Electronics device

Abstract

The invention is based on an electronics device comprising a housing composed of at least a first and a second housing element, wherein at least the first housing element is formed from a weldable plastic material. The two housing elements are integrally bonded to one another in a joining zone by means of a weld seam, in particular a laser weld seam formed by laser transmission welding. In the bonded state, a cavity containing at least one circuit carrier with an electrical and / or electronic circuit arranged thereon is formed in the housing. The at least one circuit carrier is placed in at least one of the housing elements before they are joined. At least in the joining zone, the plastic material of the first housing element is chosen and designed to melt by absorbing electromagnetic radiation at wavelengths within a welding wavelength range (λ_weld) defined therefor and to form the weld seam by solidifying from the molten state of the material. The material of the second housing element is at least partially permeable to electromagnetic radiation at frequencies within the defined welding wavelength range (λ_weld) up to the joining zone. Furthermore, a protective region of the housing at least comprising a portion of the second housing element is designed in that the region to be protected has an additional material layer which is separate from the material of the second housing element. This material layer is designed to prevent interference radiation from a defined interference frequency spectrum (F_interference), at least partially comprising the welding frequency spectrum (F_weld), from penetrating into the cavity of the housing.

Description

[0001] R415347

[0002] Description

[0003] title

[0004] The invention relates to an electronic device and a method for constructing an electronic device according to the preamble of the independent claims. Within the scope of this application, the terms frequency, frequency spectrum, and wavelength range refer to electromagnetic radiation and, as is common in the field, are sometimes used synonymously to define specific ranges of radiation. Measurements in nanometers (nm) refer to the wavelength.

[0005] State of the art

[0006] For example, in the automotive industry, it has proven effective to weld the housings—consisting of a base and a cover connected to the base—using a laser beam in a transmission laser process. In this process, the cover is placed onto the base and, for example, a clamping tool applies a specific force towards the base to ensure contact between the cover and the base. A laser beam with a specific welding wavelength range (Δ_weld), whose radiation is transparent to the cover, is then directed onto the joining zone between the base and the cover. For the laser beam's energy to reach the joining zone, the cover material must be at least partially transparent to this welding wavelength range (Δ_weld).The material of the housing base is of a type that absorbs radiation in the welding wavelength range (Φ_welding), so that radiation energy from the directed laser beam is absorbed in the housing base in the area of ​​the joining zone. This melts the material of the housing base in this area and, through heat conduction, also melts the material of the cover in the joining zone. Subsequent solidification of the materials of the housing base and cover forms R415347.

[0007] - 2 - between the two a material-bonded connection in the form of a weld.

[0008] A problem with this process arises during the subsequent operation of the electronic device manufactured in this way. When operating control units with housings joined by laser transmission welding, the electronics contained within the housing may be exposed to a broad range of interference wavelengths (Δ_interference) from the operating environment. This interference wavelength range can partially or completely overlap with the welding wavelength range (Δ_welding) required for the welding process. Due to the permeability required for the welding process, the cover is therefore inevitably also permeable to interference radiation in this overlapping range. Interference from the effects of such radiation on the electronics repeatedly leads to malfunctions in the operation of the control unit. Such malfunctions, or even a complete failure of the control unit in a vehicle, can potentially severely impair its driving function.

[0009] Disclosure of the invention

[0010] The invention is based on the objective of operating electronic devices whose housings are joined by means of laser transmission welding in a fault-resistant manner.

[0011] This problem is solved by an electronic device and a method for forming, in particular, such an electronic device with the characterizing features of the independent claims.

[0012] The invention relates to an electronic device comprising a housing made of at least a first and a second housing element, wherein at least the first housing element is made of a weldable plastic material. The two housing elements are joined together in a joining zone by means of a weld seam, in particular a laser weld seam. In the joined state, a cavity is formed in the housing in which at least one circuit carrier with an electrical and / or electronic circuit arranged on it is located.

