Electronic device used in automation technology, comprising an electronics circuit board which is doubly overmolded with plastics material, and a method

Abstract

The invention relates to an electronic device used in automation technology, comprising an electronics circuit board (EP) which is doubly overmolded with plastics material and on which at least one plug connector (12) and a plurality of light sources (14) are arranged, wherein the electronics circuit board (EP), in a first production state (16a), is embedded in a first plastics injection-molded part (T1), and wherein, in a second production state (16b), the first plastics injection-molded part (T1) is at least partly encased by a second plastics injection-molded part (T2). A plurality of recesses (20) are formed between the electronics circuit board (EP) and an upper face (18) of the first plastics injection-molded part (T1), wherein the electronic device (10) comprises a plurality of light-guiding elements (22) which in the first production state (16a) are selectively insertable or inserted, for the purposes of light guidance, into the recesses (20) in order to form light-guiding portions above the light sources (14). The invention also relates to a production method.

Description

[0001] Electronic device for automation technology with an electronic circuit board overmolded twice with plastic and a method

[0002] The invention relates to an electronic device for automation technology with an electronic circuit board that is double-coated with plastic according to the preamble of claim 1. Furthermore, the invention relates to a manufacturing method for the electronic device.

[0003] In automation technology, particularly in industrial manufacturing or process measurement technology, electronic devices such as sensors, actuators, and bus connectors (gateways) are often used to automate product manufacturing. The applicant manufactures and markets a variety of such products. Electronic components can be incorporated into the interior of a housing of the electronic device, preferably circuit boards with rigidly soldered connectors (M8, M12) and several light-emitting diodes (LEDs) as light sources.

[0004] Such an electronic device is known from DE 10 2017 203 870 A1, which has a double plastic overmolded electronic circuit board with a plurality of plug connections and a plurality of light-emitting diodes, wherein the electronic circuit board is embedded in a first transparent plastic injection-molded part as a pre-molded part, which is produced in a first injection-mold process or a first manufacturing state, and wherein the transparent first plastic injection-molded part is encased in a non-transparent second plastic injection-molded part, which is produced in a second injection-mold process or second manufacturing state.Above the LEDs and on an upper side of the first plastic injection-molded part, protruding web sections can be provided as part of the first plastic injection-molded part. These web sections serve as the ends of a light guide and are not completely over-molded with the non-transparent plastic material in the second injection-mold process and are therefore visible from the outside as light elements. The plastic injection-molded parts have the particular advantage that they form a durable housing for the electronic circuit board that is sealed against environmental influences and can simultaneously enable the functionality of a light guide. The prior art has shown that the electronic circuit board can form different functionalities of the plug connections for different areas of application, whereby the number of light sources for indicating a function of a plug connection can vary depending on the application.To individually adapt the light guides in the plastic injection-molded part to the number of light sources, different injection molding tools would have to be used, which would be very costly. In addition, the tool would have to be changed for different electronic boards, which would mean additional changeover time.

[0005] For example, depending on its functionality, a connector may be assigned one, two, or no light sources. If a light guide is nevertheless installed in a position without a light source, the user may not be able to clearly identify the functionality of the connector. In particular, slight crosstalk of light signals between the light sources may lead to confusion about the functionality. Therefore, it is advantageous to install light guides only in areas above the LEDs.

[0006] DE 199 01 913 A1 discloses an electrical device with a housing containing a printed circuit board equipped with electrical components and having electrical connection devices. The housing consists of an extruded profile element with side walls. The electrical connection devices are attached to the printed circuit board. Light-emitting diodes can be formed on the printed circuit board, and in addition to the connection devices, light guide elements can also be fixed to the printed circuit board above the light-emitting diodes. The housing can be encapsulated with an electrically insulating potting compound, encapsulating the connection devices and light guide elements already fixed to the printed circuit board.

[0007] DE 10 2015 222 992 A1 discloses an injection molding tool for producing an electronic device in automation technology with several plug connections that are pressed into two tool halves for sealing.

[0008] DE 10 2018 118 478 A1 describes a method for producing an illuminable assembly. EP 3 070 396 B1 shows a light module comprising a coated circuit carrier, which has at least one light-emitting diode with an associated lens attached to the circuit carrier, wherein a silicone overmold is provided as the coating for the circuit carrier.

