WO2015176752A1

WO2015176752A1 - Capacitive sensor unit and headphones having a capacitive sensor unit

Info

Publication number: WO2015176752A1
Application number: PCT/EP2014/060364
Authority: WO
Inventors: Roland KÜPFER; Nouhad Bachnak; Waldemar HONSTEIN
Original assignee: Multiple Dimensions Ag
Priority date: 2014-05-20
Filing date: 2014-05-20
Publication date: 2015-11-26

Abstract

The invention relates to a capacitive sensor unit, comprising at least one electrically conductive surface (10, 11, 12, 13), which is arranged in or on a housing wall (1), which is composed of an electrically non-conductive material, wherein the at least one electrically conductive surface (2; 10, 11, 12, 13) is produced by using MID (molded interconnect device) technology and wherein the at least one electrically conductive surface (2; 10, 11, 12, 13) is arranged closer to an inner face (3) of the housing wall (1) such that an insulating layer is present between the at least one electrically conductive surface (2; 10, 11, 12, 13) and an outer face (4) of the housing wall (1).

Description

Capacitive sensor unit and headphones with capacitive sensor unit

The present invention relates to a capacitive

Sensor unit and a headphone with a capacitive sensor unit.

Capacitive sensor units are used to control

electronic devices. This prefabricated components are used, the appropriate, good

accessible location, in particular on control panel attached. The attachment is done for example by means of screws or with the aid of adhesive.

Representing the large number of known capacitive sensor units, reference is made to the published patent application of international patent application WO 2013/173773 A1

referenced, which is a device with a

Fingerprint sensor with a series of capacitive

Discloses elements for capacitive coupling with a user's finger.

A disadvantage of all these capacitive sensors is the large number of components that are required to realize the sensor. As a result, the

Production of the known sensors relatively expensive and expensive. The object of the present invention is therefore to provide a sensor unit which the above

does not have said night parts. This object is achieved by the features stated in the characterizing part of claim 1. advantageous

Variants as well as a headphone with a

Capacitive sensor unit are specified in further claims.

The capacitive sensor unit according to the present

Invention is characterized in that at least one electrically conductive surface is arranged in or on a housing wall, which consists of an electrically non-conductive material, wherein the at least one electrically conductive surface using the MID (Molded

Interconnect Device) technology is manufactured and wherein the at least one electrically conductive surface is arranged closer to an inner side of the housing wall, so that an insulating layer between the at least one electrically conductive surface and an outer side of the

Housing wall is present.

This is the first time a very robust sensor unit has been created, which allows a high reproducibility and a very cost-effective production. The MID technology used to manufacture the sensor units also enables high integration, even with the smallest dimensions. A variant of the inventive sensor unit is characterized in that a plurality of electrically conductive surfaces are arranged in a matrix, wherein the electrically conductive surfaces are electrically insulated from each other.

This variant not only opens the

Possibility to initiate switching operations for different operations on touch, but in particular to be able to make the detection of a predetermined sequence of stimulations of individual electrically conductive surfaces in order to continuously change a parameter, such as a volume. Further variants of the inventive

Sensor unit are characterized in that the matrix has four surfaces, which are arranged in two rows and two columns. In this way circular movements, for example in a clockwise direction over the matrix, can be detected in order to increase a parameter, for example a volume. Correspondingly, circular, counterclockwise movements lead to one

Reduction of the same parameter. Further variants of the inventive

Sensor unit are characterized in that a plurality of electrically conductive surfaces are arranged in a row, wherein the electrically conductive surfaces are electrically isolated from each other. This wiping movements can be detected with the inventive sensor units. Still further embodiments of the inventive sensor unit are characterized in that a

Transmitter is present, which is operatively connected to the electrically conductive surfaces, and that the

Evaluation electronics can detect capacitance changes of the electrically conductive surfaces.

Further variants of the inventive

Sensor unit are characterized in that a

Time sequence of detected capacitance changes of the electrically conductive surfaces for controlling parameters is usable. Further variants of the inventive

Sensor unit are characterized in that the

Outside of the housing wall in the region of the electrically conductive surfaces has a structure or a color that differs from the rest of the housing wall.

Further variants of the inventive

Sensor unit are characterized in that the

electrically conductive surface of a multilayer structure

in particular at least two of the

Layer materials copper, nickel and gold, or copper and silver, or copper and tin are provided.

Further variants of the inventive

Sensor unit are characterized in that the insulating layer consists of the material of the housing wall.

Further variants of the inventive

Sensor unit are characterized in that the

Housing wall of an LDS (Laser Direct Structuring) - capable polymer, such as VECTRA or ZEONEX exists. Furthermore, the present invention relates to a headphone with a housing in which a capacitive sensor unit according to one or more of the preceding

Embodiment variants is provided. A variant of the headphone is that the headphone is of the type in-ear headphones.

It is expressly stated that the

above variants are arbitrarily combinable. Only those combinations of

Variants are excluded, which would lead to contradictions through the combination.

