POWER SEMICONDUCTOR ASSEMBLY WITH A PRESS-IN CONTACT ELEMENT WITH A COMPENSATION SECTION AND A BLOCKING SECTION

Description

[0001] The invention describes a power semiconductor assembly with at least one press-in contact element, with a press-in section, a connecting section, a compensating section, a base section, and a blocking section. Furthermore, the invention describes a power semiconductor module with such a power semiconductor assembly.

[0002] DE 10 2008 007 310 A1 discloses an electrical press-in contact, in particular a press-in pin contact, for transmitting electrical current and / or electrical signals, having a press-in section and a mounting section which are mechanically coupled to one another via a relief section, and the relief section has a compensation region and a stop region, wherein the compensation region allows a coupled relative movement of the press-in section and the mounting section and the stop region blocks a movement of the press-in section and the mounting section towards one another.

[0003] US 2015 / 364847 A1 discloses a pin for a semiconductor package, including an upper contact portion with a contact surface configured to be mechanically and electrically coupled to a pin receptacle. A lower portion of the pin is configured to flex to allow an upper portion of the pin to move toward an upper contact surface of a horizontal base of the pin in response to pressure applied along a direction collinear with a longest length of the pin toward the upper contact surface of the horizontal base when the pin is inserted into a pin receptacle.

[0004] In view of the prior art, the invention is based on the object of presenting an alternative embodiment of a power semiconductor assembly with at least one press-in contact element and a power semiconductor module with such a power semiconductor assembly, wherein the manufacturing effort of the press-in contact element is reduced.

[0005] This object is achieved according to the invention by a power semiconductor assembly with a substrate and conductor tracks arranged on its insulating material body and with a press-in contact element with a press-in section, a connecting section, a compensating section, a base section and a blocking section, wherein the compensating section is designed elastically and is designed to be compressed towards the base section during a longitudinal movement of the press-in section in a longitudinal direction of the press-in contact element and thus to reduce its longitudinal expansion, wherein the base section is materially bonded to a section of one of these conductor tracks of the substrate of the press-in contact element and wherein the blocking section is designed and provided to be supported with a blocking surface on a blocking counter-surface and thus to limit the longitudinal movement of the press-in section in the longitudinal direction towards the base section,wherein the blocking counter surface is arranged on an insulating material body of the substrate or on a conductor track of the substrate, in particular the conductor track on which the foot section is also arranged.

[0006] What is crucial and essential to the invention is that the press-in contact element itself does not have a blocking counter surface.

[0007] The term "longitudinal direction" here and below refers to the direction opposite to the direction in which the press-in section is pressed into a corresponding opening, for example, as part of a circuit board or other electrically conductive element, such as a connecting rail. The longitudinal direction therefore corresponds to a negative press-in direction.

[0008] It may be advantageous if the connecting section has a first main surface and a main surface arranged parallel thereto and each of which is flat.

[0009] It may also be advantageous if the compensating section has an arc or a plurality of, preferably adjacent, arcs. In particular, it is advantageous if the compensating section is S-shaped.

[0010] It may be preferred if a first arc portion of a first arc of the compensating section protrudes in the normal direction beyond the first main surface. Furthermore, it may be preferred if a second arc portion of a second arc of the compensating section protrudes in the normal direction beyond the second main surface.

[0011] Advantageously, the entire press-in contact element is intended to be formed from a flat sheet metal or from a flat metal strip by means of a stamping process.

[0012] It may also be advantageous if the blocking section is pin-shaped and the blocking surface is arranged at the end of the blocking section, located in the longitudinal direction. Preferably, the longitudinal direction forms the surface normal of the blocking surface.

[0013] In particular, it is preferred if the blocking section is designed as two partial blocking sections and the compensating section or a section thereof is arranged between the two partial blocking sections or if the compensating section is designed as two partial compensating sections and the blocking section or a section thereof is arranged between the two partial compensating sections.

[0014] It is also preferred if the substrate is formed with an insulating ceramic as a carrier of the conductor tracks or as a rigid circuit board or as a flexible circuit board.

[0015] The above-mentioned object is also achieved according to the invention by a power semiconductor module with a housing, with a substrate enclosed thereby and a power semiconductor assembly described above.

[0016] It may be preferred if the housing has a guide device, in particular a shaft, in which the connecting section is arranged at least partially and movably in the longitudinal direction.

[0017] It may be advantageous if a compensating section of a press-in contact element is arranged in a channel.

[0018] Of course, unless explicitly or per se excluded or contradicting the spirit of the invention, the features mentioned in the singular, in particular the base section, can be present multiple times. Likewise, and even preferably, the press-in contact element can be present multiple times on the power semiconductor assembly or in the power semiconductor module.

