Two-layer capacitive touchpad and method of making same
AssigneeSynaptics Incorporated
InventorsJoel Seely, Robert Leonard Malak, Timothy Peter Allen, Richard Robert Schediwy, William Andrew Cesarotti
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Abstract
By suitable use of screen-printed carbon ink patterning, combined with patterning of the solder-mask layer on the top (finger) surface, a compact capacitive touchpad pointing device has been realized using only a two-layer board as a substrate. The first layer, on the topside of the printed circuit board, combines both the horizontal and vertical sensor electrode traces. The second layer, located on the underside of the printed circuit board, is formed in the conventional manner by attaching the controller chip and/or related circuitry.
Claims22
A touchpad pointing device comprising:
- a printed circuit board having a top and under side,
- a first layer on the top side of the printed circuit board which includes a plurality of metal sense pads,
- and a first plurality of conductive traces disposed in a first direction connecting some of said sense pads forming sensor electrodes in said first direction,
- and a second plurality of conductive traces disposed in a substantially orthogonal direction connecting others of said sense pads forming sensor electrodes in said second direction said first and second plurality of conductive traces are on the same surface of the first layer,
- and a second layer formed on the underside of the printed circuit board which includes conductors for the interconnection of electrical components associated with the touchpad.
A method of fabricating two-layer touchpad for use in a system for moving a cursor on a display screen comprising,
- forming a first layer on the top side of the printed circuit board which includes a plurality of metal sense pads,
- and a first plurality of conductive traces disposed in a first direction connecting some of said sense pads forming sensory electrodes in said first direction,
- and a second plurality of conductive traces disposed in a substantially orthogonal direction connecting others of said sense pads forming sensor electrodes in said second direction;
- said first and second plurality of conductive traces are on the same surface of the first layer,
- and forming a second layer formed on the underside of the printed circuit board which includes conductors for the interconnection of electrical components associated with the touchpad.
A touchpad pointing device comprising,
- a two-layer printed circuit board as a substrate,
- a first layer, located on the top side of the printed circuit board, which combines both horizontal and vertical sensor traces on the same surface of the first layer,
- and a second layer, located on the underside of the printed circuit board, which is formed by touchpad electronic circuitry.
Dependencies are inferred from the claim text.