SEMICONDUCTOR DEVICE

Abstract

Semiconductor device (1) comprising: a circuit pattern (12); a contact part (30) having a cylindrical through-hole (31c) formed therein and having first (31c1) and second (31c2) opening ends opposite each other, the second opening end (31c2) being connected to the circuit pattern (12); and an external connection terminal (50) with a prismatic main body section (51), and first (52) and second (53) end portions, wherein the second end portion (53) is inserted into the through hole (31c) of the first opening end (31c1) of the contact part (30), wherein: the main body portion (51) of the external terminal (50) has an insertion prevention portion formed thereon, the contact part (30) has an insertion prevention portion (35) formed on an inner peripheral surface of the through hole (31c), the insertion preventing portion (35) is positioned so as to be substantially downstream of the main body portion (51) of the external terminal (50) inserted into the through hole (31c) with respect to an insertion direction, the insertion direction is a direction from the first end portion (52) to the second end portion (53) of the external terminal (50), the prismatic main body portion (51) has a plurality of outer surfaces (51b) and a plurality of edges (51a) each between two of the outer surfaces, the external connection terminal (50) further comprises a removal preventing portion (51c) formed on the outer surfaces of the main body portion (51), the contact part (30) further comprises a removal prevention portion (34) formed on the inner peripheral surface of the through hole (31c), the removal preventing section (51c) is separate and arranged upstream of the insertion preventing section in the insertion direction, and the removal preventing portion (34) is arranged upstream of the removal preventing portion (51c) of the main body portion (51) inserted into the through hole (31c) with respect to the insertion direction.

Description

BACKGROUND OF THE INVENTION1. Technical FieldThe embodiments described herein relate to a semiconductor device.2. Prior ArtA semiconductor device includes semiconductor elements such as insulated gate bipolar transistors (IGBT) and power metal oxide semiconductor field effect transistors (MOSFET). Such a semiconductor device is used as a power converter, for example.A semiconductor device includes a substrate having an insulating plate and a plurality of circuit patterns formed on a front surface of the insulating plate. Further, semiconductor elements and external terminals are disposed on the circuit patterns. A signal applied via an external terminal passes through a circuit pattern into a semiconductor element.In order to fix the external terminal to the circuit patterns, cylindrical contact parts are used. The contact portions are soldered to the circuit patterns. The external terminals are press-fitted into the contact parts. Thereby, the external terminals are electrically connected to the circuit patterns via the contact parts (see, e.g., U.S. Patent Application No. US 2009 / 0 194 884 A1 or U.S. Patent Application No. US 2016 / 0 343 647 A1).To fabricate a semiconductor device, a plurality of heating (or cooling) steps are performed. For example, heating steps are performed to solder semiconductor chips and contact parts to circuit patterns and to fix a package to a substrate via an adhesive. Therefore, the constituent elements of the semiconductor device are subjected to a plurality of temperature changes.In the semiconductor device that has been subjected to temperature variations or other influences, different pressing forces may be required to press the external terminals into the plurality of contact parts. Also, when a predetermined device is used for simultaneously pressing the external terminals into the plurality of contact parts, the pressed states of the external terminals in the contact parts may be different. For example, the insertion depths of the external terminals in the contact parts may be different. This causes different heights of the plurality of external terminals press-fitted into the plurality of contact parts. The different heights of the plurality of external terminals prevents proper attachment of a printed circuit board to the plurality of external terminals.BRIEF DESCRIPTION OF THE INVENTIONThe embodiments have been made in view of the above, and aims to provide a semiconductor device that ensures a firm pressing force.According to one aspect, there is provided a semiconductor device according to claim 1. Further aspects of the invention are the subject matter of the dependent claims, the drawings and the description of exemplary embodiments.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a sectional view of a semiconductor device according to a first embodiment; FIG. 2 is a plan view of an insulated circuit board in the semiconductor device according to the first embodiment; FIGS. 3A and 3B are views for explaining a contact part disposed in the semiconductor device according to the first embodiment; FIG. 4 is a front view of an external terminal disposed in the semiconductor device according to the first embodiment; FIGS. 5A and 5B are plan sectional views of the external terminal disposed in the semiconductor device according to the first embodiment; FIG. 6 is a side sectional view before inserting the external terminal into the contact part disposed in the semiconductor device according to the first embodiment; FIG. 7 is a side sectional view after the external terminal is inserted into the contact part disposed in the semiconductor device according to the first embodiment; FIGS. 8A and 8B are first plan sectional views after the external terminal is inserted into the contact part disposed in the semiconductor device according to the first embodiment; FIG. 9 is a second planar sectional view after inserting an external terminal into a contact part disposed in the semiconductor device according to the first embodiment; FIG. 10 is a view explaining a contact part disposed in a semiconductor device according to a second embodiment; FIG. 11 is a front view of an external terminal disposed in the semiconductor device according to the second embodiment; FIGS. 12A and 12B are plan sectional views of the external terminal disposed in the semiconductor device according to the second embodiment; FIG. 13 is a side sectional view after inserting the external terminal into the contact part disposed in the semiconductor device according to the second embodiment; FIGS. 14A and 14B are first plan sectional views after the external terminal is inserted into the contact part disposed in the semiconductor device according to the second embodiment; FIG. 15 is a second planar sectional view after the external terminal is inserted into the contact part disposed in the semiconductor device according to the second embodiment; FIG. 16 is a first side sectional view after inserting an external terminal into another contact part disposed in the semiconductor device according to the second embodiment; FIG. 17 is a second side sectional view after inserting an external terminal into another contact part disposed in the semiconductor device according to the second embodiment; FIG. 18 is a view explaining a contact part disposed in a semiconductor device according to a third embodiment; FIGS. 19A and 19B are views for explaining an external terminal disposed in the semiconductor device according to the third embodiment; FIG. 20 is a side sectional view after inserting the external terminal into the contact part disposed in the semiconductor device according to the third embodiment; and FIGS. 21A and 21B are plan sectional views after the external terminal is inserted into the contact part disposed in the semiconductor device according to the third embodiment.DETAILED DESCRIPTION OF THE INVENTIONHereinafter, some embodiments will be described with reference to the accompanying drawings. In the following description, the terms "front surface" and "upper surface" refer to surfaces facing upward in a semiconductor device 1 illustrated in FIG. 1. Similarly, the term "upper" refers to an upward direction in the semiconductor device 1 of FIG. 1. The term "lower" refers to a downward direction in the semiconductor device 1 of FIG. 1. The terms "front surface", "upper surface", "upper", "rear surface", "lower surface", "lower" and "side surface" are terms for determining a relative positional relationship, but do not limit the technical concept of the embodiments. For example, the terms "upper" and "lower" do not always denote a perpendicular direction with respect to the ground. That is, the "up" and "down" directions are limited to the direction of gravity. Further, in the following description, a component that constitutes 80 vol % or more is referred to as "main component".