[0013] - 3 - is recorded. The at least one circuit carrier is arranged in at least one of the housing elements before joining. The plastic material of the first housing element is selected and configured, at least in the joining zone, to melt by absorbing electromagnetic radiation within a welding wavelength range (A_weld) defined for the welding process and to form the weld seam by solidifying from the molten material state. Such a plastic material is generally available, for example, for use in laser transmission welding. The material of the second housing element is at least partially transparent to electromagnetic radiation within this welding wavelength range (A_weld) up to the joining zone.This ensures that the electromagnetic radiation required for absorption in the first housing element can be directed and / or focused from the second housing element onto the area of ​​the planned joining zone, so that only a locally limited melting of at least the plastic material of the first housing element takes place within the joining zone.

[0014] Furthermore, a protective area of ​​the housing, encompassing at least part or all of the second housing element, is now provided by an additional material layer in the area to be protected, separate from the material of the second housing element. This material layer is designed to block interference radiation from a defined interference wavelength range (A_interference) from penetrating the cavity of the housing. The interference wavelength range (A_interference) includes at least the wavelength range that overlaps with the welding wavelength range (A_welding). This advantageously results in a significant reduction, or preferably a complete elimination, of interference during the operation of the electronic device caused by electromagnetic radiation from the operating environment.If necessary, the additional material layer can also be designed to block interfering radiation with wavelengths outside the welding wavelength range (A_welding). For example, the additional material layer can be made of the same material as the first housing element, which at least blocks the electromagnetic radiation in the welding wavelength range R415347.

[0015] - 4 -

[0016] (E_sweat) is absorbed, thus preventing transmission or blocking penetration. It can be assumed that the electronic device is not operated in an environment where electromagnetic radiation in the defined interference wavelength range (E_interference) is of such intensity that its absorption during operation would cause remelting in the joint or melting of the additional material layer in the area to be protected. In principle, the materials of the first housing element and the additional material layer located in the area to be protected can also differ. Therefore, electronic devices can be operated without interference from electromagnetic radiation in the operating environment, even if, in designs according to the known state of the art, a frequency gap exists for such interference due to the process conditions for joining the housing.

[0017] The measures listed in the dependent claims enable advantageous further developments and improvements of the electronic device according to the invention.

[0018] There are various possibilities for arranging the additional material layer. For example, the additional material layer can be arranged on an inner surface of the housing facing the cavity. In this advantageous embodiment, the additional material layer can also be applied to a portion, preferably the entire inner surface, of the first housing element before the housing is joined and before the circuit carrier is attached. The joining zone, viewed from the cavity, always projects radially further than the applied additional material layer. In this respect, the joining zone remains accessible to the action of electromagnetic radiation used for welding, with frequencies within the defined welding wavelength range (A_welding). Thus, the arrangement of the additional material layer has no effect on enabling the joining of the housing.Such a design can offer manufacturing and cost advantages, as, for example, the application of the additional material layer can be carried out simultaneously or at least more easily during the production of the second housing element. R415347.

[0019] - 5 -

[0020] In a similar embodiment, the additional material layer is arranged in a radial direction, viewed from the cavity, between the cavity and the joining zone, such that the joining zone remains accessible to electromagnetic radiation used for welding with frequencies in the defined welding wavelength range (A_welding). The additional material layer can, for example, be embedded within the wall of the second housing element during manufacturing. Alternatively, the material layer can be formed, for example, by particles distributed within the material of the second housing element, such as carbon black particles, aluminum particles, or silver particles, which are locally concentrated within a surface between an outer and an inner surface in such a way that the area to be protected is thereby formed.

