Electronic component and methods for its manufacture

Abstract

Electronic component (10) for a motor vehicle, comprising a printed circuit board (12) and at least one sensor element (16) which is inserted into a recess (14) in an end face of the printed circuit board (12) such that the sensor element (16) is completely embedded in a material of the printed circuit board (12).

Description

The invention relates to an electronic component, in particular for a motor vehicle, and a method for its manufacture. Electronic components, such as those used in control units, are increasingly found in modern motor vehicles. These components often include sensors that detect vehicle operating parameters. For example, Hall effect sensors or magnetoresistive sensors are used to monitor the position of transmission components. Due to limited installation space, such sensors are usually mounted separately in so-called sensor domes and connected to associated evaluation electronics via electrical cables. This involves significant manufacturing effort and can also negatively impact durability due to the exposed connecting cables. Exposed connecting cables also impair the quality of the signal provided by the sensor, as electrical interference signals can be coupled in via these connecting cables and chemical attack on the material of the connecting cables is possible. From US 2015 / 0 163 912 A1, a printed circuit board with stacked units is known, in which a projecting section of a first unit extends over and projects beyond at least one of the outer edges of a non-conductive substrate of a second unit. The projecting section of the first unit includes at least a portion of a conductor of the first unit, and this portion of the conductor is configured to connect to an electronic device. The electronic device has conductive terminals that project from the housing of the electronic device such that a gap is formed between the terminals. The projecting section of the first unit can be positioned in this gap. US Patent 7,348,497 B2 discloses a mounting device for electronic components comprising a printed circuit board (PCB) having a stepped section at one of its end sections. A terminal of the electronic component is enclosed within the stepped section to secure the terminal to the stepped section. The stepped section is formed by perforating an area on a surface of the PCB and then peeling back a portion of the PCB corresponding to the perforated area to reduce the PCB thickness in that area. From DE 38 31 551 A1, a printed circuit board with a metallic substrate is known, on which a planar insulating layer and on this an insulating layer with individual metallic conductors for connecting electrical components are provided. At least one recess for receiving a component is embossed into the printed circuit board. This allows the component to be positioned precisely and easily. It is therefore an object of the present invention to provide an electronic component for a motor vehicle that is simple and inexpensive to manufacture, durable, and not very susceptible to failure. It is further an object of the present invention to provide a method for manufacturing such an electronic component. This problem is solved by an electronic component having the features of claim 1 and by a method having the features of claim 10. Such an electronic component, designed in particular for a motor vehicle, comprises at least one printed circuit board and at least one sensor element which is inserted into a recess in an end face of the printed circuit board in such a way that the sensor element is completely embedded in a material of the printed circuit board. This results in a particularly compact design for the electronic component. This allows the entire electronic component to be installed directly within a sensor dome, eliminating the need for additional connecting cables. Such a component can therefore be manufactured using very few parts and assembly steps. Furthermore, the component according to the invention thus has a particularly short signal path between the sensor element and the associated circuits arranged on the circuit board, resulting in only a low susceptibility to electrical interference. At least a first stage of signal processing can therefore be carried out in the immediate vicinity of the sensor element, so that a particularly good signal-to-noise ratio can be achieved. According to the invention, the recess is provided in an end face of the circuit board. In this way, the sensor can be at least partially or completely embedded in the printed circuit board material, resulting in a very compact design. This allows the electrical component to be used even in confined spaces. Furthermore, it is advantageous to use a sensor with a compact form factor, such as an SMD sensor (surface-mounted device). In another preferred embodiment, the circuit board is equipped with additional electronic components on both sides. This allows a particularly large number of components to be accommodated in a small space, resulting in a particularly small surface area of ​​the circuit board, which can therefore also be used under confined conditions. Furthermore, it is advantageous if at least one first contact of the at least one sensor element is connected to a first component side of the circuit board and at least one second contact of the at least one sensor element is connected to a second component side of the circuit board. In a further preferred embodiment of the invention, the sensing direction of the at least one sensor element is directed away from the circuit board. This prevents the mass of the circuit board from interfering with the sensing. In a further preferred embodiment of the invention, a positioning groove is provided for the at least one sensor element. This facilitates the positioning of the at least one sensor element during installation. In this way, incorrect installation and the resulting rejects can be avoided. In a further preferred embodiment of the invention, at least one additional recess is provided for a shielding plate and / or a pole plate of the at least one sensor element. Such components can improve the sensor's measurement quality. By also arranging shielding plates or pole plates in recesses of the circuit board, these components can be used without increasing the space required for the electronic component. In another preferred embodiment of the invention, the circuit board is equipped with at least one interference suppression component. This also contributes to achieving a particularly high signal quality with respect to the sensor signal. Such an arrangement is also advantageous because the interference suppression can take place in the immediate vicinity of the sensor element without the need for long signal paths. In a further preferred embodiment of the invention, the at least one sensor element is designed as a Hall sensor or magnetoresistive