Sensor and method for manufacturing a sensor

Abstract

The invention relates to a sensor, in particular a pressure sensor, comprising a sensing element for detecting a property and / or a composition of a surrounding medium of the sensor, a transmission medium for transmitting the property and / or the composition of the surrounding medium to the sensing element, wherein the transmission medium is arranged such that the sensing element is loaded by the transmission medium, wherein the transmission medium is configured such that the transmission medium at least partially diffusely scatters and / or at least partially absorbs waves, in particular acoustic waves, which occur on the transmission medium in at least one frequency range.

Description

Technical Field

[0001] The present invention relates to a sensor, particularly a pressure sensor, comprising a sensing element for detecting the properties and / or composition of the ambient medium surrounding the sensor.

[0002] Furthermore, the present invention also relates to a method for manufacturing sensors, particularly pressure sensors. Background Technology

[0003] Although the present invention can be generally applied to any sensor, it is described with reference to a barometric pressure sensor.

[0004] Currently, barometric pressure sensors are used in many consumer electronic devices, such as smartphones and smartwatches. Here, the measurement signal from the pressure sensor is primarily used to determine altitude, which, for example, enables floor selection in indoor navigation. Because pressure sensors utilize ambient pressure to detect environmental characteristics, the sensing element of the pressure sensor must have a pressure transmission inlet to the surrounding environment. This requirement conflicts with the goal of watertight implementation in consumer electronic devices: known methods for watertight sealing do not allow for sufficiently sensitive transmission of ambient pressure signals to the sensing element of the pressure sensor.

[0005] To address this issue, it is known to use a gel for pressure transmission. In this pressure sensor, the sensing element is located inside the housing. After chip mounting and wiring are completed, the inside of the housing is filled with gel. Because the gel sealably wets the inner wall of the sleeve and because the gel itself is watertight, it protects the sensing element from environmental media such as water. The pressure signal is transmitted from the surrounding environment to the sensing element via the gel itself, as the gel is flexible enough to serve as a transmission medium.

[0006] When integrating a system, such as when mounted into a smartphone housing, the pressure sensor is typically positioned close to the speaker and / or microphone because these components have similar requirements regarding access to the surrounding environment. These components are usually arranged in a tubular channel that extends into the outer surface of the smartphone housing, thus ensuring access to ambient air for the microphone, speaker, and pressure sensor, while simultaneously isolating the rest of the smartphone's interior space from the surrounding environment.

[0007] However, the close proximity of the gel-filled, watertight pressure sensor to the speaker and / or microphone within the tubular channel presents potential problems for the device's acoustic performance. The acoustic properties of the exposed gel of the pressure sensor can, by their very nature, cause undesirable interactions with the speaker and / or microphone, such as echoes, or lead to a reduction in signal strength due to interference. In particular, the concave shape of the gel surface (as it typically forms during the common hardening / crosslinking of gels) can act as a focusing reflector. Summary of the Invention

[0008] In one embodiment of the present invention, a sensor, particularly a pressure sensor, is provided, comprising:

[0009] Sensing element for detecting the properties and / or composition of the ambient medium surrounding the sensor;

[0010] A transmission medium for transmitting the properties and / or composition of the surrounding environment medium to the sensing element, wherein the transmission medium is arranged such that the sensing element is loaded by the transmission medium, wherein the transmission medium is configured such that it at least partially diffuses and / or at least partially absorbs waves, particularly sound waves, appearing on the transmission medium in at least one frequency range.

[0011] In another embodiment, the present invention provides a method for manufacturing a sensor, particularly a pressure sensor, comprising the following steps:

[0012] -Provide sensing elements;

[0013] - Provide a hardenable transmission medium so that the sensing element is loaded by the transmission medium;

[0014] - Harden the transmission medium;

[0015] - The transmission medium is constructed such that it diffuses and / or absorbs at least partially waves, particularly sound waves, that appear on the transmission medium in at least one frequency range.

[0016] The term "sound wave" is understood in the broadest sense and, particularly in the claims and preferably in the specification, refers to any progressive mechanical deformation of the surrounding environmental medium.