[0009] DE 10 2012 211 760 A1 shows a method for producing an electrical component carrier which comprises an electrically insulating base part and electrical conductor tracks arranged therein, wherein the conductor tracks are overmolded with a foamed insulating material.

[0010] DE 11 2019 000 790 T5 discloses a mounting device that mounts an electronic component on a substrate with a simple design. Further mounting devices are known from DE 10 2012 106 710 A1, DE 11 2004 000640 T5, or DE 11 2015 006 989 T5.

[0011] The object of the invention relates to the provision of an electronic device which, while avoiding the disadvantages known in the prior art, enables flexible overmolding of electronic circuit boards with differently designed light sources and thereby ensures reliable operation of the electronic device.

[0012] Furthermore, the task is to specify a manufacturing process.

[0013] The problem is solved with regard to the electronic device by the features of claim 1 and with regard to the method by the features of claim 9.

[0014] Advantageous embodiments of the invention are specified in the subclaims.

[0015] According to the invention, an electronic device of automation technology is claimed with an electronic circuit board which is double-encapsulated with plastic and on which at least one plug connection, preferably a plurality of plug connections, and a plurality of light sources are arranged, wherein the electronic circuit board is embedded in a first plastic injection-molded part in a first manufacturing state and wherein, in a second manufacturing state, the first plastic injection-molded part is at least partially, preferably completely, encapsulated by a preferably non-transparent, second plastic injection-molded part.A plurality of recesses are formed between the electronic circuit board and a top side of the first plastic injection-molded part. The electronic device comprises a plurality of preferably transparent light-guiding elements that, in the first manufacturing state, can be or are inserted selectively into the recesses for light guidance in order to form light-guiding sections above the light sources. In the second manufacturing state, protruding web sections of the inserted light-guiding elements on the top side of the first plastic injection-molded part are overmolded by the second plastic injection-molded part for fixation and are not completely overmolded for light emission. Open recesses are preferably filled in the second manufacturing state.

[0016] Preferably, the light-guiding elements are inserted into the recesses following the production of the first plastic injection-molded part and before overmolding with the second plastic injection-molded part. In the first manufacturing stage, the first plastic injection-molded part is already formed with recesses, and the light-guiding elements can be inserted into them. This has the advantage that the light-guiding elements can be positioned and secured, and the positioning withstands the mechanical stress of a subsequent injection-mold process, particularly a high-pressure injection-mold process. Furthermore, the first plastic injection-molded part advantageously protects the electronic circuit board from environmental influences.

[0017] Further preferably, the web sections are overmolded by the second plastic injection-molded part for fixation and preferably form an undercut to fix the light-guiding elements within the recesses. Preferably, an upper side of the light-guiding elements for the light exit is not overmolded.

[0018] In other words, the electronic device has flexibly deployable light-guiding elements that, when inserted, enable light to be guided between the light sources of the electronic circuit board and preferably a device surface. If no light-guiding element is inserted in a recess, the recess is preferably filled by the second plastic injection-molded part in the second manufacturing state, which is why no light transmission occurs.

[0019] The recesses are preferably formed above predefined lighting positions on the electronic circuit board, which are provided for mounting the light source. Depending on the application, a light source can be arranged at the lighting positions or not, with light-guiding elements preferably only being used at lighting positions occupied by light sources. Particularly preferably, each lighting position is assigned a recess to prevent crosstalk between the light sources.

[0020] The light sources are preferably LED light-emitting diodes, which can be arranged on the surface of the electronic circuit board to save space.

[0021] The projecting web sections at the ends of the light-guiding elements preferably serve to ensure that, in the second manufacturing state, the light-guiding elements can be overmolded and fixed in the recesses of the second plastic injection-molded part, wherein the light-guiding elements, in particular an upper side of the light-guiding elements, in particular an upper side parallel to the electronic circuit board, remain visible from an outer side. In other words, the light from the light sources can be transmitted through the light-guiding elements after the second overmold to a device end or a device surface and is advantageously visible from multiple perspectives due to the raised contour of the web sections.

