Optoelectronic device chip having a composite spacer structure and method making same
An optoelectronic device chip, and a method for making the chip, are disclosed. The chip comprises a device substrate, an optically transparent upper substrate, and a composite spacer layer which includes an adhesive material and a plurality of particles dispersed in said adhesive material. The distance between the device substrate and the upper substrate is controlled by the thickness of the composite spacer layer so that the variation is within the depth of focus of optical system.
1. An optoelectronic device chip comprising:
a device substrate;
an optoelectronic device provided on said device substrate;
an upper package substrate; and
a composite spacer adjacent to said optoelectronic device and connecting said upper package layer with said device substrate,
wherein said composite spacer includes an adhesive material and a plurality of particles dispersed in said adhesive material,
wherein said particles comprise a core made of polymer or resins and the surface of said core is coated with a conductive layer.
2. The optoelectronic device chip as claimed in claim 1 , wherein the distance between the bottom surface of said upper package layer substrate and the top surface of said device substrate is in a range of a target distance 10-50 μm plus or minus the depth of focus of an associated optical system.
3. The optoelectronic device chip as claimed in claim 1 , wherein said adhesive material comprises a photopolymer material curable under ultra-violate light, and said particles are made of polymers or resins.
4. The optoelectronic device chip as claimed in claim 1 , wherein said composite spacer is anisotropic conductive.
5. The optoelectronic device chip as claimed in claim 4 , wherein adhesive material is an insulating adhesive material, and said particles are conductive.
6. The optoelectronic device chip as claimed in claim 4 , further comprising a conductive pad at the bottom surface of said upper package layer substrate.
7. The optoelectronic device chip as claimed in claim 6 , further comprising a conductive layer at least within said upper package layer substrate and connecting with said conductive pad.