Composite phosphor powder, light emitting device using the same and method for manufacturing composite phoshpor powder
View Patent ↗The invention provides a high quality composite phosphor powder which ensures diversity in emission spectrum, color reproduction index, color temperature and color, a light emitting device using the same and a method for manufacturing the composite phosphor powder. The composite phosphor powder comprises composite particles. Each of the composite particles includes at least two types of phosphor particles and a light transmitting binder. The phosphor particles have different emission spectrums. In addition, the light transmitting binder is formed between the phosphor particles and binds them together.
1. A method for manufacturing a composite phosphor powder, comprising steps of:
mixing at least two types of phosphor particles with a light transmitting binder to form a precursor of a composite phosphor;
mixing a dispersion medium added with a surfactant with the precursor and stirring the mixture to form stabilized unit particles of the composite phosphor within the dispersion medium; and
heating the dispersion medium to cure the light transmitting binder, thereby solidifying composite phosphor particles,
wherein the light transmitting binder comprises an epoxy resin or a silicone resin.
2. The method according to claim 1 , wherein the dispersion medium comprises distilled water.
3. The method according to claim 2 , wherein a water hardening agent is added to the precursor.
4. The method according to claim 1 , wherein the dispersion medium comprises alcohol.
5. A method for manufacturing a composite phosphor powder, comprising steps of:
mixing at least two types of phosphor particles with a light transmitting binder to form a precursor of a composite phosphor;
mixing a dispersion medium added with a surfactant with the precursor and stirring the mixture to form stabilized unit particles of the composite phosphor within the dispersion medium; and
heating the dispersion medium to cure the light transmitting binder, thereby solidifying composite phosphor particles,
wherein the dispersion medium comprises distilled water, and the surfactant comprises Poly Acryl Amide (PAA).
6. A light emitting device comprising:
a light emitting diode chip;
a molding resin for encapsulating the light emitting diode chip; and
a composite phosphor powder dispersed within the molding resin, the composite phosphor powder comprising composite particles, wherein each of the composite particles comprises at least two types of phosphor particles having different emission spectrums and a light transmitting binder for binding the phosphor particles, the light transmitting binder formed between the phosphor particles.
7. The light emitting device according to claim 6 , further comprising a housing having a recess for seating the light emitting diode chip therein.
8. The light emitting device according to claim 6 , the light transmitting binder binds the phosphor particles to maintain a shape of individual composite particle.