[0021] In an alternative embodiment, the additional material layer is arranged on the outer surface of the second housing element, facing away from the cavity. In this embodiment, the additional material layer is applied, in particular, after the housing has been joined. This allows the housing to be joined as before, so that, for example, existing manufacturing processes do not need to be changed. Existing products can thus be manufactured with the achievable protective function in a very simple manner, or such a protective function can be retrofitted. Preferably, the entire outer surface of at least the second housing element is completely covered by the additional material layer. It is also possible for the joining zone to be covered by the additional material layer on its outer surface, so that any remaining imperfections are not affected.Remaining gaps for the penetration of electromagnetic radiation with frequencies within the defined interference wavelength range (Ä_Stör) are blocked.

[0022] In the described embodiments, it is advantageous if the additional material layer is applied as a coating, in particular as a build-up coating. Such coatings can be produced particularly easily using established methods. An alternative advantageous R415347

[0023] - 6 -

[0024] This embodiment is characterized by the fact that the additional material layer is formed as a foil or sheet material adhering to the housing. In this form, the additional material layer can be prefabricated cost-effectively and flexibly adapted to specific product designs. Prefabrication is achieved, for example, by forming a multitude of elements from a base sheet or foil as the additional material layer in a defined size and shape, for example, by a cutting process, in particular laser cutting or punching. The foil or sheet material can also be provided as a composite material, wherein at least one composite component provides the necessary blocking effect for electromagnetic radiation. Such a composite material can also include an adhesive layer, and optionally a cover and / or carrier film arranged for this adhesive layer.This allows for the automated or manual application of additional material layers to the housing, ensuring long-term durability. Alternatively, the adhesive layer can be applied separately to the housing beforehand, before the subsequent material layer, in the form of foil or sheet metal, is then adhered to it. The adhesive layer itself can be a foil material or applied as a coating layer, for example, as an adhesive layer.

[0025] In a further advantageous embodiment of the electronic device, the second housing element is an injection-molded part in which the additional material layer is designed as part of an insert. The blocking function for electromagnetic radiation with frequencies in the defined interference wavelength range (Δ_interference) is thus achieved by the insert, while the plastic material enables the joining process with the first housing element. It is also conceivable that the additional material layer is designed as a component of a multi-component injection-molded part. In this case, the additional material layer can be made of a different plastic material that possesses material properties suitable for the blocking function. Both plastic materials, i.e., one without and the other with a blocking function, can be processed within a single manufacturing process, resulting in a cost-effective second housing element. R415347

[0026] - 7 -

[0027] It is generally advantageous if the additional material layer, when projected onto the inner surface of the housing facing the cavity, completely covers at least the second housing element. This ensures that the penetration of electromagnetic radiation with frequencies within the defined interference wavelength range (Δ_interference) into the cavity is completely prevented, both by the material of the first housing element and by the additional material layer in the area to be protected. It is also generally advantageous to arrange the additional material layer to completely cover the inner and / or outer surface of both the first and second housing elements. This is particularly useful if electromagnetic radiation with wavelengths outside the defined welding wavelength range (Δ_welding) is also to be shielded against penetration into the cavity.Furthermore, manufacturing and cost advantages can also arise if no measures are taken to separate areas with the additional material layer from those without.

[0028] In a particular embodiment of the electronic device, the defined interference wavelength range (Φ_interference) includes at least infrared light. This eliminates electromagnetic radiation that is often identified as operational interference.

[0029] Furthermore, it is advantageous to shield against additional frequencies of electromagnetic radiation that have been proven or may potentially cause malfunctions in the electronic device. Effective shielding has been achieved when the defined interference wavelength range (Δ_interference) covers a wavelength range from 700 nm to 3000 nm.

[0030] A major advantage of a particular embodiment of the electronic device results from the fact that the second housing element is also made of a plastic material. By providing corresponding pairings of plastic materials for both the first and second housing elements, a conventional laser transmission process can be used for joining the housing. In this way, an R415347

[0031] - 8 -

[0032] A wide variety of electronic device designs can be manufactured cost-effectively and as part of mass production.