(First Embodiment)A semiconductor device 1 according to a first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a sectional view of the semiconductor device according to the first embodiment, and FIG. 2 is a plan view of an insulated circuit board disposed in the semiconductor device according to the first embodiment. In this connection, in the plan view of FIG. 2, a housing 40 has been removed from the semiconductor device 1 of FIG. 1. Moreover, in the following description, constituent elements each of which is plural are expressed in the singular without being distinguished from each other and without using different reference numerals unless expressly stated otherwise. This means that the terms in the singular are also to be understood as including the plural. Such constituent elements include a plurality of circuit patterns 12, a plurality of first semiconductor chips 20, a plurality of second semiconductor chips 21, a plurality of contact parts 30, a plurality of bonding wires 15, and a plurality of external connection terminals 50.As illustrated in FIGS. 1 and 2, the semiconductor device 1 includes an insulated circuit board 10 and first and second semiconductor chips 20 and 21, and an electronic component 23 connected to the front surface of the insulated circuit board 10. The semiconductor device 1 also includes a contact part 30 connected to the front surface of the insulated circuit board 10. The first and second semiconductor chips 20 and 21, the electronic component 23, and the contact part 30 are connected to the front surface of the insulated circuit board 10 with a connection member (not illustrated) such as solder. In addition, the semiconductor device 1 includes a bonding wire 15 that connects the front surface of the insulated circuit board 10 and the main electrodes of the first and second semiconductor chips 20 and 21. The external terminal 50 is press-fitted into the contact part 30. In the semiconductor device 1, these components are covered by the package 40. The housing 40 is bonded to the outer periphery of the insulating plate 11 of the insulated circuit board 10 by an adhesive 41a. In this connection, an end portion of the external terminal 50 extends upward from the housing 40. Further, in the semiconductor device 1, the inside of the case 40 is filled with a sealing member 43.The insulated circuit board 10 includes the insulating plate 11, the plurality of circuit patterns 12 formed on the front surface of the insulating plate 11, and a metal plate 13 disposed on the back surface of the insulating plate 11. The insulating plate 11 and the metal plate 13 are rectangular in plan view.Further, the corners of the insulating plate 11 and the metal plate 13 may be rounded or chamfered. In plan view, the metal plate 13 is smaller in size than the insulating plate 11 and is disposed inside the insulating plate 11. The insulating plate 11 has an insulating property and is made of a material having high thermal conductivity. The insulating plate 11 is made of ceramic or insulating resin.The plurality of circuit patterns 12 are made of a metal having high conductivity. Examples of the metal include copper, aluminum, and an alloy containing at least one of these elements as a main component. In addition, the thickness of each circuit pattern 12 is in a range of 0.5 mm to 2.0 mm inclusive. In order to improve corrosion resistance, a coating process may be performed on the surfaces of the plurality of circuit patterns 12. Examples of the coating material include nickel, a nickel-phosphorus alloy, and a nickel-boron alloy. The plurality of circuit patterns 12 are formed by forming a metal layer on the front surface of the insulating plate 11 and performing etching or the like of the metal layer on the insulating plate 11. Alternatively, the plurality of circuit patterns 12 may be cut out of a metal layer in advance and pressure-bonded to the front surface of the insulating plate 11. In this connection, the plurality of circuit patterns 12 illustrated in FIG. 2 is only an example, and the number of circuit patterns 12 and the shapes and sizes thereof may be set as required.The contact portions 30 are mostly soldered to outer circuit patterns 12 among the plurality of circuit patterns 12 located at the outer peripheral portion of the insulating plate 11. The first and second semiconductor chips 20 and 21 are mostly soldered to inner circuit patterns 12 located inside the outer circuit patterns 12 of the plurality of circuit patterns 12.The metal plate 13 is made of metal having high thermal conductivity. Examples of the metal include copper, aluminum, nickel, and an alloy containing at least one of these elements as a main component. The thickness of the metal plate 13 is in a range of 0.1 mm to 2.5 mm inclusive. In order to improve corrosion resistance, a coating process may be performed on the surface of the metal plate 13. Examples of the coating material include nickel, a nickel-phosphorus alloy, and a nickel-boron alloy. In this connection, the insulating plate 11 and the metal plate 13 are rectangular in plan view. In addition, the size of the metal plate 13 is smaller than the insulating plate 11 in plan view and larger in area than a region where the circuit patterns 13 are formed and rectangular.The bonding wire 15 electrically connects a first or second semiconductor chip 20 or 21 and the circuit pattern 12 or the first and second semiconductor chips 20 and 21 to each other as required. The bonding wire 15 is made of a material having high conductivity. Examples of the material include gold, silver, copper, aluminum, and an alloy containing at least one of these elements. The diameter of the bonding wire 15 is in a range of 110 μm to 200 μm, inclusive. Alternatively, the diameter of the bonding wire 15 may be in a range of 350 μm to 500 μm, inclusive.As the insulated circuit board 10 having the above configuration, a DCB (Direct Copper Bonding) substrate, an AMB (Active Metal Bonded) substrate, or an insulated resin substrate may be used. Further, a cooling unit (not illustrated) may be connected to the metal plate 13 of the insulated circuit board 10 via a thermal intermediate material. This configuration makes it possible to improve the heat dissipation property of the semiconductor device 1.The first semiconductor chip 20 comprises a power device of silicon or silicon carbide. The power device is a switching element such as an IGBT or a power MOSFET. Such a first semiconductor chip 20 has, for example, a drain electrode (or collector electrode) as a main electrode on its back surface, and a gate electrode and a source electrode (or emitter electrode) as a main electrode on its front surface. The second semiconductor chip 21 is a diode element made of silicon or silicon carbide. The diode element is, for example, a free-wheel diode (FWD) such as a Schottky barrier diode (SBD) or a PiN ("P-intrinsic-N") diode. Such a second semiconductor chip 21 has a cathode electrode as a main electrode on its rear surface and an anode electrode as a main electrode on its front surface. The first and second semiconductor chips 20 and 21 are connected to predetermined circuit patterns 12 via a connector (not shown), and their back surfaces face the circuit patterns 12. In this context, the bonding material is solder or sintered metal. Further, for example, a lead frame, external terminals (pin terminals, contact parts, and others), electronic components (thermistors, current sensors), and other elements may be arranged instead of the first and second semiconductor chips 20 and 21, as required. The electronic component 23 includes capacitors, resistors, thermistors, current sensors, control integrated circuits (IC), and others. An electronic component 23 or a plurality of electronic components 23 may be disposed on the circuit patterns 12 so that the semiconductor device 1 performs desired functions. In order to perform the functions, various types of electronic components 23 may be used.The contact part 30 has a body portion having a cylindrical through hole formed therein, and flanges formed along the opening end of the body portion. The contact part 30 is made of a metal having high conductivity. Examples of the metal include silver, copper, nickel, and an alloy containing at least one of these elements. In order to improve corrosion resistance, a coating process may be performed to form a coating film on the surface of the contact part 30. Examples of the coating material for coating include nickel, a nickel-phosphorus alloy, and a nickel-boron alloy. In the contact part 30, each radius at the opening ends of the through hole is in a range of 0.1 mm to 1.0 mm inclusive. In addition, the radius of each outer diameter of the flange at the opening ends is from 0.5 mm to 2.0 mm inclusive. The contact part 30 will be described in detail later.The external terminal 50 has a prismatic main body portion and truncated cone-shaped end portions at both ends of the main body part. The external terminal 50 is inserted into the through hole of the contact part 30. The external terminal 50 is made of a metal having high conductivity. Examples of the metal material include copper, aluminum, nickel, and an alloy containing at least one of these elements. In order to improve corrosion resistance, a coating process may be performed to form a coating film on the surface of the external terminal 50. Examples of the coating material for coating include nickel, a nickel-phosphorus alloy, and a nickel-boron alloy. The external terminal 50 will be described in detail later.The housing 40 has an outer peripheral portion 41 and an upper lid 42. the outer peripheral portion 41 surrounds the above-described insulated circuit board 10. The outer circumferential portion 41 has a fixed hole (not illustrated) at each of its four corners in plan view. The fixed holes are continuous from the front surface to the back surface of the outer circumferential portion 41. The upper lid 42 covers the upper part of the opening of the outer peripheral portion 41 and is integrally connected to the outer peripheral portion 41. In addition, an