Power electronic assembly with a substrate, a bushing and a contact pin

Abstract

The invention relates to a power electronics assembly having a substrate, a sleeve and a contact pin, having a substrate, a sleeve and a contact pin, wherein the sleeve is arranged on a conductor track of the substrate and a foot section of the sleeve is connected to the conductor track in a material-locked and electrically conductive manner, wherein the contact pin is arranged in an inner interspace of the sleeve with an insertion section, and wherein a material-locked and electrically conductive solder connection constituted by means of a laser weld is formed between a pin connection section of the insertion section of the contact pin and an associated sleeve connection section of the sleeve.

Description

TECHNICAL FIELD

[0001] A power electronics assembly is described, having a substrate, a bushing and a contact pin, wherein the bushing is arranged on a conductor track of the substrate and a foot section of the bushing is connected to the conductor track in a material-locked and electrically conductive manner, and wherein the contact pin is arranged in an inner interspace of the bushing with an insertion section. BACKGROUND

[0002] DE 10 2008 005 547 A1 discloses as prior art a conductive contact element, i.e. a bushing, which extends in a longitudinal direction and has a first end and a second end opposite the first end. The contact element has a first flange on its first end, which is configured in such a way that, when the contact element is placed onto a plane extending perpendicular to the longitudinal direction z with the first flange in front, the first flange has a number (N1≥2) of first contact surfaces spaced apart from one another from the plane. Furthermore, a power semiconductor module is disclosed, which has such a contact element and a contact pin arranged in the contact element. SUMMARY

[0003] Based on the knowledge of the prior art, it is the task of the present application to improve the connection between a bushing and a contact pin arranged in the bushing and to propose a corresponding assembly and a manufacturing method thereof.

[0004] According to the application, this task is solved by a power electronics assembly having a substrate, a bushing and a contact pin, wherein the bushing is arranged on a conductor track of the substrate and a foot section of the bushing is connected to the conductor track in a material-locked and electrically conductive manner, wherein the contact pin is arranged in an inner interspace of the bushing with an insertion section, and wherein a material-locked and electrically conductive welded connection by means of laser welding is formed between a pin connection section of the insertion section of the contact pin and an associated bushing connection section of the bushing.

[0005] It is advantageous here that the substrate is selected from the following group:

[0006] • a power electronics substrate, in particular having a body of a ceramic insulating material and conductor tracks arranged on the body of the ceramic insulating material;

[0007] • a power electronics connection device, in particular a thin-film-based power electronics connection device;

[0008] • a circuit board.

[0009] It is furthermore advantageous here that the material-locked connection between the conductor track of the substrate and the foot section of the bushing is selected from the following group:

[0010] • a sintered connection, in particular a press-sintered connection;

[0011] • a soldered connection;

[0012] • a glued connection;

[0013] • a welded connection, in particular a laser-welded connection.

[0014] It can also be advantageous for the contact pin to have a rounded, polygonal, in particular rectangular, in particular square, cross section, in particular in the region of the insertion section.

[0015] Furthermore, the contact pin can have a compensation section for length compensation, which can in particular be configured in an s-shaped or meandering course.

[0016] It is particularly advantageous for the sleeve to have a conical opening on its foot section, on its end section or on both sections.

[0017] It can also be advantageous for the sleeve to have a linear expansion section in a central section between the foot section and the end section, which is preferably arranged between the sleeve connection section and the foot section, and which can in particular be configured by means of a slit or by a material weakening, by a thinning. The slit can in particular be configured as a longitudinal or transverse slit, or also as an s-shaped or meandering slit.

[0018] It can also be preferred for the base plate to have a recess which is aligned with the internal recess of the sleeve and which in particular has the same or a greater diameter. It can furthermore be preferred here for the contact pin to have a first intermediate section which is arranged in the recess of the base plate.

[0019] It is preferred for the internal recess of the sleeve to have an inner contour which is rounded, preferably circular. Alternatively, the internal recess can also be configured polygonally, in particular rectangularly, in particular square. It is not necessary for the insertion section to have the same cross section, in particular in the case of a rounded inner contour. It is particularly advantageous for the internal recess of the sleeve to be configured rounded and for the cross section of the end section to be configured square.

[0020] According to the application, this task is solved by a method for producing the assembly described above, which has the following steps:

[0021] a) materially bonding the foot section of the sleeve to the associated conductor track material of the base plate;

[0022] b) arranging the insertion section of the contact pin in the sleeve;

[0023] c) producing a welded connection between the sleeve connection section of the sleeve and the pin connection section of the contact pin by loading the sleeve connection section with a laser beam.