[0022] The invention advantageously recognizes that the insertable light-guiding elements can be flexibly distributed among the recesses in the first plastic injection-molded part. Thus, depending on the electronic circuit board used, recesses can also be left open in order to create different states or variants of the electronic device. Preferably, recesses can be left open without any associated light source, which are then preferably closed in the second manufacturing state. This advantageously ensures clear assignment of light signals to the at least one plug connection, preferably to several plug connections, with good recognizability. In particular, false signaling can be largely eliminated. Furthermore, advantageously, no new injection-molding tools are required to produce electronic devices with varying numbers of light sources.

[0023] In particular, electronic devices with different LED layouts can be configured on the electronic circuit board. For example, one or two light sources can preferably be assigned to a plug connection. It is also conceivable for a plug connection to have no light sources, and the recesses adjacent to this plug connection are preferably closed.

[0024] Alternatively or additionally, a cable outlet can be provided as a plug connection.

[0025] According to a preferred embodiment, the light-guiding elements are designed as a transparent third plastic injection-molded part for guiding light, wherein the second plastic injection-molded part is not transparent and wherein open recesses are filled in the second manufacturing state. This preferably makes it possible to set a high contrast between the light-guiding element and the second plastic injection-molded part and to improve a clear light display for an operator. More preferably, the second plastic injection-molded part completely encloses the first plastic injection-molded part, wherein holding sections for the first plastic injection-molded part in the injection mold can preferably only be visible on an underside. At least on an upper side of the electronic device, the second plastic injection-molded part can advantageously fix the light-guiding elements in the recesses and fill open recesses.

[0026] Furthermore, it is conceivable that the light-guiding element is partially transparent in order to adjust the intensity of the light guide.

[0027] Furthermore, it may be preferred that the first plastic injection-molded part has a transparent or at least partially transparent plastic layer as part of the light-guiding sections between a top side of the light sources and a bottom side of the recesses, in order to seal the electronic circuit board in the area of ​​the light sources as well. This has the advantage that the electronic circuit board can preferably be completely sealed against external environmental influences and the ingress of moisture is prevented.

[0028] The thickness of the plastic layer is preferably between 0.3 mm and 0.7 mm, particularly preferably 0.5 mm. Such a thin layer is sufficient to seal the electronic circuit board and simultaneously enable light guidance even for partially transparent first plastic injection-molded parts. In other words, due to the low thickness, even first plastic injection-molded parts can be used that are not completely transparent. This increases the choice of materials for overmolding the electronic circuit board, and partially opaque plastics optimized for the injection-molding process can be used. Furthermore, optical crosstalk between the light sources can be prevented by the partially opaque first plastic injection-molded part.

[0029] Alternatively or additionally, it may be preferred for the light-guiding element to be formed as a third plastic injection-molded part made of the same material as the first plastic injection-molded part. Advantageously, the identical thermal expansion coefficient can reduce thermal stresses on the light-guiding elements used. In this context, the first plastic injection-molded part is preferably also transparent to improve light transmission to the light-guiding elements.

[0030] The first plastic injection-molded part can preferably be formed from a foam-molded material. In particular, the first plastic injection-molded part can be produced using a thermoplastic foam injection molding (TSG) process. The foam-molded material preferably has a first pore density, particularly in the region of the at least one plug connection, wherein the preferred plastic layer above the light sources has a reduced second pore density or completely closed pores. The second pore density is reduced by selecting the thickness of the plastic layer and / or a blowing agent for the foam-molded material such that the plastic layer is transparent or at least partially transparent to light radiation from the light sources. In other words, the intermediate layer between the light source and the recess has such a low pore density that the foam-molded material locally forms part of the light-guiding section.In particular, the low thickness of the plastic layer allows for a locally higher pressure to be built up during the injection molding process, which prevents or reduces the expansion of a plastic melt and reduces the second pore density compared to the first pore density. This allows the advantageous properties of injection-molded foam material to be utilized while simultaneously forming a homogeneous light-guiding section through the plastic layer with little or no air inclusions for guiding the light. Furthermore, the foam material with the first pore density can be used advantageously for materials with low transparency or that strongly scatter light due to pores. Preferably, a transparent plastic material is foamed.

[0031] The use of foam-molded materials offers the particular advantages of weight reduction, reduced warpage of the overmolded electronic device, increased rigidity relative to weight, and / or lower process temperatures. Furthermore, mechanical and / or thermal stress on the electronic components of the electronic board during the overmold process can be advantageously reduced.

