Patent Application
20250167099
This application claims benefit of priority under 35 USC 119 based on Japanese Patent Application No. 2023-194880 filed on Nov. 16, 2023, the entire contents of which are incorporated by reference herein.
The present disclosure relates to a semiconductor device and a method for manufacturing thereof.
JP2019-161174A discloses that a hole into which a terminal provided in a metal plate on a circuit board is inserted has a reversed trapezoidal shape. JP2013-102112A discloses that a plating layer is provided on a press-fitting surface of a terminal. JP1997-283682A discloses that an engaging pin is press-fitted to a heat dissipation plate. JP2018-113326A discloses that a terminal block having a threaded hole is joined onto a circuit pattern. JP2014-175444A discloses that a connection terminal is inserted into a terminal insertion hole provided on a case. JP2019-506753A discloses that a press-fit pin may be used as a terminal.
JP2020-136369A discloses that a circular hole into which a pin portion is inserted is provided on a heat dissipation plate. JP2021-19064A discloses that a hollow member into which an external terminal is inserted is provided on a conductive layer. U.S. Pat. No. 8,563,364B2 discloses that a terminal (a contact pin) is joined to a metal plate of a circuit board by laser, an electron beam, resistance welding, spinning, friction, ultrasonic welding, or ball bonding. U.S. Pat. No. 8,586,420B2 discloses that a contact pin is press-fitted to a metal plate of a circuit board.
In a conventional semiconductor device, it is considered to join a metal layer of a conductive plate or the like of an insulating circuit board to a terminal by press-fitting the terminal to a hole provided in the metal layer.
However, a mechanism to hold the terminal is only a force caused by press-fitting, and therefore, the joining strength between the terminal and the metal layer is weak, and the terminal may fall out of the metal layer after long-term drive.
In view of the above problem, an object of this disclosure is to provide a semiconductor device and a method for manufacturing thereof each of which can improve the joining strength between a terminal and a metal layer.
An aspect of the present disclosure inheres in a semiconductor device including: a metal layer including a top surface having a hole including a recessed-projecting portion constituted by recesses and projections continuously formed on a surface of the hole; and a terminal having one end inserted into the hole and extending upward from the top surface of the metal layer.
Another aspect of the present disclosure inheres in a method for manufacturing a semiconductor device including: preparing a metal layer having a hole including a recessed-projecting portion constituted by recesses and projections continuously formed on a surface of the hole; preparing a terminal; and joining the terminal to the metal layer by inserting one end of the terminal into the hole.
Further aspect of the present disclosure inheres in a method for manufacturing a semiconductor device including: preparing a metal layer having a hole; preparing a terminal including a recessed-projecting portion constituted by recesses and projections formed continuously on a surface of at least one end of the terminal; and joining the terminal to the metal layer by inserting, into the hole, the one end of the terminal including the recessed-projecting portion.
With reference to the drawings, first to thirteenth embodiments of the present disclosure will be described below.
In the drawings, the same or similar elements are indicated by the same or similar reference numerals, and overlapping explanations are not repeated. The drawings are schematic, and it should be noted that the relationship between thickness and planer dimensions, the thickness proportion of each layer, and the like are different from real ones. Accordingly, specific thicknesses or dimensions should be determined with reference to the following description. Moreover, in some drawings, portions are illustrated with different dimensional relationships and proportions. The first to thirteenth embodiments described below merely illustrate schematically devices and methods for specifying and giving shapes to the technical idea of the present disclosure, and the span of the technical idea is not limited to materials, shapes, structures, and relative positions of elements described herein.
Further, definitions of directions such as an up-and-down direction in the following description are merely definitions for convenience of understanding, and are not intended to limit the technical ideas of the present disclosure. For example, as a matter of course, when the subject is observed while being rotated by 90°, the subject is understood by converting the up-and-down direction into the right-and-left direction. When the subject is observed while being rotated by 180°, the subject is understood by inverting the up-and-down direction.
As a semiconductor device according to a first embodiment, a so-called 2-in -1 power semiconductor device including two serially-connected semiconductor modules, as illustrated in
A semiconductor module on the left side in
The insulating circuit boards (1a, 2a, 2b, 3a), (1b, 2c to 2e, 3b) may be direct copper bonding (DCB) substrates, active metal brazing (AMB) substrates, or the like, for example, and the following deals with a case where the insulating circuit boards (1a, 2a, 2b, 3a), (1b, 2c to 2e, 3b) are DCB substrates. The insulating circuit board (1a, 2a, 2b, 3a) includes an insulating substrate 1a, metal layers 2a, 2b as conductive plates provided on the top surface side of the insulating substrate 1a, and a metal layer 3a as a heat dissipation plate provided on the bottom surface side of the insulating substrate 1a. The insulating circuit board (1b, 2c to 2e, 3b) includes an insulating substrate 1b, metal layers 2c to 2e as conductive plates provided on the top surface side of the insulating substrate 1b, and a metal layer 3b as a heat dissipation plate provided on the bottom surface side of the insulating substrate 1b.
