Incorporating reflective layers into LED systems and/or components
View Patent ↗A light emitting apparatus includes a support having circuitry disposed thereon, at least one light emitting diode (LED) chip mounted on the support and in electrical communication with the circuitry and a reflective layer on the support adjacent the at least one chip.
1. A light emitting apparatus comprising:
one or more light emitting chips;
a printed circuit board on which the one or more light emitting chips are disposed, the printed circuit board including an electrically insulating board, electrically conductive printed circuitry, and an electrically insulating solder mask having vias through which the one or more light emitting chips electrically contact the printed circuitry, wherein the solder mask has a reflectance level less than about 80% for visible light; and
a reflective film on the solder mask, the reflective film including polytetrafluoroethylene (PTFE) and having openings that align with respective vias in the solder mask through which the one or more light emitting chips electrically contact the printed circuitry, the reflective film having a reflectance of greater than about 90% at least between about 400 nanometers to about 750 nanometers.
2. The apparatus of claim 1 , wherein the solder mask comprises a solder mask layer overlaying the electrically conductive printed circuitry and disposed beneath the reflective film.
3. The apparatus of claim 2 , wherein the reflective film adheres to the solder mask layer and is of a generally uniform thickness.
4. The apparatus of claim 3 , wherein the reflective film generally follows the contour of the solder mask layer.
5. The apparatus of claim 1 , wherein the reflective film includes granular PTFE.
6. The apparatus of claim 1 , wherein the reflective film is a PTFE film having openings that each receive a respective chip.
7. The apparatus of claim 1 , further comprising an optical component disposed in relation to the printed circuit board and the one or more light emitting chips such that when the one or more light emitting chips is energized and emits light, light reflects from the optical component back towards the reflective film on the printed circuit board.
8. The apparatus of claim 7 , wherein the optical component includes a reflective surface and a light transmissive surface, wherein the optical component is configured to diffuse light that passes through the light transmissive surface.
9. The apparatus of claim 8 , wherein the reflective surface is at least partially covered by the reflective film.
10. The apparatus of claim 7 , wherein the optical component includes a phosphor arranged to be irradiated by the one or more light emitting chips to emit light in a wavelength range predominantly above 470 nanometers responsive to the irradiating.
11. The apparatus of claim 10 , wherein the phosphor and the one or more light emitting chips are relatively arranged such that at least some of the light emitted by the one or more light emitting chips predominantly in the wavelength range between about 400 nanometers and about 470 nanometers reflects from the phosphor onto the reflective film of the printed circuit board.
12. The apparatus of claim 1 , wherein the one or more light emitting chips includes a first chip that emits light of a first color and a second chip that emits light of a second color.
13. The apparatus of claim 1 , further comprising a housing inside of which the one or more light emitting chips and the printed circuit board are disposed, the housing including a phosphor arranged to be irradiated by the one or more light emitting chips and emitting light in a wavelength range predominantly above 470 nanometers responsive to the irradiating, the phosphor and the printed circuit board being relatively arranged such that at least some of the light emitted by the one or more light emitting chips predominantly in the wavelength range between about 400 nanometers and about 470 nanometers reflects from the phosphor onto reflective film on the printed circuit board.
14. A method for fabricating a light emitting apparatus, the method comprising:
providing an electrically insulating board with electrically conductive printed circuitry disposed thereon;
disposing an electrically insulating solder mask on the electrically insulating board leaving exposed at least a portion of the printed circuitry;
disposing one or more light emitting chips on the insulating solder mask, the one or more light emitting chips electrically contacting the exposed printed circuitry; and
disposing a reflective layer on the insulating solder mask around the one or more light emitting chips, the reflective layer including polytetrafluoroethylene (PTFE) and having a reflectance of greater than about 90% at least between about 400 nanometers and about 470 nanometers.
15. The method of claim 14 , further comprising:
providing an optical component disposed in relation to the board and the one or more chips such that when the one or more chips is/are energized to emit light, light is reflected by the optical component back towards the reflective layer.
16. The method of claim 15 , wherein the reflective layer comprises PTFE and the solder mask has a reflectance below 60% for wavelengths less than about 410 nanometers.