Semiconductor device on string circuit and method of making the same
An elongated light circuit includes an elongated circuit trace and a plurality of micro-sized, unpackaged LEDs disposed sequentially on the circuit trace. A height of the LEDs ranges from about 12.5 microns to about 200 microns. The elongated circuit trace and the LEDs are coated with a protective coating.
1. A light string including at least a pair of conductive wires, and a plurality of micro-sized, unpackaged LEDs electrically connected to the pair of conductive wires, the LEDs being distributed along a length of the pair of conductive wires, and the LEDs being transferred to the pair of conductive wires via a method comprising acts of:
positioning the pair of conductive wires to be adjacent to a first surface of an LED carrier carrying multiple LEDs of the plurality of LEDs thereon;
actuating a reciprocating transfer member to thrust against a second surface of the LED carrier at a position corresponding to a location of an initial LED of the plurality of LED on the first surface of the LED carrier, the actuating of the transfer member causing a localized deflection of the LED carrier in a direction of the pair of conductive wires to position the initial LED proximate to the pair of conductive wires;
transferring the initial LED directly to the pair of conductive wires;
shifting the LED carrier such that the transfer member aligns with a subsequent location of a subsequent LED of the multiple LEDs on the first surface of the LED carrier; and
repeating the acts of actuating, transferring, and shifting with respect to consecutive subsequent locations and corresponding consecutive subsequent LED at a predetermined transfer rate to effectuate a transfer of the multiple LEDs onto the pair of conductive wires.
2. The light string of claim 1 , wherein the method further comprises an act of feeding the pair of conductive wires into a finishing device after the step of shifting the LED carrier.
3. The light string of claim 2 , wherein the finishing device performs at least one of:
curing the pair of conductive wires with the plurality of LEDs, or
coating the pair of conductive wires with the plurality of LEDs.
4. The light string of claim 1 , wherein the predetermined transfer rate ranges between about 6 LEDs per second to about 20 LEDs per second.
5. The light string of claim 1 , wherein the LEDs have a height not greater than about 200 microns.
6. The light string of claim 1 , wherein the LEDs have a height not greater than about 50 microns.
7. The light string of claim 1 , wherein the pair of conductive wires is secured to an elongated substrate strip.