WO2007104528A1

WO2007104528A1 - Switch arrangement with a plurality of switches arranged in the form of a matrix and method for switching switches arranged in the form of a matrix

Info

Publication number: WO2007104528A1
Application number: PCT/EP2007/002185
Authority: WO
Inventors: Steffen Kurth; Jörg FRÖMEL; Sebastian Voigt; Stefan Leidich; Jörg Nestler; Alexej Shaporin; Wolfram DÖTZEL; Thomas Gessner
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.; Technische Universität Chemnitz
Priority date: 2006-03-10
Filing date: 2007-03-08
Publication date: 2007-09-20

Abstract

The invention proposes a circuit arrangement having a plurality of switches, which are arranged in rows and columns and which each have at least one moveable contact which is subjected to spring prestress and at least one fixed contact, a coil arrangement being associated with each switch, wherein the respective switch can be actuated depending on a magnetic field produced via the coil arrangement. At least one coil (2) in a first plane with electrical drive connections (16) is associated with each row of switches (20), and at least one coil (1) in a second plane with electrical drive terminals (17) is associated with each column of switches (20), wherein the magnetic force required for actuating a switch lying at a node point (13) of a row and a column can be produced by applying current in the same direction to the terminals of the respective row and the respective column and adding the magnetic fields of the first and second coil (1, 2) of the respective switch (20).

Description

Switch arrangement with a plurality of switches arranged in matrix form and method for switching switches arranged in matrix form

The invention relates to a switch arrangement with a plurality of switches arranged in rows and columns according to the preamble of the main claim and a method for actuating switches arranged in matrix form.

In mobile communication technology, there is a growing demand for reconfigurable antennas, which can be realized here, for example by interconnecting smaller individual antenna elements to so-called patch antennas of different geometries. For this purpose, a larger number of separately controllable switches is necessary. However, the cost of such intelligent antennas should not significantly exceed that of currently used non-controllable antennas. From the- For this reason, a technology for mass production of reconfigurable antennas, including the switches, is required in a cost-effective manner.

From US 2004/0183 633 Al a bistable, magnetically actuated switch in a single version is known, wherein the bistable arrangement allows each of the two switching states remain stable without continuous energy supply. In this case, a plurality of structured layers is provided, which include at least one structured layer with a movable element. The structured layers are arranged one above the other and each layer is connected to the adjacent layer. One of the layers has an electromagnet or a coil. The known solutions are used for the realization of individual or few switches on technically relevant surfaces, such as a chip area, since in such configurations, the cost of interconnection and addressing of the coils with the number of actuators increases massively. Geometrically dense arrays can not be realized so far. In order to integrate a very large number of such switches in a small area, it is necessary to make the actuation and addressing compact and efficient.

EP 0 856 866 B1 discloses magnetically actuated switches organized in a regular grid, which have a layered arrangement of a movable contact, a coil plate arranged at a distance therefrom, a contact plate with an iron core and an insulating layer. The known configuration requires the connection of the coil arranged on the coil plate with orthogonally arranged address lines. The local electric The connection of the conductors, which are otherwise insulated from one another, requires a production technology with a high lateral resolution with the possibility of reliably producing these connection points. Furthermore, it has to be prevented by inserting diodes that flow paths form over non-addressed coils. This in turn prevents a switching of the switching contact by changing the current directions and represents a further increase in the Herstellungsaufwands.

The invention has for its object to realize an array with geometrically tight, preferably bistable magnetically actuated switches Sieren, which provides low technological requirements for addressing and wiring, thereby enabling cost-effective production. In addition, there is the requirement for suitability for the realization of reconfigurable antennas for frequencies of the GSM and UMTS bands, the frequencies are in a range in the state of the art configurable by switching arrays antennas because of the specific size, the use of conventional relay not permit and a monolithic integration into the antenna is also not possible. In addition, due to the expected application in mobile devices a suitable robustness continues to be required.

This object is achieved by the characterizing features of the main claim in conjunction with the features of the preamble and by the features of the independent claim.

The measures specified in the dependent claims advantageous refinements and improvements possible.