The insulating substrate 1a, 1b is constituted by a ceramics substrate made of aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), boron nitride (BN), or the like, or a resin insulating substrate made of a high polymer material or the like, for example. The metal layers 2a to 2e form circuit patterns. The metal layers 2a to 2e are not particularly limited in size, number, and arrangement position. The metal layers 2a to 2e and the metal layers 3a, 3b are made of a metal material such as copper (Cu), Cu alloy mainly containing Cu, aluminum (Al), or Al alloy mainly containing Al, for example.
A semiconductor element (semiconductor chip) 4 is joined to the top surface side of the metal layer 2a, 2c via a bonding material 5 such as solder. The semiconductor element 4 is constituted by, for example, a power semiconductor element such as an insulated gate bipolar transistor (IGBT), a field effect transistor (FET) such as a metal-oxide-semiconductor field-effect transistor (MOSFET), a static induction (SI) thyristor, a gate turnoff (GTO) thyristor, or a freewheeling diode (FWD). For example, in a case where the semiconductor element 4 is constituted by an IGBT, the semiconductor element 4 includes a first main electrode (collector electrode) on the bottom surface side, and a control electrode (gate electrode) and a second main electrode (emitter electrode) on the top surface side. The semiconductor element 4 is not particularly limited in type, size, number, and arrangement position. The semiconductor element 4 may be constituted by silicon (Si), for example, or may be constituted by a wideband gap semiconductor such as silicon carbide (SiC), gallium nitride (GaN), gallium arsenide (GaAs), gallium oxide (Ga2O3), or diamond (C).
A first implant pin 10a is provided on the semiconductor chip 4 via a bonding material 7 such as solder. The first implant pin 10a is electrically connected to the semiconductor element 4. A second implant pin 10b is provided in a region other than the semiconductor chip 4 on the metal layer 2a to 2e via a bonding material 11 such as solder. The second implant pin 10b is electrically connected to the metal layer 2a, 2b.
One end (lower end) of each of bar-shaped or pin-shaped terminals 6a to 6e is joined to the top surface side of its corresponding one of the metal layers 2a to 2e. The terminals 6a to 6e extend upward vertically to the top surfaces of the metal layers 2a to 2e. The other end (upper end) of each of the terminals 6a to 6e projects from the top surface of the sealing resin 9 and is exposed in such a manner as to be connectable with an external circuit (not illustrated).
In the semiconductor device according to the first embodiment, the terminals 6a to 6e function as external connection terminals. An output current, a measurement current, or the like flows through the terminals 6a to 6e between an external circuit (not illustrated) and the semiconductor element 4. For example, in a case of a semiconductor device in which an IGBT is used as the semiconductor chip 4 and a plurality of IGBTS is serially connected to each other in a forward direction, the terminal 6a can be used as an output terminal connected to a wiring line connecting an emitter electrode of one of the IGBTS to a collector electrode of another one of the IGBTS. The terminal 6b can be used as an emitter-side connection terminal electrically connected to the emitter electrode of the one of the IGBTS. The terminal 6c can be used as a collector-side connection terminal electrically connected to the collector electrode of the other one of the IGBTS. The terminals 6d, 6e can be used as a gate signal control terminal and an emitter signal terminal, respectively.
The printed circuit board 8 includes an insulating substrate 81, an upper circuit pattern 82 provided on the top surface of the insulating substrate 81, and a lower circuit pattern 83 provided on the bottom surface of the insulating substrate 81. The upper circuit pattern 82 and the lower circuit pattern 83 are conductive films made of metal or the like. The printed circuit board 8 has through-holes. The plurality of terminals 6a to 6e, the first implant pin 10a, and the second implant pin 10b are press-fitted to the through-holes on the printed circuit board 8 and supported (integrated). The printed circuit board 8 in which the plurality of terminals 6a to 6e, the first implant pin 10a, and the second implant pin 10b are integrated is also referred to as an “implant printed circuit board.”
The sealing resin 9 is made of a resin material such as epoxy resin, maleimide resin, or cyanate resin. Respective bottom surfaces of the metal layers 3a, 3b of the insulating circuit boards (1a, 2a, 2b, 3a), (1b, 2c to 2e, 3b) are exposed from the bottom surface of the sealing resin 9. A case (not illustrated) may be disposed outside the sealing resin 9.
