Electric circuit arrangement with protected electric component, and method for production

Abstract

The invention relates to an electric circuit arrangement (1) with at least one electric component (13) which is load-appropriately protected for subsequent processing, said electric circuit arrangement comprising a carrier layer (10) which has integrated conductor tracks (11) and has a surface (12) to which the at least one electric component (13) is fixed and is in contact with the conductor tracks (11), wherein on the surface (12) of the carrier layer (10), adjacent to the at least one component (13), at least one protective element (20) for protecting the at least one electric component (13) is provided and fixed to the carrier layer (10), the at least one protective body (20) being designed to absorb and / or deflect a force acting on the at least one component (13) as a result of a deformation of the carrier layer (10) and / or to absorb and / or deflect a force acting on the at least one component (13) by a material moving parallel to the surface.

Description

[0001] Electrical circuit arrangement with protected electrical component and method for manufacturing

[0002] Description:

[0003] The invention relates to an electrical circuit arrangement with at least one electrical component protected in a load-appropriate manner for subsequent processing, as well as to a method for producing such a circuit arrangement or to a method for producing an assembly with such a circuit arrangement.

[0004] In the prior art, electrical circuits—i.e., carriers equipped with electrical components, which can be rigid or flexible printed circuit boards or even conductor foils—are often further processed, which can result in damage to the electrical circuits during processing. For example, circuits with a flexible carrier layer are often reshaped as intended, so that the circuit or its carrier layer is given a new shape. However, this can result in the components arranged on the carrier layer becoming detached, losing their electrical contact with the conductor tracks integrated into the carrier layer, or even becoming damaged.

[0005] In addition, many circuits require a surface of the carrier layer to be coated after components have been populated, for example, using an injection molding process. This process involves a material flowing along the surface, which can drag the components along and thus detach them from their fixation and electrical contact with the carrier layer or the integrated conductor tracks. Furthermore, such a material is often very hot during processing, so the components are subjected to thermal stress and can even be damaged, even if the components do not detach from their fixation on the carrier layer.

[0006] Even if the circuits are deformed or overmolded as intended during further processing, improper handling can still cause damage to the circuit.

[0007] In order to overcome these problems, the state of the art has so far provided for adapting the processing parameters during further processing, ie during forming of the carrier layer or overmolding, to the resulting load limits, which, however, leads to corresponding restrictions for further processing.

[0008] Furthermore, components with a small frontal area or small dimensions are sometimes selected, and the components are arranged on the carrier layer in such a way that they are subjected to as little stress as possible during further processing. However, this leads to significant design limitations when creating a circuit layout. The invention is therefore based on the object of overcoming the aforementioned disadvantages and providing an electrical circuit arrangement whose electrical components are protected from forces or stresses occurring during further processing of the circuit arrangement, so that damage to the components or the circuit arrangement does not occur during further processing.

[0009] This problem is solved by the combination of features according to patent claim 1 and patent claim 13.

[0010] According to the invention, an electrical circuit arrangement is therefore proposed with at least one electrical component that is protected in a load-appropriate manner for subsequent processing. The at least one electrical component or components can be a wide variety of active or passive electrical components, such as resistors, ICs, LEDs, MOSFETs and others. The circuit arrangement has a carrier layer with integrated conductor tracks, in particular printed ones or those produced by etching technology, wherein the carrier layer has a surface to which the at least one electrical component is fixed and contacted with the conductor tracks. To protect the at least one electrical component, at least one protective body is provided on the surface of the carrier layer adjacent to the at least one component and is fixed to the carrier layer.The at least one protective body is designed to absorb and / or redirect a force acting on the at least one component or components in question as a result of a deformation of the carrier layer. If the electrical circuit arrangement or its carrier layer is, for example, three-dimensionally deformed to produce an assembly, a force acting orthogonally to the surface can occur on the at least one component, as a result of which force the electrical component can become detached from the carrier layer or conductor tracks on one side. The protective body can be designed to stiffen the carrier layer in the region of the at least one component, so that the force is absorbed by the protective body and the at least one component does not become detached from the surface. Additionally or alternatively, the protective body can be designed to absorb and / or redirect a force acting on the at least one component or components in question as a result of a material moving parallel to the surface.the respective component and accordingly in particular to absorb and / or redirect forces acting parallel to the surface or generally shear forces. In particular, if the circuit arrangement or the surface of the circuit arrangement is to be coated in a subsequent processing step or further processing of the circuit arrangement, it is customary to coat the surface with a plastic in an injection molding process and in particular in an in-mold injection molding process, which plastic is injected onto or into the surface as a flowable material parallel to the surface. The material can be liquid, powdery or pourable. Regardless of the exact type or the exact state of the material, when the material impacts on at least one component, a force acting parallel to the surface or a shear force occurs, by means of which the loaded component can be detached from the surface.To protect against this, the protective body is designed to absorb the force and divert the material or force so that it no longer acts on the component.

