Insert for a plastic component and method for producing an electrical connection between an insert and a plastic component

Abstract

The invention relates to an insert (10) which is embedded in a plastic component (42) and is designed as a metallic or electronic component. The insert (10) is connected to the plastic component (42) in a floating bearing (40) via at least one flexible connection (18; 50, 52, 54, 56).

Description

Technical Field

[0001] The invention relates to an insert part which is embedded in a plastic material, wherein the insert part is designed as a metallic or electronic component. The invention also relates to a method for producing an electrical connection between an insert part and a plastic component. Background Art

[0002] DE 10 2018 208 491 A relates to a contact system for a modularly constructed battery. The contact system is provided for a modularly constructed battery, wherein the battery comprises a plurality of battery cells. The contact system comprises a carrier element made of a first plastic for arranging at least one functionally important component for operating the battery, and a plurality of conductive conductor tracks for connecting the battery cells. The carrier element is coated with the conductor tracks.

[0003] In the manufacture of batteries, for example, in addition to the contact systems mentioned, different materials and different processes are used. Due to the use of different materials, such as plastic and metal materials, different shrinkage values ​​and thermal expansions occur, which are different from the shrinkage values ​​and thermal expansions of, for example, soldering materials. This leads to different inherent stresses and length changes due to the different shrinkage values ​​and thermal expansions of the different materials used, so that, for example, the material composite produced before the start of shrinkage and before cooling may break. This leads to component failure in extreme cases. If, for example, a metallic insert or an electronic insert is used when the soldering material is in electrical contact with the insert within the framework of construction and connection technology, and if a soldering material is used when they are in contact, the already existing different material combinations add another material component. This means that due to the use of multiple materials, the life of the electrical contact part of the insert becomes critical. Summary of the invention

[0004] According to the invention, an insert is provided which is embedded in a plastic component, wherein the insert can be designed as a metallic or electronic component. The insert is connected to the plastic component by at least one flexible connection while being supported in a floating manner in the plastic component. The at least one flexible connection extending between the metallic or electronic insert and the plastic component can absorb forces and compensate for relative movements which occur, for example, when the plastic material shrinks or when the metal component expands thermally. By means of the solution provided according to the invention of at least one flexible connection between the insert and the plastic component receiving the insert, the length expansion which occurs due to the above-mentioned effects can be taken into account, so that the material composite produced can be maintained at one time and remains intact due to the relative movement within the composite. In addition, by means of the solution provided according to the invention, shorter cycle times can be achieved, because shrinkage processes or thermal expansion are now uncritical, and the newly produced material composite can be waited for during the cooling phase, because the relevant material is not damaged by the solution provided according to the invention. In a refinement of the solution provided according to the invention, the at least one flexible connection extending between the insert and the plastic component is designed as a plastic tab. Compared to metal materials, the plastic material itself is inherently endowed with greater flexibility.

[0005] Furthermore, according to the solution proposed according to the invention, at least one flexible connection between the insert and the plastic component that receives or surrounds the insert is designed to extend in a meandering or rectangular shape. Alternative design variants are, for example, semicircular or circular (radienform). By configuring at least one flexible connection in a meandering or rectangular shape, it is possible to compensate for relative movements of the relevant materials of the composite of materials having different materials due to shrinkage processes that cause length changes or temperature-induced expansion processes, and the connection produced once is not damaged. The meandering or rectangular shape of the at least one flexible connection provides a material surplus, which, if necessary, is used to compensate for changes in the distance between the insert and the plastic component for the increase in length in the composite of materials when the length changes, for example.

[0006] The electrical joint extends on at least one flexible connection, which is made of, for example, a soldering material, and is connected to a contact portion, for example, designed as a pad, on an insert. The contact portion can also be designed as a through hole (through hole), into which the soldering material flows, so as to make contact, and in addition, the contact portion can be a contact pin surrounded by the soldering material. When a metal insert is used, planar contact can be made directly on the metal. The insert can be, for example, an LED component group, a printed circuit board, a sensor, or can also be a plug or a single cell connector.

[0007] The materials used, plastics, soldering materials, inserts, in particular at the contact points, should have similar coefficients of thermal expansion in order to reduce stresses. In addition, the invention provides a method for producing an electrical connection, wherein the electrical connection between the insert and the plastic component is produced by carrying out at least the following method steps:

[0008] a) injecting a plastic component into a mold to form a carrier material;

[0009] b) embedding metallic or electronic inserts into carrier materials;

[0010] c) fixing the insert part with the plastic component according to method step a) and injection molding at least one flexible connection between the insert part and the plastic component; and

[0011] d) Contacting the insert part by applying soldering material to at least one flexible connection and at least one connection point on the insert part.

