Switch adapted to be mounted in plastic housings for electrical components or control panels

0001The invention relates to a control-panel, comprising a Switch with fixed contacts and a switching element of a Plastic with pressure-dependent electrical conductivity.

0002Such a switch is disclosed in German Patent DE 31 15 271 C2. This switch can according to FIG 2 For example, in a control-panel below the display device a watch case are used. According to Figure 4 shows the switch used a rubber member of a pressure dependent on electrically conductive elastomer. With this Rubber part a so-called switch body is connected, which fixed contacts for electrically contacting the having switch. remote from the switch body Side of the rubber part is a push button provided with its Help exercised a manual shift force to the rubber part may be, to make it electrically conductive, and as an electrically conductive connection between the fixed contacts produce.

0003The object of the invention is a control-panel with specify a switch, which is comparatively easy can be produced.

0004The object is achieved in that the fixed contacts in the made of plastic operation and control board are integrated and the switching element with that in the multicomponent injection molding process is prepared. This results advantageously a simple component to be produced, where the Application of multi-component injection molding process a final assembly is saved. Particularly vorteilthaft it is when the fixed contacts forming interconnect conductive Plastic together with the operation and control board and the switching element produced in multicomponent injection molding process are. This may additionally comprise the fixed contacts and the is inexpensive in these subsequent interconnects Injection molding together with the other injection molded Components are manufactured. This results in a particularly cost-effective operation and control board.

0005Furthermore, it is advantageous if that operation and control board a forms conversion part of a housing for electronic components. In this case, advantageously, the switch of the operation and control board are electrically connected to the electronic components. In addition, particularly advantageously the housing as a circuit carrier be used for the electronic components. Here, for the electronic components as well as the switch be completely dispensed with a separate carrier plate, whereby firstly the production costs are reduced and secondly realized a particularly compact design of the housing becomes.

0006The operator panel can for example by means of a plug connection be connected to the housing and, for example, at the same time the function of a lid for a Housing opening assume that the installation of the electronic Components is provided in the housing. particularly advantageous however, the one-piece production of the housing and the operation and control board by injection molding.

0007As the electrically conductive plastic is advantageously a compound of metal powder and a thermoplastic elastomer used. Decisive filled for the function of conductive Compounds is that forms a continuous network, where touching the filler or to about 10 nm annähnern. With a continuous increase the filler content increases the conductivity initially only slightly up to a certain concentration of a. In a narrow concentration range above a certain Filler concentration, the so-called percolation, the conductivity then increases by a multiple at. With a further increase in the filler concentration a plateau is reached at which the conductivity not changed significantly. This plateau value is substantially on the shape of the filler particles and their tendency agglomeration of networks depends, but also such. As the statistical disturbances of filler.

0008If the filler concentration in the early Perkolationsbereiches, so it comes in pressure acting on the plastic to a sharp increase in the electrical conductivity. This property can be to implement a use button function. If the housing mechanical means provided for engaging in the actuated position, so can implemented a switch function like a toggle switch will.

0009omitted All assembly work for the switch installation with the inventive solution. If the cable connections with prepared Mehrkomponentenspritzgießverfahren, so there are not even involved in the manufacture of necessary wiring connections.

0010The switch is extremely robust, since it from a uniform Material and has mechanical parts omitted. also No housing breakthroughs for the switch necessary so now manufactured in a simple manner housing may be, which are sealed against aggressive Media or to dust.

0011The advantages of the invention are also described below from the Embodiment seen. The associated Drawing shows an injection molded housing part with an injected Switch.

0012An operator panel 1 of an electronic device, eg. As the keypad a power window of a car carries, two button 2. The button 2 made of an electrically conductive plastic. You are in Mehrkomponentenspritzgießverfahren together with the control panel 1 and the other manufactured housing parts, and electrical interconnects 3 can be injected if it also conductive plastic is used. Alternatively, the Interconnects 3 but also by coating the operating panel and the probe 2 are made (not shown). The illustrated conductor tracks 3 forming fixed contacts 4 between the operating panel 1 and the buttons 2, one of which in the Drawing is indicated.

0013The electrically conductive plastic for the button 2 is comprising a compound of metal powder, for. example, aluminum powder, and a thermoplastic elastomer, wherein the filler concentration just reaches the range in which the plastic begins to be conductive. Now, a pressure effect applied to a button 2, so approaching the filler and the electric conductivity increases by leaps and bounds.