[0017] One advantage of this is that it avoids undesirable interactions with, for example, speakers and / or microphones in end devices when the sensor is poorly integrated into the system. Another advantage is that it avoids costly and time-consuming calibration of the sensor and the arrangement of microphones, speakers, or similar devices, especially in the context that undesirable interactions can mostly only be discovered by testing functionally, nearly production-ready models.

[0018] Other features, advantages and other embodiments of the invention are described or disclosed below.

[0019] According to a further embodiment, the transmission medium has a surface for diffuse scattering and / or at least partially absorbing scattering elements arranged and / or constructed on the surface. This allows for simple and efficient at least partially diffuse scattering and / or absorption.

[0020] According to another further embodiment, the scattering element is made of the transmission medium. One possible advantage is that the scattering element can be provided in a cost-effective manner. Another possible advantage is that when the scattering element is made of the transmission medium, for example, no material stress occurs during temperature changes.

[0021] According to another further embodiment, the scattering element is formed by a recess and a raised portion on the surface of the transmission medium. This allows for the provision of the scattering element in a particularly simple manner.

[0022] According to another further embodiment, the scattering elements are symmetrically distributed on the surface of the transmission medium and / or concentrically arranged about at least one point on the surface. A potential advantage is that the scattering elements can be provided in a simple and cost-effective manner.

[0023] According to another further embodiment, the transmission medium is provided in the form of a hardened gel. This provides a low-cost and flexible transmission medium.

[0024] According to another further embodiment, the sensing element is arranged in a housing open to at least one side, and the transmission medium at least partially fills the housing. A potential advantage is that the transmission medium can be arranged particularly easily in an uncured state and subsequently cured, as the transmission medium is constrained by the housing.

[0025] According to a further embodiment of the method, the construction steps of the transmission medium include arranging and / or constructing scattering elements on the surface. This enables simple and efficient, at least partially diffuse, scattering and / or absorption.

[0026] According to another further embodiment of the method, the scattering element is constructed during the hardening of the transmission medium. This generally improves the efficiency of the method because the hardening of the transmission medium and the arrangement or construction of the scattering element are performed simultaneously.

[0027] According to another further embodiment of the method, the scattering element is constructed using a punch acting on the surface of the transmission medium, the punch having a die for the scattering element. The advantage of the punch is its simple applicability. Furthermore, the punch can be used to set scattering elements for multiple sensor elements.

[0028] According to another further aspect of the method, prior to the construction step of the transmission medium, an intermediate layer, particularly in the form of a foil and / or film, is arranged between the punch and the surface of the transmission medium, such that the intermediate layer separates the punch and the surface of the transmission medium from each other during the construction of the transmission medium. This efficiently prevents potential contamination of the punch: a new intermediate layer is applied to the surface of the transmission medium after each application of the punch, and this intermediate layer can then be used to perform another imprinting process for fabricating a scattering element on the surface of the transmission medium of another sensor. This avoids material transfer between the two sensors caused by the stamping process.

[0029] Other important features and advantages of the invention are revealed by the dependent claims, the accompanying drawings and the description of the drawings.

[0030] It goes without saying that the features described above and will be elaborated below can be applied not only in the corresponding combinations given, but also in other combinations or individually, without departing from the framework of the present invention.

[0031] Preferred embodiments and implementations of the invention are shown in the accompanying drawings, which are described in detail below, wherein the same reference numerals refer to the same or similar or functionally identical components or elements. Attached Figure Description

[0032] Here, the accompanying drawings schematically illustrate:

[0033] Figure 1 A cross-sectional view is shown of a sensor according to an embodiment of the invention during manufacturing.

[0034] Figure 2 Shown in perspective Figure 1 Sensors manufactured in China;

[0035] Figure 3 : Shown in cross-sectional view Figure 2 Sensors in; and

[0036] Figure 4 The steps of a method according to an embodiment of the present invention are shown. Detailed Implementation

[0037] Figure 1 A cross-sectional view is shown of a sensor according to an embodiment of the invention during manufacturing.