[0032] According to a preferred embodiment, the light-guiding element has a circumferential edge structure which, in the second manufacturing state, is enveloped by the second plastic injection-molded part in order to fix the light-guiding element in the recess. In the assembled state, the edge structure preferably forms a support surface transverse to a mounting direction in order to align the light-guiding element on the upper side of the first plastic injection-molded part. Advantageously, the edge structure can improve sealing of the electronic component against external environmental influences. Furthermore, the edge structure enables a defined mounting orientation and can prevent varying inclination. In addition, it can be prevented that the light-guiding element is inserted too deeply into the recess along the mounting direction and possibly damages the electronic circuit board. A defined mounting distance from the light sources can also preferably be set in this way.

[0033] In this context, it may be further preferred for the upper side of the first plastic injection-molded part to be laterally sloping or curved transversely to an assembly direction, with recesses being formed adjacent to the recesses to accommodate the peripheral edge structure of the light-guiding element. Preferably, despite a non-flat or curved upper side, a plane-parallel support surface for the edge structure can be formed in this way in order to align the light-guiding element.

[0034] Furthermore, it may be preferred that the edge structure is formed by a cross-sectional reduction of the light-guiding element such that, in the second manufacturing state, the second plastic injection-molded part encloses the cross-sectional reduction and forms an undercut to secure the light-guiding element. Preferably, the second plastic injection-molded part encloses the light-guiding element such that an upper side of the light-guiding element remains visible for the light exit, and particularly preferably, the second plastic injection-molded part adjoins the upper side of the light-guiding element in order to form the most flat surface possible of the electronic device.

[0035] According to a preferred development, the recesses have an enlarged cross-section along the insertion direction between the electronic circuit board and the top side of the first plastic injection-molded part. In other words, the recess is preferably conical in shape to enable undercut-free injection molding. Additionally, the light-guiding element can be pressed into the recess to enable a force-fit connection and, additionally, improved sealing.

[0036] Preferably, the second plastic injection-molded part and preferably the first plastic injection-molded part are manufactured using a high-pressure injection molding process. The high-pressure injection molding process preferably provides a good seal for an exit area of ​​the optical fiber element on a top side of the electronic device. The device manufactured using the high-pressure injection molding process is therefore resistant to water jets, submersion, and dust. Advantageously, the high-pressure injection molding parameters for the thermoplastic material are 300–1000 bar and 280°C.

[0037] Compared to high-pressure injection molding, casting processes have the disadvantage that gaps can occur, and frequent temperature changes can cause cracks to form in the area of ​​openings such as the optical fiber element. In particular, moisture penetration into the device cannot be prevented. These disadvantages can be advantageously overcome by the high-pressure injection molding process.

[0038] The invention further relates to a method for producing an electronic device, in particular the device described above, having an electronic circuit board on which at least one plug connection, in particular a plurality of plug connections, and a plurality of light sources are arranged. The method comprises the following steps in a preferred order. According to a preferred first step, the electronic circuit board is overmolded with a first plastic injection-molded material such that a first plastic injection-molded part with recesses for guiding light is formed between the electronic circuit board and an upper side of the first plastic injection-molded part. In a preferred second step, preferably transparent and preferably injection-molded light-guiding elements are inserted into the recesses.In a preferred third step, the first plastic injection-molded part is overmolded with a preferably non-transparent second plastic injection-molding material using a high-pressure injection-molding process, whereby the light-guiding elements are not completely overmolded and light-guiding sections for the light sources are formed. Particularly preferably, open recesses or recesses into which no light-guiding element is selectively inserted are filled with the second plastic injection-molding material. The light-guiding elements are preferably arranged in regions above the light sources, whereby recesses to which no light source is assigned are preferably not filled with light-guiding elements.

[0039] According to a preferred embodiment, the first plastic injection molding material can be foamed as a foam molding material and the electronic circuit board can preferably be overmolded in a thermoplastic foam injection molding process, wherein a foam molding material surrounds the electronic circuit board with a first pore density and wherein above the light source the plastic layer has a lower second pore density or is formed without pore formation.

