Abstract:
A hearing assistance device, comprising a microphone to receive sound, signal processing electronics electrically connected to the microphone, a receiver electrically connected to the signal processing electronics and a switch electrically connected to the signal processing electronics, wherein the switch includes conductive silicone adapted to change the switch from a first state to a second state when activated.

Description:
CLAIM OF PRIORITY AND RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application Ser. No. 60/888,724, filed Feb. 7, 2007, the entire disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This document relates generally to hearing assistance devices and more particularly to electrical contacts using conductive silicone in hearing assistance devices. 
     BACKGROUND 
     Hearing assistance devices have a variety of design and packaging issues. Components are increasingly small in size and require One type of hearing assistance device is a hearing aid. Hearing aids include in-the-ear (ITE), in-the-canal (ITC), completely-in-the-canal (CIC) and behind-the-ear (BTE) designs. Each of these types of hearing aid has its benefits and technical challenges. Generally speaking, CIC designs are placed entirely in the canal and do not rely on manually accessible controls for operation, but are almost impossible to see from the perspective of another casual observer. On the other hand, BTE designs are much more visible and have controls which are readily manually accessible by the user, since the BTE rests on the back side of the ear. In BTE designs conventional switches may be employed, however such switches can fail due to wear and tear or can get dirty, thereby decreasing product benefit and lifetime. 
     Other tradeoffs in packaging and performance exist. For example, a number of electrical connections are made in such devices, and the room with which a manufacturer has to work with is more limited as device sizes decrease. Device components are typically soldered together, but such connections are prone to failure over time and with extended use of the hearing assistance devices. 
     SUMMARY 
     Various embodiments described herein relate to solderless connections and contacts for hearing assistance devices comprising a microphone to receive sound, signal processing electronics electrically connected to the microphone, a receiver electrically connected to the signal processing electronics; and a switch electrically connected to the signal processing electronics, the switch including conductive silicone adapted to change the switch from a first state to a second state when activated. Various embodiments also include hearings assistance devices comprising a microphone to receive sound, signal processing electronics electrically connected to the microphone, a receiver electrically connected to the signal processing electronics and at least one contact comprising conductive silicone for electrically connecting at least one electrical component to the signal processing electronics. Various embodiments include hearing assistance devices for wearing behind the ear, in the ear, in the canal and completely in the canal. 
     This Summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details about the present subject matter are found in the detailed description and the appended claims. The scope of the present invention is defined by the appended claims and their legal equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross section of a hearing assistance device having a switch using conductive silicone according to one embodiment of the present subject matter. 
         FIG. 2A  is a side view of one example of a conductive switch using conductive silicone in a first state according to one embodiment of the present subject matter. 
         FIG. 2B  is a side view of one example of a conductive switch using conductive silicone in a second state according to one embodiment of the present subject matter. 
         FIG. 2C  is a plan view of one example of circuit traces for which the conductive silicone forms a conductive bridge when pressed to form a switch according to one embodiment of the present subject matter. 
         FIG. 3  is a cross section of a hearing assistance device having a plurality of switches using conductive silicone according to one embodiment of the present subject matter. 
         FIGS. 4 and 5  are perspective views of a portion of a hearing assistance device having contacts for components including conductive silicone according to various embodiments of the present subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     The following description includes examples which demonstrate only some of the embodiments of the present invention. The following description and drawings provide examples for illustration, and are not intended to provide an exhaustive treatment of all possible implementations. It should be noted that references to “an”, “one”, or “various” embodiments in this disclosure are not necessarily to the same embodiment, and such references contemplate more than one embodiment. 
       FIG. 1  is a cross section of a hearing assistance device  100  having a switch using conductive silicone according to one embodiment of the present subject matter. In various embodiments, a hearing assistance device has at least one pushbutton for manually selecting and/or adjusting operation parameters of the device. In the embodiment of  FIG. 1 , the pushbutton  102  uses conductive silicone  106  instead of traditional mechanical contact schemes for providing a contact associated with the pushbutton. The pushbutton is shown in an open state. As the button is pressed, the conductive silicone  106  contacts the circuit board  104 . In various embodiments, the conductive silicone  106  engages exposed terminations on the circuit board, thus closing a circuit. In various embodiments, the circuit is connected to a processor and can provide an input signal to the processor, for example, to select a parameter for adjustment and/or to change the volume of the hearing assistance device. In various embodiments, a barrier skirt is included around the conductive silicon to prevent contaminates from settling on the conductive traces of the circuit board. In the example of  FIG. 1 , pushbutton  102  includes a portion  111  that remains in contact with the circuit board at all times. This portion of the pushbutton functions as a barrier skirt  111  to protect the circuit board  104 , the exposed traces and the conductive silicone  106  from contaminants. The barrier skirt  111  of pushbutton  102  completely surrounds the interface between the circuit board  104  and the conductive silicon  106 . In various embodiments, the pushbutton  102  and barrier skirt  111  are formed from the same material and are bonded to the conductive silicon using various over-molding processes. Nonconductive silicone is an example of a material that may be used to form the pushbutton and barrier skirt. 
