Pressure sensor with improved self-healing diaphragm

Abstract

A sensor includes a sensing element for detecting a property and/or a composition of a surrounding medium of the sensor, a transmission medium for transmitting a property and/or a composition of the surroundings medium onto the sensing element, the transmission medium being situated in such a way that the transmission medium is applied to the sensing element, and a cover, which distances the transmission medium from the surrounding medium, the cover being manufactured from a self-healing material, in particular, the cover being designed as a flexible membrane which is made up of a self-healing material.

Claims

1. A sensor, comprising: a sensing element configured to detect a property and/or a composition of a surrounding medium of the sensor; a transmission medium for transmitting a property and/or a composition of the surrounding medium onto the sensing element, the transmission medium being situated in such a way that the transmission medium is applied to the sensing element; a cover which distances the transmission medium from the surrounding medium, the cover being manufactured from a self-healing material and being a flexible membrane; and a housing including an opening, wherein: the sensing element is situated in an interior space of the housing; and the cover is arranged as a closure of the opening of the housing, the transmission medium having been introduced into the interior space through at least one temporary opening in the cover that is subsequently closed, wherein the at least one temporary opening includes two temporary openings, and the cover is structured so that the introduction of the transmission medium is able to take place via one of the two temporary openings which the interior space is vented via a second of the two openings.

2. The sensor as recited in claim 1, wherein the sensor is a pressure sensor.

3. The sensor as recited in claim 1, wherein the transmission medium is an incompressible fluid.

4. The sensor as recited in claim 3, wherein the incompressible fluid is an oil.

5. The sensor as recited in claim 1, wherein a protective layer is situated on the cover.

6. The sensor as recited in claim 5, wherein the protective layer is a metal layer.

7. The sensor as recited in claim 1, wherein the sensor includes a housing in which the sensing element and the transmission medium are situated, the cover closing the housing toward at least one side, and a circumferential seal situated on an outer side of the housing.

8. The sensor as recited in claim 1, wherein the cover is structured so that the closing of the at least one temporary opening occurs automatically and/or only after an appropriate initiation using initiation means.

9. The sensor as recited in claim 1, further comprising a protective layer applied onto the cover.

10. The sensor as recited in claim 1, further comprising a seal on an outer side of the housing formed simultaneously with formation of the cover and a two-component injection molding formation of the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a sensor according to one specific embodiment of the present invention in the cross-section prior to filling.

(2) FIG. 2 shows the sensor according to FIG. 1 including cannulas pushed through the membrane.

(3) FIG. 3 shows the sensor according to FIG. 2 including cannulas pushed through the membrane after complete filling.

(4) FIG. 4 shows the sensor according to FIG. 3 in the final state.

(5) FIG. 5 shows a sensor according to one specific embodiment of the present invention in the final state.

(6) FIG. 6 shows steps of a method for manufacturing a sensor according to one specific embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(7) FIG. 1 shows a sensor according to one specific embodiment of the present invention in the cross-section prior to filling;

(8) FIG. 2 shows the sensor according to FIG. 1 including cannulas pushed through the membrane; FIG. 3 shows the sensor according to FIG. 2 including cannulas pushed through the membrane after complete filling; and FIG. 4 shows the sensor according to FIG. 3 in the final state.

(9) In detail, FIGS. 1 through 4 each show a sensor 1, which includes a substrate 2 and a rewiring plane (not shown) situated in substrate 2. A chipset 4 including at least one sensing element 4a is situated in a housing, in the form of a sleeve 6, situated on substrate 2. Chipset 4 includes, for example, an evaluation electronics for sensing element 4a. Sensing element 4a may be designed as a MEMS sensing element 4a.

(10) Sleeve 6 is thus closed on the one side by substrate 2, and on the other side sleeve 6 is closed with the aid of a flexible membrane 7 made up of self-healing material. In this way, an interior space 5 is formed. Self-healing membrane 7 may be joined in the process with the aid of welding, or housing 6 and membrane 7 may be jointly manufactured by two-component injection molding.

(11) For filling interior space 5, two narrow cannulas 8 are now pushed at a sufficient distance from one another through flexible membrane 7. In this way, two temporary openings 12 are formed. This step may optionally be carried out under a vacuum.

(12) An incompressible fluid 9 is now filled into interior space 5 via the one of the two cannulas 8, the left cannula in FIG. 3. In the process, the interior space may be actively vented via second cannula 8 and/or be subjected to underpressure. Interior space 5 is completely filled when the level in the right cannula 8 is above the plane of flexible membrane 7. Thereafter, the two cannulas 8 are removed.

(13) After cannulas 8 have been removed, the self-healing of flexible membrane 7 occurs either without further intervention or supported by a suitable stimulus, for example with the aid of optical and/or thermal irradiation or, in general, by a thermal reorganization of the membrane components. Temporary openings 12 are closed thereby.

(14) In one further optional process step, the application of a thin metal layer 10 takes place, for example, with the aid of physical vapor phase deposition, to suppress diffusion processes through flexible membrane 7, and to protect flexible membrane 7 from environmental influences, such as for example UV light.

(15) FIG. 5 shows a sensor according to one specific embodiment of the present invention in the final state.

(16) FIG. 5 essentially shows a sensor 1 according to FIG. 4. In contrast to sensor 1 according to FIG. 4, metal layer 10 is missing in sensor 1 according to FIG. 5. Furthermore, a circumferential seal 11 is situated on the outer side of sleeve 6. Seal 11 may be used, during further installation, i.e., during the system integration of sensor 1 into, for example, a consumer electronics product, such as for example a smart phone, to seal the joint between housing 6 of sensor 1 and the housing of the higher-level system, for example of a smart phone or the like. The two-component injection molding manufacturing method may be used for this purpose: in the first molding shot, housing 6 of sensor 1 is generated as a hard component. Thereafter, in the second molding shot, flexible membrane 7 as well as outer seal 11 are jointly generated.

(17) FIG. 6 shows steps of a method for manufacturing a sensor according to one specific embodiment of the present invention.

(18) FIG. 6 shows steps of a method for manufacturing a sensor, in particular, a pressure sensor, in detail.

(19) It includes the steps: providing S1 a housing including an opening; introducing S2 the sensing element into the housing; closing S3 the opening of the housing with the aid of a cover, in particular, designed as a flexible membrane, the cover being manufactured from a self-healing material, and an interior space being formed in the housing; creating S4 at least one temporary opening in the cover; introducing S5 the transmission medium into the interior space through the at least one temporary opening in the cover; and closing S6 the temporary opening.

(20) In summary, at least one of the specific embodiments of the present invention may provide at least one of the following features and/or one of the following advantages: simple manufacture, in particular, of a plurality of sensors, in particular, of media-resistant sealed pressure sensors small installation space reliable and rapid filling with the incompressible fluid low manufacturing costs

(21) Although the present invention has been described based on preferred exemplary embodiments, it is not limited thereto, but is modifiable in a variety of ways.