Sensor Device and Method of Manufacturing a Sensor Device

Abstract

In an embodiment a portable electronic device includes a sensor device including at least one light emitter, at least one light detector, a housing in which the at least one light emitter and the at least one light detector are arranged and at least one channel forming a passageway through the housing, wherein the at least one light emitter and the at least one light detector are arranged such that light emitted from the at least one light emitter passes through the at least one channel and is thereafter detected by the at least one light detector.

Claims

1-18. (canceled)

19. A portable electronic device comprising: a sensor device comprising: at least one light emitter; at least one light detector; a housing in which the at least one light emitter and the at least one light detector are arranged; and at least one channel forming a passageway through the housing, wherein the at least one light emitter and the at least one light detector are arranged such that light emitted from the at least one light emitter passes through the at least one channel and is thereafter detected by the at least one light detector.

20. The portable electronic device according to claim 19, wherein the sensor device comprises a size of at most 10 mm in a first dimension and a second dimension, respectively, and a size of at most 3 mm in a third dimension.

21. The portable electronic device according to claim 19, wherein the sensor device comprises a substrate having at least one opening, wherein the at least one light emitter and the at least one light detector are mounted on the substrate, and wherein the at least one channel extends through the at least one opening.

22. The portable electronic device according to claim 21, further comprising a transparent body having at least one passageway forming part of the at least one channel, wherein the transparent body is mounted on the at least one opening of the substrate.

23. The portable electronic device according to claim 21, further comprising a transparent body, wherein a plurality of microchannels of the transparent body is located in the at least one opening of the substrate, and wherein the microchannels form at least a portion of the at least one channel.

24. The portable electronic device according to claim 19, wherein the at least one light emitter and the at least one light detector are encapsulated with a transparent material.

25. The portable electronic device according to claim 24, wherein a light reflective material is applied to the transparent material.

26. The portable electronic device according to claim 25, wherein the at least one channel has sidewalls formed at least in part by the transparent material and the light reflective material.

27. The portable electronic device according to claim 19, wherein the sensor device comprises a substrate and the at least one light emitter and the at least one light detector are mounted on the substrate, and wherein the at least one channel extends above the at least one light emitter and the at least one light detector.

28. The portable electronic device according to claim 27, further comprising a light reflective layer arranged above the at least one channel.

29. The portable electronic device according to claim 27, further comprising a light reflective material arranged on the substrate between the at least one light emitter and the at least one light detector.

30. The portable electronic device according to claim 19, wherein the sensor device comprises an analysis unit configured to analyse liquid and/or gas in the at least one channel based on the light detected by the at least one light detector.

31. The portable electronic device according to claim 19, wherein the sensor device comprises a plurality of light emitters and at least two of the plurality of light emitters are configured to emit light of different wavelengths, and/or wherein the sensor device comprises a plurality of light detectors and at least two of the plurality of light detectors are configured to detect light of different wavelengths.

32. The portable electronic device according to claim 19, wherein the at least one light emitter and/or the at least one light detector are optoelectronic semiconductor devices.

33. The portable electronic device according to claim 19, further comprising an attachment device connected to the sensor device, wherein the attachment device is a wristband or pulse strap for attaching the sensor device to a body part of a person.

34. The portable electronic device according to claim 19, wherein the portable electronic device is configured to analyse body fluids.

35. A method of manufacturing a sensor device, the method comprising: providing at least one light emitter and at least one light detector; and encapsulating the at least one light emitter and the at least one light detector in a housing, wherein at least one channel forms a passageway through the housing, and wherein the at least one light emitter and the at least one light detector are arranged such that light emitted from the at least one light emitter passes through the at least one channel and is thereafter detected by the at least one light detector.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In the following, embodiments of the invention are explained in more detail with reference to the accompanying drawings.

[0038] FIGS. 1A to 1B show illustrations of an embodiment of a sensor device with a channel for receiving body fluids;

[0039] FIG. 2 shows an illustration of an embodiment of a method of manufacturing a sensor device;

[0040] FIG. 3 shows an illustration of an embodiment of a wearable electronic device with a sensor device;

[0041] FIGS. 4A to 4B show illustrations of an embodiment of a sensor device with a plurality of microchannels;

[0042] FIG. 5 shows an illustration of an embodiment of a sensor device having a channel in a layer of transparent and reflective material; and

[0043] FIG. 6 shows an illustration of an embodiment of a sensor device with a plurality of horizontally running microchannels.

