| Title |
Improvement of Color Temperature Uniformity of Integrated Optic Lens Type LED Packaged using Compression Molding Method |
| Authors |
Wan-Ho Kim ; Young-Rae Kang ; Min-Suk Jang ; Jae-Young Joo ; Sang-Bin Song ; Jae-Pil Kim ; In-Seon Yeo |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2013.27.4.001 |
| Keywords |
Color Temperature Uniformity ; View Angle ; Phosphor Coating ; Compression Molding Method |
| Abstract |
Optical characteristics including the view angle and color temperature uniformity of LED packages with an integrated lens fabricated by compression molding method are investigated according to lens shape, lens materials, and phosphor coating methods. Four types of lens shape are designed and their optical output power dependence on the refractive index of silicone encapsulant are evaluated. Also, spatial color temperature uniformities of packages fabricated with different phosphor coating methodsdirect coating on a chip vs. uniformly mixed with silicone encapsulant- are compared at various view angles. As the result, it is found that phosphor coating method is more effective on color temperature uniformity than lens shape. The maximum color temperature difference of a package with direct coating of phosphor on a chip is 1,340K according to the view angle at the color temperature of 5,000K, and that of a package with uniformly mixed phosphor is 250K, which indicates 1,090K improvement of color uniformity for the latter case. |