendicular to the press-fit direction.

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