[0012] In a development of the method proposed according to the invention, the insert can be received in a recess, for example, shaped like a trough, in the plastic component by means of a floating mount. A floating mount is very advantageous for compensating for shrinkage effects and temperature-induced length changes, since inherent stresses in the material composite can be avoided.

[0013] In a variant of the sequence of the method steps, the insert part can be inserted into the mold directly before method step a) is carried out and mechanically fixed directly in the carrier metal during the injection of the plastic component.

[0014] In addition, the method proposed according to the present invention opens the following feasibility: the insert (which may be a metal or electronic insert) is fixed in the plastic material, so that, for example, when the insert is configured as a printed circuit board, the exposed fibers, in particular the exposed glass fibers, form a rough surface, which is conducive to improving the connection between the insert and the plastic material surrounding the insert. The web width of the flexible connection can be changed, so that it can be designed directly for the corresponding load situation. Compared with the smaller web width, the wider web width, for example, gives the flexible connection greater stability. In addition, the shape of the flexible connection can meet the corresponding application situation. The flexible connection does not have to be forced to directly abut on the insert, but can also directly generate length compensation in the molding die. This can be done for the following design: in the design, the printed conductor (soldering wire) is subjected to mechanical or thermal loads between the connection points of the insert, and the insert may be of electronic type or mechanical type.

[0015] The method proposed according to the invention is preferably carried out with its method steps a) to d) in an integrated metal-plastic injection molding process.

[0016] Advantages of the invention: By means of the solution proposed according to the invention, a flexible connection can be provided at least at one location between an insert (which can be a metallic insert or an electronic insert) and a plastic component. The forces acting on the electrical connection can be significantly reduced. By designing at least one connection between the insert and the plastic component as a plastic tab, for example, the electrical connection can be guided to the plastic tab and move with the at least one flexible connection during relative movement. By means of the solution proposed according to the invention, the generation of excessive inherent stresses in the material composite is avoided, which can occur, in particular, due to shrinkage effects of the plastic material and due to temperature-induced expansion in the event of temperature changes or temperature shocks.

[0017] By means of the solution proposed according to the invention, the electrical joint between the material composite or combination or insert and the plastic component which receives or surrounds the insert is designed to be significantly improved in terms of its robustness; in particular, the component composite has no pre-damage.

[0018] For the solution proposed according to the invention, in particular the process of integrated metal plastic injection molding (IMKS) can be used, wherein in a first step a plastic component is injected into a mold. This forms a carrier material, in which recesses are formed, into which a soldering material is injected as a second component in addition to the plastic component. This makes it possible to produce electrical components with conductor tracks. This process allows the insertion of electronic or metallic inserts, which can be electrically contacted directly via the soldering material.

[0019] As inserts, for example, LEDs, printed circuit boards, sensors, plugs, and single-cell connectors for battery technology are considered. These inserts are first mechanically fixed by means of plastic components. Then, the soldering material is introduced into the injection mold so as to electrically and directly contact the mechanical or electronic inserts. When contacting the inserts, flexible connections are preferred, thereby avoiding stresses in the component complex. For this purpose, the inserts are connected to each other by means of the mentioned flexible plastic tabs, wherein the flexible plastic tabs can be designed, for example, in a meandering shape, a rectangular shape, a semicircular shape, or a circular shape. Through these flexible plastic tabs, the soldering material is contacted at the corresponding contact points (pads) of the inserts, and the soldering material forms an electrical joint.

[0020] In terms of the application to batteries, the flexible connection of the insert, which may be metallic or electronic, is an advantage with regard to the breathing of the battery cell. The charging and discharging processes of the battery cell, however, cause the battery cell to expand and subsequently reduce in volume. Due to this volume change, mechanical stresses arise that must be absorbed. This task can be met by the flexible connection proposed according to the invention. This applies analogously to mechanical loads to which the battery may be exposed, such as vibrations or shocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is described in detail below with the aid of the accompanying drawings:

[0022] Figure 1 is a schematic diagram of a flexible plastic tab injection molded onto the edge of an insert; and

[0023] Figure 2 A plan view of a cuboid insert which is inserted into a recess or depression in a plastic component and is connected to the plastic component via a plurality of flexible connections. DETAILED DESCRIPTION

[0024] In the following description of embodiments of the invention, identical or similar elements are provided with the same reference numerals, wherein a repeated description of these elements is omitted in individual cases. The figures merely schematically illustrate the subject matter of the invention.

