Mounting device and method for producing an electrical contact

Abstract

The invention relates to an assembly device for producing an electrical contact (9) between an electronic component (3) and a printed circuit board (1), wherein the electrical contact (9) has at least one contact pin (11) formed on the electronic component (3) which can be pressed into a corresponding through-hole (13) of the printed circuit board (1) during a joining process. The assembly device has a stroke-adjustable press tool (25) on which the printed circuit board (1) is held for carrying out the joining process. The press tool (25) has a stroke-adjustable in the direction of the electronic component (3) during a joining stroke in order to press the contact pin (11) formed on the electronic component (3) into the printed circuit board through-hole (13) in press-fit contact. According to the invention, the printed circuit board (1) is held in a floating position in the press tool (25) during the joining stroke in a transverse plane (xz) transverse to the joining stroke.

Description

[0001] The invention relates to a mounting device and a method for producing an electrical contact according to the preamble of claim 1 and according to the preamble of claim 10.

[0002] The drive unit of an electrically powered vehicle has a pulse-controlled inverter, which, among other components, is equipped with a control board and power modules connected to a cooler. During assembly of the pulse-controlled inverter, the power modules are first soldered to the cooler using a soldering process. This is followed by a joining process in which the contact pins of the power modules are pressed into corresponding vias on the control board. To perform the press-fit contacting, a pre-assembly unit, which includes the cooler with the power modules soldered to it, is inserted into a stationary lower tool of a press, while the control board is held in an adjustable-stroke upper tool of the press.In a joining stroke, the upper tool is moved towards the lower tool in order to insert the contact pins of the power modules into the corresponding vias of the control board and to press them into place.

[0003] One problem with the process sequence outlined above is that the soldering process is associated with significant tolerance inaccuracies in the positioning of the power modules on the cooler. This can result in a tolerance position of the power modules connected to the cooler in which the contact pins of the power modules are out of alignment with the corresponding vias on the control board during the joining process. In this case, the contact pins may no longer be pressed into the corresponding vias on the control board without creating interference contours during the joining process.

[0004] DE 10 2009 054 440 A1 discloses a device for electrical connection comprising a first connector part and a second connector part. These are each arranged in a housing, each with an externally accessible contact area. The first connector part is firmly connected to a first circuit board, and the second connector part is firmly connected to a second circuit board. The first circuit board and the second circuit board are each arranged in the housing and are movable relative to the housing. DE 20 2016 101 974 U1 discloses an electrical interlinking module for a pneumatic valve system. This module has a square housing, which has a connection opening on one side of the housing for an electrical functional module separate from the interlinking module, and a plurality of interlinking contacts. These contacts are designed to interlink the interlinking module with at least one further interlinking module.From US 9 877 404 B1 an adapter device with socket contacts is known which are held in openings by holding structures.

[0005] The object of the invention is to provide an assembly device and a method with the aid of which the production of an electrical contact can be carried out in a simple, process-reliable and interference-free manner compared to the prior art.

[0006] The object is achieved by the features of claim 1 or 10. Preferred developments of the invention are disclosed in the subclaims.

[0007] The invention relates to an assembly device for establishing electrical contact between an electronic component (i.e., at least one power module of a pulse-controlled inverter) and a printed circuit board (i.e., a control board of the pulse-controlled inverter). The electrical contact comprises at least one contact pin formed on the electronic component. This contact pin is pressed into a corresponding through-hole in the printed circuit board during a joining process. To carry out the joining process, the assembly device comprises a stroke-adjustable press tool, on which the printed circuit board is held. The press tool is stroke-adjusted in a joining stroke toward the electronic component in order to press the contact pin formed on the electronic component into the printed circuit board through-hole in a press-fit contact.According to the characterizing part of claim 1, the circuit board is held in a floating position in the press tool during the joining stroke in a transverse direction perpendicular to the joining stroke. This ensures that, as the contact pin is threaded into the circuit board via in the transverse plane, the circuit board is aligned with respect to the electronic component. The floating position of the circuit board largely prevents deformation or forced positioning of the contact pins during the joining process due to compensating movements of the circuit board, thus enabling interference-free electrical contact.

[0008] In a technical implementation, the PCB alignment can be divided into a fine alignment and a final alignment. To support the fine alignment, the electronic component (i.e., the at least one power module) has at least one, in particular two, alignment pins. The alignment pin protrudes beyond the contact pin in the joining direction. Therefore, during the joining stroke, the leading alignment pin is first threaded into a corresponding PCB alignment opening. The final alignment takes place during the further course of the joining stroke, during which the contact pin is threaded into the PCB via without any interference contours.

