DE102014007849A1 - Contact electrode for less tear-resistant substrates - Google Patents

Abstract

Electrical contact between two conductive surfaces of a contact electrode pair (1), (7), which is caused by a bearing force (3), with which (1) is pressed on (7), wherein the force (3) is achieved without mechanical clamping.

Description

1. State of the art

Known is the functional pressure in which a soft substrate on the type of paper, a foil or a textile can be provided with a functional element by z. As a planar resistor, or a planar luminous surface or a planar sensor element is applied as a number of printed patterns on a film. In this case, a variety of fluid substances can be used as printing ink, which are also referred to simply as color in this document.

Known are formed from printable polymers colors which are functionalized by introduced particles. For this purpose, metal inks are known, which become highly conductive after thermal curing.

Preferably, the above functional elements must be connected to an external device in the manner of a controller, a measuring device or a source of electrical energy. Discrete plugs are known for this purpose. These plugs usually have a height of a few millimeters and their operation includes a mechanical clamping force by z. B. a plug by means of an insertion force overcomes frictional forces and then due to these forces, eg. B. in a socket, clamped. They are usually inserted manually and can be solved by applying a counter force to the clamping force, the substrate is loaded. Furthermore, such plugs may wear out, so that the clamping force decreases or disappears completely, and their pins may bend or break.

It would be advantageous to have an electrical connection which would be closed by simply placing a first contact electrode mounted on a soft substrate on a counterelectrode, wherein the connection would be solvable by exerting a traction force which could be adjusted as much as possible on this substrate, whereby the forces arising in the substrate surface would be distributed in that the soft substrate does not irreversibly stretch or tear.

2. Description of the invention

The invention described below achieves the above object with a device according to claim 1 and a manufacturing method according to claim 6. Further characteristics of the invention are laid down in the dependent claims.

2.1 Description of a preferred embodiment

1 shows schematically and preferably a first electrically conductive contact element ( 1 ) formed by a circular cutout of a conductive surface ( 6 ) is formed, ( 6 ) on a soft substrate ( 4 ) and wherein ( 4 ) 6 ) are both diamagnetic. For example, ( 6 ) a polymeric sheet resistance which is deposited on a soft paper filter surface ( 4 ) is glued. Preferred is under ( 6 ) and ( 4 ) a rotationally symmetrical, magnetizable body ( 1a ) concentric to ( 1 ), which preferably includes soft iron or superparamagnetic particles in a polymeric matrix, and which is also bendable.

As in 1 will be shown ( 1 ) in the vicinity of a likewise rotationally symmetrical and electrically conductive second electrically conductive contact element ( 7 ) with symmetry axis ( 2 ), which is preferably applied to a substrate ( 8th ) is applied fix (where 7 ) preferably a cylindrical, on ( 2 ) centered and completely in ( 7 ) permanent magnets ( 7a ), and wherein ( 7 ) z. B. part of a conductor or is electrically connected to such, and ( 1 ) becomes like in 1 shown by a magnetic force ( 3 ) on ( 7 ) and on ( 7 ). Preferably ( 7 ) and ( 1 ) has a common axis of symmetry ( 2 ) on. It is preferably assumed that ( 8th ) is fixed on a support, and ( 7 ) not only soft, but also movable.

To contact ( 1 ) and ( 7 ), can ( 4 ), so that on ( 1 ) a tensile force whose magnitude is greater than that of ( 3 ) and the opposite works. The amount of ( 3 ) is preferably adjustable by z. B. ( 1a ) with a printing ink, in which ferromagnetic particles are embedded, printed and then thermally cured, wherein z. B. by material selection of the particles in ( 1a ), or by their dosage, or by the area and / or thickness of ( 1a ) the bearing force ( 3 ) certainly.

2.2 Further embodiments of the invention

Conceivable are further variants in which an inventive electrically conductive contact element ( 1 ) mechanically and permanently with at least one magnetizable and preferably printable body ( 1a ), wherein z. B. ( 1a ) a part of ( 1 ) or wherein said mechanical connection can be elastic. The electrode according to the invention ( 7 ) is also mechanical and permanent with at least one ( 7a ) connected by z. B. the magnetizable body ( 7a ) above ( 7 ) or in that a soldering paste contains ferromagnetic particles, e.g. B. be melted in a via in a flexible printed circuit, or by z. B. on a substrate ( 8th ) with a contact ( 7 ) is fixedly connected, a number of permanent magnets is applied.

It is conceivable that ( 1a ) instead of ( 7a ) is permanently magnetized, or that both ( 7a ) as well as ( 1a ) are permanently magnetized.

It is conceivable that between the contact elements ( 1 ) 7 ) a dielectric through ( 3 ), so that an AC-conducting capacitor is formed.