[0025] According to Figure 1 , the flexible connection which is injection-molded onto the insert can be seen in a three-dimensional view.

[0026] Figure 1 1 shows an insert 10 and a plastic tab 20 which is injection molded onto the insert from a plastic material and forms a flexible connection 18. The insert 10 is a metallic or electronic component, for example a printed circuit board, an LED, a sensor, a plug or also a cell connector in the battery field. The insert 10 is contacted at the edge 12 by the plastic tab 20 which forms the flexible connection 18. Preferably, the flexible connection 18 is injection molded onto the insert 10 in the design of the plastic tab 20. At least one contact point 14 is located on the top side of the insert 10, which contact point can be designed as a pad 16, for example.

[0027] Figure 1 1 shows that the plastic tab 20 forming the flexible connection 18 extends in a meandering shape 22 and comprises a projection 24 between a first straight section 26 and a further second straight section 28. By forming the plastic tab 20 in a meandering shape 22, the plastic tab 20 is able to compensate for length expansion or contraction effects, since, due to the meandering shape 22, the plastic tab 20 is inherently endowed with a high degree of elasticity and flexibility. Figure 1 In the illustration of FIG. 1 , the protrusion 24 is designed as a circular arc.

[0028] An electrical connection 30 extends on the upper side of the plastic web 20 and is made of a soldering material 32. The soldering material 32 also extends in a meandering shape 22 on the upper side of the plastic web 20, wherein the soldering material 32 makes electrical contact with the contact point 14 designed as a pad 16 on the upper side of the insert 10. The electrical connection 30 arranged on the upper side of the plastic web 20, like the plastic web 20 serving as a flexible connection 18, compensates or compensates for movements, so that even when the insert 10 is in contact with the electrical connection 14, the electrical connection 30 can be made. Figure 1 The plastic component 42 not shown in FIG. Figure 2 When relative movement occurs between the two components (view), the electrical joint 30 is also maintained.

[0029] according to Figure 1 The perspective view of FIG. 2 also shows that the solder material 32 has a curved or constricted extension 34 which runs in accordance with the meandering shape 22 of the plastic web 20 .

[0030] In accordance with Figure 1 In the illustration of , the boundary surface extending between the insert 10 and the plastic web 20 is indicated by the reference numeral 31. There, different materials abut one another, so that a good connection is provided here, which can be improved, for example, by exposed glass fibers.

[0031] Figure 2 1 shows a top view of an insert part 10 which is connected to a plastic component via a plurality of flexible connections 18 .

[0032] In accordance with Figure 2 In the illustration, the insert 10 can be a metallic or electronic component, which is embedded in a recess 44 designed as a pit in the plastic component 42. Alternatively, there is the possibility of constructing a recess in the plastic component 42, into which the insert 10 is placed. Preferably, the insert 10 is supported in the plastic component 42 by a floating support 40, which allows and also compensates for the relative movement between the insert 10 and the plastic component 42. In order to compensate for the length extension caused by temperature, or due to different shrinkage values ​​regarding the material of the insert 10 and the plastic material of the plastic component 42, the insert 10 is connected to the insert 10 by multiple flexible connections 50, 52, 54, 56. The electrical connection 30 extends on any one of the flexible connections 50, 52, 54 and 56, which connection is made of a soldering material 32 and is connected at one end to a contact point 14 on the top surface of the insert 10. As shown by Figure 2 It can be seen from the top view that according to Figure 2In a design variant of , a distance 60 is bridged by flexible connections 50, 52, 54 and 56, which extends between the boundary 48 of the trough-shaped recess 44 in the plastic component 42 and the edge 12 of the insert 10. Due to the flexibility of the floating support 40 of the insert 10 and the four flexible connections 50, 52, 54, 56, the insert 10 can perform relative movements relative to the plastic component 42 and can be compensated by the flexible connections 50, 52, 54, 56 shown.

[0033] If according to Figure 2 As can be seen from the diagram, in this design variation, the flexible connecting parts 50, 52, 54, 56 are designed to be rectangular shaped 58, and the flexible connecting part 18 is designed according to Figure 1 The projection 24 is rounded in the illustration. The projection 24 is used to compensate for changes in length that occur due to thermal or mechanical loads. Figure 2 In the diagram of FIG. 5 , the flexible connecting parts 50, 52, 54, 56 each have a rectangular shape 58 and are similar to Figure 1 The flexible connection 18 shown in perspective in FIG. 1 each has a first straight section 26 and a second straight section 28 .