[0009] To assist with circuit board alignment, the alignment and / or contact pins have, for example, a conically tapered tip, which can preferably be shaped like a truncated pyramid. This simplifies the threading process. Furthermore, the alignment and contact pins can be designed as identical parts for manufacturing reasons and therefore have identical press-fit contours. The identical parts are simply positioned at different heights on the electronic component. In this case, the circuit board alignment opening can be larger than the circuit board via, which simplifies the threading process of the alignment pin. Designing the contact and alignment pins as identical parts results in cost advantages. However, the invention is not limited to this embodiment. Rather, the alignment pins can also be designed more rigidly than the contact pins, for example.

[0010] As the joining stroke continues, the leading alignment pin with its press-fit contour is moved through the circuit board alignment opening. When the press tool reaches the end position of the joining stroke, the leading alignment pin with its press-fit contour emerges from the circuit board alignment opening on the circuit board side facing away from the electronic component. At the same time, the lagging contact pin with its press-fit contour is pressed into the circuit board via. The leading of the alignment pin is preferably designed such that the alignment pin does not influence the resulting circuit board position. Against this background, according to the invention, the leading of the alignment pin can be designed such that the alignment pin emerges from the side facing away from the electronic component and has lost its guiding properties when the contact pin is pressed into the via.

[0011] The printed circuit board alignment described above can be preceded by rough tool positioning in the process. For this purpose, a locking mechanism is assigned to the press tool. When the locking mechanism is released, the press tool is floatingly mounted with play in a transverse plane transverse to the joining stroke. When the locking mechanism is locked, the floating mount is eliminated. Accordingly, the press tool is no longer subject to transverse play in the transverse plane, but rather is fixed in position. The press tool has at least one positioning ram that is adjustable in the joining direction and can be inserted into a corresponding positioning hole in the electronic component. To carry out the rough tool alignment, the positioning ram is moved to its lower end position. In the lower end position, the positioning ram is retracted into the positioning hole of the electronic component, i.e. it is in mating engagement with the positioning hole.In this case, the floating tool support is eliminated. This means that the press tool is aligned and fixed in position with respect to the electronic component. After the rough tool positioning has been completed, the locking mechanism is locked, so that the press tool remains fixed in position in the transverse plane and aligned with respect to the electronic component throughout the rest of the process. In an alternative design variant, the rough tool positioning can be performed not with the positioning ram, but using camera alignment.

[0012] It is preferred if, during rough tool positioning, the positioning plunger serves a dual function, not only engaging the positioning hole of the electronic component, but also engaging a PCB fitting opening. This eliminates the floating mounting of the PCB. This means that the PCB is aligned and fixed in position with respect to the press tool.

[0013] To start the PCB fine alignment, which takes place after the rough tool positioning, the positioning plunger is moved out of engagement with the PCB registration opening. This ensures a floating PCB support in the press tool during the joining process, which is necessary for aligning the PCB in the transverse plane with respect to the electronic component.

[0014] Embodiments of the invention are described below with reference to the attached figures.

[0015] They show: Fig. 1 to 15 different views illustrating the structure and functioning of the mounting device according to the invention.

[0016] In the Fig. 1, an assembled pulse inverter 6 is shown to the extent necessary for understanding the invention. Accordingly, the pulse inverter 6 comprises a control board 1, three power modules, of which Fig. 1 only one power module 3 is shown, as well as a cooler 5. The power module 3 is soldered to the top side of the cooler 5 through which coolant flows. In addition, the power module 3 is connected to the control board 1 via an electrical press-fit contact 9. The press-fit contact 9 consists of contact pins 11 formed on the power module 3, which are pressed with their press-fit contours 17 into corresponding vias 13 of the control board 1. In addition to the contact pins 17, two alignment pins 19 are also formed on the power module 3. The alignment pins 19 and the contact pins 17 are designed as identical parts that are positioned at different heights in the pre-assembly unit VM.

[0017] As from the Fig. 1, the contact pins 11 extend through a bowl-shaped plastic carrier 4, which is arranged on the cooler 3 and encloses the power module 3. The alignment pins 19 are located on the plastic carrier 4, which, together with the contact pins 11, are held by a further carrier 2 ( Fig. 1) protrude outwards. The contact pins 11 and the alignment pins 19 are positioned according to the Fig. 1 each with a tapered tip 15 (for example in the form of a truncated pyramid) and with the cross-sectionally expanded press-fit contour 17. In contrast to the contact pins 11, the alignment pins 19 protrude in the Fig. 1 with hole clearance through corresponding control board alignment openings 21, whereby their press-fit contours 17 are located outside the control board 1.