insertion opening 42 ais formed in the upper lid 42 at a position corresponding to the external terminal 50. The housing 40 is made of a thermoplastic resin. Examples of the resin include polybutylene sulfide resin, polybutylene terephthalate resin, polybutylene succinate resin, polyimide resin, and acrylonitrile-butadiene-styrene resin.The sealing element 43 can be silicone gel, for example. The sealing member 43 contains a thermosetting resin and a filler contained in the thermosetting resin. Examples of the thermosetting resin are epoxy resin, phenol resin and melamine resin. Examples of the filler include silicon oxide, aluminum oxide, boron nitride, and aluminum nitride. The sealing element 43 is made of epoxy resin, for example, and includes silicon oxide, aluminum oxide, boron nitride, aluminum nitride or others as the filler.A printed circuit board (not shown) may be mounted on the semiconductor device 1 configured with the above-described constituent elements. The printed circuit includes an insulating plate and a plurality of circuit patterns formed on the front surface and / or the back surface of the insulating plate. In the printed circuit board, a plurality of through holes, which pass from the front surface to the back surface, are formed at positions corresponding to the external terminals 50 of the semiconductor device 1. The insulating plate is planar and formed of an insulating material. Specific examples of the insulating plate include a paper-phenol plate, a paper-epoxy plate, a glass-epoxy plate, a glass-polyimide plate, and a glass composite substrate. Such an insulating plate is rectangular in plan view. The corners of the insulating plate may be rounded or chamfered. The circuit patterns include a plurality of patterns, thus making it possible to form predetermined circuits thereon. The circuit patterns are made of a material having high conductivity. Examples of the material include copper, aluminum, nickel, and an alloy containing at least one of these elements. In order to improve corrosion resistance, a coating process may be performed on the surfaces of the upper circuit patterns and the lower circuit patterns. Examples of the coating material include nickel, a nickel-phosphorus alloy, and a nickel-boron alloy. Further, the through holes are electrically connected to the upper circuit patterns, the lower circuit patterns, or all the circuit patterns, as required. In the semiconductor device 1, the external terminals 50 are inserted into the through holes of the printed circuit board for electrical connection. Thus, the printed circuit board and the semiconductor device 1 are electrically connected to each other.Next, the contact part 30 disposed in the semiconductor device 1 will be described with reference to FIGS. 3A and 3B. FIGS. 3A and 3B are views for explaining the contact part disposed in the semiconductor device according to the first embodiment; in this connection, FIG. 3A is a plan view at an opening end 31 c 1 of FIG. 3B. FIG. 3B is a sectional view taken along the dashed-dotted line X-X in FIG. 3A.The contact part 30 includes a body portion 31 and flanges 32 and 33 respectively disposed at the opening ends 31 c 1 (i.e., the first opening end) and 31 c 2 (i.e., the second opening end) of the body portion. The body portion 31 has a cylindrical through hole 31 cformed therein, an inner circumferential surface 31 a, and an outer circumferential surface 31 b. The body portion 31 includes a removal preventing portion 34 formed on the side closer to the opening end 31 c 1 on the inner circumferential surface 31 aof the through hole 31 c, and an insertion preventing portion 35 formed on the side closer to the opening end 31 c 2 on the inner circumferential surface 31 a. The removal preventing portion 34 and the insertion preventing portion 35 are each formed as a ring on the inner circumferential surface 31 aand are projected toward the center of the through hole 31 c. The removal preventing portion 34 and the insertion preventing portion 35 are not limited to having a ring shape on the inner circumferential surface 31 a, but may be discontinuously formed along the inner circumference on the inner circumferential surface 31 aas long as they are capable of catching the external terminal 50. In addition, the removal preventing portion 34 and the insertion preventing portion 35 can be formed on the inner circumferential surface 31 aof the through hole 31 cby performing deformation processing, grinding processing, turning processing, cutting processing, or other processing. Alternatively, the removal preventing portion 34 and the insertion preventing portion 35 may be joined to the inner circumferential surface 31 aof the through hole 31 cby heat, adhesive, and / or welding. Although FIGS. 3A, 3B and others represent the removal preventing portion 34 and the insertion preventing portion 35 by diagonal lines, the removal preventing portion 34 and the insertion preventing portion 35 may be formed of the same material as the body portion 31 unlike the body portion 31.In addition, in the body portion 31, the inner diameter B 1 of the through hole 31 cis larger than the inner diameter B 2 of the removal preventing portion 34 and the inner diameter B 3 of the insertion preventing portion 35, and the inner diameter B 2 of the removal preventing portion 34 is larger than or equal to the inner diameter B 3 of the insertion preventing portion 35 (i.e., inner diameter B 1>inner diameter B 2≥inner diameter B 3). When the height (length) from the insertion preventing portion 35 to the removal preventing portion 34 is taken as H, the height H is set so that thick portions 51 c(serving as the removal preventing portion) of the external terminal 50 press-fitted into the contact part 30 are included within the height H, as will be described later. That is, the height H is equal to or slightly smaller than the length from the top of a tapered surface 53 a(serving as an insertion preventing portion) of the external terminal 50 to the top of the thick portions 51 c(removal preventing portion). The height H is preferably in a range of 80% to 100% inclusive of the length from the top of the tapered surface 53 a(insertion preventing portion) of the external terminal 50 to the tops of the thick portions 51 c(removal preventing portion). The flanges 32 and 33 are formed at both opening ends 31 c 1 and 31 c 2 of the through hole 31 cof the body portion 31. The outer diameter of each flange 32 and 33 is larger than that of the body portion 31.Next, the external terminal 50 disposed in the semiconductor device 1 will be described with reference to FIGS. 4, 5A, and 5B. FIG. 4 is a front view of the external terminal disposed in the semiconductor device according to the first embodiment, and FIGS. 5A and 5B are plane sectional views of the external terminal disposed in the semiconductor device according to the first embodiment. In this connection, FIG. 5A is a sectional view taken along the dashed-dotted line X-X in FIG. 4, and FIG. 5 is a plan view of the external terminal 50 (as viewed from above or below in FIG. 4 ).The external terminal 50 includes a main body portion 51 and end portions 52 (i.e., the first end portion) and 53 (i.e., the second end portion). The main body portion 51 is prismatic. The main body portion 51 has four circumferential outer surfaces 51 band four edges 51 aextending between two meeting outer surfaces 51 b. The main body portion 51 also includes, at each edge 51 a, a thick portion 51 cprotruding outward from the edge 51 aand extending from a lower part to a predetermined position of the main body portion 51, as illustrated in FIG. 4. The thick portions 51c serve as the removal preventing portion. In addition, the thick portions 51 care formed on the upstream side of the end portion 53 in the insertion direction of the external terminal 50 into the contact part 30, in which connection the insertion direction points from the end portion 52 to the end portion 53.The thick portions 51 care formed by deformation processing in which the outer surfaces 51 bof the main body portion 51 are pressed toward the center of the main body portion 51. Therefore, as illustrated in FIG. 5A, the main body portion 51 of the external terminal 50 has a recess in the center of each outer surface 51 b, and also has, at each edge 51 a, the thick portion 51 cwhich protrudes outward from the edge 51 a. In addition, the outer surface of each thick portion 51 ccomprises a removal preventing surface 51 c 3. The removal preventing surfaces 51 c 3 have a predetermined length in a direction parallel to the insertion direction. Each removal preventing surface 51 c 3 is a curved surface such that the removal preventing surface 51 c 3 is farther from the main body portion 51 as the distance from the end portion 52 increases, is farthest from the main body portion 51 in the center of the removal preventing surface 51 c 3, and is closer to the main body portion 51 beyond the center as the distance from the end portion 53 increases. The edges 51 eof the removal preventing surfaces 51 c 3 are rounded as illustrated in FIG. 5B.The end portions 52 and 53 are disposed at both ends of the main body portion 51 and each have a truncated cone shape. That is, each end portion 52 and 53 has a conical surface 42 a, 53 a(insertion preventing portion). The conical surface 52 a, 53 aconstitutes a side surface that tapers in diameter toward the top or bottom of the external terminal 50 In