[0011] The core idea of ​​the invention is therefore to place a protective body on a carrier layer in such a way that an electrical component or the connection of the component to the carrier layer is protected against damage by the protective body during subsequent processing steps. In particular, the surface of the carrier layer is to be coated in a subsequent processing method, for example, an in-mold process, for which a hot, liquid plastic or a flowable or pourable material is injected parallel to the surface into a mold in which the circuit arrangement is arranged. The material can tear the components arranged on the carrier layer off or detach them from the carrier layer or damage an electrical connection area of ​​the component.

[0012] Therefore, the protective body is arranged in front of the component in such a way that the protective body absorbs the force that would otherwise be exerted by the material on the component before it can act on the component.

[0013] Since the electrical components are usually connected to the carrier layer exclusively via their electrical contact, an advantageous variant provides that the at least one component has a connection area at which it is contacted with the conductor tracks and which is in particular completely covered and / or stiffened by the protective body.

[0014] A defined flow direction can be determined on the surface of the carrier layer, along which the material can or should flow or be moved parallel to the surface, in particular in a later processing step. The flow direction determines a main load side on the at least one component, wherein the main load side of a respective component corresponds in particular to the end face of the component which is directed opposite to the flow direction or which the material encounters or would encounter when flowing in the flow direction if no protective body were provided. The protective body is preferably designed to direct the material flowing along the flow direction onto a predetermined flow path, along which the respective components are not subjected to any force by the flow.

[0015] According to an advantageous variant, it is provided that the protective body is arranged upstream of the main load side, opposite to the flow direction, ie upstream from the main load side, and is designed to direct the material around the at least one or respective component and in particular to direct it away from it.

[0016] Alternatively, it can be provided that the protective body is not arranged in front of, i.e. at a distance from, the respective component, but adjoins the main load side of the respective component, wherein the protective body covers the component exclusively on the main load side and is in turn designed to direct the material around the at least one or respective component and in particular to direct it away from it.

[0017] As an alternative to this, it can also be provided that the protective body does not cover the component exclusively on the main load side, but rather covers the component at least partially on the main load side and at least one other side, and is designed to direct the material around the at least one or respective component and, in particular, to direct it away from it. According to this variant, it can also be provided that the protective body covers the at least one component or the respective component on five sides, so that it can be completely encased by the protective body together with the carrier layer.

[0018] With reference to the flow direction defined on the surface, particularly for further processing or subsequent processing steps, and the resulting main load side of the component, an advantageous variant provides that the protective body can be ramp-shaped and / or wedge-shaped and / or plow-shaped and / or concavely curved, widening from a tapered tip or edge to a base facing the main load side. Accordingly, the tip or edge can be referred to as upstream, and the base as downstream in the flow direction.

[0019] Further referring to the flow direction and the main load side determined thereby, the protective body can have at least one guide surface directed opposite to the flow direction and preferably two guide surfaces converging at the tip or edge, which have a differentiable surface and / or are free of flow obstacles and / or are fluidically optimized so that the material flowing along the flow direction is guided along the guide surface and in particular a turbulent flow can be converted into a laminar flow or the turbulent flow components can at least be reduced.

