The present invention relates to an electrical and/or electronic component, to a contact system including the electrical and/or electronic component, and to a method for forming the contact system.
It is generally conventional to establish a mechanical and an electrical connection of metallic workpieces with the aid of welding, for example with the aid of laser welding. This is used, among other things, when welding together power contacts of power modules within electronic power circuits, for example. In the process, the two weld partners, for example the power contact and a connecting point of the electronic circuit, have to be brought together very closely, in general below a gap width of 100 μm. If gap distances are larger, metallic spatter may otherwise occur during laser welding, all the way to non-welded contacts. Additionally, poorly welded or non-welded contacts, in particular, are visually hardly discernible, and they may thus represent a source of defects for malfunctions. An ideal zero gap between the weld partners may be easily achieved from a technical perspective in that both weld partners are compressed with the aid of a tongs-like device, except for a gap-free site contact, under elastic and/or plastic deformation. In particular, in the case of very compact electronic circuits, a necessary space for such a device is not always present. Furthermore, such a device is often difficult to handle since an access has to occur from both sides of the weld partners. In addition, a counter support is generally required for the welding device, for which purpose a support surface has to be provided, for example on the carrier substrate of the electronic circuit.
It is an object of the present invention to provide weld contacts of electrical and/or electronic components within compact circuits to be as gap-free as possible.
This object may be achieved by an electrical and/or electronic component, by a contact system including the electrical and/or electronic component, and by a method for forming the contact system, in accordance with example embodiments of the present invention.
The present invention proceeds from an electrical and/or electronic component including at least one electrical outside terminal contact. In accordance with an example embodiment of the present invention, the outside terminal contact is designed as a terminal lug, which is attached at one side, for the electrical contacting with a contacting partner. The terminal lug includes a connecting side including a planar connecting surface for the electrical contacting. It therefore corresponds, in the mechanical model, to a bending beam which is clamped on one side. The terminal lug is preferably formed of a sheet metal material, in particular as a stamped metal sheet or laser metal sheet, for example made up of copper, and contacts an electrical functional area of the component. As an outside terminal contact contacted from the outside, it allows the electrical functional area to be integrated, for example, within an electronic circuit. The exposed end of the terminal lug includes a bending leg, which is bent out of the plane by a compensating angle toward the connecting side. The bending leg includes the connecting surface. The terminal lug is furthermore designed in such a flexible manner that, when a contacting partner, which is planar at least in this area, makes site contact with the free end of the bending leg with a force applied from the connecting side, a position orientation of the connecting surface is adaptable at least counter to the compensating angle until a gap-free contact is made between the connecting surface and the planar contacting partner. With respect to a weld contact to be formed, the terminal lug is thus advantageously previously prepared as an optimized welding partner. By orienting the bending leg, on the connecting side, counter to a force application acting from this side, for example with the aid of a welding mask resting at least indirectly thereon, an initial site contact of a planar contacting partner, for example a connecting clip, which is moved relatively from the connecting side toward the terminal lug, is made possible in the area of the free end of the terminal lug, i.e., the bending leg. In the process, first a gap may be formed during the initial site contact between the terminal lug and the contacting partner, which extends in a wedge-shaped manner to the initial site contact point. This gap may now be reduced to a gap-free contact in that a forced bending of the terminal lug is effectuated with the aid of a further force application, for example by a further relative movement of the described welding mask, preferably a rectilinear relative movement. Due to the continued bending of the terminal lug, the surface position of the connecting surface rotates counter to the compensating angle toward the plane of the contacting partner, all the way to the planar and thus gap-free contact. This then corresponds to an optimal welding position in which a gap-free weld contact is formable with the aid of a welding process. The provided compensating angle thus enables the reliable necessary position correction of the connecting surface and compensates for malpositions, for example due to assembly and/or manufacturing tolerances. Since only a one-sided force application from the connecting side is required, the formation of a weld contact within a very space-constrained electronic circuit is made possible without an otherwise required counter site.
The measures disclosed herein allow advantageous refinements of and improvements on the electronic assembly according to the present invention.
In one advantageous specific embodiment of the electrical and/or electronic component of the present invention, the compensating angle has a value in a range of 0.5° to 5°, preferably in a range of 0.5° to 1.5°. It has been shown that, in this range, many initial malpositions which are subject to tolerances may already be compensated for by the position correction of the connecting surface which is made possible, and the manufacturing times for forming a gap-free weld contact may be kept small due to the distances being kept short until the optimal weld position is reached. Reaching the optimal weld position preferably takes place by a fully elastic flexibility of the terminal lug, at least however, alternatively, preferably by a partially elastic flexibility of the terminal lug. In this way, it is also possible to keep the application forces for the position correction of the connecting surface small so that damage may be precluded during the formation of a weld contact.
In one advantageous refinement of the electrical and/or electronic component, the terminal lug includes a terminal leg. It opens, with its one end, via a bending area into the bending leg and, at its other end, then includes the one-sided attachment of the terminal lug within the electrical and/or electronic component. The terminal lug advantageously only includes one bending point, so that the preparation of the terminal lug may be implemented very cost-effectively for a weld contact to be optimally designed. In the process, the bend may preferably be introduced into an original terminal lug made up of a planar sheet material so that, in particular, a rectilinearly extending terminal leg remains. It is generally advantageous for a longitudinal extension of the terminal leg to be several times shorter than a longitudinal extension of the bending leg, in particular about 2 to 20 times shorter, and preferably 5 to 10 times shorter. In this way, a flexibility of the terminal lug increasingly results more or less solely from the bending leg. The bending point then approximately represents the function of a rigid swivel joint. Furthermore, the optimal welding position may be set more precisely.