[0018] The following is based on the Fig. 2 to 9 a process for producing the Fig. 1. In the method, a pulse inverter 6 shown in the Fig. 2, in which the power module 3 is soldered to the cooler 5 via a solder joint (not shown). The pre-assembly unit VM is in the Fig. 2 into a stationary lower tool 23 (only in the Fig. 2) of a press, while the control board 1 is held by a stroke-adjustable upper tool 25 of the press. In the Fig. 1, the stroke-adjustable upper tool 25 is provided with a locking mechanism 27 (only in the Fig. 4). When the locking mechanism 27 is released, the upper tool 25 is mounted in a floating manner in a transverse plane xz transverse to a joining stroke of the upper tool 25 with a degree of play. In contrast, when the locking mechanism 27 is locked, the floating bearing is removed, so that the upper tool 25 is fixed in a defined transverse position in the transverse plane xz.

[0019] The upper tool 25 further comprises two positioning plungers 29, of which the one in the Fig. 2 left positioning plungers 29 can be inserted precisely into a positioning hole 31 of the plastic carrier 4 of the pre-assembly unit VM, while the Fig. 2 right-hand positioning plungers 29 can be inserted into a positioning slot 33 of the plastic carrier 4 of the pre-assembly unit VM, which slot is elongated in a transverse direction z. Each of the positioning plungers 29 is guided in a fitting engagement through a control board fitting opening 35. Furthermore, each of the positioning plungers 29 is formed with a large-diameter section 37 at the plunger base and with a small-diameter section 39 at the plunger tip. The large-diameter section 37 of the positioning plunger 29 can be guided through the control board fitting opening 35 with minimal clearance, whereby the control board 1 can be aligned with respect to the upper tool 25. The small-diameter section of the positioning plunger 39 can be inserted into the positioning bore 31 or into the positioning slot 33 with little clearance, whereby the upper tool 25 can be aligned with respect to the pre-assembly unit VM.The width of the positioning slot 33 measured in the depth direction x corresponds approximately to the diameter of the small-diameter section 39 of the right-hand positioning plunger 29. Furthermore, the control plate 1 is mounted in a floating manner with a play in the transverse plane xz, provided that the positioning plungers 29 are retracted upwards into the upper tool 25 and their large-diameter sections 37 are out of engagement with the control plate fitting openings 35.

[0020] In an initial situation ( Fig. 3) the upper tool is still at its top dead center, while the two positioning rams 29 are moved downwards out of the upper tool 25. As a result, the large-diameter section 37 of the respective positioning ram 29 is located in the associated control board fitting opening 35, so that the floating mounting of the control board 1 in the upper tool 25 is canceled. The control board 1 is therefore aligned with respect to the upper tool 25 and fixed in position. The two process rams 29 are moved further downwards to a lower ram end position ( Fig. 4) to perform rough tool positioning. In the ram end position, the two positioning rams 29 are retracted into the positioning bore 31 and the elongated positioning hole 33 of the pre-assembly unit VM. This also eliminates the floating upper tool bearing. This means that the upper tool 25 is aligned with respect to the pre-assembly unit VM and is fixed in position.

[0021] As soon as both the upper tool 25 with respect to the pre-assembly unit VM and the control board 1 with respect to the upper tool 25 are fixed in position (the position fixation is marked by a cross in the figures), the Fig. 5 the joining stroke. During the joining stroke, the upper tool 25 is moved downwards from its top dead center towards the stationary lower tool 23. In this case, the leading alignment pins 19 are first inserted with their tips 15 and with sufficient hole clearance into the corresponding control board alignment openings 21, as shown in the Fig. 5. At the same time, during the further course of the joining stroke ( Fig. 6) the two positioning plungers 29 are retracted into the upper tool 25 in a reversing movement. The positioning plungers 29 therefore come out of engagement with the positioning bore 31 and the positioning slot 33, as well as with the two control board fitting openings 35. This releases the floating bearing of the control board 1 in the upper tool 25, while the locking mechanism 27 continues to lock the floating bearing of the upper tool 25.

[0022] In the further joining stroke process ( Fig. 7) starts a fine alignment of the floating control board 1. Here, the leading alignment pins 19 with their press-fit contours 17 are guided in a tight fit through the control board alignment openings 21, whereby the floating control board 1 is aligned with the alignment pins 19. Upon reaching a joining stroke end position of the upper tool 25 ( Fig. 8 and Fig. 9), the leading alignment pins 19 with their press-fit contours 17 emerge from the respective alignment openings 21 on the control board side facing away from the pre-assembly unit VM. At the same time, a final alignment takes place, in which the trailing contact pins 11 with their press-fit contours 17 thread into the control board vias 13 and are pressed into them. The lead of the two alignment pins 19 is designed such that the alignment pins 19 emerge from the control board side facing away from the pre-assembly unit VM and have lost their guiding properties when the contact pins 11 are pressed into the control board vias 13. This ensures that the alignment pins 19 do not influence the control board position that is established by mediation.