[0033] Advantages of materials are exemplary or preferred

[0034] - for the first housing element: polypropylene (PP), polybutylene terephthalate (PBT) or polyamide (PA) variants filled with carbon black particles, optionally with glass fiber reinforcement

[0035] - for the second housing element: natural-colored polybutylene terephthalate (PBT) or polyamide (PA) variants, optionally with glass fiber reinforcement

[0036] - for the next material layer: a black-colored, thin plastic film, a layer of paint, or a thin aluminum foil

[0037] The invention also leads to a method for forming an electronic device, in particular according to at least one of the embodiments described above.

[0038] The method comprises the following process steps: a. Provision of at least one first and one second housing element, wherein at least the first housing element is made of a weldable plastic material and at least one circuit carrier with an electrical and / or electronic circuit arranged on it is arranged in at least one of the housing elements, b. Arrangement of the at least first and the second housing element to each other in such a way that they are in contact with each other at least in a provided joining zone and the circuit carrier is received within a cavity formed by the two adjacent housing elements, c.Introducing melting energy to the plastic material of the first housing element at least in the intended joining zone by means of electromagnetic rays, wherein at least a part of the electromagnetic rays, in particular all electromagnetic rays, pass through at least a part of the second housing element to the intended joining zone, wherein the electromagnetic rays have at least one or all wavelengths within a defined welding wavelength range (Ä_weld), which are absorbed by the plastic material with heat generation up to its at least local R415347.

[0039] - 9 -

[0040] Melting within the intended joining zone is absorbed and which are permeable to the material of the second housing element, d. Solidification of the previously melted portion of the plastic material by forming a weld seam, whereby the two housing elements are joined materially, e. Placement of a further material layer on at least one area of ​​the housing to be protected, comprising at least a part of the second housing element, wherein the further material layer blocks a portion of the electromagnetic radiation incident in the area to be protected with wavelengths within the defined interference wavelength range (Δ_interference) from penetrating into the cavity of the housing, wherein the placement of the further material layer takes place before process step b.) and in doing so, at least one part of the second housing element encompassed by the area to be protected is selected in such a way that the joining zone is kept freely accessible for incoming electromagnetic radiation in process step c.) and / or the arrangement of the further material layer after process step d.) takes place on at least one part of the outside of the housing as the at least one area to be protected.

[0041] It can be advantageously stated that, in the operation of the electronic device thus designed, electrical interference on the electrical and / or electronic circuit caused by electromagnetic radiation, in particular light radiation from the operating environment, with at least one or all wavelengths within the defined interference wavelength range (Ä_Interference), striking the housing, in particular the second housing element, is reduced or prevented compared to a designed electronic device put into operation without process step e.).

[0042] A preferred embodiment of the method involves introducing the melting energy by means of a laser device that emits laser beams, particularly in a wavelength range of 940 nm to 1080 nm. This includes frequencies that allow the housing to be joined by corresponding adsorption of the radiation energy.

[0043] - 10 - Furthermore, frequencies are also included simultaneously, which are effectively eliminated by the described measures to prevent operational disruptions. Advantageously, both housing elements are made of a suitable plastic material, which allows the housing to be joined by laser transmission welding.

[0044] In a further advantageous embodiment of the method, the additional material layer is formed by means of an adhesive deposition process, particularly one containing particles, such as a spraying process, a printing process, or a dipping process. For example, particles with material properties are selected that enable the blocking function of the corresponding electromagnetic radiation. The particles themselves are, for example, encapsulated in a sufficient proportion in a carrier medium, which facilitates the deposition of the additional material layer. After deposition, the carrier medium can solidify or chemically bond to the housing. It is also conceivable that a carrier medium is selected which essentially evaporates after deposition, so that the particles remain adherent to the housing.Alternatively, the additional material layer can also be formed in the form of a foil or sheet material, whereby the foil or sheet material is held to the housing in particular by an adhesive layer.