The following description mainly focuses on a joined portion between the terminal 6a and the metal layer 2a, the joined portion being surrounded by a region A indicated by a broken line in
As illustrated in
The hole 21 has a recessed-projecting portion (roughness) 21a, 21b having a surface on which recesses and projections are continuously formed intentionally by performing roughing. The recessed-projecting portion 21a is formed on the bottom surface of the hole 21, and the recessed-projecting portion 21b is provided on the side surface (side wall surface) of the hole 21. Note that both the recessed-projecting portions 21a, 21b may not be necessarily provided such that no recessed-projecting portion 21a is formed on the bottom surface of the hole 21 so that the bottom surface of the hole 21 is flat, and the recessed-projecting portion 21b is provided only on the side surface of the hole 21. Alternatively, no recessed-projecting portion 21b may be formed on the side surface of the hole 21 so that the side surface of the hole 21 is flat, and the recessed-projecting portion 21a may be provided only on the bottom surface of the hole 21. Note that the height and depth, the cycle, or the shape of the recesses and projections is not necessarily regular but is irregular, but they are illustrated in a regular shape in the following drawings for convenience.
An inner-side virtual inner peripheral surface in contact with the projections of the recessed-projecting portion 21b on the side surface of the hole 21 has a diameter w0, which is generally the same as a diameter w3 of a portion of the terminal 6a which is not inserted into the hole 21 and which is slightly smaller than the diameter w3. The diameter w0 is, for example, about 0.6 mm or more but 2.9 mm or less. An outer-side virtual inner peripheral surface in contact with the recesses of the recessed-projecting portion 21b on the side surface of the hole 21 has a diameter w1, which is larger than the diameter w0 and slightly larger than the diameter w3 of the portion of the terminal 6a which is not inserted into the hole 21. The diameter w3 of the portion of the terminal 6a which is not inserted into the hole 21 is, for example, about 1 mm or more but 2 mm or less. In the present specification, the “diameter of the hole 21” indicates the diameter w0 of the inner-side virtual inner peripheral surface in contact with the projections of the recessed-projecting portion 21b on the side surface of the hole 21.
The diameter w3 of the portion of the terminal 6a which is not inserted into the hole 21 is a diameter of the terminal 6a before the terminal 6a is press-fitted to the hole 21.
As illustrated in
The metal layer 2a has a thickness of about 2 mm or more but 3 mm or less, for example. The hole 21 has a depth d1 that is about 3/5 or more but 4/5 or less of the thickness of the metal layer 2a, for example, and the depth d1 is about 1 mm or more but 2.5 mm or less, for example. The depth d1 of the hole 21 is a depth from the bottom surface of the step 22 to a virtual plane in contact with the recesses of the recessed-projecting portion 21a on the bottom surface of the hole 21. A depth d2 of the step 22 from the top surface of the metal layer 2a is about 0.2 mm or more but 0.5 mm or less, for example.
The terminal 6a includes a bar-shaped or pin-shaped main body 61, and the plating layer 62 provided on the surface side of the main body 61. Here, the main body 61 has a circular column shape. The main body 61 is not limited to a circular column shape and may have a polygonal column shape such as a square column shape, for example. The main body 61 is made of a metal material such as copper (Cu), Cu alloy mainly containing Cu, aluminum (Al), or Al alloy mainly containing Al, for example. The main body 61 may be made of the same material as the metal layer 2a or may be made of a material different from that of the metal layer 2a. For example, the main body 61 and the metal layer 2a may be both made of Cu.
The plating layer 62 is provided on at least an end surface and an outer peripheral surface of a portion of the main body 61 which is inserted into the hole 21. As illustrated in
The plating layer 62 is made of a metal material such as tin (Sn) or nickel (Ni). In the first embodiment, the plating layer 62 is made of a material softer than the main body 61 and the metal layer 2a. The hardness (softness) of metal of the main body 61, the metal layer 2a, and the like can be expressed by Vickers hardness, for example, such that the metal is harder as the Vickers hardness is higher, and the metal is softer as the Vickers hardness is lower. For example, in a case where the main body 61 and the metal layer 2a are made of Cu, the plating layer 62 may be made of Sn, which is softer than Cu.
Since the diameter w0 of the hole 21 is generally the same as but slightly smaller than the diameter w3 of the portion of the terminal 6a which is not inserted into the hole 21, the plating layer 62 softer than the metal layer 2a, in the portion of the terminal 6a which is inserted into the hole 21, deforms to fit the recessed-projecting portions 21a, 21b of the hole 21. The plating layer 62 placed on the end surface of the terminal 6a includes a recessed-projecting portion 62a fitted (engaged) to the recessed-projecting portion 21a on the bottom surface of the hole 21. The plating layer 62 placed on the outer peripheral surface of the terminal 6a includes a recessed-projecting portion 62b fitted (engaged) to the recessed-projecting portion 21b on the side surface of the hole 21. Note that the recessed-projecting portions 21a, 21b of the hole 21 may have portions penetrating through the plating layer 62 and coming into contact with the main body 61 of the terminal 6a. The lower end of the terminal 6a may not be necessarily in contact with the bottom surface of the hole 21 and may be separated from the bottom surface of the hole 21.