[0020] According to one variant, a large number of components, i.e. at least two components, are provided on the carrier layer and contacted with the conductor tracks. The components are divided into a first group of components and a second group of components, wherein the material, along the direction of flow, first strikes the components of the first and correspondingly upstream group and only subsequently strikes the components of the second and correspondingly downstream group. In this case, it can be provided that protective bodies are provided exclusively adjacent to the components of the first group and are designed to reduce a flow velocity of the material. As a result, lower forces act on the components of the second group due to the material moving parallel to the surface, so that the protective bodies can be omitted.The at least one protective body can be formed from a thermoplastic, which can in particular be polyamide (PA) or polycarbonate (PC). The melting temperature of the plastic is preferably higher than a melting temperature of the material, so that the protective body remains dimensionally stable and is not damaged when the material heated to its melting temperature flows around the protective body. Additionally or alternatively, it can be provided that the melting temperature of the plastic is lower than a melting temperature of the component and / or a housing of the component, so that neither the component nor the housing of the component is damaged if the protective body is formed on the carrier layer on or adjacent to the component.Furthermore, the melting temperature of the plastic is preferably lower than the melting temperature of a solder or connecting agent with which the component is contacted with the conductor tracks or fixed to the carrier layer. Additionally or alternatively, the melting temperature of the plastic can also be lower than the melting temperature of the carrier layer so that the latter is not damaged. Alternatively, however, it can also be provided that the melting temperature of the plastic is the same as the melting temperature of the carrier layer so that they can melt together and be bonded together. In addition, a plastic is preferably selected with an adhesion properties by means of which the protective body adheres to the carrier layer and / or the component with a predetermined adhesive force or at least up to a predetermined limit force.

[0021] For improved connection of the at least one protective body, it can also be provided that the carrier layer provides a through-opening for at least one protective body, through which the respective protective body extends. The protective body can also fulfil other functions in addition to its primary protective function. For this purpose, at least one protective body can be translucent and / or transparent and can also be designed to form a light guide and / or a scattering surface, i.e. an optical diffuser, for light emitted in particular by the at least one component or for light emitted by one of the components. Furthermore, additionally or alternatively, at least one protective body, i.e. another protective body, can be non-transparent and / or opaque and can also be designed to form a light barrier for shielding an area on the surface of the carrier layer from light propagating in particular parallel to the surface.

[0022] In addition to mechanical stresses, the at least one electrical component can also be protected from thermal stresses by the protective body. For this purpose, the at least one protective body can be pressure-resistant, temperature-resistant and thermally conductive, wherein the at least one protective body is preferably temperature-resistant up to at least a temperature corresponding to the temperature of the material moving parallel to the surface. In such a variant, the at least one protective body is further designed to absorb and / or dissipate a thermal load acting on the at least one component as a result of heating of the carrier layer or of the at least one component. The heat can be dissipated, for example, via the surface of the protective body, which is larger than the component, and which can also have additional cooling fins for this purpose.

[0023] The carrier layer can, in particular, be a rigid circuit board or a flexible circuit board or a conductor foil, which is correspondingly also flexible. Although the protective body can be formed as a layer covering the entire surface, it is preferably provided that the at least one protective body is formed or provided locally on the surface of the carrier layer and, furthermore, is in particular assigned to exactly one component.

[0024] If a through-hole is provided in the carrier layer, the protective body can extend through it and thus be positively fixed to the carrier layer. However, it is advantageous if the protective body is bonded to the carrier layer or glued to it instead or in addition to this and independently of a through-hole.

[0025] A further aspect of the invention relates to a method for producing a circuit arrangement according to the invention. According to the method, at least one electrical component is arranged on a carrier layer with integrated conductor tracks, fixed to the carrier layer and contacted with the conductor tracks. Subsequently, at least one protective body for protecting the at least one electrical component is provided on the surface of the carrier layer adjacent to the at least one component and fixed to the carrier layer. The protective body can be formed directly on the surface and connected to it, for example by an injection molding or rapid prototyping process and in particular in an FDM process, or it can be formed separately from the carrier layer and only then arranged on it and connected to it.The protective body is designed to absorb and / or redirect a force acting on the at least one component due to a deformation of the carrier layer. Alternatively or additionally, the protective body is designed to absorb and / or redirect a force acting on the at least one component due to a material moving parallel to the surface. An advantageous variant of the method provides that the carrier layer is subsequently deformed three-dimensionally and brought into a predetermined shape and fixed in this shape. Additionally or alternatively, a defined flow direction can be determined on the surface, along which flow direction the material is then guided parallel to the surface, whereby the entire surface can be coated and, for example, a protective layer and / or a leveling layer can be provided on the surface of the carrier layer.