In the following, the present invention will be explained with reference to exemplary embodiments illustrated in drawings. Showing:

Fig. 1 is a plan view of an inside of a

Housing wall of a first embodiment variant for a capacitive sensor unit according to the

present invention,

2 shows a cross section perpendicular through the housing wall of the first embodiment according to FIG. 1, FIG.

Fig. 3 is a plan view of an inside of a second

Embodiment of the invention with four arranged as a matrix sensor surfaces,

3, a perspective view of a housing component of a headphone having a matrix with inventive sensor surfaces according to the second embodiment and a plan view of an inner side of a third embodiment of the invention with four in a row arranged sensor surfaces.

In Fig. 1 is a plan view of a section of a housing wall 1 of a housing, with the example, electronic components are protected against external influences. The top view shows the inside of the housing wall 1, on which or in which an electrically conductive surface 2 is provided. The electrically conductive surface 2 is manufactured using the MID (Molded Interconnect Device) technology and forms the main component of the capacitive sensor unit according to the invention, wherein the surface 2 is electrically connected to an evaluation electronics (not shown in FIG. 1) for detecting changes in capacitance. The evaluation electronics for

Determining a change in capacity or for determining loading shifts is well known and will not be explained further here.

The ID technology is used for metallizing and

Structuring the existing of a polymer housing wall 1 used, for which various MID methods can be used, of which the most common are briefly explained below: In the hot stamping process, the plastic substrate is metallized and structured in one step. With an embossing stamp on which the positive conductor pattern is applied, a copper embossing film with adhesion-promoting

Layer under pressure and heat on the

Plastic substrate pressed. The substrate is melted by the heat at the surface. The

Conductors are sheared out of the copper foil and connected to the substrate. When film-back injection is formed by sieve or

Pad printing of a primer on a film

structured conductor pattern. During one

Temperature conditioning process, the primer makes a chemical bond with the substrate surface and provides good adhesion. In this process At the same time, the film is reshaped. Subsequently, the film is placed in an injection molding machine and

back-molded. After the back injection, the

Conductor tracks galvanically reinforced and finished.

In the two-component injection molding process, the structure of the conductor pattern with a first injection molding

made of metallizable plastic, which serves as a substrate for the chemical metallization. Depending on the plastic, after the first injection molding the surface of the

Plastic still to be treated. The sprue is placed again in a mold and not with

metallized plastic encapsulated. The remaining conductor tracks are then chemically metallized and refined.

In the mask process, the metallization of the

Plastic carrier by chemical coating. When

Substrate serves a plastic injection molded part, in which the surface is first prepared for pickling by pickling or etching. Subsequently, the

Metallization. For structuring, a photoresist is applied and exposed through a three-dimensional mask with UV light. After development of the photoresist, the exposed metal layer is galvanically reinforced and coated with an etching mask. After removal of the photoresist, the remaining metal is etched away and then the surface is finished. In contrast to the mask method, the direct laser structuring structures the etching resist directly with the laser. At the locations where the etch resist was removed by the laser, the metal is etched away.

Finally, the surface is finished.

In the LPKF laser direct structuring process, which is named after the company LPKF, a plastic part is first injected. Subsequently, the transfer of the

Structure picture with a writing or a picture

Laser system. The subsequent metallization takes place in a chemically reductive bath.

Using one of these MID methods, the

electrically conductive surfaces 2 applied to the inside 3 of the housing wall 1. The electrical connection between the surface 2 and the mentioned evaluation electronics (not shown in FIG. 1) can be applied to the housing wall 1 by the same method. Alternatively, again with an MID method, the electrically conductive surface 2 is embedded in the housing wall 1, so that the housing wall thickness in the region of the recessed

Housing wall 1 is reduced. FIG. 2 shows a cross section of the embodiment variant of the capacitive sensor unit according to the invention shown in FIG. The electrically conductive surface 2 is - as already mentioned - applied to the inside 3. If a user's finger moves towards the outside 4 or if it touches the outside of the finger 4, in the region of the outside, where the electrically conductive surface 2 is arranged opposite on the inside 3, so the capacitance, which by the finger, the electrically conductive surface 2, the thickness of the intermediate layer between fingers and electrically conductive Surface as well as the material characteristics

(Dielectric) of the housing wall is formed in this area. This capacity change, which also means of a

Charge change can be determined in a known manner is detected by the transmitter, whereby, for example, a switching operation can be triggered.

To give a user an orientation where the

Detection of a switching operation is most effective, it is provided in a further embodiment of the present invention, on the outside 4, a structure

5, for example, a survey or a depression to arrange. Such a structure 5 can be produced by embossing the outer housing wall 1 or by gluing elements and serves for the tactile or visual orientation of the user of the sensor unit according to the invention. It is also conceivable that the recognizability is expressed by a color that differs from the color of the rest of the housing.