[0040] A foam injection molding process has the advantage that a flow length can be increased with a reduced melt viscosity. In addition, a clamping force for an injection mold and a cycle time can be reduced. Furthermore, a melt and mold temperature can advantageously be reduced. In addition, volume shrinkage during a cooling process and a transition from the liquid to the solid state can be advantageously reduced due to the gas pressure present during foaming. This can reduce mechanical stresses on electronic components of the electronics board, which can be transmitted through the injection molding material in the solidified state. Furthermore, warpage stresses can be reduced due to the increased elasticity of the foam molding material. For the foam injection molding process, a plastic, in particular a thermoplastic, can preferably be melted and enriched with a blowing agent.The plastic melt is then injected into an injection mold, where it expands due to a pressure drop and forms pores. Within the injection mold, the melt is distributed with a first pore density, whereby foaming within gap-like mold sections can be reduced to a second pore density, or pores can close completely. After cooling, the foamed material can be removed from the injection mold.

[0041] According to a further preferred embodiment, it is additionally or alternatively conceivable that an inert gas is supplied to the plastic melt under pressure to form a gas-melt mixture. The pressure drop within the injection mold also leads to pore formation and foaming.

[0042] The foam molding material with the second reduced pore density is preferably produced in the region of the light sources to enable the light-guiding section. In particular, foamed plastic material is injected into a gap channel formed along a lighting direction between the at least one light source and an injection mold by a reduced mold height of the injection mold. The foamed plastic material is compressed in the gap channel and foaming is reduced or prevented in order to form a light exit layer for the at least one light source with completely closed pores or a reduced second pore density. This is preferably a transparent plastic material that is foamed and retains its transparent properties above the light sources.

[0043] According to a preferred embodiment, an alignment device is used to position the light-guiding elements in order to mount them simultaneously and automatically into the recesses.

[0044] The invention is explained in more detail below using exemplary embodiments with reference to the drawings.

[0045] They show schematically: Fig. 1 : perspective view of an electronic device with first

[0046] Plastic injection-molded part in a first production state,

[0047] Fig. 2: Perspective view of a light guide element which is inserted into the first

[0048] Plastic injection-molded part according to Fig. 1 can be used,

[0049] Fig. 3: Cross-sectional view of the electronic device according to Fig. 1 in a section AA,

[0050] Fig. 4: perspective view of the electronic device according to Fig. 1 in a second manufacturing state with a second plastic injection-molded part,

[0051] Fig. 5: Cross-sectional view of the electronic device according to Fig. 4 in a section area BB.

[0052] In the following description of the preferred embodiments, like reference numerals designate like or comparable components.

[0053] Fig. 1 and Fig. 3 show an electronic device 10 in a first manufacturing state 16a, in particular a so-called pre-molded part, wherein an electronic circuit board EP, in particular an electronic distribution component, is shown overmolded by a first plastic injection-molded part T1. The interior of the first plastic injection-molded part T1 with the electronic circuit board EP and the exemplary light source 14 arranged thereon and the overmolded plug connection 12 can be seen in detail in Fig. 3.

[0054] As Fig. 1 further shows, recesses 20 are formed in the first plastic injection-molded part T1, with preferably two recesses 20 being assigned to each plug connection 12. The recesses 20 are preferably arranged along an assembly direction M between an upper side 18 of the first plastic injection-molded part T1 and the electronics circuit board EP. Light-guiding elements 22 can be inserted or are inserted into the recesses 20 in order to guide light from the light sources 14 towards the upper side 18. This light guidance can indicate a function of the plug connection 12 during operation. It may happen that not every recess 20 is assigned a light source 14 on the electronics circuit board EP. Preferably, no light-guiding element 22 is inserted into these recesses 20 without a light source 14. In the assembled state, the light-guiding element 22 preferably protrudes from the upper side 18 of the first plastic injection-molded part T1 with a web section ST.

[0055] The light-guiding element 22 can preferably be formed as a third transparent or at least partially transparent plastic injection-molded part T3 to enable light guidance. The first and third plastic injection-molded parts T1, T3 can preferably be formed from the same material. Alternatively, it is also conceivable for the first plastic injection-molded part T1 to be formed from a different material. This has the advantage that the material of the first plastic injection-molded part T1 can be selected with a view to optimizing the injection-molding process and is not limited to a particularly transparent plastic for light guidance.