sensor. Such sensors can be used in particular for monitoring the position of mechanical components. In another preferred embodiment of the invention, the electronic component is designed for a transmission control system of a motor vehicle. Especially under the confined installation space conditions in modern automatic transmissions, the component according to the invention can particularly demonstrate its advantages. Naturally, an electronic component of the described type can also be used in other applications, particularly when sensor elements are used that require signal processing located in close proximity. The invention further relates to a method for manufacturing an electronic component. The method according to the invention comprises the steps of: - providing a printed circuit board; - creating at least one recess in an end face of the printed circuit board; - inserting at least one sensor element into the recess and electrically contacting the at least one sensor element with the printed circuit board such that the sensor element is completely embedded in a material of the printed circuit board. As already explained with reference to the electronic component according to the invention, an electronic component can be created in this way whose manufacture requires very few steps and components. In particular, the installation of additional connecting lines and associated connecting elements such as plugs or stamped strips can be dispensed with. Additional injection molding steps for producing a mechanical base body for the connection to the sensor element are also eliminated. In a further preferred embodiment of the invention, the at least one recess is created by milling, in particular into an end face of the printed circuit board. This allows the recess to be created without interfering with the subsequent manufacturing process for the printed circuit board (PCB). The PCB can therefore be manufactured using all standard conductive trace technology methods. The recess can be created after the complete PCB has been prepared. In addition to milling, other separating processing techniques, such as laser cutting, can also be used to create the recess. In a further preferred embodiment of the invention, a positioning groove is provided in the circuit board before the insertion of the at least one sensor element, and the at least one sensor element is positioned by means of the positioning groove during insertion. This simplifies the positioning of at least one sensor element during installation. In this way, incorrect installation and the resulting scrap can be avoided. In a further preferred embodiment of the invention, at least one further recess is provided in the circuit board, into which a pole plate and / or a shielding plate of the at least one sensor element is inserted. As already explained, in this way additional elements that improve the signal quality of the sensor element can be integrated into the electronic component without significantly increasing the installation space required. In a further preferred embodiment of the invention, the electrical contact of the at least one sensor element is carried out by soldering, in particular reflow soldering, and / or gluing with a conductive adhesive. This creates a reliable and durable electrical connection between the sensor element and the circuit board, without the need for additional components. The invention and its embodiments are explained in more detail below with reference to the drawing. Fig. 1 shows a schematic perspective view of an embodiment of an electronic component according to the invention. An electronic component, designated as a whole by 10, which may, for example, be part of a transmission control unit for an automatic transmission of a motor vehicle, is mounted on a printed circuit board 12. The printed circuit board 12 includes a recess 14 in its end face, into which a sensor element 16 is inserted. The sensor element 16 can, for example, be a Hall sensor or a magnetoresistive sensor, whose sensing direction is directed away from the circuit board 12, and which can be designed in SMD construction. The sensor element 16 is connected via contacts 18 to conductor tracks (not shown in the figure) on a first component side 20 of the circuit board 12. The circuit board 12 also has a second component side 22, which is hidden in the figure. The sensor element 16 is also connected to the second component side 22 via further contacts. On the first component side 20 of the circuit board 12, electronic components 24 are arranged which can, for example, form an interference suppression circuit to protect the measured values ​​detected by the sensor element 16 from interference. The circuit board 12 also has mounting openings 26, via which the circuit board 12 can be connected to other components, for example by screwing them in. The printed circuit board 12 can be manufactured using standard printed circuit board manufacturing processes. For example, it can be a single- or multi-layer epoxy board, which can be produced by curing one or more layers of a resin-impregnated fiber prepreg. Boards based on polyimide or similar plastics can also be used. Conventional methods such as mask etching, electroplating, laser drilling, or similar processes can be used to apply conductive traces, mounting holes, or vias. The recess 14 is preferably milled into the printed circuit board 12, but other separation methods such as laser cutting are also conceivable. This can be done before or after the printed circuit board 12 is populated with components. The thickness of the circuit board 12 depends on the width of the sensor package. The dimensions of the recess 14 depend on the length of the sensor package. In addition to the recess 14, further recesses may be provided into which, for example, components supporting the sensor element 16, such as pole plates or shielding plates, can be inserted. Positioning grooves that facilitate the insertion of the sensor element 16 into the recess 14 may also be provided. The components 24 can be any type of active or passive electronic component. In addition to the aforementioned interference suppression circuit, they can also form other or further circuits for processing the signals from the sensor element 16, such as preamplifiers, filters, analog-to-digital converters, or the like. This results in a particularly compact electronic component 10, which can be used, for example, as a local control unit for an automatic transmission or as a sensor driver for a sensor dome. The short signal paths between the sensor element 16 and the electronic components 24 ensure particularly good signal quality. Furthermore, because the sensor element 16 is installed in the recess 14 of the circuit board 12, connecting elements between the circuit board 12 and the sensor element 16 are unnecessary. Thus, the electronic component 10 is manufactured with very few process steps.