[0044] In the following detailed description, reference is made to the accompanying drawings, which form a part of this description and in which specific embodiments in which the invention may be practiced are shown for illustrative purposes. Since components of embodiments may be positioned in a number of different orientations, the directional terminology is for illustrative purposes and is not limiting in any way. It is understood that other embodiments may be used and structural or logical changes may be made without departing from the scope of protection. It is understood that the features of the various embodiments described herein may be combined with each other, unless specifically indicated otherwise. Therefore, the following detailed description is not to be construed in a limiting sense. In the figures, identical or similar elements are provided with identical reference signs where appropriate.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0045] FIG. 1A schematically shows a sensor device 10 in a sectional view. FIG. 1B shows the sensor device 10 in a top view from above.

[0046] The sensor device 10 includes a substrate 11 on which a light emitter 12 in the form of an LED semiconductor chip and a light detector 13 also in the form of an LED semiconductor chip are mounted.

[0047] In the present embodiment, the substrate 11 is a QFN flatmold comprising a coated copper lead frame 14 that has been overmolded by a mold compound 15. The mold compound 15 has the same height as the lead frame 14, i.e., the top and bottom surfaces of the lead frame 14 are not covered by the mold compound 15. The LED semiconductor chips of the light emitter 12 and the light detector 13 each have an electrode on their bottom side and their top side. The light emitter 12 and the light detector 13 are soldered with their electrode on the bottom side to a respective contact element of the lead frame 14. A bonding wire 19 leads from the electrodes on the upper sides of each of the light emitter 12 and the light detector 13 to a further contact element of the lead frame 14.

[0048] The substrate 11 further includes an opening 16 in the form of a recess extending completely through the substrate 11. A body 17 is applied over the opening 16 in the substrate 11, which comprises transparent side walls and through which a passageway 18 extends in the vertical direction. The body 17 may be, for example, a thin glass capillary. The opening 16 in the substrate 11 and the passageway 18 through the body 17 form a channel 20. The channel 20 is arranged between the light emitter 12 and the light detector 13.

[0049] The light emitter 12 and the light detector 13 are encapsulated with a transparent material 21, which may be a transparent silicone. A highly reflective material 22 is applied to the transparent material 21, which may be, for example, a silicone mixed with TiO.sub.2 particles. The transparent material 21 and the highly reflective material 22, together with the substrate 11, form a housing 25 in which the light emitter 12 and the light detector 13 are arranged.

[0050] The channel 20 forms a passageway through the housing 25, i.e., it extends from a bottom surface 26, i.e., a first outer surface, to a top surface 27, i.e., a second outer surface, of the housing 25.

[0051] An interface 28 between the transparent material 21 and the highly reflective material 22 has a predetermined shape. In the sectional view of FIG. 1A, the interface 28 is parabolic.

[0052] In addition to the light emitter 12 and the light detector 13, further light emitters and/or light detectors can be mounted on the substrate 11. In particular, the further light emitters or detectors can be designed to generate or detect light of different wavelengths.

[0053] The sensor device 10 resp. the housing 25 may have a size in the x-direction shown in FIGS. 1A and 1B of at most 10 mm. In the y-direction, the sensor device 10 resp. the housing 25 may also have a size of at most 10 mm. In the z-direction, the sensor device 10 resp. the housing 25 may have a size of at most 3 mm.

[0054] During operation of the sensor device 10, a portion of the light emitted from the light emitter 12 travels directly to the light detector 13. The light thereby passes through the transparent material 21 and the channel 20 located between the light emitter 12 and the light detector 13. Light that is not emitted from the light emitter 12 in a direct direction to the light detector 13 is reflected at the interface 28 by the highly reflective material 22 and is reflected toward the channel 20 due to the shape of the interface 28. It passes through the channel 20 and can be detected by the light detector 13 after any possible further reflection at the interface 28. Consequently, the design of the interface 28 causes a large portion of the light emitted by the light emitter 12 to pass through the channel 20 and subsequently be detected by the light detector 13. In FIG. 1A, the beam path of the light emitted by the light detector 13 is symbolically represented by an arrow 29.

[0055] FIG. 2 schematically illustrates a method of manufacturing the sensor device 10 shown in FIGS. 1A and 1B.

[0056] In a step 31, the substrate 11 with the opening 16 is provided. The substrate 11 can be pre-produced.

[0057] In a step 32, the transparent body 17 is applied to the substrate 11 such that the opening 16 in the substrate 11 and the passageway 18 through the body 17 form the channel 20. The body 17 may, for example, be glued to the substrate 11 or otherwise attached to the substrate 11.

[0058] In a step 33, the light emitter 12 and the light detector 13 are soldered to the substrate 11 and the bonding wires 16 are generated.

[0059] In a step 34, the light emitter 12 and the light detector 13 are encapsulated with the transparent material 21.

[0060] In a step 35, the highly reflective material 22 is applied to the transparent material 21.

[0061] FIG. 3 schematically shows a wearable electronic device 40, for example an activity or fitness tracker or a smartwatch, with the sensor device 10 described above in a sectional view.

