This invention relates generally to electrical connectors, and more specifically, to layered connectors having dedicated contact elements for connecting closely spaced contact surfaces.
An increasing complexity of electronic assemblies in smaller packages are generating a need for new connectors to interconnect electronic components. For example, liquid crystal displays, vibratory motors, speakers and microphones are now being employed in devices of smaller and smaller size, such as cellular phone products and hand held devices. As the components become smaller and the terminals to connect the components are located closer together, known connectors are proving incapable of establishing reliable electrical connections.
The use of elastomeric connectors has become increasingly popular in some electronic devices because the connectors are readily adaptable in size and geometry to meet a large variety of applications. One type of elastomeric connector typically includes alternating layers of dielectric elastomer, such as silicon rubber, and an elastomer filled or doped with electrically conductive material such as silver particles, graphite particles, conductive fabrics, wires, etc. The dielectric elastomer layers are sandwiched between the conductive layers and are of sufficient thickness to insulate the conductive layers from one another and therefore prevent the formation of electrically conductive or leakage pathways between the conductive layers. The alternating dielectric and conductive layers provide a connector having a large number of conductive pathways in a small volume for closer contact spacing.
Components have now reached a size, however, where the contact spacing between contacts is reduced to a level that may cause shorting between the contacts through the conductive layers of the connector. For example, some microphone assemblies for cellular phones employ concentric positive and negative terminals in a disk-shaped arrangement. The positive terminal is located in the center portion of the disk and the negative terminal located in the surrounding portions of the disk with a small annular clearance extending between the positive and negative terminals. When a layered elastomeric connector is connected to the positive and negative terminals, some of the conductive layers may contact both the positive terminal and the negative terminal of the microphone assembly, therefore shorting the microphone terminals.
In an exemplary embodiment of the invention, an electrical connector is provided. The connector comprises at least a first contact element and a second contact element, wherein each of the first and second contact elements includes alternating conductive materials and nonconductive materials. An insulating layer separates the first contact element and the second contact element.
Optionally, the insulating layer comprises a first end edge abutting the first contact element and a second end edge abutting the second contact element, and the first end edge and the second end edge extend substantially perpendicular to the alternating conductive layers and nonconductive layers. For example, the connector comprises a longitudinal axis, the insulating layer being oriented transverse to the longitudinal axis. Each contact element includes a top contact surface and a bottom contact surface, and the conductive and nonconductive materials extend between the top contact surface and the bottom contact surface. The insulation layer divides the first and second contact elements into dedicated contact regions and has a length to prevent the first contact element and the second contact element from contacting more than one terminal contact surface on an electrical component.
In another exemplary embodiment of the invention, an electronic assembly includes an electrical component having at least a first terminal contact surface and a second terminal contact surface separated by a gap. A connector comprising at least a first elastomeric element and a second elastomeric element, wherein each of the first and second elastomeric elements include alternating conductive layers and nonconductive layers. An insulating layer separates the first elastomeric element and the second elastomeric element, and the insulating layer spans the gap when the connector contacts the board to prevent shorting contact between the first terminal contact surface and the second terminal contact surface through the first elastomeric element and the second elastomeric element.