[0045] In an advantageous alternative embodiment of the method, the second housing element is provided as an injection-molded part in process step a.), wherein the further material layer is formed at least as part of an insert or as a component of a multi-component injection-molded part.

[0046] It is generally advantageous for an electronic device designed according to the inventive method if it is operated in an operating environment in which electromagnetic radiation with at least one wavelength in the defined interference wavelength range (Δ_interference) at least impacts the protective area and is thereby blocked from penetrating the cavity of the housing. R415347

[0047] - 11 -

[0048] Otherwise, the same advantages arise for the method as have already been described previously for the electronic device.

[0049] Brief description of the drawings

[0050] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawing. This drawing shows:

[0051] Fig. 1 shows a first exemplary embodiment of an electronic device in a perspective view comprising an area on the housing to be protected against the penetration of electromagnetic radiation,

[0052] Figs. 2a - 2e show further embodiments of the electronic device in a schematic sectional view.

[0053] Embodiments of the invention

[0054] In the figures, functionally identical components are each marked with the same reference symbol.

[0055] Figure 1 shows a first exemplary embodiment of an electronic device 100 in a perspective view. The electronic device 100 is, for example, a control unit. It comprises a housing 10, which consists of at least one first and one second housing element 10.1, 10.2 joined together within a joining zone 10.12. The connection between the first and the second housing element 10.1, 10.2 is formed by a material bond, which is formed, in particular, by means of a laser transmission process in the form of a laser weld seam 10a. In this embodiment, both housing elements 10.1, 10.2 are each made of a weldable plastic material, R415347

[0056] - 12 - which, however, differ quite specifically in their material properties due to the conditions for the joining process described below. The laser weld seam follows the profile of the joining zone 10.12, which is defined by the design of the first and second housing elements 10.1, 10.2. Within the joining zone 10.12, the two housing elements 10.1, 10.2 rest in contact with each other in preparation for the joining connection. For illustrative purposes only, the laser weld seam 10a is shown as completely closed and frame-like. Due to the laser transmission process, the laser weld seam 10a can be very thin. Specifically, for joining, a laser device 10A is positioned in relation to the resting arrangement of the two housing elements 10.1, 10.2 such that an emitted laser beam S is directed or focused onto the joining zone 10.12.The laser beam S emits electromagnetic radiation with wavelengths within a suitable welding wavelength range ( _ weld), which is absorbed by the plastic material of the first housing element 10.1 in the form of melting energy. The plastic material of the second housing element 10.2, in turn, is at least partially transparent to electromagnetic radiation precisely within this welding wavelength range (A_ weld). By directing or focusing the laser beam S from the side of the second housing element 10.2 through its transparent plastic material, particularly perpendicular to the surface of the joining zone 10.2, the plastic material of the first housing element 10.1 melts locally in the area of ​​the joining zone 10.12. Through heat conduction, the plastic material of the second housing element 10.1 adjacent to the molten plastic material is also heated.2 - particularly also locally limited - in the area of ​​the joining zone 10.12. By moving the laser beam S relatively along the course of the joining zone 10.12, new sections can be melted, while the two already melted plastic materials solidify again, forming a section of the weld seam 10a. The overlapping and joining of both housing elements 10.1, 10.2 creates a cavity 30 in the joined housing 10. A circuit carrier 20 with an electrical and / or electronic circuit 21 of the electronic device 100 arranged on it is accommodated in this cavity 30. The circuit carrier 20 is inserted into one of the R415347 before joining.

[0057] - 13 - both housing elements 10.1, 10.2 are arranged, for example by means of otherwise known fastening methods. The joining process can be further supported by a supporting force on one or both housing elements 10.1, 10.2, so that they come into optimal contact with each other in the joining zone 10.12.