The invention relates to a micromechanical switch terarray with preferably bistable, magnetically actuated switches. The force required for switching is generated electromagnetically. The holding force in the final states is applied by springs or permanent magnets. The arrangement with two separate coil layers allows by superposition of magnetic forces from a technological point of view significant reduction in the driving complexity of arranged in a grid individual switch. The possibility of using inexpensive production technologies makes it possible to open up new fields of application.

The stated object is achieved according to the invention by further developing the interconnection of coils known from ferrite core memories by superposition of the magnetic flux. The field overlay is not used to magnetize a memory bit, but used to superimpose the force between two current flowing through coil and a permanent magnet to cause a change in the switching state of each of a bistable, magnetically actuated switch. The addition of the magnetic fields or the superposition of the force of the two superimposed coils has the advantage that not all actuator coils must be connected locally with addressing lines, but that each coil of a row or a column of a continuous, insulated conductor, eg a insulated wire, can be made. It is thus possible to use a microwinning technology derived from conventional macroscopic coil production and thus multilayer metallizations with laterally high structural resolution. avoidance. The use of expensive substrate materials such as high-resistance semiconductor wafers or non-conductors, such as glass, sapphire or alumina ceramic for the production of MEMS elements is determined less by the advantageous material properties, as to meet the customary for microtechnological processes high demands on material flatness and reproducibility , The combination of modern microstructuring according to the invention, such as, for example, microembossing and modified conventional methods, such as, for example, micro coil winding, constitutes an essential development step for the realization of comparatively large, mechanically complex, reconfigurable components. The invention thus opens up completely new possibilities in many areas of information technology. and communication technology in which functional elements can not be downsized for physical reasons. It is considered essential to significantly improve the component quality in terms of functionality and flexibility under the conditions of a market-limiting cost limit.

The switch arrangement according to the invention can be hermetized simply due to the two closed material layers, namely the carrier substrate and the actuator substrate, and thereby satisfies the technical requirements of mobile communication technology.

Preferably, the movable contact of each switch and optionally also the permanent magnet associated with each switch is attached to a foil membrane, the required mechanical robustness being given for mobile applications due to the suspension designed as a foil membrane and the low mass of the moving parts. Advantageously, the two coil layers of the switch array provided in different planes can be designed so that only one elongate narrow coil is provided for each row or each column, which encloses the various coil cores. However, it can be arranged around each bobbin associated with him coil of the corresponding row and the corresponding column.

It is particularly advantageous that due to the presence of the two coil layers, it is possible to energize only one coil layer and to measure the induced voltage in the other coil layer, whereby the functionality can be diagnosed and the current switching state can be detected, since the measured voltage depends on the switching state.

An embodiment of the invention is illustrated in the drawing and will be explained in more detail in the following description. Show it:

Fig. 1 is a plan view of the invention

Switch array applied to an array of antenna elements, and

Fig. 2 is a partial section through the switch array according to the invention.

According to FIGS. 1 and 2, the switch arrangement according to the invention has a carrier substrate 4 and an actuator substrate 3 lying above in the drawing, both substrates in the exemplary embodiment consisting of a material suitable for the use of high frequency technology, such as liquid crystal polymers, polyamide, Kapton and like. On the carrier germaterial 4 is shown in FIG. 1, a field of individual antenna elements 14 in rows and columns applied at a distance from each other. Each antenna element is connected in rows and columns by way of switches 20 to the respectively adjacent antenna element 14, so that the switches 20 likewise form a matrix field.

As can be seen from Fig. 2, 4 wells 5 are provided in the carrier substrate, which are structured for example by molding and in which by deposition of suitable material layers contact surfaces are provided as fixed contacts 6. These contact surfaces are connected to the individual antenna elements 14.

A foil membrane 7 is applied to the carrier substrate 4 or to the antenna element layer, contact elements 8 being structured opposite to the fixed contacts 6 on the foil membrane 7. The film membrane 7 is attached to the carrier 4 so that a bias is applied to the contact elements 8, such that they are pressed onto the fixed contacts 6. In the region of the trough 5, the membrane film 7 is free to move. With the help of the bias the functionally important membrane rigidity is achieved. On the upper side of the film membrane 7, ie, on the side opposite the contact elements 8, the film membrane is covered, for example, by a screen printing process with structured, magnetized hard magnetic material in the area of the switches 20, such that each switch 20 has a Permanent magnet 9 is assigned. However, the permanent magnet can also be embodied as magnetic nano- or microparticles introduced into the film. As can be seen in Fig. 2, the Foil membrane 7 for a switch 20 in the closed state 10 already deflected, due to the bias, the necessary contact force is generated.