addition, the diameter A 4 of the tip surface (upper surface) A 4 of each end portion 52 and 53 is smaller than the diameter A 3 of the lower surface opposite to the upper surface. These end portions 52 and 53 may be joined to both ends of the main body portion 51 by heat, adhesive, and / or welding. Alternatively, the end portions 52 and 53 may be formed by performing deformation processing, grinding processing, turning processing, cutting processing, or other processing on both ends of the main body portion 51.Moreover, the external terminal 50 is configured to satisfy the condition "length A 2>length A 1> diameter A 3> diameter A 4", where the length A 1 denotes a diagonal length of the main body portion 51, and the length A 2 denotes the length between the edges 51 eof the thick portions 51 c, which are opposed to each other, with the center of the main body portion 51 therebetween (see FIG. 5B ).Next, the insertion of the external terminal 50 into the contact part 30 will be described with reference to FIGS. 6 to 9. FIG. 6 is a side sectional view before the external terminal is inserted into the contact part disposed in the semiconductor device according to the first embodiment. FIG. 7 is a side sectional view after the external terminal is inserted into the contact part disposed in the semiconductor device according to the first embodiment. FIGS. 8A and 8B are plan sectional views after the external terminal is inserted into the contact part disposed in the semiconductor device according to the first embodiment. In this connection, a circuit pattern 12 on which the contact part 30 is disposed is not illustrated in FIGS. 6 and 7. In addition, in FIGS. 6 and 7, only the reference numerals used in the explanation are illustrated. FIG. 8A is a sectional view taken along the dashed-dotted line X 1-X 1 in FIG. 7, and FIG. 8B is a sectional view taken along the dashed-dotted line X 2-X 2 in FIG. 7. in addition, FIG. 9 corresponds to FIG. 8A and illustrates the case where the contact part 30 and the external terminal 50 of FIG. 8A have different dimensions.First, as illustrated in FIG. 6, the end portion 53 of the external terminal 50 is inserted from the opening end 31 c 1 into the contact part through hole 31 c. Since the end portion 53 has a conical surface 53 a, the external terminal 50 is easily inserted into the opening end 31 c 1 of the through hole 31 c. Then, the external terminal 50 is further inserted toward the opening end 31 c 2. Hereinafter, the direction from the opening end 31 c 1 to the opening end 31 c 2 is used as an insertion direction. Since the thick portions 51 ceach have the removal preventing curved surface 51 c 3, the thick portions 51 cof the external terminal 50 can pass through the removal preventing portion 34 formed in the through hole 31 c. In this connection, when the thick portions 51 cpass through the removal preventing portion 34, the through hole 31 cis fully expanded so that the thick portions 51 cand the removal preventing portion 34 maintain their shape without being crushed even when abutting each other. Then, after the thick portions 51 ccross the removal preventing portion 34, the through hole 31 cbecomes almost its original shape again.Then, when the external terminal 50 is further inserted after the thick portions 51 cpass through the removal preventing portion 34, the tapered surface 53 aof the end portion 53 faces the insertion preventing portion 35 of the through hole 31 c, as illustrated in FIG. 7. The conical surface 53 aof the end portion 53 serves as an insertion preventing portion. At this time, the tapered surface 53 a(insertion preventing portion) of the external terminal 50 only needs to abut on the insertion preventing portion 35, so that further insertion of the external terminal 50 is prevented. When the further insertion is prevented, the tip surface of the end portion 53 may be located above, at the same level as, or below the insertion preventing portion 35. That is, when the further insertion of the external terminal 50 by the contact part 30 is prevented in this manner, the insertion preventing portion 35 is located on the downstream side of the main body portion 51 of the external terminal 50 inserted into the through hole 31 cin the insertion direction and abuts the tapered surface 53 a(insertion preventing portion). In addition, the insertion preventing portion 35 is not squeezed upon abutment by the tapered surface 53 a(insertion preventing portion) of the external terminal 50, but protrudes from the inner peripheral surface 31 ato the center and almost maintains its shape.Moreover, at this time, the external terminal 50 is press-fitted into the through hole 31 c, with the thick portions 51 cof the external terminal 50 contacting the inner circumferential surface 31 aof the through hole 31 c. In addition, the thick portions 51 c(upper surfaces thereof) of the external terminal 50 abut on the removal preventing portion 34 of the through hole 31 c. In this connection, the thick portions 51 c(upper surfaces thereof) of the external terminal 50 may be spaced apart from the removal preventing portion 34 of the through hole 31 cwithout abutting the removal preventing portion 34. That is, when the external terminal 50 is press-fitted into the through hole 31 c, the thick portions 51 care located between the removal preventing portion 34 and the insertion preventing portion 35. Moreover, even if it abuts the thick portions 51c, the removal preventing portion 34 is not squeezed by the abutment, but protrudes from the inner peripheral surface 31a toward the center and almost maintains its shape. Therefore, the external terminal 50 is press-fitted into the through hole 31 cand is fixed by the removal preventing portion 34 and the insertion preventing portion 35.For inserting the external terminal 50 into the contact part 30 as described above, the contact part 30 and the external terminal 50 are configured to have dimensions satisfying "length A 2≥inner diameter B 1>inner diameter B 2≥length A 1" with respect to the removal prevention portion 34, as illustrated in FIG. 8A. In the case of "length A2=inner diameter B1", the external terminal 50 itself may be press-fitted into the contact part 30 in the cross-sectional direction. Specifically, in the case of "length A 2>inner diameter B 1", the inner circumferential surface 31 aof the contact part 30 is partially recessed by pressing the thick portions 51 cof the outer terminal 50, so that the external terminal 50 is pressed more firmly into the contact part 30. In addition, the contact part 30 and the external terminal 50 are configured to have dimensions satisfying "length A 3>inner diameter B 3> diameter A 4" with respect to the insertion preventing portion 35, as illustrated in FIG. 8B. Thus, the conical surface 53 ais reliably caught by the insertion preventing portion 35.Alternatively, the contact part 30 and the external terminal 50 may be configured to have dimensions satisfying "inner diameter B1>length A2>inner diameter B2>length A1", as illustrated in FIG. 9. In this case, space is provided between the contact part 30 and the external terminal 50 in the cutting direction, so that pressing is not necessary. Even in this case, the thick portions 51 cof the external terminal 50 are caught by the removal preventing portion 34 and the tapered surface 53 ais caught by the insertion preventing portion 35, and therefore, the external terminal 50 is press-fitted into the through hole 31 cand fixed by the removal preventing portion 34 and the insertion preventing portion 35.The contact part 30 and the external terminal 50 have appropriate dimensions as illustrated in FIGS. 8A, 8B, and 9, whereby the insertion preventing portion 35 of the contact part 30 can prevent the external terminal 50 from being inserted into the contact part 30 too much. Thus, a firm press-fit force for inserting the external terminal 50 into the contact part 30 is ensured. By pressing a plurality of external terminals 50 into a plurality of contact parts 30 with the fixed pressing-in force, it is possible to reliably press the plurality of external terminals 50 into the plurality of contact parts 30 and to make the heights of the plurality of external terminals 50 coincide with each other. Thus, it is possible to reliably and securely attach a printed circuit board to the plurality of external terminals 50 of the semiconductor device 1 and reduce the occurrence of damage in the semiconductor device 1.In addition, the contact part 30 includes the removal preventing portion 34 formed on the upstream side of the insertion preventing portion 35 in the insertion direction. This ensures a firm extraction force for extracting the external terminal 50 from the contact part 30.The semiconductor device 1 described above includes the circuit pattern 12, the contact part 30 having the cylindrical through hole 31 cformed therein and an opening end 31 c 2 connected to the circuit pattern 12, and the external terminal 50 having the prismatic main body portion 51 whose end portion 53 is inserted into the through hole 31 c. The external terminal 50 also has the tapered surface 53 aat the end portion 53 of the main body portion 51. the contact part 30 includes the removal preventing portion 35 formed on the inner circumferential surface 31 aof the through hole 31 c. In this connection, the insertion preventing portion 35 is disposed on the downstream side of the main body portion 51 of the external terminal 50 inserted into the through hole 31 cin the insertion direction, and abuts the tapered surface 53 a. Thus, a firm press-fit force for inserting the external terminal 50 into the contact part 30 is ensured. Therefore, by pressing a plurality of external terminals 50 into a plurality of contact parts 30 with the fixed pressing force, it is possible to reliably insert the plurality of external terminals 50 into the plurality of contact parts 30 and to make the heights of the plurality of external terminals 50 coincide with each other.