Based On The Wafer Surface Coating Of White Led Packaging Technology Research

Advantages of LED have been reflected on many application fields, because of this, many governments and companies paid more and more attentions on LED. With the development of semiconductor process, the luminous efficiency is increasing continuously.In1993, the first blue LED was produced. And in1996, the white-LED was manufactured. CREE reported that:in2011, luminous efficiency of the white-LED had reached to2311m/W under the condition of driving by350mA-current, and in2012, LED’s luminous efficiency of our country can reach1771m/W under the condition of driving by20mA-current.In the light of international advanced technology, we propose another new technology of phosphor conformal coating. That is a kind of phosphor coating technology basing on water-soluble sensitive adhesive (self-adaptive phosphor coating technology). This technology is tending to mature through our hard work. And this article propose a new package process basing on above mentioned technology, that is a kind of package process, which covers phosphor on LED wafer.Some main conclusions of this article are listed as follows.According to analyzing and juxtaposing the spatial chroma uniformity of LED which was produced with self-adaptive phosphor coating technology and all kinds of commercialized white-LED packaging process. We obtained different standard deviation of color coordinate coming from different white-LED packaging processes: standard deviation of color coordinate getting from self-adaptive phosphor coating technology is approximately (0.0039,0.0043). but the standard deviation of color coordinate of flat white-LED coating process seen in market commonly is (0.00997,0.01072), standard deviation of color coordinate employing the traditional packaging process is (0.01372,0.01541). It can be seen that the color uniformity of self-adaptive phosphor coating technology is superior to traditional packaging technology and normal coated products. So the macular and blue spots which appear in traditional packaging usually will not appear if employ self-adaptive phosphor coating technology, this process can meet all kinds of high-end lighting need.According to analyze the comparison test of traditional packaging process and self-adaptive phosphor coating technology, we can see that if employ self-adaptive phosphor coating technology, the luminous flux can promote by10.47%, and the luminous efficiency can promote by10.38%.According to doing experiments of self-adaptive phosphor coating technology on wafer,this experiment indicated that we can use employ phosphor coating technology in the process of producing LED, which make the manufactures of LED chip provide white-LED chip directly, and there is no need to package the traditional single chip, so it can promote production capacity and meet client’s need. And because of employing PVA sensitive adhesive to coat, the thickness of phosphor layer is match to light intensity of LED, which makes light disperse uniformly and promote overall luminous efficiency.According to the test about integration module of LED chip, we can get the conclusion that self-adaptive phosphor coating technology can be not only used to packaging of single LED, but also integration packaging process:using this technology can promote over luminous efficiency of devices.