The recessed-projecting portions 21a, 21b of the hole 21 are formed intentionally by performing roughing, and the recessed-projecting portions 21a, 21b of the hole 21 are different from recessed-projecting portions formed not intentionally but inevitably. The recessed-projecting portions 21a, 21b of the hole 21 are formed with recesses and projections larger (rougher) than those of the recessed-projecting portions formed not intentionally but inevitably, for example. Accordingly, the recessed-projecting portions 21a, 21b of the hole 21 can be distinguished from the recessed-projecting portions formed not intentionally but inevitably, based on the size (roughness) of the recesses and projections of the recessed-projecting portions 21a, 21b.
The arithmetic average roughness (Ra) of the recessed-projecting portions 21a, 21b of the hole 21 before the terminal 6a is press-fitted to the hole 21 is about 20 μm or more but 300 μm or less, for example, depending on the formation method of the recessed-projecting portions 21a, 21b. In a case where the recessed-projecting portions 21a, 21b are formed mechanically by a drill, a screw thread, or the like or the recessed-projecting portions 21a, 21b are formed by laser, the arithmetic average roughness (Ra) is about 20 μm or more but 180 μm or less and may be 100 μm or more but 200 μm or less, for example. In a case where the recessed-projecting portions 21a, 21b are formed by etching or the like, the arithmetic average roughness (Ra) is about 10 μm or more but 100 μm or less and may be 50 μm or more but 100 μm or less, for example.
In comparison with the state before the terminal 6a is press-fitted to the hole 21, the arithmetic average roughness (Ra) of the recessed-projecting portions 21a, 21b of the hole 21 after the terminal 6a is press-fitted to the hole 21 increases or decreases depending on the diameter w3 of the terminal 6a, the shape of the terminal 6a, whether or not the terminal 6a rotates at the time of press-fitting, or the like, and the arithmetic average roughness (Ra) is about 20 μm or more but 300 μm or less, for example. In a case where the recessed-projecting portions 21a, 21b are formed mechanically by a drill, a screw thread, or the like or the recessed-projecting portions 21a, 21b are formed by laser, the arithmetic average roughness (Ra) is about 20 μm or more but 180 μm or less and may be 100 μm or more but 200 μm or less, for example. In a case where the recessed-projecting portions 21a, 21b are formed by etching or the like, the arithmetic average roughness (Ra) is about 10 μm or more but 100 μm or less and may be 50 μm or more but 100 μm or less, for example.
In the state before or after the terminal 6a is press-fitted to the hole 21, the size (roughness) of the recessed-projecting portion 21a on the bottom surface of the hole 21 may be generally the same as the size (roughness) of the recessed-projecting portion 21b on the side surface of the hole 21. That is, the arithmetic average roughness (Ra) of the recessed-projecting portion 21a on the bottom surface of the hole 21 may be generally the same as the arithmetic average roughness (Ra) of the recessed-projecting portion 21b on the side surface of the hole 21. The size (roughness) of the recessed-projecting portion 21a on the bottom surface of the hole 21 may be larger or smaller than the size (roughness) of the recessed-projecting portion 21b on the side surface of the hole 21. That is, the arithmetic average roughness (Ra) of the recessed-projecting portion 21a on the bottom surface of the hole 21 may be larger or smaller than the arithmetic average roughness (Ra) of the recessed-projecting portion 21b on the side surface of the hole 21.
As a formation method of the recessed-projecting portion 21b on the side surface of the hole 21, the recessed-projecting portion 21b is formed on the side surface of the hole 21 while the hole 21 is formed by digging the metal layer 2a by a threaded drill, for example. Then, the drill is reversed to remove the drill from the metal layer 2a with the recessed-projecting portion 21b on the side surface of the hole 21 being left behind, and hereby, the recessed-projecting portion 21b on the side surface of the hole 21 can be formed mechanically. In a case where the recessed-projecting portion 21b is formed by the drill, the arithmetic average roughness (Ra) of the recessed-projecting portion 21b on the side surface of the hole 21 is about 20 μm or more but 300 μm or less, for example.
Further, as another formation method of the recessed-projecting portion 21b on the side surface of the hole 21, the hole 21 is formed by a drill, etching, or the like. Then, the side surface of the hole 21 may be roughened by diagonally applying laser on the side surface of the hole 21. The laser may be fiber laser, YAG laser, carbon dioxide (CO2) laser, or the like, for example. By adjusting application power, a spot diameter, or the like of the laser, the size (roughness) of the recessed-projecting portion 21b on the side surface of the hole 21 can be adjusted. In a case where the recessed-projecting portion 21b is formed by laser application, the arithmetic average roughness (Ra) of the recessed-projecting portion 21b on the side surface of the hole 21 is about 20 μm or more but 180 μm or less and may be about 100 μm or more but 200 μm or less, for example.