[0062] The sensor device 10 may be integrated into the device 40 such that the bottom surface 26 and/or the top surface 27 of the housing 25 are exposed. However, it is also conceivable that the bottom surface 26 and/or the top surface 27 are not exposed. In many applications, however, it should be ensured that during operation of the device 40 a surface of the device 40, for example the bottom surface 26 or the top surface 27 of the housing 25, rests on the skin of the user, so that body fluid 41, in particular sweat, enters the channel 20, in particular by a capillary effect, and can be analysed by means of the light emitted by the light emitter 12 and detected by the light detector 13.

[0063] For analysing the body fluid 41, the device 40 has an analysis unit not shown in FIG. 3, which may in particular be designed as an integrated circuit. The analysis unit evaluates the light detected by the light detector using methods familiar to those skilled in the art, and can draw conclusions about the fluid 41 therefrom. The analysis unit may be integrated into the sensor device 10 or may be located outside the sensor device 10 in the device 40.

[0064] FIG. 4A schematically shows a sensor device 50 in a sectional view. FIG. 4B shows the sensor device 50 in a top view.

[0065] The sensor device 50 corresponds in large parts to the sensor device 10 described above. However, unlike the sensor device 10, the sensor device 50 does not include the transparent body 10 with the passageway 18, but a transparent body 51 with a plurality of microchannels forming a plurality of channels 20.

[0066] Furthermore, the body 51 is not placed on the opening 16 in the substrate 11, but is inserted into the opening 16. Consequently, the microchannels of the body 51 extend from the bottom 26 to the top 27 of the housing 25.

[0067] The microchannels can each have a diameter in the range from 1 μm to 1,000 μm and in particular in the range from 200 m to 300 μm. The advantage of the many thin microchannels is the enhanced capillary effect, through which the body fluid is transported into the microchannels more quickly or more easily.

[0068] FIG. 5 schematically shows a sensor device 60 in a sectional view similar to sensor devices 10 and 50. However, the sensor device 60 does not include a transparent body with a passageway or a plurality of microchannels.

[0069] After the light emitter 12 and the light detector 13 have been applied to the substrate 11, they are overmolded with a transparent material 21, e.g. by transfer molding, also called injection molding. In this process, a recess is kept free in the transparent material 21 above the opening 16 in the substrate 11.

[0070] A reflective mold compound is then applied as reflective material 22 in a further transfer molding step. A recess is also kept free in the reflective material 22 above the opening 16 in the substrate 11. The mold compound may contain, for example, an epoxy resin or a silicone.

[0071] The recesses in the transparent and reflective materials 21, 22, together with the opening 16 in the substrate 11, form the channel 20 into which the body fluid can be introduced for analysis. Consequently, the side walls of the channel 20 are formed by the substrate 11, the transparent material 21 and the reflective material 22. Thus, the transparent body with a passageway or a plurality of microchannels can be saved.

[0072] During operation of the sensing device 60, light emitted from the light emitter 12 reflects off the reflective material 22 and travels in a horizontal direction after passing through the channel 20 to the light detector 13.

[0073] FIG. 6 schematically shows a sensor device 70 in a sectional view.

[0074] In the sensor device 70, the light emitter 12 and the light detector 13 are mounted on a substrate 11, which may be a QFN flatmold, a printed circuit board, a ceramic substrate, or any other suitable substrate. In the present embodiment, an optional filter 71 is also mounted on the light detector.

[0075] After the light emitter 12 and the light detector 13 are applied, both are embedded in a transparent material 21, for example an epoxy resin or a silicone. The space or spaces between the light emitter 12 and the light detector 13 are then filled with a highly reflective material 22 such that there is no line of sight between the light emitter 12 and the light detector 13 and light emitted by the light emitter 12 can only reach the light detector 13 via the liquid to be analysed.

[0076] In a subsequent step, a transparent body 72 having a plurality of microchannels is applied to the transparent material 21 and the highly reflective material 22. The microchannels in the body 72 form the plurality of channels 20. The microchannels of the body 72 may be formed similarly to the microchannels of the body 51 described above, but the microchannels in the sensor device 70 extend horizontally, i.e., the microchannels extend parallel to a main surface of the substrate 11. The microchannels may each have a diameter in the range of 1 μm to 1,000 μm, and in particular in the range of 200 μm to 300 μm.

[0077] A mirror 73 is then placed on the body 72.

[0078] During operation of the sensor device 70, light from the light emitter 12 passes through the fluid in the microchannels of the body 72 and is reflected back via the mirror 73, causing the reflected light to pass to the light detector 13.

[0079] Although the invention has been illustrated and described in detail by means of the preferred embodiment examples, the present invention is not restricted by the disclosed examples and other variations may be derived by the skilled person without exceeding the scope of protection of the invention.