Structured elements of a magnetic material are also applied as spool cores 11 to the actuator substrate 3 opposite to the permanent magnets 9 applied to the film membrane 7. To the coil cores 11 around carries the actuator substrate 3, which may also be structured by molding, two separate layers each column in series connected coils 1 and series-connected in series coils 2, which are superimposed in different planes. The coils 1, 2 and the coil cores 11 are embedded in total in an insulating material 15, which is connected as an insulating layer with the actuator substrate and also serves for mechanically fixing the coil.

As in the embodiment of FIGS. 1 and 2 can be seen, each core two superposed coils 1, 2 are assigned. In another embodiment, instead of the individual coils, a long coil can be formed for each row or each column, which then encloses all the coil cores 11 of the respective row or column. In principle, the coils of each column or each row of both embodiments can be wound from a continuous wire and it is locally on the switch no change between the levels or no contact needed.

For the control of the coils, i. for their energization, terminals 17 are provided for each row and terminals 17 for each column.

In the de-energized state of the coils 1, 2, the Switches have two states, as shown in Fig. 2, namely the closed state 10 of the switch 20 and the opened state 12. The stable holding state with the switch 12 is opened is achieved by the respective coil core 11 in connection with the permanent magnet 9. In this case, the holding force generated between the permanent magnet 9 and the coil core 11 is greater than the restoring force or spring force of the film membrane 7. The closed state 10 of the switch 20, left in FIG. 2, is also stable, since the magnetic force between the coil core 11 and permanent magnet 10 is no longer sufficient through the larger gap portion to pull the film membrane 7 upwards.

When a switch is to be brought from the one switching state 10 in the other switching state 12, the coils 1 of each column and the coils 2 of the respective row are energized in the same direction through the respective terminals 16 and 17, which can be referred to as address lines a magnetic field is generated by each coil of the respective column and row. However, only one addition of the respective two coils 1, 2 of the switch lying in the crossing point 13 is achieved. Only in this point of intersection 13 do two coils 1, 2 located one above the other lead or drive in the same row or column in the same direction, whereby in each case depending on the previous switching state the same direction Bestrossnung takes place in a positive or negative current direction. Thus, all switches can be changed sequentially or in groups in the state. Due to the addition of the magnetic fields or the magnetic force, it is possible the magnetic holding force or the

Restoring force of the foil membrane in the final states to overcome and thus to convert the switch in the other state. At the switches 20 which are not located at the intersection point 13, the magnetic force generated by the respective coils of a plane is insufficient to change the switching state.

The carrier substrate 4, optionally also the actuator substrate 3, can have the function of a chip housing or an outer wall of a device. Such a chip housing can be easily hermetized due to the two closed material layers. In the case of an application of the switch array for the reconfiguration of patch antennas, the radiation is preferably carried out by the carrier substrate 4.

Example:

Hereinafter, a more specific example of the arrangement of FIG. 1 and FIG. 2 will be described. The carrier substrate is made of liquid crystal polymer and is patterned by hot stamping. The individual antenna elements 14 and the contact regions 6 are defined by means of sputtering technology and lithography and subsequently galvanically reinforced. The film membrane 7 has a Mylar film which carries on the side facing the carrier substrate 4 electroplated contact elements 8 and on the other side applied by screen printing and subsequently magnetized NdFeB permanent magnets 9. The film membrane 7 is stretched and by means of an adhesive with the

Carrier substrate 4 connected. The processing of the actuator substrate 3 begins with the printing and curing of the coil cores 11 of MnZn ferrite. The columns and rows organized coils 1, 2 are made by winding a thin copper enamel wire. The standing out of the plane coil core serves each as a winding mandrel. The winding of the individual coils 1, 2 is carried out sequentially, starting one above the other, optionally with the row or column. Finally, the insulating layer 15 is applied.