(Second Embodiment)The second embodiment uses a contact part 30 and an external terminal 50 different from those of the first embodiment. However, the second embodiment uses the same semiconductor device 1 as the first embodiment. Next, the contact part 30 and the external terminal 50 of the second embodiment will be described with reference to FIGS. 10, 11, 12A, and 12B. FIG. 10 is a view explaining the contact part disposed in the semiconductor device according to the second embodiment. FIG. 11 is a front view of the external terminal disposed in the semiconductor device according to the second embodiment. FIGS. 12A and 12B are plan sectional views of the external terminal disposed in the semiconductor device according to the second embodiment. In this connection, FIGS. 12A and 12B are both sectional views taken along the dashed-dotted line X-X in FIG. 11, and FIG. 12B is a sectional view different from FIG. 12A.As in the first embodiment, the contact part 30 of the second embodiment illustrated in FIG. 10 includes a body portion 31 and flanges 32 and 33 disposed at both opening ends 31 c 1 and 31 c 2 of the body portion 31. In this connection, with respect to the contact part 30 of the second embodiment, a removal preventing portion 34 and an insertion preventing portion 35 are formed in the inner peripheral surface 31 aby applying pressure at prescribed locations of the outer peripheral surface 31 bof the body portion 31 around the outer periphery of the outer peripheral surface 31 btoward the center of the body portion 31. In this case, each removal preventing portion 34 and insertion preventing portion 35 may also be formed as a ring on the inner circumferential surface 31 aand may be projected toward the center of the through hole 31 c, respectively. Alternatively, each removal preventing portion 34 and insertion preventing portion 35 may be discontinuously formed along the inner periphery. Moreover, in the contact part 30 of the second embodiment, the removal preventing portion 34 and the insertion preventing portion 35 are formed to have dimensions satisfying "inner diameter B1> inner diameter B2≥ inner diameter B3" with respect to the inner circumferential surface 31 a.As in the first embodiment, the external terminal 50 of the second embodiment shown in Fig. 11 includes a prismatic main body portion 51 and truncated cone-shaped end portions 52 and 53. however, in the second embodiment, thick portions 51c are disposed on a pair of opposite outer surfaces 51b of the main body portion 51 and project outwardly from these outer surfaces 51b (see Fig. 12A). The thick portions 51 care formed by, for example, deformation processing in which the main body portion 51 is sandwiched and pressed by a pair of opposing outer surfaces 51 b(on which the thick portions 51 care not formed) in the direction in which they approach each other. These thick portions 51c serve as a removal preventing portion and have removal preventing surfaces 51c3 on the outer surfaces thereof. The removal preventing surfaces 51 c 3 have a predetermined length in a direction parallel to the insertion direction. Each removal preventing surface 51 c 3 is a curved surface such that the removal preventing surface 51 c 3 is farther from the main body portion 51 as the distance from the end portion 52 toward the end portion 53 increases, is farthest from the main body portion 51 at the center thereof, and is closer to the main body portion 51 beyond the center as the distance from the end portion 53 increases. In addition, the diagonal length A 5 of the thick portion 51 csurrounding the main body portion 51 is set to be larger than the diagonal length A 1 of the main body portion 51 (i.e., A 5>A 1).Alternatively, as shown in FIG. 12B, thick portions 51 care formed on a pair of opposite edges 51 aof the main body portion 51 and project outward from the edges 51 a. These thick portions 51c serve as a removal preventing portion and have removal preventing curved surfaces 51c3 on their outer surfaces as in FIG. 12A. In this connection, the edges 51 eof the removal preventing surfaces 51 c 3 are rounded as illustrated in FIG. 5B. These thick portions 51 care formed by deformation processing of the main body portion 51. That is, the thick portions 51 care formed by inserting and pressing the main body portion 51 from a pair of opposite edges 51 atoward the center of the main body portion 51. As a result of the deformation processing, the pressed surfaces are perpendicular to the diagonal line of the main body portion 51, and the thick portions 51 care formed at the edges 51 aof the main body portion 51 and protrude outward from the edges 51 a, as illustrated in FIG. 12B. In addition, the length A 6 between the opposite edges 51 eof the thick portions 51 cwith the center of the main body portion 51 therebetween is set larger than the diagonal length A 1 of the main body portion 51 (i.e., A 6>A 1).Next, the insertion of the external terminal 50 into the contact part 30 will be described with reference to FIGS. 13 to 15. In this connection, the insertion of the external terminal 50 in the case of FIG. 12 awill be described. FIG. 13 is a side sectional view after the external terminal is inserted into the contact part disposed in the semiconductor device according to the second embodiment. FIGS. 14A, 14B, and 15 are plan sectional views after the external terminal is inserted into the contact part disposed in the semiconductor device according to the second embodiment. In addition, in FIGS. 13 to 15, only the reference numerals used in the explanation are shown. In addition, FIG. 14A is a sectional view taken along the dashed-dotted line X 1-X 1 in FIG. 13, and FIG. 14B is a sectional view taken along the dashed-dotted line X 2-X 2 in FIG. 13. MOREOVER, FIG. 15 corresponds to FIG. 14A and illustrates the case where the contact part 30 and the external terminal 50 of FIG. 14A have different dimensions.First, as in the first embodiment, the end portion 53 of the external terminal 50 is inserted from the opening end 31 c 1 into the through hole 31 cof the contact part 30 (see FIG. 6 ). Since the end portion 53 has a conical surface 53 a, the external terminal 50 is easily inserted into the opening end 31 c 1 of the through hole 31 c. Then, the external terminal 50 is further inserted toward the opening end 31 c 2. Since the removal preventing surfaces 51 c 3 of the thick portions 51 care curved surfaces, the thick portions 51 cof the external terminal 50 can pass through the removal preventing portion 34.When the external terminal 50 is further inserted after the thick portions 51 cpass through the removal preventing portion 34, the tapered surface 53 aof the end portion 53 faces the insertion preventing portion 35 of the through hole 31 c, as illustrated in FIG. 13. In this case, the tapered surface 53 a(insertion preventing portion) of the end portion 53 only needs to abut on the insertion preventing portion 35, so that further insertion of the external terminal 50 by the insertion preventing portion 35 is prevented. When the further insertion is prevented, the tip surface of the end portion 53 may be located above, at the same level as, or below the insertion preventing portion 35. When further insertion of the external terminal 50 is prevented by the contact part 30, the insertion preventing portion 35 is located on the downstream side of the main body portion 51 of the external terminal 50 inserted into the through hole 31 cin the insertion direction and abuts the tapered surface 53 a. In addition, the insertion preventing portion 35 is not squeezed by the taper surface 53 aof the external terminal 50 upon abutment, but almost maintains its shape.In this case as well, as in the first embodiment, the external terminal 50 is press-fitted into the through hole 31 c, with the thick portions 51 cof the external terminal 50 contacting the inner circumferential surface 31 aof the through hole 31 c. In addition, the thick portions 51 c(upper surfaces thereof) of the external terminal 50 may abut on the removal preventing portion 34 of the through hole 31 cor be slightly spaced from the removal preventing portion 34. That is, when the external terminal 50 is press-fitted into the through hole 31 c, the thick portions 51 care located between the removal preventing portion 34 and the insertion preventing portion 35. For this reason, the external terminal 50 is press-fitted into the through hole 31 cand is fixed by the removal preventing portion 34 and the insertion preventing portion 35.For inserting the external terminal 50 into the contact part 30 as described above, the contact part 30 and the external terminal 50 are configured to have dimensions satisfying "length A 6≥inner diameter B 1>inner diameter B 2≥length A 1" with respect to the removal prevention portion 34, as illustrated in FIG. 14A. In the case of "length A6=inner diameter B1", it is possible to press the external terminal 50 