[0023] After completion of the pressing process ( Fig. 9) the upper tool 25 is moved in a reversing movement towards its upper dead center ( Fig. 2) and the assembled pulse inverter 6 is removed from the press.

[0024] In the Fig. 10 to 15, an assembly device or press according to a second embodiment is shown. Its structure and operation are largely identical to the structure and operation of the Fig. 2 to 9. Therefore, reference is made to the previous description.

[0025] In the Fig. Figure 10 shows the press in the open state with the pre-assembly unit VM inserted onto the lower tool 23. The upper tool 25 is extended upwards by a superstructure 41. Furthermore, each of the two positioning rams 29 is connected by its ram base to a ram plate 43. Spring elements 45 are supported between the ram plate 43 and the superstructure 41 of the upper tool 25. These pre-tension the two positioning rams 29 into their lower end position. The ram plate 43 has vertical movement stops 47 that project downwards beyond the upper tool 25 in the joining stroke direction and interact with stop surfaces 49 of the PWR carrier 2.

[0026] To start a joining stroke ( Fig. 11), the upper tool 25 is stroke-adjusted toward the lower tool 23. As a result, the positioning plungers 29, with their small-diameter sections 39, come into fitting engagement with the positioning bore 31 and with the positioning slot 33. At the same time, the large-diameter section 37 of the respective positioning plunger 29 is in fitting engagement with the control board fitting opening 35, so that the floating bearing of the control board 1 with respect to the upper tool 25 is eliminated.

[0027] The stroke movement of the upper tool 25 and the positioning ram 29 is coupled until the two movement stops 47 of the spring-loaded ram plate 43 come into contact with the stop surfaces 49 of the PWR carrier 2 ( Fig. 12 and Fig. 13). In the further course of the process ( Fig. 14), the upper tool 25 (now decoupled from the ram plate 43) continues its downward stroke movement, so that the large-diameter sections 39 of the positioning rams 29 come out of engagement with the control board fitting openings 35. This releases the floating bearing of the control board 1 with respect to the upper tool 25. At the same time, a fine alignment of the control board 1 takes place by the leading alignment pins 19 threading into the control board alignment openings 21. Upon reaching the lower joining stroke end position ( Fig. 15) of the upper tool 25, a final alignment takes place in which the trailing contact pins 11 with their press-fit contours 17 are threaded into the control board vias 13 and pressed into them. List of reference symbols 1 control board or control board 2 carriers 3 Power module 4 plastic supports 5 coolers 6 pulse inverters 7 Solder connection 9 Pressfit contacting 11 Contact pin 13 Through-hole plating 15 lace 17 Pressfit contour 19 Alignment pin 21 PCB alignment hole 23 Lower tool 25 upper tool 27 Locking mechanism 29 Positioning plunger 31 Positioning hole 33 Positioning slot 35 PCB fitting opening 37 diameter section 39 small diameter section 41 Superstructure 43 Tappet plate 45 spring element 47 Movement stop 49 Stop surface xz transverse plane VM pre-assembly unit QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2009 054 440 A1

[0004] DE 20 2016 101 974 U1

[0004] US 9 877 404 B1

[0004]