[0019] It is understood that the various embodiments of the invention, regardless of whether they are disclosed in the description of the press-in contact element or the power semiconductor assembly or the power semiconductor module, can be implemented individually or in any combination to achieve improvements. In particular, the features mentioned and explained above and below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

[0020] Further explanations of the invention, advantageous details and features, emerge from the following description of the Figures 1 to 7 schematically illustrated embodiments of the invention or of respective parts thereof. Figure 1shows schematically various views of a press-in contact element of a power semiconductor assembly according to the invention. Figures 2 to 4 show a first embodiment of a press-in contact element of a power semiconductor assembly according to the invention. Figures 5 to 8 show further embodiments of a press-in contact element of a power semiconductor assembly according to the invention.

[0021] Figure 1 shows schematically various views of a press-in contact element 1 of a power semiconductor assembly according to the invention with a longitudinal extension 100 in the z-direction, which simultaneously corresponds to the press-in direction. Figure 1b a top view from the y-direction, while Figure 1a a section along the line AA and a top layer on this section in the x-direction. Figure 1c shows a corresponding section along the line BB and also a top layer on this section in the x-direction.

[0022] The press-in contact element 1 of the power semiconductor assembly according to the invention has a preferably conventional press-in section 2 and, in the negative z-direction, a connecting section 3 that connects the press-in section 2 to a compensating section 4. This compensating section 4 is followed by a base section 5, with the compensating section and the base section 5 merging directly into one another. In the positive and negative x-direction, the press-in contact element 1 also has a partial blocking section 60, 62, with the two partial blocking sections 60, 62 together forming a blocking section 6. The partial blocking sections 60, 62 are each separated from the compensating section 4 by recesses.

[0023] The compensating section 4 itself is designed to be elastic, particularly in the longitudinal direction and thus also in the z-direction. For this purpose, it is S-shaped with two merging bends 40, 42. This design allows the compensating section 4 to be compressed toward the base section 5 during a longitudinal movement of the press-in section 2 in the longitudinal direction, i.e., the negative z-direction, of the press-in contact element 1, thus reducing its longitudinal expansion 100 in the compensating section 4.

[0024] The foot section 5 is designed to be arranged in a material-locking manner with a foot surface 500 on a conductor track 70 of a substrate 7, cf. Figure 3 and 4This integral connection can be formed either by means of a welded joint, i.e., without an additional connecting means arranged between the base section 5 and the conductor track. Alternatively, the integral connection can be formed as a soldered or sintered connection, in which case a connecting means is located between the base section 5 and the conductor track. The respective integral connection determines the possible reduction in linear expansion in the application, as will be explained below.

[0025] The blocking section 6 is basically designed to engage with a blocking surface 600 onto a blocking counter surface 700, cf. Figure 4, and thus limit the longitudinal movement of the press-in section 2 in the direction of the base section 5. This blocking counter surface 700 can in principle be arranged on an insulating body 72 of the substrate 7 or on a conductor track 70 of the substrate 7. This configuration also influences the possible reduction of the linear expansion in the application.

[0026] In the embodiment of the press-in contact element 1 shown here, the respective blocking surface 600 is offset 560 in the z-direction relative to the base surface 500. If this base surface 500 is arranged directly on the conductor track and connected to it by means of the aforementioned welded connection, the offset 560 corresponds exactly to the possible reduction in the linear expansion 100.

[0027] For an arrangement of the base surface 500 by means of a connecting means on the conductor track, a greater possible reduction of the length extension 100 results, provided that the blocking counter surface is formed directly on the conductor track.

[0028] The conductor track often protrudes from the insulating material body of the substrate in the z-direction, which also leads to a larger possible reduction in the linear expansion 100 when the blocking counter surface is arranged on the insulating material body.

[0029] These differences mean that the design of the connection of the press-in contact element 1 to the substrate and the position of the blocking counter surface must be taken into account when designing the dimensions, in particular the offset 560. On the other hand, this design of the press-in contact element 1, in which the blocking counter surface is not an integral part of the press-in contact element 1 itself, has the advantage that the manufacturing effort for the press-in contact element 1, particularly within the framework of a stamping and bending process, is lower compared to the prior art.

[0030] Figures 2 to 4 show a first embodiment of a press-in contact element 1 of a power semiconductor assembly according to the invention, more precisely a section thereof, and in the Figures 3 and 4 its arrangement on a substrate 7 as part of a power semiconductor assembly or a power semiconductor module.

[0031] The press-in contact element 1 shown is basically similar to that according to Figure 1 It has a press-in section 2 (not shown) of conventional design and, in the negative z-direction, a connecting section 3 which has a first and a second main surface 30, 32 arranged parallel thereto and each of which is flat, the normal direction of which runs in the positive and negative y-direction, respectively.