[0024] It is particularly preferred that, in step b), the third section of the contact pin is arranged in the gap of the substrate.

[0025] Obviously, unless explicitly excluded or contradicted by the concept of the invention, features mentioned in the singular, especially sleeves and contact pins, may appear multiple times in components according to the invention. Similarly, individual, and especially all, method steps may appear multiple times in the method or process according to the invention.

[0026] It should be understood that, in order to achieve improvements, different design schemes of the present invention, whether or not they are disclosed within the scope of the description of the components or methods, can be implemented individually or in any combination. In particular, the features mentioned and set forth herein can be used not only in the illustrated combinations, but also in other combinations or individually, without departing from the scope of protection of the present invention. Attached Figure Description

[0027] Further description, advantageous details and features of the invention are given in the following description. Figures 1 to 6 The embodiments illustrated herein or their respective portions are described.

[0028] Figure 1 A three-dimensional view of the sleeve is shown;

[0029] Figure 2 A three-dimensional view of the substrate is shown, on which a sleeve is arranged;

[0030] Figure 3 A first design of the power electronic component according to the present invention is shown in a side view;

[0031] Figure 4 A second design of the power electronic component according to the present invention is shown in a side view;

[0032] Figure 5 A third design of the power electronic component according to the present invention is shown in a side view;

[0033] Figure 6 The modified version of the third design scheme is shown;

[0034] Figure 7 Showing according to Figure 1 An improved solution for the bushing. Detailed Implementation

[0035] Figure 1A three-dimensional view of a sleeve 4, which is generally common in the art, is shown, having a foot section 40, an end section 44, and a central section 42 disposed therebetween. Here, both the foot section 40 and the end section 44 are constructed as perforated discs with concentric, rounded openings 400, 440, wherein the two openings 400, 440 are aligned with each other and have the same diameter. The central section 42 is constructed as a cylindrical shell, the inner region 420 of which is aligned with the openings 400, 440 of the foot section 40 and the end section 44. The central section 42 has an inner diameter that is the same as the inner diameter of the two openings 400, 440 of the foot section 40 and the end section 44. The openings 400, 440 and the inner region 420 of the central section 42 together constitute an inner opening 48.

[0036] Alternatively, but not shown, the foot section 40 or the end section 44 may also be without a gap, thereby forming a sleeve cup shape, and thus, the interior of the cup-shaped part forms an internal gap.

[0037] The conical design of the outer openings of the respective gaps 400 and 440 is not shown, but it is either forced to exist for manufacturing reasons or is clearly and obviously constructed in this way.

[0038] The sleeve 4 is made of a metallic material (in this case, copper). Typically, the sleeve 4 has a length ranging from 3 mm to 10 mm, while the internal cavity has a diameter on the order of 1 mm.

[0039] Figure 2 A three-dimensional view of substrate 2 is shown, on which are arranged... Figure 1 The sleeve 4. The substrate 2 shown here is a power electronics substrate having a ceramic insulating material body 20 and conductor traces 22, 24 disposed on the ceramic insulating material body. Sleeves are disposed on two of the conductor traces 24. Power semiconductor structural elements 3 are disposed only exemplary on the other conductor trace 22. Obviously, the sleeve 4 and the power semiconductor structural elements 3 can also be disposed on the same conductor trace. In other respects, the substrate 2 is commonly constructed in the art as part of a power electronic assembly 1.

[0040] Figure 3 A first design of the power electronic component 1 according to the present invention is shown in a side view. The substrate 2 is in... Figure 2 The substrate is consistent with that described in the paper, and has a power semiconductor structure element 3 electrically connected to the conductor trace 22 on the conductor trace 22. The power semiconductor structure element is also electrically connected to another conductor trace by means of a lead crimp portion, which is purely exemplary.

[0041] The foot section 40 of the sleeve 4 is arranged on the further conductor track 24 by means of a solder connection 7 in a material-locking and electrically conductive manner. The sleeve 4 has a rounded inner recess 48 which is provided for accommodating the insertion section 520 of the contact pin 5 during the manufacturing process. The insertion section 520 of the contact pin 5 has a square cross section whose diagonal is identical to the diameter of the inner recess 420 within the limits of manufacturing possibilities and can thus be arranged in the sleeve without great force expenditure.