Claims

claims

1. Circuit arrangement having a plurality of switches arranged in rows and columns, each having at least one resiliently biased movable contact and at least one fixed contact and which is associated with a coil arrangement, wherein the respective switch is actuated depending on a magnetic field generated by the coil assembly , characterized in that in a first plane each row of

Switches (20) at least one coil (2) with electrical control terminals (16) and in a second level of each column of switches (20) at least one coil (1) with electrical control terminals (17) is assigned, wherein for actuating one in a Node (13) of a row and a column lying switch required magnetic force by energizing the terminals of the respective row and the respective column and addition of the magnetic fields of the first and second coil (1, 2) of the respective switch (20) can be generated.

2. A circuit arrangement according to claim 1, characterized in that the fixed contacts (6) of the switch (20) on a first carrier (4) and the coils (1, 2) on a second, at a distance from the first carrier (4) provided carrier (3) are arranged.

3. Circuit arrangement according to claim 1 or claim 2, characterized in that each switch (20) is associated with a magnetic core (11).

4. Circuit arrangement according to one of claims 1 to 3, characterized in that each switch (20) is associated with a coil (1, 2) in the first and second levels, which are superimposed, wherein the coils of each row (2) and the Coils of each column (1) each electrically in

Series are switched.

5. Circuit arrangement according to claim 1, characterized in that the coils (2) of each row and the coils (1) of each column are made of a continuously insulated conductor, preferably wire, around the cores.

6. Circuit arrangement according to one of claims 1 to 5, characterized in that the movable contact (8) is connected to a part (9) of magnetic material.

7. Circuit arrangement according to one of claims 1 to 6, characterized in that the switch (20) is designed as a bistable switch with two stable switch states.

8. Circuit arrangement according to one of claims 1 to 7, characterized in that a first stable switch state is given by a force acting on the movable member spring force.

9. Circuit arrangement according to one of claims 6 to 8, characterized in that the part of magnetic material is a permanent magnet (9), which in a second stable switch state with the core (11) comes into holding connection.

10. Circuit arrangement according to one of claims 1 to 9, characterized in that the movable contact (8) of each switch (20) with a

Film membrane (7) firmly connected, and that the film membrane (7) with bias to such a fixed contacts (6) carrying the carrier (4) is fixed, that the movable contacts (8) and the fixed contacts (6) in the first switch state ( 10) in electrical connection.

11. Circuit arrangement according to claim 10, characterized in that the permanent magnet (9) of each switch (20) with the opposite to the movable contact (8) lying side of the film membrane (7) is firmly connected.

12. Circuit arrangement according to claim 10, characterized in that the permanent magnet is formed as introduced into the film magnetic particles.

13. Circuit arrangement according to one of claims 10 to 12, characterized in that the film membrane (7) is connected between the switches with the carrier.

14. Circuit arrangement according to one of claims 1 to 13 with a plurality on the carrier (4) arranged separate antenna elements (14) which are connectable via the plurality of switches (20).

15. Circuit arrangement according to claim 14, characterized in that the carrier (4) consists of a Material exists, which allows the radiation of the antenna elements (14) therethrough.

16. A method for switching switches arranged in matrix form in rows and columns, each having a movable contact and at least one fixed contact and opposite to the contacts at a distance from the matrix-like first and second coils are arranged in different planes to each other, wherein the first and second Coils are respectively controlled in rows and / or columns such that the first and second coils associated with the switch to be switched generate two magnetic fields which cause a strong magnetic force by superposing and bring the switch (20) from one switch state to the other, while only a low-power magnetic field is generated for the remaining switches of the driven row and column, and the induced force is insufficient to bring the associated switches (20) from one switch state to the other.

17. The method according to claim 16, characterized in that the first and second coils are energized in rows and columns to generate the superposition of the magnetic fields in the crossing point of the control in the same direction, wherein Ü for transferring the switch from the first to the second switch state, the energization in one direction and from the second to the first switch state, the energization in the other

Direction is performed.

18. The method according to claim 16 or claim 17, characterized in that for determining the operability or the current Schaltzu- Stands only the coils of a plane energized and the induced voltage in the coils of the other level is measured.