[0032] The connecting section 3 is then followed by a compensating section 4. This is immediately followed by a foot section 5, wherein the foot section, at least at its end, is wider than the compensating section 4. The foot section 5 is designed to be arranged with its foot surface 500 in a material-locking manner on a conductor track 70 of a substrate 7. This material-locking connection can be designed as described above. Figures 3 and 4What is shown, without loss of generality, is a material connection without an explicit connecting means.

[0033] The compensating section 4 itself is designed to be elastic. For this purpose, it is S-shaped with two arches 40, 42 that merge into one another, i.e., adjoin one another. A first arched section 44 of the first arch 40 protrudes in the normal direction beyond the first main surface 30, while a second arched section 46 of the second arch 42 protrudes in the normal direction beyond the second main surface 32. Due to this design, the compensating section 4 is designed to be compressed towards the foot section 5 during a longitudinal movement of the press-in section 2 in a longitudinal direction, here the negative z-direction, of the press-in contact element 1, and thus to achieve its longitudinal extension 100, cf. Figure 1 , to reduce.

[0034] According to the invention, the press-in contact element 1 of the power semiconductor assembly also has a blocking section 6. This is designed as two partial blocking sections 60, 62, with the compensating section 4 being arranged almost entirely between the two partial blocking sections 60, 62. The blocking section 6, here both partial blocking sections 60, 62, are pin-shaped. Both partial blocking sections 60, 62 have a blocking surface 600 at their longitudinal end, thus facing the substrate. The respective blocking surface 600 is oriented parallel to an associated counter-blocking surface 700.

[0035] The power semiconductor module according to the invention, shown in a section according to Figure 3 and 4is designed as part of a power semiconductor module. It comprises a substrate 7 and a plurality of press-in contact elements 1, only one of which is shown by way of example. The substrate 7 itself comprises, without limitation of generality, a rigid insulating body 72 and a plurality of conductor tracks 70 thereon, only one of which is also shown. The press-in contact element 1 is arranged with its base section 5 in a materially bonded manner on a section of one of these conductor tracks 70 and is materially bonded thereto.

[0036] Without the application of force in the longitudinal direction of the press-in contact element 1, the blocking surface 600 of the respective partial blocking section 60, 62 is spaced from the surface of the conductor track 70 and the blocking counter-surface formed there. In principle, the blocking counter-surface 700 is a surface section of the conductor track 70 as such. However, a further metallization can also be arranged on the conductor track 70, the surface of which then forms the blocking counter-surface. Such a metallization can, for example, be a solder layer or a sintered metal layer, particularly if the integral connection of the base section 5 to the conductor track 70 is also formed as a solder or sintered connection.

[0037] The blocking section 6, or here the two partial blocking sections 60, 62, in cooperation with the respectively associated blocking counter surfaces 700 of the substrate 7, serve to support the base section 5 or the substrate 7 with its respective blocking surface 600 on the associated blocking counter surface 700 during a movement of the press-in section 2, particularly during the press-in process, in the longitudinal direction toward the base section 5 or the substrate 7, and thus to limit the longitudinal movement of the press-in section 2 in the longitudinal direction. This limitation is achieved as soon as the respective blocking surface 600 rests flatly on the associated blocking counter surface 700.

[0038] The Figures 5 to 8show further embodiments of a press-in contact element 1 according to the invention. Only a part of the connecting section 3 is shown in each case, to which a compensating section 4 and, thereafter, a base section 5 are connected. The press-in section itself is not shown, since its design is, in principle, arbitrary.

[0039] Shown in Figure 5is a compensating section 4, which is designed as two partial compensating sections. These two partial compensating sections are each formed with an arc, wherein a first arc section 44 of the first arc of the first partial compensating section protrudes in the normal direction beyond a first main surface 30 of the connecting section 3. Correspondingly, a second arc section 46 of the second arc of the second partial compensating section protrudes in the normal direction beyond a second main surface 32 of the connecting section 3. Both arcs end directly in a respective foot section 5, which thus directly adjoins the respective partial compensating sections.

[0040] The two arches are arranged next to each other and spaced apart in the y-direction. A pin-like blocking section 6 is arranged between the two partial compensation sections. This design of the press-in contact element 1 is thus very compact. Furthermore, equal forces act on the press-in contact element 1 in the negative and positive x- and y-directions when a longitudinal movement of the press-in section occurs in the longitudinal direction on the foot sections 5. Naturally, the blocking section 6 has a blocking surface 600 functionally as described above.

[0041] Figure 6shows a further variant of a press-in contact element 1, wherein the press-in section has again been omitted. In this embodiment, the connecting section 3 merges directly into the blocking section 6 in the longitudinal direction, i.e., the negative z-direction. The compensating section 4 protrudes from the unit consisting of the connecting and blocking sections 3, 6 in the negative y-direction, is S-shaped, and has the base section 5 directly at its end.