Claims

Electronic component (10) for a motor vehicle, comprising a printed circuit board (12) and at least one sensor element (16) which is inserted into a recess (14) in an end face of the printed circuit board (12) such that the sensor element (16) is completely embedded in a material of the printed circuit board (12). Electronic component (10) according to claim 1, wherein the circuit board (12) is equipped on both sides with further electronic components (24). Electronic component (10) according to claim 2, in which at least a first contact (18) of the at least one sensor element (16) is connected to a first component side (20) of the printed circuit board (12) and at least a second contact of the at least one sensor element (16) is connected to a second component side (22) of the printed circuit board (12). Electronic component (10) according to one of the preceding claims, wherein a sensing direction of the at least one sensor element (16) is directed away from the circuit board (12). Electronic component (10) according to one of the preceding claims, in which a positioning groove is provided for the at least one sensor element (16). Electronic component (10) according to one of the preceding claims, in which at least one further recess is provided for a shielding plate and / or a pole plate of the at least one sensor element (16). Electronic component (10) according to one of the preceding claims, wherein the printed circuit board (12) is equipped with at least one interference suppression component. Electronic component (10) according to one of the preceding claims, wherein the at least one sensor element (16) is designed as a Hall sensor or magnetoresistive sensor. Electronic component (10) according to one of the preceding claims, which is designed for a transmission control of a motor vehicle. Method for manufacturing an electronic component (10), comprising the steps: - providing a printed circuit board (12); - providing at least one recess (14) in an end face of the printed circuit board (12); - inserting at least one sensor element (16) into the recess (14) and electrically contacting the at least one sensor element (16) with the printed circuit board (12) such that the sensor element (16) is completely embedded in a material of the printed circuit board (12). Method according to claim 10, wherein the at least one recess (14) is milled into the end face of the printed circuit board (12). Method according to claim 10 or 11, in which a positioning groove is provided in the circuit board (12) before the insertion of the at least one sensor element (16) and the at least one sensor element (16) is positioned by means of the positioning groove during insertion. Method according to one of claims 10 to 12, in which at least one further recess is provided in the circuit board (12) into which a pole plate and / or a shielding plate of the at least one sensor element (16) is inserted. Method according to one of claims 10 - 13, wherein the electrical contacting of the at least one sensor element (16) is carried out by soldering, in particular reflow soldering, and / or bonding with a conductive adhesive.

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