Connecting conductive layers using in-mould lamination and decoration
In one embodiment, a method for forming a touch sensor is provided. The method includes forming a plurality of electrodes on a first substrate. The plurality of electrodes are configured to form a plurality of capacitive nodes. Each capacitive node is configured to sense touch of an object proximate a touch sensing area of the substrate. The method further includes compressing together a plurality of conductive pads at least in part by applying a resin in liquid form to a first substrate, the resin being applied under pressure. A first one of the plurality of conductive pads had been formed on the first substrate. A second one of the plurality of conductive pads had been formed on a second substrate.
1. A touch sensor comprising:
a first substrate comprising a plurality of electrodes formed on a surface of the first substrate;
a second substrate comprising a plurality of electrodes formed on a surface of the second substrate, the surface of the second substrate comprising the plurality of electrodes opposing the surface of the first substrate comprising the plurality of electrodes, respective portions of the first and second substrates spaced being apart from each other by a dielectric material disposed between the respective portions of the first and second substrates, the plurality of electrodes forming of the first substrate each configured to form a capacitively coupled node with at least one of the plurality of electrodes of the second substrate, each capacitively coupled node configured to sense touch of an object, a portion of the second substrate deformed by compression such that a conductive pad on the second substrate and a conductive pad on the first substrate are connected and electrically coupled to each other wherein the portion of the second substrate is deformed by compression such that the conductive pad on the second substrate and the conductive pad on the first substrate are directly touching and galvanically coupled to each other;
a solidified resin that had been injected in a liquid form on the second substrate, the conductive pad on the second substrate being compressed against the conductive pad on the first substrate by the injection of the resin while in the liquid form.
2. The touch sensor of claim 1 , further comprising a flexible printed circuit (FPC) held in compression, between the first and second substrates, by the solidified resin.
3. The touch sensor of claim 1 , further comprising a flexible printed circuit (FPC) bonded to the surface of the first substrate comprising the plurality of electrodes.
4. The touch sensor of claim 1 , further comprising a transparent cover panel formed through an in-mould lamination process on a surface of the first substrate that is opposite from the surface of the first substrate comprising the plurality of electrodes.
5. The touch sensor of claim 4 , the transparent cover panel comprising solidified resin that had been injected in a liquid form on the first substrate during the in-mould lamination process.
6. The touch sensor of claim 1 , further comprising a dielectric layer coupled to each of the first and second substrates, the dielectric layer disposed between the surface of the first substrate comprising the plurality of electrodes and the surface of the second substrate comprising the plurality of electrodes.
7. The touch sensor of claim 6 , the first and second substrates each extending outwardly from the dielectric layer along respective axes that are each parallel to the surface of the first substrate comprising the plurality of electrodes, such that the dielectric layer occupies a majority but not all of a total volume between the first and second substrates.
8. The touch sensor of claim 6 , the dielectric layer being a transparent adhesive layer less than 100 microns thick.
9. The touch sensor of claim 2 , wherein the flexible printed circuit directly touches the first and second substrates.