into the contact part 30 even in the cross-sectional direction. Specifically, in the case of "length A 6>inner diameter B 1", the inner periphery of the contact part 30 is partially recessed by pressing the thick portions 51 cof the outer terminal 50, so that the external terminal 50 is more firmly pressed into the contact part 30. In addition, the contact part 30 and the external terminal 50 are configured to have dimensions satisfying "length A 3>inner diameter B 3> diameter A 4" with respect to the insertion preventing portion 35, as illustrated in FIG. 14B. Therefore, the tapered surface 53 ais reliably caught by the insertion preventing portion 35.Alternatively, the contact part 30 and the external terminal 50 may be configured to have dimensions satisfying "inner diameter B1>length A6> inner diameter B2≥length A1", as illustrated in FIG. 15. In this connection, space is provided between the contact part 30 and the external terminal 50 in the cutting direction, so that pressing is not necessary. Even in this case, the thick portions 51 cof the external terminal 50 are caught by the removal preventing portion 34 and the tapered surface 53 ais caught by the insertion preventing portion 35, and therefore, the external terminal 50 is press-fitted into the through hole 31 cand fixed by the removal preventing portion 34 and the insertion preventing portion 35.The contact part 30 and the external terminal 50 have the above dimensions. Thus, as in the first embodiment, a fixed press-fit force for inserting the external terminal 50 into the contact part 30 is ensured. Therefore, by pressing a plurality of external terminals 50 into a plurality of contact parts 30 with the fixed pressing force, it is possible to reliably insert the plurality of external terminals 50 into the plurality of contact parts 30 and to make the heights of the plurality of external terminals 50 coincide with each other. Thus, it is possible to reliably and securely attach a printed circuit board to the plurality of external connection terminals 50 of the semiconductor device 1 and reduce the occurrence of damage in the semiconductor device 1.Further, as in the first embodiment, a firm removal force is ensured when the external terminal 50 is pulled out from the contact part 30. Therefore, without a force exceeding the extraction force, it is not possible to extract the external terminal 50.Another example of the removal preventing portion 34 and the insertion preventing portion 35 disposed in the contact part 30 and the thick portions 51 cdisposed in the external terminal 50 will be described with reference to FIGS. 16 and 17. FIGS. 16 and 17 are each a side sectional view after inserting an external terminal into another contact part disposed in the semiconductor device according to the second embodiment.As illustrated in FIG. 16, a removal preventing portion 34 and an insertion preventing portion 35 may be formed with a triangular cross section, for example. Further, each removal preventing portion 34 and insertion preventing portion 35 may be formed as a ring on the inner circumferential surface 31 aor may be discontinuously formed on the inner circumferential surface 31 aas long as they are capable of catching the external terminal 50. In addition, the removal preventing portion 34 and the insertion preventing portion 35 can be formed on the inner circumferential surface 31 aof the through hole 31 cby performing deformation processing, grinding processing, turning processing, cutting processing, or other processing. Alternatively, the removal preventing portion 34 and the insertion preventing portion 35 may be joined to the inner circumferential surface 31 aof the through hole 31 cby heat, adhesive, and / or welding.Corresponding to the triangular cross section of the removal preventing portion 34, the thick portions of the external terminal 50 are each formed with an inverted triangular cross section. The thick portions 51 care formed so as to protrude outward from the outer surfaces 51 bof the main body portion 51, as illustrated in FIGS. 5A and 5B or FIGS. 12A and 12B. The thick portions 51 cfunction as a removal preventing portion and have removal preventing surfaces 51 c 3 on the outer surfaces thereof. In addition, the thick portions 51 cmay be formed by deformation processing of the main body portion 51. The above thick portions 51 c easely fit through the removal preventing portion 34 and are easily caught by the removal preventing portion 34. In addition, the inclination angle of the insertion preventing portion 35 is preferably equal to that of the tapered surface 53 aof the end portion 53 of the external terminal 50.Referring now to FIG. 17, a removal preventing portion 34 and an insertion preventing portion 35 may each be formed with a quadrangular cross section. Further, each removal preventing portion 34 and insertion preventing portion 35 may be formed as a ring on the inner circumferential surface 31 aor may be discontinuously formed as long as they are capable of catching the external terminal 50. The removal preventing portion 34 and the insertion preventing portion 35 can be formed on the inner circumferential surface 31 aof the through hole 31 cby performing deformation processing, grinding processing, turning processing, cutting processing, or other processing. Alternatively, the removal preventing portion 34 and the insertion preventing portion 35 may be joined to the inner circumferential surface 31 aof the through hole 31 cby heat, adhesive, and / or welding.Corresponding to the quadrangular cross section of the removal preventing portion 34, the thick portions of the external terminal 50 are each formed with an inverted quadrangular cross section. The thick portions 51 care formed so as to protrude outward from the outer surfaces 51 bof the main body portion 51, as illustrated in FIGS. 5A and 5B or FIGS. 12A and 12B. The thick portions 51 cfunction as a removal preventing portion and have removal preventing surfaces 51 c 3 on the outer surfaces thereof. In addition, the thick portions 51 cmay be formed by deformation processing of the main body portion 51. The thick portions 51 c easely fit through the removal preventing portion 34 and are easily caught by the removal preventing portion 34. Also in the cases of FIGS. 16 and 17, the inner diameter B 1 of the through hole 31 cis larger than the inner diameter B 2 of the removal preventing portion 34 and the inner diameter B 3 of the insertion preventing portion 35, and the inner diameter B 2 of the removal preventing portion 34 is larger than or equal to the inner diameter B 3 of the insertion preventing portion 35 (i.e., inner diameter B 1>inner diameter B 2≥inner diameter B 3). Even the contact part 30 illustrated in FIGS. 16 and 17 and the external terminal 50 produce the same effect as in the first embodiment.(Third Embodiment)A contact part 30 and an external terminal 50 of a third embodiment will be described with reference to FIGS. 18, 19A, and 19B. FIG. 18 is a view explaining the contact part disposed in a semiconductor device according to a third embodiment, and FIGS. 19A and 19B are views for explaining the external terminal disposed in the semiconductor device according to the third embodiment. In this connection, FIG. 19A is a front view of the external terminal 50, and FIG. 19B is a plan sectional view taken along the dashed-dotted line X-X in FIG. 19A.The contact part 30 of the third embodiment illustrated in FIG. 18 includes a body portion 31 and flanges 32 and 33 disposed at both opening ends 31 c 1 and 31 c 2 of the body portion 31. The body portion 31 has a cylindrical through hole 31 cformed therein, an inner circumferential surface 31 a, and an outer circumferential surface 31 b. The body portion 31 includes an upper protrusion 31 dformed on the side closer to the opening end 31 c 1 on the inner circumferential surface 31 aof the through hole 31 c, and a lower protrusion 31 eformed on the side closer to the opening end 31 c 2 on the inner circumferential surface 31 a. This body portion 31 is formed by, for example, bulging a rectangular sheet blank to form the upper and lower protrusions 31d and 31e, and then the sheet is rolled into a cylindrical shape. The body portion 31 may be formed by another method.The upper protrusion 31 dmay be formed as a ring in the inner circumferential surface 31 aor discontinuously as long as it is capable of catching the external terminal 50. In addition, the upper protrusion 31 dincludes an upper insertion preventing surface 31 d 1, an auxiliary surface 31 d 2, and a removal preventing surface 31 d 3. The upper insertion preventing surface 31 d 1 is disposed in the inner circumferential surface 31 aand is inclined against a direction opposite to the insertion direction. That is, the upper insertion preventing surface 31 d 1 is inclined toward the opening end 31 c 1. More specifically, one side of the insertion upper prevention surface 31 d 1 that is closer to the opening end 31 c 2 is located more inside the through hole 31 cthan another side of the insertion upper prevention surface 31 d 1 that is closer to the opening end 31 c 1. The auxiliary surface 31 d 2 is parallel to the insertion direction. The removal preventing surface 31 d 3 is disposed in the inner circumferential surface 31 aand is inclined toward the insertion direction. That is, the removal preventing surface 31 d 3 is inclined toward the opening end 31 c 2.In addition, the lower protrusion 31 emay be