The invention is based on a sensor casing of the kind referred to in independent patent claim 1. The subject-matter of the present invention is also a method for potting an open receiving space of a sensor casing of this kind.
It is known from the prior art for electronic components to be potted using sealing compounds such as epoxides and silicones, for example, in order to protect against humidity, corrosion and electrical shunt. Consequently, it is common practice for an open receiving space in a sensor casing, which receives electronic components of the sensor, to be filled with an epoxy resin compound or a silicon compound, in order to protect against humidity, corrosion, electrical shunts, etc.
Particularly in the case of compact sensors, such as a speed sensor, for example, the combination of the capillarity of small dimensions, a complex geometry and/or concave edges and a hydrophilic wetting behavior can cause the potting compound to run off during the potting process. This may result in the contamination of products and facilities with potting compound.
A workpiece composite for a pressure sensor is known from DE 10 2008 042 489 B4. The workpiece composite comprises a preform and a gel which is received in a recess in the preform. The recess is enclosed by at least one edge acting as a creep barrier, in order to prevent the gel from spreading. At least one area closed off by the edge is provided with a coating made of an oleophobic material in a region adjacent to the edge. The coating of an oleophobic material prevents the gel from creeping into this area.
The sensor casing having the features of the independent patent claim 1 has the advantage that the circumferential edge is suitable for holding the potting compound in the defined region. In this way, the circumferential edge prevents the potting compound from running out and contaminating the product and facility due to the outwardly descending slope. In addition, a permitted temporary overfilling of the receiving space allows a stable and robust potting process with quicker cycle times.
Furthermore, exemplary embodiments of the sensor casing according to the invention in the region of the open receiving space have a simple geometry that can easily be transferred to different design variants which may differ in terms of sensor length, sensor width, number of electronic components, for example. In addition, the sensor casing can be produced as an expendable injection-molded part.
Embodiments of the present invention provide a sensor casing with an open receiving space, which has a circumferential edge at the open end as a creep barrier. The receiving space is filled with a potting compound, wherein the hardened potting compound forms a concave surface to the circumferential edge. In this case, the circumferential edge has an outwardly descending slope which allows temporary overfilling of the receiving space during a potting process, forming a stable convex potting compound surface.
In addition, a method is proposed for potting an open receiving space of a sensor casing of this kind. In this case, the receiving space is filled with potting compound until a stable convex potting compound surface is formed at a circumferential edge of the open end. The potting compound filling is then hardened.
Embodiments of the sensor casing can preferably be used in compact speed sensors. Embodiments of the sensor casing can of course also be used for other compact sensors.
Through the measures and developments specified in the dependent claims, advantageous improvements of the sensor casing specified in independent patent claim 1 are possible.
It is particularly advantageous for edges of the receiving space to be able to be configured as fillets in the ascending direction. Hence, the receiving space may have a rectangular base area with round or concave corner regions, for example. In addition, the receiving space may have at least one rounded or concave indentation or at least one rounded or concave projection. The fillets formed in the ascending direction of the potting compound mean that sharp edges are avoided, which can favor a run-off of the potting compound during the potting process.
In an advantageous embodiment of the sensor casing, the outwardly descending slope may have a slope angle in the range of 20° to 70°, preferably a slope angle of 45°. In addition, the circumferential edge may have a height in the range of 0.1 to 1 mm.
In a further advantageous embodiment of the sensor casing, the receiving space may receive at least one electronic component of a sensor, which can be protected by the hardened potting compound. The at least one electronic component may be configured as an ASIC component (ASIC: Application-Specific Integrated Circuit), for example.
Exemplary embodiments of the invention are depicted in the drawing and are explained in greater detail in the following description. In the drawing, the same reference signs denote components or elements which perform the same or similar functions.
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In accordance with the method according to the invention for potting an open receiving space 3, 3A, 3B of a sensor casing 1, 1A, 1B of this kind, the receiving space 3, 3A, 3B is filled with potting compound 16 until a stable convex potting compound surface 16A depicted in
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In an alternative exemplary embodiment of the sensor housing 1 according to the invention which is not shown, the receiving space 3 has at least one rounded indentation.
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The exemplary embodiments of the sensor casing 1, 1A, 1B shown are preferably used for a speed sensor. In this case, the receiving space 3, 3A, 3B receives at least one electronic component of the speed sensor, which is protected by the hardened potting compound 16. In this case, the first exemplary embodiment of the sensor casing 1A according to the invention shown in
Number | Date | Country | Kind |
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10 2020 200 848.5 | Jan 2020 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/051137 | 1/20/2021 | WO |