As another formation method of the recessed-projecting portion 21b on the side surface of the hole 21, the metal layer 2a may be made of metal particles (for example, copper particles) having a relatively small average particle diameter, and the recessed-projecting portion 21b on the side surface of the hole 21 may be formed while the hole 21 is formed by etching with the use of a mask. In this disclosure, the average particle diameter indicates a value of a particle diameter (D50) with a volume frequency of 50% which volume frequency is measured by laser diffractometry. By adjusting the size of metal particles constituting the metal layer 2a, the size (roughness) of the recessed-projecting portion 21b on the side surface of the hole 21 can be adjusted. In a case where the recessed-projecting portion 21b is formed by etching, the arithmetic average roughness (Ra) of the recessed-projecting portion 21b on the side surface of the hole 21 is about 10 μm or more but 100 μm or less and may be about 50 μm or more but 100 μm or less, for example.
As a formation method of the recessed-projecting portion 21a on the bottom surface of the hole 21, the hole 21 is formed by a drill, etching, or the like. Then, the bottom surface of the hole 21 may be roughened by vertically or diagonally applying laser on the bottom surface of the hole 21. The recessed-projecting portions 21a, 21b may be formed on the bottom surface and the side surface of the hole 21 at the same time by one laser application. By adjusting application power, a spot diameter, or the like of the laser, the size (roughness) of the recessed-projecting portion 21a on the bottom surface of the hole 21 can be adjusted. In a case where the recessed-projecting portion 21a is formed by laser application, the arithmetic average roughness (Ra) of the recessed-projecting portion 21a on the bottom surface of the hole 21 is about 20 μm or more but 150 μm or less.
As another formation method of the recessed-projecting portion 21a on the bottom surface of the hole 21, the metal layer 2a may be made of metal particles (for example, copper particles) having a relatively large average particle diameter, and the recessed-projecting portion 21a may be formed on the bottom surface of the hole 21 while the hole 21 is formed by etching with the use of a mask. By adjusting the size of the metal particles constituting the metal layer 2a, the degree (roughness) of the recessed-projecting portion 21a on the bottom surface of the hole 21 can be adjusted. The recessed-projecting portions 21a, 21b may be formed on the bottom surface and the side surface of the hole 21 at the same time by etching. In a case where the recessed-projecting portion 21a is formed by etching, the arithmetic average roughness (Ra) of the recessed-projecting portion 21a on the bottom surface of the hole 21 is about 10 μm or more but 100 μm or less and may be about 50 μm or more but 100 μm or less.
With reference to
First, the printed circuit board 8, the terminals 6a to 6e, the first implant pin 10a, and the second implant pin 10b illustrated in
Subsequently, the insulating circuit boards (1a, 2a, 2b, 3a), (1b, 2c to 2e, 3b) illustrated in
Subsequently, the semiconductor chip 4 is put on the top surfaces of the metal layers 2a to 2e of the insulating circuit boards (1a, 2a, 2b, 3a), (1b, 2c to 2e, 3b) via the bonding material 5. Subsequently, the bonding material 7 is provided on the top surface of the semiconductor chip 4, and the bonding material 11 is provided on the top surface of the metal layer 2b.
Subsequently, the implant printed circuit board is aligned to face the top surface sides of the insulating circuit boards (1a, 2a, 2b, 3a), (1b, 2c to 2e, 3b), and the terminals 6a to be are press-fitted to the metal layers 2a to 2e, respectively, and joined thereto by use of a pressure device.
Here, as illustrated in
The terminal 6a may be firmly fitted to the side surface of the hole 21 by rotating and press-fitting the terminal 6a to the hole 21 at the time when the terminal 6a is press-fitted to the hole 21. Alternatively, the terminal 6a may be press-fitted to the hole 21 without rotating the terminal 6a. The terminal 6a may be firmly fitted to the bottom surface of the hole 21 by rotating the terminal 6a after the lower end of the terminal 6a is in contact with the bottom surface of the hole 21. Similarly to the terminal 6a, the terminals 6b to 6e illustrated in
Subsequently, the bonding materials 5, 7, 11 are melted by heating and then solidified by cooling, so that the implant printed circuit board is integrated with the insulating circuit boards (1a, 2a, 2b, 3a), (1b, 2c to 2e, 3b). After that, the semiconductor element 4 is sealed with the sealing resin 9. Hereby, the semiconductor device according to the first embodiment as illustrated in
Herein, with reference to
In the semiconductor device according to the comparative example, since the bottom surface and the side surface of the hole 21x are flat, the terminal 6a press-fitted to the hole 21x easily falls out from the hole 21x, so that a long-term reliability decreases. In contrast, in the semiconductor device according to the first embodiment, since the recessed-projecting portions 21a, 21b are intentionally formed in the hole 21, as illustrated in
Furthermore, in the semiconductor device according to the first embodiment, since the plating layer 62 provided on the surface of the terminal 6a is made of a material softer than that of the metal layer 2a, the plating layer 62 can be easily deformed to be fitted to the recessed-projecting portions 21a, 21b of the hole 21, thereby allowing the terminal 6a to be firmly fitted to the metal layer 2a.