formed as a ring in the inner circumferential surface 31 aor discontinuously as long as it is capable of catching the external terminal 50. This lower protrusion 31 eincludes at least one lower insertion preventing surface 31 e 1. The insertion preventing lower surface 31 e 1 is inclined in the direction opposite to the insertion direction. That is, the insertion preventing lower surface 31 e 1 is inclined toward the opening end 31 c 1. More specifically, one side of the insertion lower prevention surface 31 e 1 closer to the opening end 31 c 2 is located more inside the through hole 31 cthan another side of the insertion lower prevention surface 31 e 1 closer to the opening end 31 c 1. In this body portion 31, the inner diameter B 1 of the through hole 31 cis larger than the inner diameter B 2 of the upper boss 31 dand the inner diameter B 3 of the lower boss 31 e, and the inner diameter B 2 of the upper boss 31 dis larger than or equal to the inner diameter B 3 of the lower boss 31 e(i.e., inner diameter B 1>inner diameter B 2≥inner diameter B 3). In addition, taking the height (length) from the upper protrusion 31 dto the lower protrusion 31 eas H, the height H is set so that a head portion 51 fof the external terminal 50 inserted into the contact part 30 is included within the height H, as will be described later. That is, the height H is equal to or slightly smaller than the length from the top of the tapered surface 53 a(insertion preventing portion) of the external terminal 50 to the top of the removal preventing surface 51 d 3. The height H is preferably in a range of 80% to 100% inclusive of the length from the top of the tapered surface 53 a(insertion preventing portion) of the external terminal 50 to the top of the removal preventing surface 51 d 3. The flanges 32 and 33 are formed at both opening ends 31 c 1 and 31 c 2 of the through hole 31 cof the body portion 31. The outer diameter of each flange 32 and 33 is larger than that of the body portion 31.As in the first embodiment, the external terminal 50 of the third embodiment includes a main body portion 51 and end portions 52 and 53 as shown in FIG. 19A. Note that in the third embodiment, a recess 51 dis formed at each edge 51 aof the main body portion 51 on the upstream side of the end portions 53 in the insertion direction. Each recess 51 dincludes an insertion preventing portion and a removal preventing portion. The third embodiment describes the case where the recess 51 dis formed at each of the four edges 51 aof the main body portion 51. The recesses 51 dare not limited to this configuration, and may be formed as at least a pair of opposing edges 51 aof the main body portion 51. In addition, each recess 51 dincludes an insertion preventing surface 51 d 1, an auxiliary surface 51 d 2, and a removal preventing surface 51 d 3. The insertion preventing portion is a portion having the insertion preventing surface 51 d 1. The removal preventing portion is a portion having the removal preventing surface 51 d 3. The insertion preventing surface 51 d 1 is disposed on the main body portion 51 and is inclined against a direction opposite to the insertion direction. That is, the insertion preventing surface 51 d 1 is inclined toward the opening end 53. More specifically, one side of the insertion preventing surface 51 d 1 that is closer to the opening end 53 is located more inside the body portion 51 than another side of the insertion preventing surface 51 d 1 that is closer to the opening end 52. The auxiliary surface 51 d 2 is formed parallel to the insertion direction. The removal preventing surface 51 d 3 is disposed on the main body portion 51 and is inclined toward the insertion direction. That is, the removal preventing surface 51 d 3 is inclined toward the opening end 52. In this connection, in the external terminal 50, a portion from the end portion 53 to the recesses 51 dis taken as the head portion 51 f. Moreover, in the external terminal 50, a diagonal length A 1 of the main body portion 51 is set to be larger than the length A 7 of a diagonal (longest diagonal) of the recesses 51 dthat passes through the center of the main body portion 51 in plan view and connects the edges of the recesses as illustrated in FIG. 19B (i.e., length A 1>length A 7). Such recesses 51 dare formed by deformation processing, grinding processing, turning processing, cutting processing, or other processing.Next, the insertion of the contact part 30 into the external terminal 50 will be described with reference to FIGS. 20, 21A, and 21B. FIG. 20 is a side sectional view after the external terminal is inserted into the contact part disposed in the semiconductor device according to the third embodiment. FIGS. 21A and 21B are plan sectional views after the external terminal is inserted into the contact part disposed in the semiconductor device according to the third embodiment. In this connection, FIG. 21A is a sectional view taken along the chain dotted line X 1-X 1 in FIG. 20, and FIG. 21B is a sectional view taken along the chain dotted line X 2-X 2 in FIG. 20.First, as in the first embodiment, the end portion 53 of the external terminal 50 is inserted from the opening end 31 c 1 into the through hole 31 cof the contact part 30 (see FIG. 6 ). Since the end portion 53 has a reduced diameter, the external terminal 50 is easily inserted into the opening end 31 c 1 of the through hole 31 c. Then, the external terminal 50 is further inserted toward the opening end 31 c 2. While the conical surface 53 aof the end portion 53 slides on the upper insertion preventing surface 31 d 1 of the upper boss 31 d, the head portion 51 ftrakes on the upper boss 31 d. When the external terminal 50 is further inserted, the head portion 51 fpass through the upper protrusion 31 d, and the tapered surface 53 aof the end portion 53 abuts the lower insertion preventing surface 31 e 1 of the lower protrusion 31 eof the through hole 31 c, as illustrated in FIG. 20. When the head portion 51f passes through the upper boss 31d, the through hole 31c is fully widened, and when the external terminal 50 abuts thereon, the upper boss 31d is not squeezed by the abutment but almost maintains its shape. After the head portion 51 fcrosses the upper boss 31 d, the through hole 31 ctakes its shape almost again. In this connection, further insertion of the external terminal 50 only needs to be prevented by the lower protrusion 31 e, and the tip surface of the end portion 53 may be located above, at the same level as, or below the lower insertion preventing surface 31 e 1. When further insertion of the external terminal 50 is prevented by the contact part 30, the lower insertion preventing surface 31 e 1 is located on the downstream side of the main body portion 51 of the external terminal 50 inserted into the through hole 31 cin the insertion direction and abuts the tapered surface 53 a. In addition, at this time, the external terminal 50 is inserted into the through hole 31 c, and the head portion 51 fof the external terminal 50 contacts the inner circumferential surface 31 a(between the upper protrusion 31 dand the lower protrusion 31 d) of the through hole 31 c.In addition, at this time, the upper protrusion 31 dof the contact part 30 fits into the recess 51 dof the external terminal 50, and the removal preventing surfaces 51 d 3 of the recesses 51 dof the external terminal 50 abut on the removal preventing surface 31 d 3 of the upper protrusion 31 d. In the above-described manner, the external terminal 50 is inserted into the contact part 30. For inserting the external terminal 50 into the contact part 30, the contact part 30 and the external terminal 50 are configured to have dimensions satisfying "length A 1≥inner diameter B 1" with respect to the main body portion 51 and the through hole 31 c,as illustrated in FIG. 21A. In addition, the contact part 30 and the external terminal 50 are configured to have dimensions satisfying "length A 1≥inner diameter B 1>inner diameter B 2≥length A 7" with respect to the main body portion 51 and the upper protrusion 31 d, as illustrated in FIG. 21B. In the case of "length A1>inner diameter B1", the inner periphery of the contact part 30 is partially recessed, which makes it possible to press the external terminal 50 into the contact part 30.The contact part 30 and the external terminal 50 have the above dimensions. Thus, as in the first embodiment, a fixed press-fit force for inserting the external terminal 50 into the contact part 30 is ensured. Therefore, by pressing a plurality of external terminals 50 into a plurality of contact parts 30 with the fixed pressing force, it is possible to reliably insert the plurality of external terminals 50 into the plurality of contact parts 30 and to make the heights of the plurality of external terminals 50 coincide with each other. Thus, it is possible to reliably and securely attach a printed circuit board to the plurality of external connection terminals 50 of the semiconductor device 1 and reduce the occurrence of damage in the semiconductor device 1.Further, as in the first embodiment, a firm removal force is ensured when the external terminal 50 is pulled out from the contact part 30. Therefore, without a force exceeding the extraction force, it is not possible to extract the external terminal 50.According to the disclosed methods, there is provided a semiconductor device that ensures a firm press-fit force and that allows external terminals to be properly inserted into contact parts.

