Light emitting device and manufacturing method thereof
A light emitting device includes a first substrate, a second substrate and a plurality of micro epitaxial structures. The second substrate is disposed opposite to the first substrate. The micro epitaxial structures are periodically disposed on the substrate and located between the first substrate and the second substrate. A coefficient of thermal expansion of the first substrate is CTE 1 , a coefficient of thermal expansion of the second substrate is CTE 2 , a side length of each of the micro epitaxial structures is W, W is in the range between 1 micrometer and 100 micrometers, and a pitch of any two adjacent micro epitaxial structures is P, wherein W/P=0.1 to 0.95, and CTE 2 /CTE 1 =0.8 to 1.2.
1. A manufacturing method of a light emitting device, comprising:
providing a first substrate, a coefficient of thermal expansion of the first substrate being CTE 1 , and the first substrate having a plurality of micro epitaxial structures disposed thereon, wherein the micro epitaxial structures are connected to the first substrate through an adhesive layer, wherein a side length of each of the micro epitaxial structures is W, W ranges from 1 to 100 micrometers, a pitch of any two adjacent micro epitaxial structures is P, and W/P=0.1 to 0.95;
providing an adhesive material on the first substrate;
disposing a second substrate opposite to the first substrate, wherein the micro epitaxial structures is located between the first substrate and the second substrate, and the adhesive material covers the micro epitaxial structures via a film coating method and then bonded with the second substrate via a thermocompression bonding method, and the adhesive material contacts a plurality of side-walls of the micro epitaxial structures, wherein a coefficient of thermal expansion of the second substrate is CTE 2 , and CTE 2 /CTE 1 =0.8 to 1.2; and
separating the first substrate from the micro epitaxial structures.
2. The manufacturing method of the light emitting device as recited in claim 1 , wherein each of the micro epitaxial structures comprises a first type semiconductor layer, a second type semiconductor layer and an active layer located between the first type semiconductor layer and the second type semiconductor layer, and the adhesive layer directly contacts the second type semiconductor layer.
3. The manufacturing method of the light emitting device as recited in claim 1 , wherein each of the micro epitaxial structures defines a vertical light-emitting diode chip.
4. The manufacturing method of the light emitting device as recited in claim 2 , wherein each of the micro epitaxial structures defines a horizontal light-emitting diode chip and has two bonding pad disposed between the first type semiconductor layer and the first substrate.