[0056] Figure 2 shows the light-guiding element 22 in detail with a preferred circumferential edge structure 24 and the web section ST. Below the edge structure 24, the light-guiding element 22 is configured to match the geometry of the recesses 20 to enable a preferably force-fitting press-fit into the recesses 20 in the assembled state.

[0057] Fig. 3 further shows that recesses 26 are formed adjacent to the cutouts 20 on the upper side 18 in order to receive the edge structure 24 of the light-guiding element 22 in a plane-parallel manner and to align it along the mounting direction M. The recess 26 is preferably also formed because the upper side 18 of the first plastic injection-molded part T1 is preferably beveled or curved laterally or transversely to the mounting direction M in order to improve lateral visibility of the light-guiding elements 22. Further preferably, the recess 20 is conically tapered, in particular with a decreasing cross-section in the direction of the electronics board EP along the mounting direction M.

[0058] Additionally, Fig. 3 shows that a thin plastic layer 30 or intermediate layer is formed between a top side 28 of the light sources 14 and a bottom side 27 of the recesses 20 by the first plastic injection-molded part T1 in order to completely enclose and seal the electronic circuit board EP. The plastic layer 30 is transparent or at least partially transparent in order to form, together with the light-guiding element 22, a light-guiding section 32 for the light sources 14.

[0059] A thickness t of the plastic layer 30 is preferably selected such that even with a partially non-transparent first plastic injection-molded part T1, light guidance along the mounting direction M is enabled. The thickness t is preferably less than 1 mm, in particular 0.3 mm to 0.7 mm, particularly preferably 0.5 mm.

[0060] In this context, it may alternatively or additionally be preferred that the first plastic injection-molded part T1 is formed from a foam molding material, in particular a thermoplastic foam molding material, or is produced using a foam injection molding process. Preferably, the first plastic injection-molded part T1 has a first pore density adjacent to the plug connections 12 and the electronic circuit board EP, with a second pore density being reduced in the plastic layer 30 in order to form the light guide. The small thickness t of the plastic layer 30 has the advantage that foaming is reduced or prevented during the injection molding process, and the light guide can advantageously be formed.

[0061] Fig. 4 and Fig. 5 show the electronic device 10 in the second manufacturing state 16b, wherein the first plastic injection-molded part T1 is overmolded by a second non-transparent plastic injection-molded part T2, wherein the light-guiding elements 22 are not completely overmolded for light guidance. In the region of the recesses 20 without an inserted light-guiding element 22, the recess 20 is completely filled by the material of the second plastic injection-molded part T2. This advantageously prevents no light guides from being formed for regions without a light source 14. Advantageously, this allows light guides for electronic circuit boards EP with a different number of light sources 14 to be formed without having to modify or adapt an injection mold for the first plastic injection-molded part T1.

[0062] In other words, an active light guide can be formed by the light-guiding element 22. In this case, Fig. 5 additionally shows a closed recess region 21 in the second plastic injection-molded part T2, wherein the light guide is advantageously closed by the electronic overmolding.