In one preferred specific embodiment of the electrical and/or electronic component of the present invention, it includes a fixed housing, from which the terminal lug, which is attached at one side, protrudes. The housing is preferably made of a plastic material, in particular a mold material. In the process, the terminal lug, at its attached end, is, further preferably, surrounded or enclosed on all sides by the plastic material. With the aid of the housing, increased application forces acting on the terminal lug may then advantageously be absorbed without damage by the electrical and/or electronic component.
Further advantages arise in one specific embodiment of the electrical and/or electronic component of the present invention which includes, for example, an underside terminal and/or support side to a carrier substrate. The terminal lug is situated spaced apart toward the underside terminal and/or support side. In a top view onto the terminal or support side, the terminal lug, projecting laterally therefrom, is furthermore attached at one side within the electrical and/or electronic component. In the process, the bending leg points away from the terminal and/or support side. In this way, overall a free access to the terminal lugs is provided for a one-sided force application from the connecting side. Moreover, as a result of the spacing, an unimpaired bending of the terminal lug in the direction of the terminal or support side is made possible. A housed electrical and/or electronic component preferably includes an exit point of a terminal leg of the terminal lug out of the housing in a terminal plane parallel to the terminal or support side. Further preferably, the terminal leg is situated within this terminal plane up to the bending point, while the bending leg is bent, in particular, perpendicularly to a longitudinal extension of the terminal leg out of the terminal plane in the direction of the connecting side of the terminal lug.
The electrical and/or electronic component is, in general, preferably designed as a power module, in particular, in the form of a mold module. In the process, the terminal lug is designed as a power contact. The electrical and/or electronic component may overall also include two, three or even more such terminal lugs exclusively or in addition to at least one differently designed outside terminal contact.
The present invention also provides a contact system, including at least one electrical and/or electronic component in at least one of the above-described specific embodiments of the present invention, an, in particular, gap-free connecting contact being formed between the terminal lug in the area of the connecting surface and a planar contacting partner which, at least in the formed connecting area, is gap-free. Such a connecting contact represents a connection, for example to an electronic circuit, which is functionally reliable over the service life. The connecting contact is, in particular, designed as a weld contact in the process. During the use of a laser process, in particular, a laser weld contact is obtained.
In one preferred specific embodiment of the contact system of the present invention, it is designed as part of an electronic circuit on a carrier substrate. The contacting partner is, in particular, a connecting clip which connects the terminal lug and a terminal point of the electronic circuit to one another, bridging the same. The connecting clip is, for example, a stamped sheet metal part, in particular, made up of copper. In addition to planar surfaces in the connecting areas to the terminal lug or to the terminal point, the connecting clip may include one or multiple bend(s), for example to span an application-induced vertical offset between the terminal lug and the connecting point of the electronic circuit. The connecting clip may furthermore include recesses, in particular, in the form of longitudinal slots between the connecting points. In this way, the connecting clip is given sufficient mechanical elasticity to enable an alignment of the provided joining surfaces in the connecting areas by a bending and/or torsion up to a gap-free contact with the respective weld partner.
The electronic circuit is preferably designed as a B2 or B6 bridge, in particular, as a circuit part of an inverter.
The present invention also provides a method for forming a contact system according to at least one of the above-described specific embodiments. In accordance with an example embodiment of the present invention, the method includes the following method steps:
In one advantageous specific embodiment of the method of the present invention, the contacting partner is designed as a connecting clip, an end of the connecting clip which is spaced apart from the site contact being held in a stationary manner prior to or during method step b). This may take place, for example, with the aid of a holding tool, which receives and fixes the described end in a stationary manner. As an alternative, a stationary fixation takes place by an at least indirect integral or force-fit and/or form-locked connection to the carrier substrate. As a result of the one-sided fixation, the terminal lug and the connecting clip may align with one another, up to a gap-free contact in the connecting area, solely by the force application and bending.
In one advantageous refinement of the method of the present invention, a further connecting contact is formed between the connecting clip and a terminal point of an electronic circuit, in particular as a weld contact, between the end of the connecting clip held in a stationary manner and the connecting contact with the terminal lug to be formed or having been formed. The further connecting contact is preferably formed chronologically before, after or together with the connecting contact between the connecting clip and the terminal lug.
Further advantages, features and details of the present invention are derived from the following description of preferred exemplary embodiments and based on the figures.
In the figures, functionally equivalent components are each denoted by identical reference numerals.
For forming a contact system 100 including electrical and/or electronic component 10 including a connecting contact 40 to a contacting partner 20, a procedure is described hereafter with the aid of
In principle, after an initial site point E is present, a force is applied to initial system 100′ by a further, for example rectilinear, relative movement R of welding mask 20 in the direction of connecting side 16 of terminal lug 15. As a result of the acting push-down force F, terminal lug 15 yields elastically or at least partially elastically in the direction of carrier substrate 20 due to an at least proportionate rotary movement D, by which also a changed position orientation of connecting surface 16a occurs at least counter to compensating angle α of bending leg 15.2. Relative movement R of welding mask 80 is first maintained in a welding position in which connecting surface 16a of terminal lug 15 and support side 20a of contacting partner 20 rest planarly against one another. Thereupon, a weld contact 40 is formed as a connecting contact with the aid of a welding process, while maintaining the welding position. The welding process takes place, for example, with the aid of a laser 50, whose laser radiation L is directed at welding side 20b of contacting partner 20. Welding mask 80 is preferably configured in a tubular manner and, in particular, has a wall height by which metallic spatter during laser welding may be prevented from spreading outside welding mask 80.
Number | Date | Country | Kind |
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10 2019 211 077.0 | Jul 2019 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/070758 | 7/23/2020 | WO |