[0042] In order to achieve a secure and permanent electrically conductive connection between the sleeve 4 and the contact pin 5, the sleeve connection section 46 is loaded with a laser beam 6 after the insertion section 520 of the contact pin 5 has been arranged. By this loading within the scope of the laser welding process 6, the sleeve connection section 46 is connected in a material-locking manner with the pin connection section 56 which is the section of the insertion section 520. This laser-welded connection thus constituted also fixes the contact pin 5 against being pulled out of the sleeve 4.

[0043] The contact pin 5 has, in addition to the insertion section 520, a second intermediate section 510 and, coupled thereto, a press-in pin section 500.

[0044] Figure 4 A second design variant of a power electronics assembly 1 according to the application is shown in a side view. The contact pin 5 shown here has three essential sections. Coupled to the insertion section 520 are a compensation section 530 and a connection section 540. The connection section 540 is connected in a material-locking and electrically conductive manner by means of a laser-welded connection 6 directly with a conductor track 22 of a power electronics substrate 2 which is similar to the power electronics substrate according to Figure 2 or 3.

[0045] Furthermore, a circuit board 8 is shown which is conventional in the art and has a plurality of conductor tracks 84. On one of the conductor tracks 84 and on the side facing away from the power electronics substrate 2, a sleeve 4 is arranged, wherein the foot section 40 of the sleeve is electrically conductively connected with the conductor track 84 by means of a solder connection.

[0046] In order to arrange the insertion section 520 of the contact pin 5 in the sleeve 4, more precisely in the inner recess 48 thereof, the circuit board 8 has a recess 88 for the passage of the insertion section 520. The recess 88 is arranged in alignment with the inner recess 48 and has a larger diameter than the inner recess.

[0047] After the assembly 1 has been manufactured, the intermediate section 580 which is constructed between the insertion section 520 and the compensation section 530 is arranged in the recess 88.

[0048] In this design, the insertion section 520 projects slightly from the sleeve 4 at the end section 44. In the region of the laser-welded connection, this end section 44 is loaded with the laser beam 6 and thus constitutes a sleeve connection section 46, which is in electrically conductive connection with the pin connection section 56 of the end section 520 of the contact pin 5.

[0049] The compensation section 530 is arranged between the power electronics substrate 2 and the circuit board 8 and thus enables a compensation of the distance variation between them not only in the context of the manufacturing method, but also in the context of the subsequent operation.

[0050] Figure 5 A third design of the power electronics assembly 1 according to the application is shown in a side view. The contact pin 5 here constitutes without a compensation section and with a rod shape and on both ends with an insertion section 520 each for arrangement in a sleeve 4 each.

[0051] Furthermore, two substrates 8, 9 are shown, which each have a sleeve 4. The lower substrate here is a connection device 9 based on a film, which is common in the art and which is composed of two conductive films 94, 96 and an electrically insulating film 90 arranged between them, wherein at least one of the conductive films constitutes a conductor track 94 each. The sleeve 4 is in turn arranged on this one conductor track 94 of the connection device 9 by means of a solder connection, without loss of generality.

[0052] In this sleeve 4, the first insertion section 520 of the contact pin 5 is arranged and is in electrically conductive connection with this first insertion section by means of a laser-welded connection 60.

[0053] This laser-welded connection 60 thus connects the sleeve connection section 46, which here is part of the central section 42 of the sleeve 4, with the pin connection section 56 of the insertion section 520 of the contact pin 5.

[0054] The upper second substrate 8, the sleeve 4 and the insertion section of the contact pin 5 arranged there, here the second insertion section 520, are constituted identically as already described with reference to Figure 4 .

[0055] Figure 6 A modification of the third design is shown in a fragment. Here, the sleeve 4 is closed on its end section 44 and thus constitutes a cup. The advantage of this is that, if there are multiple contact pins, the circuit board can be placed onto the contact pins in the manufacturing method and the respective welded connection 60 can then be constructed.

[0056] Figure 7 A fourth design according to the application is shown in a side view. Figure 1An improved version of the sleeve 4 has a linear expansion section 422 in the region of the central section 42. This linear expansion section is arranged between the foot section 40 of the sleeve and the sleeve connection section 46 thereof. Thus, the force introduced into the sleeve by means of the laser-welded connection between the sleeve connection section 46 and the pin connection section is decoupled to some extent from the connection of the foot section 40 to the base plate.

[0057] In this design, the linear expansion section 422 is formed by a plurality of s-shaped slits introduced by means of laser cutting.