[0026] The features disclosed above can be combined as desired, as long as this is technically possible and they do not contradict each other.

[0027] Other advantageous developments of the invention are characterized in the subclaims or are presented in more detail below, together with the description of the preferred embodiment of the invention, with reference to the figures. They show:

[0028] Fig. 1a, b a circuit arrangement with a first variant of a protective body in two views;

[0029] Fig. 2a, b a circuit arrangement with a second variant of a protective body in two views;

[0030] Fig. 3a, b a circuit arrangement with a third variant of a protective body in two views;

[0031] Fig. 4a, b a circuit arrangement with a fourth variant of a protective body in two views;

[0032] Fig. 5a, b a circuit arrangement with a fifth variant of a protective body in two views;

[0033] Fig. 6a, b show two views of a circuit arrangement with a sixth variant of a protective body. The figures are schematic examples. Like reference numerals in the figures indicate like functional and / or structural features.

[0034] Figures 1a to 5b each show a section of an electrical circuit arrangement 1, with Figures 1a, 2a, 3a, 4a and 5a showing this in a side view and Figures 1b, 2b, 3b, 4b and 5b showing this in a view from above.

[0035] Each of the circuit arrangements 1 has a carrier layer 10 with conductor tracks 11, which may be, for example, a conductor foil. On a surface 12 of the carrier layer 10, a component 13 is shown, which is contacted with the conductor tracks 11 at two connection areas 14.

[0036] During subsequent further processing of the circuit arrangement 1, it can be provided that a material flows parallel to the surface 12 and in the flow direction X along the surface 12, which material can cause damage to the component 13 or detachment of the component 13 from the carrier layer 13 or from the conductor tracks 11.

[0037] In order to prevent such damage to the components 13, in the variants according to Figures 1a to 5b, a protective body 20 is provided which extends from an upstream tip 21 or an edge 22 to a downstream base 23 and is designed to redirect the material flowing in the flow direction X and to absorb a force which would otherwise act on a main load side 15 of the component 13.

[0038] In the case of the variant according to Figures 1 a and 1 b, the protective body 20 is designed as a wedge arranged in front of the component 13, which has a guide surface 24 designed as an inclined plane, along which the material can be guided, so that it does not act frontally on the main load side 15 of the component 13.

[0039] Although the wedge-shaped protective body 20 can also simply adhere or be glued to the surface 12 or the carrier layer 10, according to the variant shown, two through openings 16 are formed in the carrier layer 10, into which or through which the protective body 20 extends with a respective pin in order to thereby support itself against the force acting on the protective body 20 in the flow direction X.

[0040] According to the variants of Figures 2a to 5b, the protective bodies 20 each have two sections, wherein the protective body 20 widens in a first section analogously to the variant according to Figures 1a and 1b along the flow direction from a tip 21 or an edge 22 to a base 23 and encloses the component 13 at least in sections in a second section.

[0041] If necessary, the first sections of the variants according to Figures 1a to 5b can be combined with the second sections according to the variants of Figures 2a to 5b.

[0042] In Figures 2a and 2b, the protective body 20 widens in its first section in a wedge-shaped and at the same time ramp-shaped manner from a tip 21 to a base 23, wherein the protective body forms two or three guide surfaces 24 in the first section, which act in a plough-like manner on a material moving on the surface 12 along the flow direction X and deflect this material laterally and over the component 13.

[0043] According to the variant of Figures 2a, 2b as well as variants 3a to 5b, the second section of the protective body 20 encloses the component 13, and in particular at least one connection section 14 of the component 13, at least in sections, thereby stiffening the component. By stiffening at least one connection section 14 or all connection sections 14, the component 13 or the circuit arrangement 1 is additionally protected from a force acting orthogonally to the surface 12, such as can occur, for example, during a deformation of the carrier layer 10. Such a deformation as intended, i.e. a conversion from an initially flat to a three-dimensional shape and the fixing of the carrier layer 10 in this, can also be provided as intended in subsequent processing or manufacturing steps in order to integrate the circuit arrangement 1 into an assembly.