[0034] Although according to Figure 2 In the illustration, flexible connections 50 , 52 , 54 , 56 extend between edge 12 and boundary 48 of plastic component 42 ; they can also extend rotated 90° between upper edge 12 of insert component 10 and boundary 48 of trough-shaped recess 44 of plastic component 42 .

[0035] replace Figure 2 While four flexible connections 50 , 52 , 54 , 56 are shown in FIG. 1 , a larger or smaller number of flexible connections 50 , 52 , 54 , 56 may also be provided.

[0036] Due to the different shrinkage values ​​compared to the soldering material and the different forces arising from the thermal expansion caused by temperature changes, which lead to different inherent stresses and length changes, it is possible to Figure 2 The flexible connections 50 , 52 , 54 and 56 shown in FIG. 1 are compensated for so that the electrical connection 30 is maintained in the event of relative movements.

[0037] By means of the flexible connections 50 , 52 , 54 and 56 shown, different forces associated with shrinkage values ​​and length changes during thermal expansion can be compensated, so that the contact point 14 , on which the solder material 32 of the electrical joint 30 is applied, is securely maintained and premature failure of the component connection is avoided.

[0038] In the solution proposed according to the present invention, integrated metal-plastic injection molding is preferably used as a manufacturing method. As a first step, a plastic component is injected into a mold for this purpose. The plastic component forms a carrier material, in which a concave or groove is formed, etc., and a soldering material 32 as a second component is injected there. Thus, an electrical component with a printed conductor can be produced. The components, such as electronic or metal, that form each insert 10 are embedded in the electrical component and can be directly contacted using a joining method. As inserts 10, for example, LEDs, printed circuit boards, sensors, plugs, and single-cell connectors are considered. These inserts 10 are first mechanically fixed by means of plastic material. Then the soldering material is injected into the injection mold, so that the inserts 10 can be directly contacted. When contacting the inserts 10, flexible connections 18 or 50, 52, 54 and 56 are used to cover them with soldering material 32, which forms an electrical joint 30, and the soldering material electrically contacts the contact locations 14 that are respectively configured as pads 16 on the top surface of the inserts 10. There is the possibility of arranging the insert part 10 in the region of the floating mount 40 and of using printed circuit boards as insert parts 10 which have exposed glass fibers at the edges so that the injection-molded plastic material has improved adhesion to rough surfaces.

[0039] The invention is not limited to the embodiments described herein and the aspects disclosed therein. Rather, many variations are possible within the scope of ordinary skill in the art within the scope given by the claims.

Claims

1. An insert (10) which is embedded in a plastic component (42), and the insert (10) is designed as a metallic or electronic component, characterized in that: The insert (10) is connected to the plastic component (42) in a floating support (40) via at least one flexible connection (18; 50, 52, 54, 56), wherein at least one flexible connection (18; 50, 52, 54, 56) extends in a meandering shape (22) or a rectangular shape (58), and wherein an electrical connection (30) extends over at least one flexible connection (18; 50, 52, 54, 56) and contacts a contact point (14) on the insert (10).

2. The insert (10) according to claim 1, characterized in that At least one flexible connection (18; 50, 52, 54, 56) is designed as a plastic web (20).

3. The insert (10) according to claim 1, characterized in that At least one flexible connection (18; 50, 52, 54, 56) spans a distance (60) between the insert (10) and the plastic component (42).

4. The insert (10) according to claim 1, characterized in that The insert (10) is an LED, a printed circuit board, a sensor, a plug or a single cell connector.

5. A method for producing an electrical joint (30) between an insert (10) and a plastic component (42), comprising at least the following method steps: a) injecting a plastic component into a mold to form a carrier material; b) embedding a metallic or electronic embedding part (10) into the carrier material; c) fixing the insert part (10) with the plastic component according to method step a) and injecting at least one flexible connection (50, 52, 54, 56) onto the insert part (10) and the plastic component (42); d) contacting the insert (10) by applying a soldering material (32) to at least one flexible connection (18; 50, 52, 54, 56) and to at least one contact point (14) on the insert (10), The insert part (10) is received in a recess (44) of the plastic component (42) by means of a floating bearing (40).

6. The method according to claim 5, characterized in that The insert (10) is fixed by the plastic material with the fibers exposed at its edges.

7. The method according to claim 6, characterized in that The insert (10) is fixed by the plastic material with exposed glass fibers at its edges.

8. The method according to claim 5, characterized in that The method steps a) to d) are carried out in an integrated metal-plastic injection molding process.

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