[0058] The electronic device 100 is exposed to the influences of an operating environment G during operation. This environment includes, for example, interference radiation L, such as light radiation, from an interference wavelength range (Δ_interference). If this interference wavelength range (Δ_interference) overlaps with the welding wavelength range (Δ_welding), these electromagnetic radiations L can pass through the second housing element 10.2 into the cavity 30 because the plastic material used for the joining process is at least partially transparent to this welding wavelength range (Δ_welding). Some of these electromagnetic radiations L interfere with the operation of the electrical and / or electronic circuit 21, thus jeopardizing the operational reliability of the electronic device 100 at any time. To prevent such malfunctions, a protected area of ​​the housing 10 encompasses at least a portion of the second housing element 10.2. The arrangement is such that the electromagnetic radiation L incident on the area to be protected cannot enter the cavity 30, i.e., it is blocked. For this purpose, a further material layer 15 is arranged in the area to be protected, which blocks at least some, in particular all, electromagnetic interference radiation L with wavelengths within the defined range.

[0059] The material of the additional material layer 15 shields the interference wavelength range (A_interference), i.e., prevents transmission through the material. Furthermore, the material of the additional material layer 15 can also be selected such that, in addition to blocking the interference radiation L in the overlap region with the welding wavelength range (Ä_welding), it also blocks interference radiation whose wavelengths lie outside the welding wavelength range (Ä_welding), particularly if these are disruptive to the operation of the electrical and / or electronic circuit 21. Preferably, the material of the additional material layer 15 shields at least infrared light. The entire interference wavelength range (Ä_interference) to be blocked is R415347

[0060] - 14 - preferably comprises a frequency range of wavelength range from 700 nm to 3000 nm

[0061] In the present first embodiment, as shown in Fig. 1, the additional material layer 15 is applied to the outer surface 16 of the second housing element 10.2 in an area to be protected. The shape of the foil or sheet material 15 is adapted to the contour of the outer surface 16, but extends only a distance 15.1 to the circumferential side contour. In a perpendicular plan view of the joining zone 10.12, this distance 15.1 borders the final boundary of the joining zone 10.12, the side facing away from the side contour. This allows the foil or sheet material 15 to be applied to the outer surface 16 of the second housing element 10.2 before the housing 10 is joined, for example, by means of an adhesive layer. Laser transmission welding is still possible because a laser beam S of the laser device 40 can reach the joining zone 10.12 in the area of ​​the distance dimension 15.1.Alternatively, the foil or sheet material 15 can also extend to the side contour of the second housing element 10.2 or beyond. This is shown, for example, in Figures 2b and 2c (dashed line). In the embodiment according to Figure 2b, the entire outer surface 16 of the second housing element 10.2, as well as the joining zone 10.12, is covered by the additional material layer 15. Figure 2c, on the other hand, shows that the additional material layer 15 covers essentially the entire outer surface 16 of the housing 10, i.e., also the part of the first housing element 10.1. This is particularly useful if the first housing element 10.1 also needs to be protected against interfering electromagnetic radiation L with wavelengths that lie outside the welding wavelength range (Φ_welding). In the embodiments described last, however, the application of the additional material layer 15 to the area to be protected takes place after the two housing elements 10 have been joined.1 , 10.2. In principle, the additional material layer 15 can alternatively be applied as a coating in the area to be protected, in particular as a coating.

[0062] Fig. 2a shows a further embodiment of the electronic device 100, in which the further material layer 15 is a coating or a film or R415347

[0063] - 15 -

[0064] Sheet metal material is applied to an inner surface 17 of the second housing element 10.2 facing the cavity 30. The application of the further material layer 15 also takes place before joining the housing 10, whereby the area of ​​the second housing element 10.2 resting in the joining zone 10.12 remains uncovered by the further material layer 15. Figure 2c also shows an embodiment with a dotted line in which the entire inner surface 17 of the housing 10 facing the cavity 30 is covered by the further material layer 15.