[0044] In Figures 3a and 3b, a wedge shape is chosen for the first section of the protective body 20, whereby a material moving in the flow direction X is deflected laterally. Furthermore, the component 13 and the connecting sections 14 of the component 13 are completely encased by the second section of the protective body 13.

[0045] The variant according to Figures 4a and 4b also provides a wedge shape for the first section of the protective body 20, wherein an additional concave curvature similar to a snow plow is provided, whereby an advantageous guidance of the material along the guide surfaces 24 is enabled.

[0046] Furthermore, it is provided that the component 13 is free from the second section of the protective body 20 at the top, and that the latter covers the component 13 only orthogonal to the surface 12 and parallel to the flow direction X, so that the material flowing along the flow direction X does not reach the component 13, but the component 13 can, for example, emit light orthogonal to the surface 12. Furthermore, the second section can also be optimized in terms of flow and load, as shown in Figures 5a and 5b. According to this variant, the protective body 20 is designed in a cutting-edge or wedge- and ramp-shaped manner in both its first and second sections, wherein the second section can particularly advantageously support a force acting on the guide surfaces 14 of the first section. At the same time, the connection sections 14 are covered and thus protected from damage.

[0047] Figures 6a and 6b show a further variant of the circuit arrangement 1, wherein this variant is intended to illustrate functional integration into the protective body 20. Figure 6a again shows a side view and Figure 6b a view from above. The protective body 20 according to Figures 6a and 6b in the present case has three sections 31, 32, 33, of which a first section 31 is arranged upstream, a second section 32 downstream and a third section 33 between the first section 31 and the second section 33. The first section 31 is wedge-shaped, analogous to the protective body 20 in Figures 1a and 1b, wherein in the present case it is made of an opaque material or plastic that forms a light barrier.The same applies to the second section 32, wherein the protective body 20 in this region is mirrored to the first section 32, so that the protective body 20 in this region tapers from a wide base 34 to a narrow edge 35. With the third section 33 in between, this results in an overall shape of the protective body 20 which is favorable in terms of flow technology. Unlike the first and second sections 31, 32, the third section 33 does not form a light barrier, but rather a light guide through which light L emitted by the component 13 can propagate. Before or after injecting a material X parallel to the surface 12 of the carrier layer 10, it is also possible above dhA cover layer 40 can be arranged on a side of the protective body 20 facing away from the surface 12, so that the circuit arrangement 1 can form an assembly together with the cover layer 40 and a material injected between the cover layer 40 and the carrier layer 10 along the flow direction X. For the sake of better clarity, the cover layer 40, which has a light exit opening 41 adjacent to the third section 33 of the protective body 20, is present but not shown in Figure 6b.

[0048] Even if only one component 13 is shown in the section shown in Figures 1a to 6b, the entire circuit arrangement 1 can also contain several components 13, each with a protective body 20, wherein the shapes of the protective bodies 20 of a circuit arrangement 1 can also differ, so that each protective body 20 can be adapted to the flow conditions prevailing at the respective component 13.

Claims

Patent claims 1. Electrical circuit arrangement (1) with at least one electrical component (13) protected in a load-appropriate manner for subsequent processing, comprising a carrier layer (10) with integrated conductor tracks (11), which has a surface (12) to which the at least one electrical component (13) is fixed and contacted with the conductor tracks (11), characterized in that on the surface (12) of the carrier layer (10) adjacent to the at least one component (13) at least one protective body (20) for protecting the at least one electrical component (13) is provided and fixed to the carrier layer (10), wherein the at least one protective body (20) is formed,absorb and / or redirect a force acting on the at least one component (13) due to a deformation of the carrier layer (10) and / or absorb and / or redirect a force acting on the at least one component (13) due to a material moving parallel to the surface.

2. Circuit arrangement according to claim 1, wherein the at least one component (13) has a connection region (14) at which it is contacted with the conductor tracks (11) and which is covered and / or stiffened by the protective body (20).