In the semiconductor device according to the comparative example, it is difficult to secure accuracy of position when the terminal 6a is press-fitted to the hole 21x, and it is difficult for the terminal 6a to be press-fitted to the hole 21x. In contrast, in the semiconductor device according to the first embodiment, the step 22 is provided in the upper portion of the hole 21, as illustrated in
In the semiconductor device according to the second embodiment, the main body 61 includes no plating layer and is directly in contact with the bottom surface and the side surface of the hole 21. The lower end of the main body 61 has an end surface provided with the recessed-projecting portion 61a deforming to be fitted to the recessed-projecting portion 21a on the bottom surface of the hole 21 at the time when the terminal 6a is press-fitted to the hole 21. The lower end of the main body 61 has an outer peripheral surface provided with the recessed-projecting portion 61b deforming to be fitted to the recessed-projecting portion 21b on the side surface of the hole 21 at the time when the terminal 6a is press-fitted to the hole 21. The other configuration of the semiconductor device according to the second embodiment is similar to the configuration of the semiconductor device according to the first embodiment, and therefore, a redundant description thereof is omitted.
In the semiconductor device according to the second embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, the step 22 is provided in the upper portion of the hole 21, thereby making it possible to guide the terminal 6a into the hole 21 and to easily press-fit the terminal 6a to the hole 21.
In the semiconductor device according to the third embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a.
The projecting portion 63 has a diameter w4, which is smaller than the diameter w3 before the terminal 6a is press-fitted to the hole 21 and smaller than the diameter w0 of the hole 21. After the terminal 6a is press-fitted to the hole 21 of the metal layer 2a in the semiconductor device according to the fourth embodiment, the semiconductor device according to the fourth embodiment has generally the same section as the semiconductor device according to the third embodiment illustrated in
In the semiconductor device according to the fourth embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, in the semiconductor device according to the fourth embodiment, since the projecting portion 63 is provided on the lower end of the terminal 6a, the terminal 6a can be easily press-fitted to the hole 21.
The lower end of the terminal 6a has a diameter w5, which is smaller than the diameter w3 before the terminal 6a is press-fitted to the hole 21 and which is smaller than the diameter w0 of the hole 21. After the terminal 6a is press-fitted to the hole 21 of the metal layer 2a in the semiconductor device according to the fifth embodiment, the semiconductor device according to the fifth embodiment has generally the same section as the semiconductor device according to the third embodiment illustrated in
In the semiconductor device according to the fifth embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, in the semiconductor device according to the fifth embodiment, since the tapered portion 64 is provided on the lower end side of the terminal 6a, the terminal 6a can be easily press-fitted to the hole 21.
The lower end side of the terminal 6a has a tapered shape. After the terminal 6a is press-fitted to the hole 21 of the metal layer 2a in the semiconductor device according to the sixth embodiment, the semiconductor device according to the sixth embodiment has generally the same section as the semiconductor device according to the third embodiment illustrated in
In the semiconductor device according to the sixth embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, in the semiconductor device according to the sixth embodiment, since the tapered portion 65 is provided on the lower end side of the terminal 6a, the terminal 6a can be easily press-fitted to the hole 21.
After the terminal 6a is press-fitted to the hole 21 of the metal layer 2a in the semiconductor device according to the seventh embodiment, the semiconductor device according to the seventh embodiment has generally the same section as the semiconductor device according to the third embodiment illustrated in
In the semiconductor device according to the seventh embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, in the semiconductor device according to the seventh embodiment, since the lower end side of the terminal 6a has the curved surface 66, the terminal 6a can be easily press-fitted to the hole 21.
The diameter w3 of the terminal 6a corresponds to an outer-side virtual outer peripheral surface in contact with the projections of the recessed-projecting portion 62d of the terminal 6a and is larger than the diameter w0 of the hole 21. The diameter w3 of the terminal 6a is generally the same as the diameter w1 of the outer-side virtual inner peripheral surface in contact with the recesses of the recessed-projecting portion 21b on the side surface of the hole 21 or is smaller than the diameter w1. The recessed-projecting portion 62c is formed on the plating layer 62 on the end surface of the lower end of the terminal 6a, and the recessed-projecting portion 62d is formed on the plating layer 62 on the outer peripheral surface of the lower end of the terminal 6a. The recessed-projecting portions 62c, 62d are formable by roughing the surface of the plating layer 62 by laser application, for example. The arithmetic average roughness (Ra) of the recessed-projecting portions 62c, 62d is about 2 μm or more but 150 μm or less, for example. In the semiconductor device according to the eighth embodiment, the material of the plating layer 62 may be the same as the material of the metal layer 2a, may be harder than the material of the metal layer 2a, or may be softer than the material of the metal layer 2a.