Preferably includes ( 1a ) a polymer matrix with embedded magnetizable particles, which is applied as a printing ink so that a force ( 3 ) is adjustable in amount so that the substrate ( 4 ) neither tears nor irreversibly stretched. For this purpose, the magnetizable particles may be paramagnetic, ferromagnetic, or superparamagnetic; if they are ferromagnetic, they can be permanently magnetized after or before printing. In this case, said magnetic particles in a body ( 1a ) be chemically different, for. Example, by applying different ink colors in an inkjet or rapid prototyping printer. It is also conceivable that in one ( 1a ) by such printing processes colors with different concentrations of magnetizable particles are printed flush next to each other and a ( 1a ) is created. Finally, 3 ) also by the size and geometry of ( 1a ) and the distance between ( 1a ) and ( 7a ). It is conceivable that ( 1 ) or ( 7 ) are designed so that ( 1 ) to ( 7 ) approximately centered.

It is conceivable that ( 1 ) and ( 7 ) are pressed together and their surfaces are connected to one another via a viscous and non-evaporating conductive liquid in the manner of an ionic liquid, which is between ( 1 ) and 7 is introduced so that ( 1 ) and ( 7 ) are held together by an interaction of surface energies. There is a force ( 3 ) z. Example by selecting the ionic liquid and / or by influencing the contact energies on the respective conductive surfaces of ( 1 ) and ( 7 ) adjustable.

Preferably ( 1 ) has a modulus of elasticity commensurate with the distance of ( 2 ) radially decreases, so that the tensile force ( 3 ) during a release of ( 1 ) and ( 7 ) partly from ( 1 ) and thus ( 4 ) by a tensile force for releasing the contact ( 1 ) 7 ) is mechanically less stressed. In another preferred variant, 1 ) mechanically and permanently with a preferably elastomeric and rotationally symmetrical body ( 5 ) connected to ( 4 ) and functions similarly to a washer, the thickness of ( 5 ) preferably decreases radially with the distance from the axis of symmetry. Such imprints ( 5 ) with contactless printing process in the manner of inkjet or spraying.

3. Advantages of the invention

The invention provides an as often as possible detachable electrical contact between two conductive electrodes ( 1 ) and ( 7 ), which is produced without soldering or gluing processes and which manages without mechanical or frictional clamping forces, preferably a mobile element (FIG. 1 ) by a bearing force ( 3 ) to the space-fixated ( 7 ) and where ( 3 ) and thus a necessary for releasing electrical connection counterforce of the mechanical strength of a soft substrate ( 4 ) is adaptable, preferably by a with ( 1 ) mechanically and permanently connected magnetizable body ( 1a ) is printed in a suitable manner. In contrast to simple mated compounds, the compound of the invention can not leach. Preferably, the elements ( 1 ) and ( 7 ) can be created in a printing process.

Claims (7)

Electrical contact between two conductive surfaces of a pair of contact electrodes ( 1 ) 7 ), which is supported by a 3 ) is effected, with which ( 1 ) on ( 7 ) is pressed, the force ( 3 ) comes about without mechanical clamping. Contact electrode pair according to claim 1, wherein ( 1 ) and ( 7 ) each having at least one magnetizable body ( 1a ) 7a ) are mechanically and permanently connected, and wherein at least one of the magnetizable body ( 1a ) 7a ) includes a permanent magnet so that when applying ( 1 ) on ( 7 ), the contact electrode ( 1 ) by a magnetic force ( 3 ) on ( 7 ) is pressed. Contact electrode pair according to claim 2, wherein the contact force ( 3 ) by designing at least one of the magnetizable bodies ( 1a ) or ( 7a ) is adjustable such that one for releasing the connection between ( 1 ) and ( 7 ) counterforce the substrate ( 4 ) does not irreversibly stretch or tear. Contact electrode pair according to claim 1 or 2, wherein ( 1 ) and ( 4 ) mechanically and permanently with a preferably elastic body ( 5 ), which upon release of the contact ( 1 ) 7 ) occurring forces in ( 4 ). Contact electrode pair according to one of the preceding claims, characterized by a dielectric are disconnected so that an alternating current between ( 1 ) and ( 7 ) can flow. Method for applying a pair of contact electrodes according to one of the preceding claims, which comprises applying at least one color pattern to a substrate, the color used for this having paramagnetic, ferromagnetic or superparamagnetic constituents, and wherein the color is curable, preferably chemically, or thermally or photochemically. Method according to claim 6, wherein 1 ) or ( 7 ) are applied using a number of printing steps with a printing method, preferably without contact in the manner of an ink jet printing, aerosol printing, pipetting, or by contact pressure, for. B. by gravure or high pressure.

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