3. Circuit arrangement according to claim 1 or 2, wherein a defined flow direction (X) is determined on the surface (12), along which the material flows parallel to the surface (12) and by which a main loading side (15) on the at least one component (13) is determined, wherein the protective body (20) is arranged upstream of the main loading side (15) opposite to the flow direction and is designed to direct the material around the at least one component (13), or wherein the protective body (20) adjoins the main loading side (15), covers the component (13) exclusively on the main loading side (15) and is designed to direct the material around the at least one component (13), or wherein the protective body (20) adjoins the main loading side (15), covers the component (13) on the main loading side (15) and at least in sections on at least one further side and is designed to direct the material around the at least one component (13).

4. Circuit arrangement according to one of the preceding claims, wherein a defined flow direction (X) is determined on the surface (12), along which the material can be guided parallel to the surface (12) and by which a main load side (15) on the at least one component (13) is determined, wherein the protective body (20) is ramp-shaped and / or wedge-shaped and / or plow-shaped and / or concavely curved and widens from a tapered tip (21) or edge (22) to a base (23) which faces the main load side (15).

5. Circuit arrangement according to one of the preceding claims, wherein a defined flow direction (X) is determined on the surface (12), along which the material can be guided parallel to the surface (12) and by which a main load side (15) on the at least one component (13) is determined wherein the protective body (20) has at least one guide surface (24) directed opposite to the flow direction (X), which has a differentiable surface and / or is free of flow obstacles and / or is fluidically optimized, so that the material flowing along the flow direction (X) is guided along the guide surface.

6. Circuit arrangement according to one of the preceding claims, wherein the at least one protective body (20) is formed from a thermoplastic material whose melting temperature is higher than a melting temperature of the material, and / or whose melting temperature is lower than a melting temperature of the component (13) and / or a housing of the component (13), and / or whose melting temperature is lower than a melting temperature of the carrier layer (10), or whose melting temperature is equal to the melting temperature of the carrier layer (10), and / or whose adhesion is selected such that the protective body (20) adheres to the carrier layer (10) and / or the component (13) at least up to a predetermined limit force.

7. Circuit arrangement according to one of the preceding claims, wherein the carrier layer (10) provides a through-opening (16) for at least one protective body (20) through which the respective protective body (20) extends.

8. Circuit arrangement according to one of the preceding claims, wherein at least one protective body (20) is translucent and / or transparent and is designed to have a light guide and / or a scattering surface for a light emitted in particular by the at least one component (13) emitted light (L) and / or at least one protective body (20) is non-transparent and / or opaque and is designed to form a light barrier for shielding an area on the surface (12) of the carrier layer (10) from light propagating in particular parallel to the surface (12).

9. Circuit arrangement according to one of the preceding claims, wherein the at least one protective body (20) is pressure-resistant, temperature-resistant and thermally conductive and is designed to absorb and / or dissipate a thermal load acting on the at least one component (13) as a result of heating of the carrier layer (10) or of the at least one component (13).

10. Circuit arrangement according to one of the preceding claims, wherein the carrier layer (10) is a rigid printed circuit board or a flexible printed circuit board or a conductor foil.

11. Circuit arrangement according to one of the preceding claims, wherein the at least one protective body (20) is formed in a locally limited manner on the surface (12) of the carrier layer (10).

12. Circuit arrangement according to one of the preceding claims, wherein the at least one protective body (20) is integrally connected to the carrier layer (10).

13. A method for producing a circuit arrangement according to one of the preceding claims, wherein at least one electrical component (13) is arranged on a carrier layer (10) with integrated conductor tracks (11), fixed to the carrier layer (10) and contacted with the conductor tracks (11) wherein at least one protective body (20) for protecting the at least one electrical component (13) is provided on the surface (12) of the carrier layer (10) adjacent to the at least one component (13) and is fixed to the carrier layer (10), which protective body is designed to absorb and / or redirect a force acting on the at least one component (13) as a result of a deformation of the carrier layer (10) and / or to absorb and / or redirect a force acting on the at least one component (13) as a result of a material moving parallel to the surface (12).

14. Method according to the preceding claim, wherein the carrier layer (10) is subsequently deformed three-dimensionally and brought into a predetermined shape and fixed in this shape and / or wherein a defined flow direction (X) is determined on the surface (12), along which flow direction the material is subsequently guided parallel to the surface (12). * * * * *

Images