The electrically conductive surface 2 has, for example, a multi-layer structure, wherein - starting from the inner side 3 of the housing wall - first a layer of copper is provided with a layer thickness of usually 5 to 20pm. It follows a layer of nickel with a Layer thickness of 5 to 20μη and a thin layer of gold or silver directly on copper or tin directly on copper as oxidation protection. 3 shows an embodiment with a plurality of electrically conductive surfaces 10 to 13 arranged in a matrix. This arrangement not only offers the possibility of

Switching operations for different processes, which are associated with the individual surfaces 10 to 13, trigger on contact, and in particular the detection of a predetermined sequence of stimulations of individual

electrically conductive surfaces 10 to 13. Thus, according to an embodiment variant according to the invention, it is provided to control a change of a parameter in such a way that a sequence of stimulation in the clockwise direction, that is to say in a clockwise direction. at a

Stimulation of areas 10-13 in the sequence... 10-11- 12-13-10 -..., leading to an increase in the parameter value, and a counterclockwise stimulation sequence, i. with a stimulation of the surfaces 10 to 13 in the sequence 13-12-11-10-13 -..., leads to a reduction of the parameter value. In the evaluation electronics, preferably not only the sequence is used as a decision criterion for a given process, but also the temporal aspect is taken into account so that faulty circuits can be minimally or completely prevented. So it is intended that between two stimulations

different areas 10 to 13 within one

must be done in a predefined time frame, otherwise the intended operation - for example, a reduction or increase of a parameter values - is not made. In Fig. 5, an application of the embodiment with in a two-by-two matrix according to FIGS. 3 and 4 is shown. This is a case component of a headphone 20 of the type in-ear headphones, as it is often used today in connection with smartphones in particular. In particular, the mentioned detection of stimulations of the surfaces in a sequence is suitable

Clockwise / counterclockwise, as described above, for controlling the volume of an audio signal played through the headphone 20 is excellent.

It is to be expressly understood, however, that the present invention is not limited to being used with a headset for control. Rather, the capacitive sensor unit or the

capacitive sensor units according to the present invention

Invention for arbitrary applications for the control of electronic devices, whereby also larger matrix fields than a two-by-two matrix field are conceivable without further ado.

Finally, Fig. 6 shows a further embodiment of the present invention, in which four electrically

conductive surfaces 10 to 13 are arranged in a row. Incidentally, the surfaces 10 to 13 are in turn made the same, as has already been explained above. The arrangement of electrically conductive surfaces 10 to 13 in a row makes it possible to detect so-called wiping movements readily. However, it is also pointed out in relation to this embodiment variant that more than four electrically conductive surfaces can be provided. Accordingly, the embodiment shown in Fig. 6 is not

restrictive interpreted.

Claims

claims

1. Capacitive sensor unit, characterized in that at least one electrically conductive surface (2; 10, 11, 12,

13) in or on a housing wall (1) is arranged, which consists of an electrically non-conductive material, wherein the at least one electrically conductive surface (2, 10, 11, 12, 13) using the MID (Molded

Interconnect Device) technology is produced and wherein the at least one electrically conductive surface (2; 10, 11, 12, 13) closer to an inner side (3) of the housing wall (1) is arranged, so that an insulating layer between the at least one electrically conductive surface (2; 10, 11, 12, 13) and an outer side (4) of the housing wall (1) is present.

2. Capacitive sensor unit according to claim 1, characterized in that a plurality of electrically conductive surfaces (10, 11, 12, 13) are arranged in a matrix, wherein the electrically conductive surfaces (10, 11, 12, 13) are electrically insulated from each other.

3. Capacitive sensor unit according to claim 2, characterized in that the matrix has four surfaces (10, 11, 12, 13) arranged in two rows and two columns

are arranged.

4. Capacitive sensor unit according to claim 1, characterized in that a plurality of electrically conductive surfaces (10, 11, 12, 13) are arranged in a row, wherein the electrically conductive surfaces (10, 11, 12, 13) are electrically insulated from each other.

5. Capacitive sensor unit according to one of claims 1 to 4, characterized in that an evaluation electronics is present, which is operatively connected to the electrically conductive surfaces (2; 10, 11, 12, 13), and that the

Evaluation electronics capacitance changes of the electrically conductive surfaces (2, 10, 11, 12, 13) detected.

6. Capacitive sensor unit according to claim 5 in combination with one of claims 2 to 4, characterized in that a temporal sequence of detected

Capacitance changes of the electrically conductive surfaces (2, 10, 11, 12, 13) can be used to control parameters.

7. Capacitive sensor unit according to one of claims 1 to 6, characterized in that the outer side (4) of the

Housing wall (1) in the region of the electrically conductive surfaces (2, 10, 11, 12, 13) has a structure (5) or a color which differs from the rest of the housing wall (1).

8. Capacitive sensor unit according to one of claims 1 to 7, characterized in that the electrically conductive surface (2; 10, 11, 12, 13) has a multilayer structure

in particular at least two of the Layer materials copper, nickel and gold, or copper and silver, or copper and tin are provided.

9. Capacitive sensor unit according to one of claims 1 to 8, characterized in that the insulating layer consists of the material of the housing wall (1).

10. Capacitive sensor unit according to one of claims 1 to 9, characterized in that the housing wall (1) consists of an LDS-capable polymer, such as VECTRA or ZEONEX.

11. Headphone with a housing in which a capacitive sensor unit is provided according to one of claims 1 to 10.

12. Headphones according to claim 11, characterized in that the headphone is of the type in-ear headphones.