[0038] Specifically, Figure 1 Sensor 1 is shown. Sensor 1 has a substrate 2 with a wiring plane (not shown). Furthermore, a housing in the form of a sleeve 6 is arranged on the substrate 2. A chipset 4 with at least one sensing element 4a is disposed within the sleeve 6 on the substrate 2. The chipset 4 includes, for example, evaluation electronics for the sensing element. The sensing element 4a can be implemented as a MEMS. Thus, the sleeve 6 can be closed on one side through the substrate 2.

[0039] Now, inject gel 5 into the reserved opening 12 through sleeve 6 until sleeve 6 is substantially filled. Figure 1 In the next step, the punch 7 is pressed from above onto the surface of the gel 5 in the opening 12. The punch 7 has a topology or structure 10 on its side facing the gel 5, which includes raised portions and recessed portions. Now, before the punch 7 contacts the surface of the gel 5, a thin foil or intermediate film 8 is arranged between the gel surface and the punch 7. The film 8 adheres closely to the topology of the punch surface and transfers the topology 10 of the punch 7 to the gel surface. Thus, when the punch 7 is pressed onto or into the gel surface, the gel surface has a topology 9 corresponding to the topology 10 of the punch. The film 8 is optional and can also be omitted.

[0040] Next, the gel 5 is thermocured and then the punch 7 is removed. Here, the thermocuring can be carried out in a furnace at a temperature greater than 100 degrees Celsius.

[0041] In other words, during the curing of gel 5, structure 9 is specifically pressed into the gel surface by using punch 7 to load gel 5, which is still in a liquid state at the beginning of curing. Here, the structure of the contact surface between punch 7 and gel 5 is the die of topology 9 that is sought to be achieved in the curing state of the gel surface. The contact between punch 7 and gel 5 (as described above) can be made directly or indirectly through the foil-like intermediary 8 between punch 7 and gel 5 to avoid contamination and adhesion of the punch, similar to that commonly seen in "film-assisted molding". With the help of punch 7, the formation of a concave surface of gel 5 due to capillary forces during curing can also be prevented, thus avoiding its use as a focusing reflector.

[0042] To optimize the hardening process, the temperature of the punch 7 can be specifically adjusted. It is also conceivable to position the punch relative to the sensor 1 during hardening by means of position or force adjustment. For example, appropriate temperature, force, or position sensors can be provided, which, together with control and / or adjustment devices, can control or adjust the relative positioning of the punch 7 relative to the surface of the gel 5, the corresponding force application to the punch 7, or the temperature adjustment.

[0043] The gel surface is structured by the punch 7 such that it functions, particularly in the application context, as an acoustic diffuser and / or acoustic absorber in a range of applications crucial to the intended use of the terminal device. It is also conceivable to arrange or construct multiple larger scattering elements, and then arrange or construct multiple smaller scattering elements on top of these larger scattering elements. This mimics, for example, a porous structure that can partially absorb sound waves. The larger scattering elements can be produced, for example, by cutting or etching, and then the smaller scattering elements can be produced, for example, by roughening sandblasting.

[0044] in particular, Figure 1 The sensors involved include watertight sensors, especially watertight pressure sensors.

[0045] Figure 2 Shown in perspective Figure 1 The sensor was manufactured in China.

[0046] exist Figure 2 The middle shows Figure 1 Sensor 1 is located in the middle. The sleeve 6 is circular and the surface of the gel 5 has concentric undulating portions 9 for diffuse scattering of incoming acoustic signals. In addition to the concentric undulating portions, other topologies can be envisioned, such as checkerboard-shaped recesses or linearly extending sloping portions or similar.

[0047] Figure 3 Shown in cross-sectional view Figure 2 The sensor in it.

[0048] exist Figure 3 The diagram shows the path of the sound waves 20 that impact or appear on the surface. These paths are diffusely scattered due to the topology 9 of the gel surface (reference numeral 21).

[0049] Figure 4 The steps of a method according to an embodiment of the present invention are shown.