[0042] Figure 7 shows a further variant of a press-in contact element 1, whereby the press-in section has again been omitted. This design is similar to that according to Figure 5 However, here the two partial compensation sections are not S-shaped. Rather, the two partial compensation sections wind around the central blocking section 6 and are also twisted.

[0043] Figure 8shows two views of a further variant of a press-in contact element 1, whereby the press-in section has again been omitted. In this embodiment, the connecting section 3 merges into the compensating section 4, wherein the blocking section 6 is also formed at this transition. This is formed by dividing a flat metal strip, which serves as the starting material for the entire press-in contact element 1, into three regions at the aforementioned transition, which are arranged next to one another in the x-direction. The two outer regions then form the compensating section 4 after a bending process, while the central region forms the blocking section 6. The blocking section 6 was therefore punched out like a tongue here.

[0044] The cross-section of the compensation section 4, which subsequently becomes one area again from the two outer areas, has a smaller cross-section in this area than in the previous area.

[0045] The compensating section 4 is followed by the foot section 5, which is also formed in the punching and bending process described above. This is designed such that, viewed in the x-direction, two parts of this foot section 5 are aligned with the blocking section 6.

Claims

1. Power semiconductor assembly having a substrate (7) and conductor tracks (70) arranged on the insulating-material body (72) of said substrate and having a press-in contact element (1) having a press-in portion (2), a connecting portion (3), a compensating portion (4), a foot portion (5) and a blocking portion (6), wherein the compensating portion (4) is configured to be elastic and is designed to be compressed upon a longitudinal movement of the press-in portion in a longitudinal direction of the press-in contact element (1) towards the foot portion (5) and therefore to reduce its longitudinal extent (100), wherein the foot portion (5) press-in contact element (1) arranged in a materially-bonded manner on a portion of one of these conductor tracks (70) of the substrate (7) and wherein the blocking portion (6) is designed and provided to be supported with a blocking surface (600) on a blocking counter-surface (700) and therefore to limit the longitudinal movement of the press-in portion (2) in the longitudinal direction towards the foot portion (5), characterized in that the blocking counter-surface (700) is arranged on an insulating-material body (72) of the substrate (7) or on a conductor track (70) of the substrate (7), in particular that conductor track (70) on which the foot portion (5) is also arranged.

2. Power semiconductor assembly according to Claim 1, wherein the connecting portion (3) of the press-in contact element (1) has a first and, arranged parallel thereto, a second main surface (30, 32), each being of planar design.

3. Power semiconductor assembly according to either of the preceding claims, wherein the compensating portion (4) of the press-in contact element (1) has a curve or a plurality of, preferably mutually adjoining, curves (40, 42).

4. Power semiconductor assembly according to Claim 3, wherein the compensating portion (4) of the press-in contact element (1) is of S-shaped design.

5. Power semiconductor assembly according to Claims 2 to 4, wherein a first curve portion (44) of a first curve (40) of the compensating portion (4) of the press-in contact element (1) protrudes beyond the first main surface (30) in the normal direction.

6. Power semiconductor assembly according to Claims 2 to 5, wherein a second curve portion (46) of a second curve (42) of the compensating portion (4) of the press-in contact element (1) protrudes beyond the second main surface (32) in the normal direction.

7. Power semiconductor assembly according to either of the preceding claims, wherein the entire press-in contact element (1) is formed from a flat metal sheet or from a flat metal strip by means of a punching process.

8. Power semiconductor assembly according to either of the preceding claims, wherein the blocking portion (6) of the press-in contact element (1) is designed in the form of a pin and the blocking surface (600) is arranged at the end of the blocking portion (6) which is located in the longitudinal direction.

9. Power semiconductor assembly according to either of the preceding claims, wherein the blocking portion (6) of the press-in contact element (1) is designed as two blocking segments (60, 62) and the compensating portion (4) or a portion thereof is arranged between the two blocking segments (60, 62) or wherein the compensating portion (4) is designed as two compensating segments and the blocking portion (6) or a portion thereof is arranged between the two compensating segments.

10. Power semiconductor assembly according to any of the preceding claims, wherein the substrate is designed with an insulating ceramic as a carrier of the conductor tracks or as a rigid printed circuit board or as a flexible printed circuit board.

11. Power semiconductor module having a housing, having a substrate (7) enclosed therein and a power semiconductor assembly according to any of Claims 1 to 10.

12. Power semiconductor module according to Claim 11, wherein the housing has a guide device, in particular a shaft, in which the connecting portion (3) is at least partially arranged and such that it is movable in the longitudinal direction.