Note that only one of the recessed-projecting portions 62c, 62d on the plating layer 62 may be formed. In a case where the terminal 6a does not include the plating layer 62 but includes only the main body 61, recessed-projecting portions may be formed intentionally on the end surface and the outer peripheral surface of the lower end of the main body 61.
At the time when the terminal 6a is inserted into the hole 21, the terminal 6a is rotated and inserted into the hole 21, so that the recessed-projecting portion 62d on the outer peripheral surface of the terminal 6a can be easily fitted to the recessed-projecting portion 21b on the side surface of the hole 21. Note that the terminal 6a may be press-fitted to the hole 21 without rotating the terminal 6a.
In the semiconductor device according to the eighth embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, the step 22 is provided in the upper portion of the hole 21, thereby making it possible to guide the terminal 6a into the hole 21 and to easily press-fit the terminal 6a to the hole 21.
Besides, in the semiconductor device according to the eighth embodiment, the recessed-projecting portions 62c, 62d are also formed intentionally in the terminal 6a in advance before the terminal 6a is press-fitted to the hole 21 of the metal layer 2a. Hereby, the recessed-projecting portions 62c, 62d of the terminal 6a are fitted to the recessed-projecting portions 21a, 21b of the hole 21, thereby allowing the terminal 6a to be more firmly joined to the metal layer 2a.
The diameter w3 of the terminal 6a corresponds to an outer-side virtual outer peripheral surface in contact with the projections of the recessed-projecting portion 62d of the terminal 6a and is larger than the diameter w0 of the hole 21. The recessed-projecting portion 62c is formed on the plating layer 62 on the end surface of the lower end of the terminal 6a, and the recessed-projecting portion 62d is formed on the plating layer 62 on the outer peripheral surface of the lower end of the terminal 6a. The configuration of the terminal 6a is similar to that of the terminal 6a of the semiconductor device according to the eighth embodiment illustrated in
In a manufacturing method for manufacturing the semiconductor device according to the eighth embodiment, the terminal 6a including the recessed-projecting portions 62c, 62d formed intentionally in advance is prepared, as illustrated in
When the terminal 6a is rotated and press-fitted to the hole 21 at the time when the terminal 6a is press-fitted to the hole 21, the recessed-projecting portion 21d is easily formed on the side surface of the hole 21. When the terminal 6a is rotated after the terminal 6a is in contact with the bottom surface of the hole 21, the recessed-projecting portion 21c is easily formed on the bottom surface of the hole 21. The other configuration of the semiconductor device according to the ninth embodiment is similar to the configuration of the semiconductor device according to the first embodiment, and therefore, a redundant description thereof is omitted.
In the semiconductor device according to the ninth embodiment, the hole 21 includes the recessed-projecting portions 21c, 21d formed intentionally, similarly to the semiconductor device according to the first embodiment. This makes it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, the step 22 is provided in the upper portion of the hole 21, thereby making it possible to guide the terminal 6a into the hole 21 and to easily press-fit the terminal 6a to the hole 21.
Besides, in the semiconductor device according to the ninth embodiment, the recessed-projecting portions 62c, 62d are formed intentionally in the terminal 6a in advance before the terminal 6a is press-fitted to the hole 21 of the metal layer 2a. Hereby, even in a case where no recessed-projecting portion is formed intentionally in the hole 21, the recessed-projecting portions 21c, 21d can be formed by deforming the bottom surface and the side surface of the hole 21 at the time when the terminal 6a is press-fitted to the hole 21. In addition, with the use of the plating layer 62 harder than the metal layer 2a, the metal layer 2a is easily deformed at the time when the terminal 6a is press-fitted to the hole 21, thereby allowing the recessed-projecting portions 21c, 21d to be easily formed in the hole 21.
The arithmetic average roughness (Ra) of the recessed-projecting portion 22a of the step 22 is about 2 μm or more but 150 μm or less, for example. A formation method of the recessed-projecting portion 22a in the step 22 is similar to the formation method of the recessed-projecting portion 21a in the hole 21. The other configuration of the semiconductor device according to the tenth embodiment is similar to the configuration of the semiconductor device according to the first embodiment, and therefore, a redundant description thereof is omitted.
In the semiconductor device according to the tenth embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, the step 22 is provided in the upper portion of the hole 21, thereby making it possible to guide the terminal 6a into the hole 21 and to easily press-fit the terminal 6a to the hole 21.
Besides, in the semiconductor device according to the tenth embodiment, the recessed-projecting portion 22a is formed intentionally on the bottom surface of the step 22, and hereby, in a case where the diameter w3 of the terminal 6a becomes wide in the vicinity of the portion of the terminal 6a which is inserted into the hole 21, the terminal 6a is fitted to the recessed-projecting portion 22a on the bottom surface of the step 22, thereby allowing the terminal 6a to be further firmly joined to the metal layer 2a.