[0065] Figure 2d shows another embodiment of the electronic device 100. In this embodiment, the second housing element 10.2 is formed as an injection-molded part, with the additional metal layer 15 arranged as an insert within the injection-molded part. Alternatively, the second housing element 10.2 can also be formed as a multi-component injection-molded part, with the additional metal layer 15 then being injection-molded as one of the components. The additional metal layer 15 is shown in an arrangement on the inner surface 17 of the second housing element 10.2 facing the cavity 30. It can alternatively also be arranged on an outer surface 16 facing away from the cavity 30, resulting in a similar embodiment to that shown in Figure 1.

[0066] Fig. 2e shows another embodiment of the electronic device 100. In this embodiment, the additional material layer 15 is arranged between the cavity 30 and the joining zone 10.12. The second housing element 10.2 is, for example, designed as a composite body, such as a laminate. The additional material layer 15 is formed by a composite partner, such as a composite film. As before, a region of the second housing element 10.2 remains free of the additional material layer 15, so that the joining zone 10.12 remains accessible for the application of electromagnetic beams L with wavelengths in the defined welding wavelength range (A_welding) used for welding. Optionally, the additional material layer 15 can be formed in the same way within the plastic material of the first housing element 10.1 to be arranged, especially if the additional material layer 15 is intended to further shield the housing 10 from interfering electromagnetic radiation L with wavelengths outside the welding wavelength range (A_welding). R415347.

[0067] - 16 -

[0068] Not shown are embodiments in which the further material layer 15 is arranged multiple times in different positions, at least two, in the area to be protected of the housing 10, with one layer on the inner side 17 facing the cavity 30 or on the side facing away from the cavity 30

[0069] The outer surface 16 of the housing 10 or is arranged between the cavity 30 and the joining zone 10.12. The second housing element 10.2 alone or both housing elements 10.1, 10.2 can comprise the described multi-layered design of the further material layer 15.

Claims

1. R415347 - 17 - Claims 1. Electronic device (100) comprising a housing (10) made of at least one first and one second housing element (10.1, 10.2), wherein at least the first housing element (10.1) is made of a weldable plastic material and the two housing elements (10.1, 10.2) are joined together in a joining zone (10.12) by means of a weld seam formed by laser transmission welding, forming a cavity (30) in which at least one circuit carrier (20) with an electrical and / or electronic circuit (21) arranged on it is received, and wherein the plastic material of the first housing element (10.1) is configured, at least in the joining zone (10.12), to melt by absorption of electromagnetic radiation used for welding and to form the weld seam by solidification from the molten material state, and wherein the material of the second housing element (10.2) is at least partially transparent to the electromagnetic radiation used for welding with wavelengths within the defined welding wavelength range (A_welding) up to the joining zone (10.12), characterized in that a protected area of ​​the housing (10) comprising at least part or all of the second housing element (10.2) has a further material layer (15) separate from the material of the second housing element (10.2), which blocks interference radiation from a defined interference wavelength range (Ä_interference), which at least partially comprises the welding wavelength range (Ä_welding), from penetrating the cavity (30) of the housing (10).

2. Electronic device (100) according to claim 1 , characterized in that the further material layer (15) is arranged on an outer surface (16) facing away from the cavity (30) and / or on an inner surface (17) of the housing (10) facing the cavity (30).

3. Electronic device (100) according to claim 1 or 2, characterized in that R415347 - 18 - the further material layer (15) is applied as a coating, in particular as a coating or in the form of a foil or sheet material adhering to the housing (10).

4. Electronic device (100) according to one of the preceding claims, characterized in that the second housing element (10.2) is an injection-molded part in which the further material layer (15) is designed as part of an insert or as a component of a multi-component injection-molded part.

5. Electronic device (100) according to one of the preceding claims, characterized in that the further material layer (15) in a surface projection onto the inner side (17) of the housing (10) facing the cavity (30) completely covers at least the second housing element (10.2).