Claims

A semiconductor device (1) comprising: a circuit pattern (12); a contact part (30) having a cylindrical through hole (31c) formed therein and having first (31c1) and second (31c2) opening ends opposed to each other, the second opening end (31c2) being connected to the circuit pattern (12); and an external terminal (50) having a prismatic main body portion (51), and first (52) and second (53) end portions, the second end portion (53) being inserted into the through hole (31c) of the first opening end (31c1) of the contact part (30), wherein: the main body portion (51) of the external terminal (50) has an insertion inhibiting portion formed thereon, the contact part (30) has an insertion inhibiting portion (35) formed on an inner circumferential surface of the through hole (31c), the insertion preventing portion (35) is positioned to be substantially downstream of the main body portion (51) of the external terminal (50) inserted into the through hole (31c) with respect to an insertion direction, the insertion direction is a direction from the first end portion (52) to the second end portion (53) of the external terminal (50), the prismatic main body portion (51) has a plurality of outer surfaces (51b) and a plurality of edges (51a) respectively between two of the outer surfaces, the external terminal (50) further includes a removal preventing portion (51c) formed on the outer surfaces of the main body portion (51), the contact part (30) further includes a removal preventing portion (34) formed on the inner circumferential surface of the through hole (31c), the removal preventing portion (51c) is separated and disposed upstream of the insertion preventing portion in the insertion direction, and the removal preventing portion (34) is disposed upstream of the removal preventing portion (51c) of the main body portion (51) inserted into the through hole (31c) with respect to the insertion direction.The semiconductor device (1) according to claim 1, wherein the insertion preventing portion is a tapered surface (53a) formed at the second end portion (53) of the external terminal (50), the tapered surface (53a) being a side surface of the external terminal (50) whose diameter decreases toward the circuit pattern (12).The semiconductor device (1) according to claim 2, wherein the insertion preventing portion (35) has an insertion preventing surface that is inclined with respect to the insertion direction and that faces the tapered surface (53a).The semiconductor device (1) according to claim 1, wherein the insertion preventing portion (35) is a first protrusion protruding from the inner circumferential surface of the through hole (31c) of the contact part (30), the removal preventing portion (34) is a second protrusion protruding from the inner circumferential surface of the through hole (31c) of the contact part (30), and an inner diameter of the insertion preventing portion (35) is smaller than or equal to an inner diameter of the removal preventing portion (34).The semiconductor device (1) according to claim 1, wherein two of the plurality of edges are opposed to each other across the main body portion (51) in a diameter direction of the through hole (31c); the removal preventing portion (51c) includes a plurality of thick portions formed separately and upstream from the second insertion direction end portion (53) and at the main body portion (51) of the external terminal (50), the plurality of thick portions are protruded outward from the main body portion (51), two of the thick portions are opposed to each other across the main body portion (51) in the diameter direction; and a largest distance between the two thick portions in a sectional view of the external terminal (50) in a direction perpendicular to the insertion direction is larger than a distance between the two opposed edges in the diameter direction.The semiconductor device (1) according to claim 5, wherein, in the sectional view of the external terminal (50), the external terminal (50) includes a recess in a center of each of the outer surfaces, and the plurality of thick portions respectively protrude outward from the plurality of edges of the main body portion (51).The semiconductor device (1) according to claim 5, wherein two of the outer surfaces of the main body portion (51) are opposed to each other in the diameter direction, and the thick portions in the sectional view of the external terminal (50) are respectively disposed on these two outer surfaces.The semiconductor device (1) according to claim 5, wherein the thick portions in the sectional view of the external terminal (50) respectively project outward from these two opposite edges.The semiconductor device (1) according to claim 5, wherein the largest distance between the two opposing thick portions is greater than or equal to an inner diameter of the through hole (31c) of the contact part (30), the inner diameter of the through hole (31c) of the contact part (30) is greater than an inner diameter of the removal preventing portion (34), and the inner diameter of the removal preventing portion (34) is greater than or equal to a distance between the two opposing edges of the main body portion (51).The semiconductor device (1) according to claim 5, wherein an inner diameter of the through hole (31c) of the contact part (30) is larger than a largest distance between the two opposing thick portions of the main body portion (51), the largest distance between the two opposing thick portions of the main body portion (51) is larger than an inner diameter of the removal preventing portion (34), and the inner diameter of the removal preventing portion (34) is larger than or equal to a distance between the two opposing edges of the main body portion (51).The semiconductor device (1) according to claim 1, wherein the removal preventing portion (51c) includes a plurality of recesses which is formed upstream of the second end portion (53) in the main body portion (51) in the insertion direction and which is disposed on the outer surfaces of the main body portion (51) in a circumferential direction.The semiconductor device (1) according to claim 11, wherein the removal preventing portion (34) is a second protrusion protruding from the inner circumferential surface of the through hole (31c) of the contact part (30) and fitting the plurality of recesses.The semiconductor device (1) according to claim 12, wherein the removal preventing portion (51c) has a removal preventing surface (51c3) in each of the recesses, the removal preventing surface (51c3) being inclined with respect to the insertion direction.The semiconductor device (1) according to claim 13, wherein the removal preventing portion (34) has a removal preventing surface downstream of the second protrusion in the insertion direction, the removal preventing surface being inclined with respect to the insertion direction.The semiconductor device (1) according to claim 14, wherein portions of the edges of the main body portion (51) corresponding to the recesses are rounded off in a sectional view of the external terminal (50) perpendicular to the insertion direction,The semiconductor device (1) according to claim 15, wherein two of the plurality of edges are opposed to each other across the main body portion (51) in a diameter direction of the through hole (31c); and a diameter direction distance between the two opposed edges of the main body portion (51) in the sectional view of the external terminal (50) is greater than or equal to an inner diameter of the through hole (31c) of the contact part (30).The semiconductor device (1) according to claim 16, wherein two of the recesses of the main body portion (51) are opposed in the diameter direction via the main body portion (51), the inner diameter of the through hole (31c) of the contact part (30) is larger than an inner diameter of the removal preventing portion (34), and the inner diameter of the removal preventing portion (34) is larger than or equal to a largest distance between the two opposed recesses in the diameter direction.The semiconductor device (1) according to claim 16, wherein the recesses of the external terminal (50) each have another insertion preventing surface separated in the insertion direction of the main body portion (51) and disposed upstream of the removal preventing surface, the another insertion preventing surface being inclined with respect to the insertion direction.The semiconductor device (1) according to claim 18, wherein the second protrusion of the contact part (30) has another insertion preventing surface on the inner circumferential surface of the through hole (31c), the other insertion preventing surface being inclined with respect to the insertion direction and facing the other insertion preventing surface.

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