       FIG. 2A  is a side cutaway view of one example of a pushbutton switch using conductive silicone in a first state according to one embodiment of the present subject matter.  FIG. 2B  is a side cutaway view of one example of a pushbutton switch using conductive silicone in a second state according to one embodiment of the present subject matter.  FIGS. 2A and 2B  illustrate the use of conductive silicon to close a circuit in a pushbutton switch assembly.  FIGS. 2A and 2B  show a circuit board  204 , circuit traces  207 , conductive silicon  206  and a pushbutton body  202  including a barrier skirt  211 . In the example illustrated, the circuit traces form a switchable set of contacts that may be connected to the processor or other electronics of a hearing assistance device. In  FIG. 2A , the switch is shown as being electrically “open.”  FIG. 2B , illustrates a switch in an electrically “closed” state by application of a force to the layer of conductive silicone. The force has two effects in this example, the first effect is to deform the switch body and barrier skirt such that the conductive silicon is squeezed between the pushbutton body and the circuit board (lowering the impedance of the conductive silicone in the zone of applied pressure). The force has a second effect of engaging the conductive silicon into contact with a complimentary pair of exposed circuit board traces. The low impedance of the conductive silicon closes the circuit connected to the exposed traces. It is understood that normally closed switches can be formed using the conductive silicone, and that the example given here is not restricted to normally open embodiments. 
       FIG. 2C  is a plan view of one example of circuit traces for which the conductive silicone forms a conductive bridge when pressed to form a switch according to one embodiment of the present subject matter. The printed circuit traces  2 AA and  2 BB are connected to electronics  2 CC which sense when a relatively low impedance is presented across the traces by conductive silicone  2 DD as it is depressed in the switching process. It is understood that other configurations of traces, dimensions of traces, numbers of traces, and trace conducting materials may be employed without departing from the scope of the present subject matter. 
       FIG. 3  is a cross section of a hearing assistance device having a plurality of switches using conductive silicone according to one embodiment of the present subject matter. The figure shows a cutaway view of a hearing assistance device  300 . The hearing assistance device includes a transducer  301 , a first pushbutton  302  and a second pushbutton  303 . In various embodiments, the transducer  301  is connected to a circuit board  304  by conductive silicone  305 . The conductive silicone  305 , takes the place of solder. In various embodiments, the conductive silicone eliminates the need to solder transducers where conductive silicone can be sized and installed between electrical terminals of the transducer and the corresponding electrical terminations on the circuit board. 
       FIG. 4  is a perspective view of a portion of a hearing assistance device having conductive silicone contacts for components according to one embodiment of the present subject matter. The perspective view includes a transducer  401 , a circuit board  404 , conductive silicon contacts  405 A,  405 B and additional electronics  410 . In various embodiments, the conductive silicon contacts  405 A,  405 B are adapted to provide a low resistance contact between the terminals of the transducer  408  and the corresponding terminals  409  and traces  407  of the circuit board  404 . The low resistance contact facilitates the transfer of the electrical signal of the transducer  401  to other electronics  410  of the hearing assistance device. 
       FIG. 5  is a perspective view of a portion of a hearing assistance device having conductive silicone contacts for components according to one embodiment of the present subject matter. The perspective view includes a transducer  501 , a circuit board  504 , conductive silicon contacts  505 A,  505 B and additional electronics  510 . In various embodiments, the conductive silicon contacts  505 A,  505 B are adapted to provide a low resistance contact between the terminals of the transducer, not shown, and the corresponding terminals  509  and traces  507  of the circuit board  504 . The low resistance contact facilitates the transfer of the electrical signal of the transducer  501  to other electronics  510  of the hearing assistance device. In various embodiments, the conductive silicon can be sized and shaped to accommodate unique, individual terminal configurations, as well as, multiple terminal arrangements. 
     An example of conductive silicone used in the features of the present subject matter include, but are not limited to, STAX™ Elastomeric Connectors manufactured and distributed through Tyco/Electronics. 
     This application is intended to cover adaptations and variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive. The scope of the present subject matter should be determined with reference to the appended claim, along with the full scope of legal equivalents to which the claims are entitled.