[0050] exist Figure 4 The steps of a method for manufacturing a sensor, particularly a pressure sensor, are shown.

[0051] Here, the method includes the following steps:

[0052] - Provide S1 sensor elements or sensing elements;

[0053] - Provides a hardenable transmission medium for S2, thereby allowing the sensing element to be loaded by the transmission medium;

[0054] - Harden the S3 transmission medium;

[0055] - The transmission medium is constructed such that it diffuses and / or absorbs waves, particularly sound waves, that strike or appear on the transmission medium in at least one frequency range.

[0056] In summary, at least one embodiment of the present invention can provide at least one of the following features and / or advantages:

[0057] - To manufacture sensors, especially in large quantities, simply and inexpensively;

[0058] - Avoid unwanted interactions, such as with speakers and / or microphones in the terminal device;

[0059] - Avoid costly and time-consuming calibration of sensors and microphones, speakers, or similar components;

[0060] - To reliably, cost-effectively, and flexibly arrange scattering elements.

[0061] Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to these preferred embodiments, but can be modified in a variety of ways.

Claims

1. A sensor (1), comprising: Sensing element (4a) for detecting the properties and / or composition of the surrounding environmental medium of the sensor (1); A transmission medium (5) for transmitting the characteristics and / or composition of the surrounding environment medium to the sensing element (4a), wherein the transmission medium (5) is arranged such that the sensing element (4a) is loaded by the transmission medium (5), wherein the transmission medium (5) is configured such that the transmission medium at least partially diffuses and / or at least partially absorbs (21) waves (20) appearing on the transmission medium (5) in at least one frequency range, wherein the transmission medium (5) has a surface for the transmission medium (5), and a scattering element (9) is arranged and / or constructed on the surface for diffuse scattering and / or for at least partial absorption, wherein the scattering element (9) is made of the transmission medium (5).

2. The sensor (1) according to claim 1, wherein, The scattering element (9) is made through the recessed and raised portions of the surface of the transmission medium (5).

3. The sensor (1) according to claim 1 or 2, wherein, The scattering elements (9) are symmetrically distributed on the surface of the transmission medium (5) and / or concentrically arranged about at least one point on the surface.

4. The sensor (1) according to claim 1 or 2, wherein, The transmission medium (5) is provided in the form of a hardened gel.

5. The sensor (1) according to claim 1 or 2, wherein, The sensing element (4a) is arranged in a housing (6) that is open to at least one side and the transmission medium (5) at least partially fills the housing (6).

6. The sensor (1) according to claim 1 or 2, wherein, The sensor (1) is a pressure sensor.

7. The sensor (1) according to claim 1 or 2, wherein, The wave (20) is a sound wave.

8. A method for manufacturing a sensor (1), comprising the steps of: - Provides (S1) sensing element; - Provide (S2) a hardenable transmission medium so that the sensing element is loaded by the transmission medium; - Harden (S3) the transmission medium; - Construct (S4) the transmission medium such that the transmission medium diffuses and / or absorbs at least partially waves appearing on the transmission medium in at least one frequency range, wherein scattering elements (9) are arranged and / or constructed on the surface of the transmission medium (5), wherein the scattering elements (9) are made of the transmission medium (5).

9. The method according to claim 8, wherein the scattering element (9) is constructed during the hardening of the transmission medium (5).

10. The method according to claim 8 or 9, wherein the scattering element (9) is constructed by means of a punch (7) acting on the surface of the transmission medium (5), the punch having a die (10) for the scattering element.

11. The method according to claim 10, prior to the construction step of the transmission medium (5), an intermediate layer (8) is arranged between the punch (7) and the surface of the transmission medium (5), such that the intermediate layer separates the surfaces of the punch (7) and the transmission medium (5) from each other during the construction of the transmission medium.

12. The method according to claim 8, wherein, The sensor (1) is a pressure sensor.

13. The method according to claim 8, wherein, The wave (20) is a sound wave.

14. The method according to claim 11, wherein, The intermediate layer (8) is constructed in the form of foil and / or film.

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