Optical proximity sensor and manufacturing method thereof

Abstract

The present invention is an optical proximity sensor and manufacturing method thereof. The optical proximity sensor has an optical sensing unit, an illuminating unit, multiple transparent gels and a package. The package encapsulates the optical sensing unit and the illuminating unit. The transparent gels are respectively formed on top surfaces of the optical sensing unit and the illuminating unit. The transparent gels respectively have a convex part and a recess formed in the convex part. The package has through holes communicating with the recesses of the transparent gels to form openings. In a step of injecting encapsulant gel, because the transparent gels are still plastic, the protrusions can closely attach to the transparent gels. The encapsulant gel is prevented from forming above the sensing part and the illuminating part.

What is claimed is: 
     
         1 . A manufacturing method of an optical proximity sensor comprising the steps of:
 providing a lead frame comprising a first pad, a second pad and multiple pins;   respectively mounting a sensing chip and an illuminant chip on the first pad and the second pad, wherein the sensing chip has a sensing part and the illuminant chip has an illuminating part;   bonding multiple wires to connect the sensing chip and the illuminant chip to the pins;   respectively forming transparent gels on the sensing part and the illuminating part;   pressing a mold on the transparent gels, wherein the mold has protrusions corresponding to the sensing part and the illuminating part and bottoms of the protrusions are clad in the transparent gels;   injecting encapsulant gel among the mold and the lead frame;   removing the mold after the encapsulant gel solidifies to obtain an optical proximity sensor.   
     
     
         2 . The method as claimed in  claim 1 , wherein in the step of mounting the sensing chip and the illuminant chip on the first pad and the second pad, adhesive layers are respectively formed between the sensing chip and the first pad and between the illuminant chip and the second pad. 
     
     
         3 . The method as claimed in  claim 2 , wherein the adhesive layer is an epoxy layer. 
     
     
         4 . The method as claimed in  claim 1 , wherein in the step of forming transparent gels on the sensing part and the illuminating part, the transparent gels cover the optical sensing unit and the illuminating unit. 
     
     
         5 . The method as claimed in  claim 2 , wherein in the step of forming transparent gels on the sensing part and the illuminating part, the transparent gels cover the optical sensing unit and the illuminating unit. 
     
     
         6 . The method as claimed in  claim 3 , wherein in the step of forming transparent gels on the sensing part and the illuminating part, the transparent gels cover the optical sensing unit and the illuminating unit.