In the semiconductor device according to the eleventh embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a deforms to be fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, the tapered portion 23 is provided in the upper portion of the hole 21, thereby making it possible to guide the terminal 6a into the hole 21 and to easily press-fit the terminal 6a to the hole 21.
The plurality of slits 68 is provided on an outer peripheral side of the terminal 6a and extends in parallel to the axial direction of the terminal 6a. The interval between the slits 68, the number of the slits 68, or the depth, length, or width of the slits 68 is not particularly limited. Note that the slits 68 may be provided diagonally (spirally) to the axial direction of the terminal 6a or may be provided vertically to the axial direction of the terminal 6a. The other configuration of the semiconductor device according to the twelfth embodiment is similar to that of the semiconductor device according to the first embodiment, and therefore, a redundant description thereof is omitted.
In the semiconductor device according to the twelfth embodiment, the hole 21 includes the recessed-projecting portions 21a, 21b formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a is fitted to the recessed-projecting portions 21a, 21b, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, the step 22 is provided in the upper portion of the hole 21, thereby making it possible to guide the terminal 6a into the hole 21 and to easily press-fit the terminal 6a to the hole 21.
Besides, in the semiconductor device according to the twelfth embodiment, since the terminal 6a includes the slits 68, the contact area of the outer peripheral surface of the terminal 6a to be fitted to the recessed-projecting portion 21b of the hole 21 increases, thereby allowing the terminal 6a to be more firmly joined to the metal layer 2a.
A recessed-projecting portion (internal thread) 21e corresponding to the external thread 67 of the terminal 6a is formed on the side surface of the hole 21. The bottom surface of the hole 21 is flat but may include a recessed-projecting portion. The internal thread 21e is formed intentionally in advance before the terminal 6a is inserted into the hole 21 of the metal layer 2a. At the time when the terminal 6a is inserted into the hole 21 of the metal layer 2a, the terminal 6a may be fitted to the metal layer 2a such that the external thread 67 of the terminal 6a is fastened with the internal thread 21e on the side surface of the hole 21.
Note that no internal thread may be formed on the side surface of the hole 21 in advance before the terminal 6a is inserted into the hole 21 of the metal layer 2a. In this case, the internal thread 21e may be formed intentionally such that the terminal 6a is screwed and press-fitted to the hole 21 to deform the side surface of the hole 21 at the time when the terminal 6a is inserted into the hole 21 of the metal layer 2a. A plating layer harder than the metal layer 2a may be formed on the surface of the external thread 67 of the terminal 6a. The other configuration of the semiconductor device according to the thirteenth embodiment is similar to the configuration of the semiconductor device according to the first embodiment, and therefore, a redundant description thereof is omitted.
In the semiconductor device according to the thirteenth embodiment, the hole 21 includes the recessed-projecting portion (internal thread) 21e formed intentionally, similarly to the semiconductor device according to the first embodiment. Hereby, the terminal 6a is fitted to the recessed-projecting portions 21e, thereby making it possible to prevent the terminal 6a from falling out and to improve the joining strength between the terminal 6a and the metal layer 2a. In addition, the step 22 is provided in the upper portion of the hole 21, thereby making it possible to guide the terminal 6a into the hole 21 and to easily press-fit the terminal 6a to the hole 21.
Besides, in the semiconductor device according to the thirteenth embodiment, at least the portion of the terminal 6a which is inserted into the hole 21 is the screw thread (external thread) 67, so that the portion of the terminal 6a can be fastened with the recessed-projecting portion (internal thread) 21e of the hole 21 and can be firmly joined thereto.
As described above, the invention has been described according to the first to thirteenth embodiments, but it should not be understood that the description and drawings implementing a portion of this disclosure limit the invention. Various alternative embodiments of the present disclosure, examples, and operational techniques will be apparent to those skilled in the art from this disclosure.
For example, the first to thirteenth embodiments deal with a case where the terminal 6a is an external connection terminal, as illustrated in
The first to thirteenth embodiments deal with a semiconductor module using the printed circuit board 8, as illustrated in
The first to thirteenth embodiments deal with a case where the metal layer 2a to which the terminal 6a is joined is an element of the insulating circuit board (1a, 2a, 2b, 3a), but the present disclosure is not limited to this. For example, the metal layer 2a may be a lead frame, a lead, or the like.
Further, the configurations disclosed in the embodiments may be combined as appropriate within a range that does not contradict with the scope of the first and thirteenth embodiments. As described above, the invention includes various embodiments of the present disclosure and the like not described herein. Therefore, the scope of the present disclosure is defined only by the technical features specifying the present disclosure, which are prescribed by claims, the words and terms in the claims shall be reasonably construed from the subject matters recited in the present specification.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-194880 | Nov 2023 | JP | national |