Claims

[1] Assembly device for producing an electrical contact (9) between an electronic component (3) and a printed circuit board (1), wherein the electrical contact (9) has at least one contact pin (11) formed on the electronic component (3) which can be pressed into a corresponding through-hole (13) of the printed circuit board (1) in a joining process, wherein the assembly device for carrying out the joining process has a stroke-adjustable press tool (25) on which the printed circuit board (1) is held, and wherein the press tool (25) is stroke-adjustable in a joining stroke in the direction of the electronic component (3) in order to press the contact pin (11) formed on the electronic component (3) into the printed circuit board through-hole (13) in press-fit contact, characterized bythat the printed circuit board (1) is held in a floating bearing in the press tool (25) during the joining stroke in a transverse plane (xz) transverse to the joining stroke, so that in particular by threading the contact pin (11) into the printed circuit board through-hole (13) in the transverse plane (xz) a printed circuit board alignment with respect to the electronic component (3) takes place in order to ensure a reliable joining process. [2] Mounting device according to claim 1, characterized bythat the circuit board alignment is divided into a fine alignment and a final alignment, and that to support the fine alignment the electronic component (3) has at least one alignment pin (19) which, viewed in the joining direction, projects beyond the contact pin (11) with a projection, so that in the joining stroke the leading alignment pin (19) initially threads into a corresponding circuit board alignment opening (21), and that in particular in the further course of the joining stroke the final alignment takes place, in which the contact pin (11) threads into the circuit board via (13). [3] Mounting device according to claim 1 or 2, characterized byin that, to support the circuit board alignment, the alignment and / or contact pins (11, 19) have a tapered tip (15), approximately in the shape of a truncated pyramid, in order to simplify the threading process, and / or in that the alignment and contact pins (11, 19) are designed as identical parts which are positioned at different heights on the electronic component (3), and / or in that the circuit board alignment opening (21) is larger than the circuit board via (13) in order to simplify the threading process of the alignment pin (19). [4] Mounting device according to claim 2 or 3, characterized bythat in the further course of the joining stroke, in particular when the press tool (25) reaches a joining stroke end position, the leading alignment pin (19) emerges from the alignment opening (21) with its press-fit contour (17) on the circuit board side facing away from the electronic component (3), while at the same time the trailing contact pin (11) is pressed into the circuit board through-hole (13) with its press-fit contour (17), and that in particular the lead of the alignment pin (19) is designed such that the alignment pin (19) emerges from the circuit board side facing away from the pre-assembly unit (VM) and has lost its guiding property when the contact pin (11) is pressed into the circuit board through-hole (13). [5] Mounting device according to one of the preceding claims, characterized bythat a locking mechanism (27) is assigned to the press tool (25), and that when the locking mechanism (27) is released, the press tool (25) is floatingly mounted in a transverse plane (xz) transverse to the joining stroke with play, and that when the locking mechanism (27) is locked, the floating mounting is canceled, so that the press tool (25) is fixed in position in the transverse plane (xz), and that in particular the press tool (25) has at least one positioning ram (29) which is adjustable in the joining direction and which can be moved into a positioning bore (31, 33) assigned to the electronic component (3). [6] Mounting device according to claim 5, characterized bythat the circuit board alignment is preceded by a rough tool positioning process, and that in particular for carrying out the rough tool positioning the positioning plunger (29) is adjusted to its end position in which it is in fitting engagement with the positioning bore (31, 33) of the electronic component (3), whereby the floating tool bearing is canceled and the press tool (25) is aligned and fixed in position with respect to the electronic component (3), or that the rough tool positioning is not carried out with the positioning plunger (29), but by means of camera alignment. [7] Mounting device according to claim 6, characterized by that after the rough positioning of the tool has been completed, the locking mechanism (27) is locked so that the press tool (25) remains fixed in position in the transverse plane (xz) and aligned with respect to the electronic component (3) during the further course of the process. [8] Mounting device according to claim 6 or 7, characterized by that during the rough positioning of the tool, the positioning plunger (29) is not only in fitting engagement with the positioning bore (31, 33) of the electronic component (3), but is additionally also guided in fitting engagement through a circuit board fitting opening (35), whereby the floating mounting of the circuit board (1) is canceled and the circuit board (1) is aligned and fixed in position with respect to the press tool (25). [9] Mounting device according to claim 8, characterized by that to start the fine alignment of the printed circuit board, the positioning plunger (29) can be brought out of engagement with the printed circuit board fitting opening (35) in order to ensure the floating printed circuit board mounting in the press tool (25), which is required for the alignment of the printed circuit board (1) in the transverse plane (xz) with respect to the electronic component (3). [10] A method for producing an electrical contact (9) between an electronic component (3) and a printed circuit board (1), in particular by means of a mounting device according to one of the preceding claims, wherein the electrical contact (9) has at least one contact pin (11) formed on the electronic component (3), which is pressed into a corresponding through-hole (13) of the printed circuit board (1) in a joining process, wherein the mounting device for carrying out the joining process has a stroke-adjustable press tool (25) on which the printed circuit board (1) is held, and wherein the press tool (25) is stroke-adjusted in a joining stroke in the direction of the electronic component (3) in order to press the contact pin (11) formed on the electronic component (3) into the printed circuit board through-hole (13) in press-fit contact, characterized bythat the printed circuit board (1) is held in a floating position in the press tool (25) during the joining stroke in a transverse plane (xz) transverse to the joining stroke, so that in particular by threading the contact pin (11) into the printed circuit board through-hole (13) in the transverse plane (xz) a printed circuit board alignment with respect to the electronic component (3) takes place in order to ensure a reliable joining process.

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