6. Electronic device (100) according to claim 5, characterized in that the further material layer (15) is located between the cavity (30) and the joining zone. (10.12) is arranged such that the joining zone (10.12) remains accessible to the impact of the electromagnetic radiation used for welding with wavelengths within the welding wavelength range (Ä_welding).

7. Electronic device (100) according to one of the preceding claims, characterized in that the further material layer (15) completely covers an outer surface (16) of the second housing element (10.2) or of the housing (10) facing away from the cavity (30).

8. Electronic device (100) according to one of the preceding claims, characterized in that the interference wavelength range (Ä_Interference) and the welding wavelength range (Ä_Welding) comprise infrared light. R415347 - 19 - 9. Electronic device (100) according to one of the preceding claims, characterized in that the second housing element (10.2) is made of a plastic material.

10. Method for forming an electronic device (100), in particular according to one of the preceding claims, comprising the following method steps: a. Provision of at least one first and one second housing element (10.1, 10.2), wherein at least the first housing element (10.1) is formed from a weldable plastic material and at least one circuit carrier (20) with an electrical and / or electronic circuit (21) arranged on it is arranged in at least one of the housing elements (10.1, 10.2), b. arranging the at least first and the second housing element (10.1, 10.2) relative to each other such that they are in contact with each other at least in a provided joining zone (10.12) and the circuit carrier (20) is received within a cavity (30) formed by the two adjoining housing elements (10.1, 10.2), c. introducing melting energy for the plastic material of the first housing element (10.1) at least in the provided joining zone (10.12).12) by means of electromagnetic radiation used for welding, wherein at least a part of the electromagnetic radiation, in particular all electromagnetic radiation, passes through at least a part of the second housing element (10.2) to the intended joining zone (10.12), wherein the electromagnetic radiation has a wavelength within a defined welding wavelength range (Φ_weld), which is absorbed by the plastic material with heat generation until at least local melting occurs within the intended joining zone (10.12) and which is permeable to the material of the second housing element (10.2), i.e. solidifying the previously melted portion of the plastic material by forming a weld seam, wherein the two housing elements. (10.1 . 10.2) are joined by material bonding, e.g., by arranging a further layer of material (15) on at least one area of ​​the housing (10) to be protected, comprising at least a part R415347 - 20 - of the second housing element (10.2), wherein the additional material layer (15) blocks a portion of the electromagnetic radiations with wavelengths within the defined interference frequency spectrum (F_Interference) incident in the area to be protected from penetrating the cavity (30) of the housing (10), wherein the arrangement of the additional material layer (15) takes place before process step b.) and the at least one part of the second housing element (10.2) encompassed by the area to be protected is selected such that the joining zone (10.12) is kept freely accessible for incident electromagnetic radiations in process step c.) and / or the arrangement of the additional material layer (15) after process step d.) takes place on at least one part of the outside (16) of the housing (10) as the at least one area to be protected.

11. Method according to claim 10, characterized in that the melting energy is introduced by means of a laser device (10A) which emits laser beams and both housing elements (10.1 , 10.2) are made of a plastic material and are joined by means of laser transmission welding.

12. Method according to one of claims 10 or 11, characterized in that the further material layer (15) is formed by means of an adhesive application method, in particular a spraying method, a printing method, a dipping method, or by means of a foil or sheet metal element, wherein the foil or sheet metal element is held in particular by an adhesive layer on the housing (10).

13. Method according to one of claims 10 to 12, characterized in that the second housing element (10.2) is provided as an injection-molded part in process step a.), wherein the further material layer (15) is at least part of a R415347 - 21 - It is designed as an insert part or as a component of a multi-component injection molded part.

14. Method according to one of claims 10 to 13, characterized in that the electronic device (100) is operated in an operating environment (G) in which electromagnetic radiation with at least one wavelength in the defined interference wavelength range (Ä_Interference) at least hits the protective area and is thereby blocked against penetration into the cavity of the housing (10).

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