[0063] 10 electronic device

[0064] 12 plug connections

[0065] 14 light sources

[0066] 16a, b first and second manufacturing stage

[0067] 18 Top of the first plastic injection molded part

[0068] 20 recesses in the first plastic injection-molded part

[0069] 21 closed recess area in the second plastic injection molded part

[0070] 22 Light guide element

[0071] 24 surrounding edge structure

[0072] 26 recess for edge structure

[0073] 27 Bottom of the recesses

[0074] 28 Top of the light sources

[0075] 30 plastic layer

[0076] 32 light guide sections

[0077] EP electronic board or electronic board

[0078] T1 first plastic injection-molded part

[0079] T2 second plastic injection molded part

[0080] T3 third plastic injection molded part

[0081] ST web sections

[0082] M Mounting direction t Thickness of the plastic layer

Claims

Patent claims 1. An electronic device for automation technology comprising an electronic circuit board (EP) overmolded twice with plastic, on which at least one plug connection (12) and a plurality of light sources (14) are arranged, wherein the electronic circuit board (EP) is embedded in a first plastic injection-molded part (T1) in a first manufacturing state (16a), and wherein, in a second manufacturing state (16b), the first plastic injection-molded part (T1) is at least partially overmolded by a second plastic injection-molded part (T2), characterized in that a plurality of recesses (20) are formed between the electronic circuit board (EP) and an upper side (18) of the first plastic injection-molded part (T1), wherein the electronic device (10) comprises a plurality of light-guiding elements (22) which, in the first manufacturing state (16a), can be or are inserted selectively into the recesses (20) for light guidance in order to form light-guiding sections (32) above the light sources (14) in the inserted state.wherein, in the second manufacturing state (16b), projecting web sections (ST) of the inserted light-guiding elements (22) on the upper side (18) of the first plastic injection-molded part (T1) are overmolded by the second plastic injection-molded part (T2) for fixing and are not completely overmolded for light emission.

2. Electronic device according to claim 1, characterized in that the light-guiding elements (22) form a transparent third plastic injection-molded part (T3) for guiding the light, wherein the second plastic injection-molded part (T2) is not transparent and wherein open recesses (20) are filled in the second manufacturing state (16b).

3. Electronic device according to claim 1 or 2, characterized in that between an upper side (28) of the light sources (14) and a lower side (27) of the recesses (20) the first plastic injection-molded part (T1) has a transparent or at least partially transparent plastic layer (30) as part of the light guide sections (32) in order to seal the electronic circuit board (EP), wherein a thickness (t) of the plastic layer (30) is preferably between 0.3 mm and 0.7 mm, particularly preferably 0.5 mm.

4. Electronic device according to claim 3, characterized in that the first plastic injection-molded part (T1) is formed from a foam-molded material, which is preferably produced in a thermoplastic foam injection-molded process, wherein a foam-molded material surrounds the electronic circuit board (EP) with a first pore density and wherein above the light sources (14) the plastic layer (30) has a lower second pore density or is formed without pore formation.

5. Electronic device according to one of claims 1 to 4, characterized in that the light-guiding element (22) has a circumferential edge structure (24) which, in the second manufacturing state (16b), is enveloped by the second plastic injection-molded part (T2) in order to fix the light-guiding element (22) in the recess (20).

6. Electronic device according to claim 5, characterized in that the upper side (18) of the first plastic injection-molded part (T1) is designed to be laterally sloping or curved transversely to a mounting direction (M), wherein recesses (26) are formed adjacent to the recesses (20) in order to receive the peripheral edge structure (24) of the light-guiding element (22).

7. Electronic device according to one of claims 1 to 6, characterized in that the recesses (20) have a tapered cross-section starting from the upper side (18) of the first plastic injection-molded part (16a) along a mounting direction (M) to the electronic circuit board (EP).

8. Electronic device according to one of claims 1 to 7, characterized in that the second plastic injection-molded part (T2) and preferably the first plastic injection-molded part (T1) is / are produced by means of a high-pressure injection-molding process.

9. A method for producing an electronic device (10), in particular according to one of claims 1 to 8, comprising an electronic circuit board (EP) on which at least one plug connection (12) and a plurality of light sources (14) are arranged, comprising the following steps: - overmolding the electronic circuit board (EP) with a first plastic injection molding material such that a first plastic injection molded part (T1) with recesses (20) for guiding light is formed between the electronic circuit board (EP) and an upper side (18) of the first plastic injection molded part (T1), - Subsequent insertion of light guide elements (22) into the recesses (20), - Overmolding the first plastic injection-molded part (T1) in a high-pressure injection-molding process with a second plastic injection-molding material, wherein the light-guiding elements (22) are not completely overmolded and form light-guiding sections (32) for the light sources (14).

10. Method according to claim 9, characterized in that an alignment device is used to position the light-guiding elements (22) in order to simultaneously and automatically mount the light-guiding elements (22) in the recesses (20).

11. Method according to claim 9 or 10, characterized in that for the production of the first injection-molded part (T1) the electronic circuit board (EP) is injection-molded with a foamed plastic material is overmolded to form a foam molding material with a first pore density, wherein during the injection molding process the foamed plastic material is injected into a gap channel which is formed along a lighting direction between the light sources (14) and the injection molding tool by a reduced mold height of the injection molding tool, wherein in the gap channel the foamed plastic material is compressed and foaming is reduced or prevented in order to form a light exit layer for the light sources (14) with completely closed pores or a reduced second pore density

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