Browse Prior Art Database

Folded Connector for Flexible Circuit Cards in Capacitor Keyboards

IP.com Disclosure Number: IPCOM000053156D
Original Publication Date: 1981-Sep-01
Included in the Prior Art Database: 2005-Feb-12
Document File: 2 page(s) / 56K

Publishing Venue

IBM

Related People

Harris, RH: AUTHOR

Abstract

Capacitive keyboards utilizing flexible circuits for the capacitive pads are known. Since the capacitive pads are normally wired into a matrix on both sides of a flexible insulated plastic substrate in these designs, two planes of circuitry exist on the flexible circuit card and a connection to them must be made on both sides of the card. Connection to a circuit or logic card is best done when only one plane is required on the card. This invention shows how both planes on the card can be easily routed through one side of the logic card to which they are to be connected and in a manner that eliminates sharp folds and provides strain relief.

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Folded Connector for Flexible Circuit Cards in Capacitor Keyboards

Capacitive keyboards utilizing flexible circuits for the capacitive pads are known. Since the capacitive pads are normally wired into a matrix on both sides of a flexible insulated plastic substrate in these designs, two planes of circuitry exist on the flexible circuit card and a connection to them must be made on both sides of the card. Connection to a circuit or logic card is best done when only one plane is required on the card. This invention shows how both planes on the card can be easily routed through one side of the logic card to which they are to be connected and in a manner that eliminates sharp folds and provides strain relief.

In the figure, the flexible pad card 9 has printed circuit elements 4 on both sides. Those labeled A are on the underside in the figure, and those labeled B are on the top surface of the flexible pad card or substrate 9. The logic card 2 contains the operative electronics (not shown) which are necessary for driving the circuits 4 in order to sense the operation of keyboard input signals at various locations (not shown) on the flexible pad card 9.

The flexible conductor lines are grouped into sections A and B as shown, and they are wrapped about an intermediate member 5. Those on portion B are wrapped over the top of the intermediate member 5, while those in section A are brought out under the member 5 and are wrapped onto its top surface so that the conductive elements 4 all appear on the outer surface on the underside of member 5. Member 5 is a soft rubber material that maintains the desired minimum bend radius in the flexible circuit elements and also insures intimate contac...