Method for transferring light-emitting elements onto a package substrate
A method for transferring light-emitting elements onto a package substrate includes: providing a light-emitting unit including a supporting substrate and a plurality of light-emitting elements, each of the light-emitting elements being removably connected to the supporting substrate and having a surface opposite to the supporting substrate; disposing the light-emitting unit spacingly above a package substrate in such a manner that the surface of each of the light-emitting elements faces the package substrate; and disconnecting the light-emitting elements from the supporting substrate to allow the light-emitting elements to fall onto the package substrate by gravity, so as to connect the light-emitting elements with the package substrate in a non-contact transferring method.
1. A method for transferring light-emitting elements onto a package substrate, comprising:
providing a light-emitting unit including a supporting substrate and a plurality of light-emitting elements, each of the light-emitting elements being removably connected to the supporting substrate and having a surface opposite to the supporting substrate;
disposing the light-emitting unit spacingly above a package substrate in such a manner that the surface of each of the light-emitting elements faces the package substrate; and
disconnecting the light-emitting elements from the supporting substrate to allow the light-emitting elements to fall onto the package substrate by gravity,
wherein the package substrate includes a plurality of connecting elements disposed correspondingly in position between the light-emitting elements and the package substrate for electrically interconnecting the light-emitting elements and the package substrate, and
wherein, after said disconnecting, each of the light-emitting elements falls onto and contacts a corresponding one of the connecting elements.
2. The method of claim 1 , wherein the step of disconnecting the light-emitting elements is conducted in a chamber under a pressure that is less than 760 torr.
3. The method of claim 1 , wherein the light-emitting elements at least include a first group of the light-emitting elements and a second group of the light-emitting elements, the second group of the light-emitting elements having a height from the supporting substrate that is different from that of the first group of the light-emitting elements.
4. The method of claim 1 , wherein the package substrate is one of a printed circuit board, a thin film transistor (TFT) substrate, and a complementary metal-oxide-semiconductor (CMOS) substrate.
5. The method of claim 1 , wherein the connecting elements are made of an alloy having a eutectic temperature ranging from 150° C. to 300° C.
6. The method of claim 1 , wherein the supporting substrate is a light release tape, and the step of disconnecting the light-emitting elements from the supporting substrate is conducted by irradiating the supporting substrate with a light having a predetermined wavelength.
7. The method of claim 1 , wherein the light-emitting elements are connected to the supporting substrate through magnetic attraction, and the step of disconnecting the light-emitting elements from the supporting substrate is conducted by diminishing the magnetic attraction.
8. The method of claim 1 , wherein the light-emitting elements are connected to the supporting substrate through a connecting layer.
9. The method of claim 8 , wherein the connecting layer is made of an alloy having a eutectic temperature ranging from 150° C. to 300° C., and the step of disconnecting the light-emitting elements from the supporting substrate is conducted by heating the connecting layer so as to melt the connecting layer.