Claims

1. Power electronics assembly (1) having a first substrate (8), a second substrate (2, 9), a first bushing (4) and a contact pin (5), wherein, The first sleeve (4) is closed on its end section (44), wherein the first sleeve (4) is arranged on a conductor track (84) on a side of the first base plate (8) facing away from the second base plate (2, 9) and a foot section (40) of the first sleeve (4) is connected to the conductor track (84) in a material-locked and electrically conductive manner, wherein the contact pin (5) is arranged in an insertion section (520) in an inner void (48) of the first sleeve (4), wherein the first base plate (8) has a void (88) which is aligned with the inner void (48) of the first sleeve (4), wherein the contact pin (5) has an intermediate section (580) which is arranged in the void (88) of the first base plate (8), wherein the contact pin (5) has a compensation section (530) which is coupled to the intermediate section (580), and wherein a material-locked and electrically conductive solder connection (60) by means of a laser soldering (6) is formed between a pin connection section (56) of the insertion section (520) of the contact pin (5) and an associated sleeve connection section (46) of the first sleeve (4), wherein the contact pin (5) has a connection section (540) which is coupled to the compensation section (530) and which is connected to a conductor track (22, 94) of the second base plate (2, 9) in a material-locked manner, or a further insertion section (520) of the contact pin (5) which is coupled to the compensation section (530) is arranged in a second sleeve (4) on a conductor track (22, 94) of the second base plate (2, 9) and is electrically conductively connected.

2. The power electronics assembly according to claim 1, wherein the first base plate (8) and / or the second base plate (2, 9) is / are selected from the group consisting of: a power electronics base plate (2); a power electronics connection device (9); a circuit board (8).

3. The power electronics assembly according to claim 1 or 2, wherein the material-locked connection between the conductor track (84) of the first base plate (8) and the foot section (40) of the first sleeve (4) and / or the material-locked connection between the conductor track (24, 94) of the second base plate (2, 9) and the foot section (40) of the second sleeve (4) is / are selected from the group consisting of: a sintered connection; a soldered connection (7); a glued connection; a welded connection.

4. The power electronics assembly according to claim 3, wherein the sintered connection is a pressurized sintered connection.

5. The power electronics assembly according to claim 3, wherein the welded connection is a laser welded connection.

6. The power electronics assembly according to claim 1 or 2, wherein the contact pin (5) has a rounded or polygonal cross section.

7. The power electronics assembly according to claim 1 or 2, wherein the contact pin (5) has a rounded or polygonal cross section in the region of the insertion section (520) and / or the further insertion section (520).

8. The power electronics assembly according to claim 1 or 2, wherein the contact pin (5) has a rectangular cross section.

9. The power electronics assembly according to claim 1 or 2, wherein the contact pin (5) has a square cross section.

10. The power electronics assembly according to claim 1 or 2, wherein the first sleeve (4) has a conically shaped opening on its foot section (40) and / or the second sleeve (4) has a conically shaped opening on both its foot section (40) and its end section (44).

11. The power electronics assembly according to claim 1 or 2, wherein the first sleeve (4) and / or the second sleeve (4) have a wire expansion section (422).

12. The power electronics assembly according to claim 11, wherein the wire expansion section is arranged between the sleeve connection section (46) and the foot section (40).

13. The power electronics assembly according to claim 1 or 2, wherein the void (88) of the first base plate (8) has the same or a larger diameter compared to the inner void (48) of the first sleeve (4).

14. The power electronics assembly according to claim 1 or 2, wherein the inner void (48) of the first sleeve (4) has an inner contour which is roundly or polygonally configured.

15. The power electronics assembly according to claim 1 or 2, wherein the inner void (48) of the first sleeve (4) has an inner contour which is rectangularly configured.

16. The power electronics assembly according to claim 1 or 2, wherein the inner void (48) of the first sleeve (4) has an inner contour which is squarely configured.

17. Method for manufacturing a power electronics assembly (1) according to any one of claims 1 to 16, the method having the following steps: a) materially lockingly connecting a foot section (40) of a first sleeve (4) with an associated conductor track (84) of a first base plate (8); b) arranging an insertion section (520) of a contact pin (5) in the first sleeve (4), wherein an intermediate section (580) of the contact pin (5) is arranged in a void (88) of the first base plate (8); c) establishing a welded connection (60) between a sleeve connection section (46) of the first sleeve (4) and a pin connection section (56) of the contact pin (5) by loading the sleeve connection section (46) with a laser beam (6); d) materially lockingly connecting a connection section (540) of the contact pin (5) with a conductor track (22, 94) of the second base plate (2, 9), or arranging a further insertion section (520) of the contact pin (5) in a second sleeve (4) on a conductor track (22, 94) of the second base plate (2, 9) and electrically conductively connecting.

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