Solid state lighting component package with conformal reflective coating
A solid state lighting package is provided. The package comprising at least one LED element positioned on a top surface of a substrate and a conformal reflective layer of inorganic particles, whereby at least of portion of the light emitted by the LED element is reflected by the conformal reflective layer. A method of manufacturing a solid state lighting package comprising the distribution of inorganic particles, and a method of increasing the luminous flux thereof, is also provided.
1. A solid state lighting package comprising:
a substrate or a submount comprising a top surface that absorbs at least one wavelength of light emitted by a plurality of LED elements, each of the plurality of LED elements comprising at least one light emitting surface;
a plurality of metal contacts or pads directly on the top surface of the substrate or the submount, the plurality of metal contacts or pads each having at least one side surface projecting vertically from the top surface of the substrate or the submount by a height, and at least one electrical connector connecting the plurality of metal contacts or pads;
the plurality of LED elements positioned on the plurality of metal contacts or pads, wherein the plurality of LED elements are in a densely packed arrangement forming a plurality of channels between adjacent ones of the plurality of LED elements;
a conformal reflective layer having a thickness, wherein the height of the at least one side surface of each of the plurality of metal contacts or pads is greater than or equal to the thickness of the conformal reflective layer, the conformal reflective layer positioned in the plurality of channels and covering the at least one electrical connector and at least a portion of the top surface and conformally attached to the at least one side surface of the plurality of metal contacts or pads without covering the at least one light emitting surface of the plurality of LED elements, wherein the conformal reflective layer comprises a plurality of inorganic compounds arranged in a dense layer of material; and
a transparent matrix deposited on the conformal reflective layer and surrounding each of the plurality of metal contacts or pads, the transparent matrix being spaced from and not covering the plurality of LED elements.
2. The solid state lighting package of claim 1 , wherein the conformal reflective layer consists essentially of inorganic particles of at least one of titanium dioxide, silicon dioxide, zinc oxide, or mixtures thereof.
3. The solid state lighting package of claim 1 , wherein the conformal reflective layer surrounds each of the plurality of LED elements.
4. The solid state lighting package of claim 1 , wherein the transparent matrix is at least one of a polydialkylsiloxane, polydialkylphenylsiloxane, polydialkylalkylphenylsiloxane, and polyalklyphenylsiloxanes, or blends thereof.
5. The solid state lighting package of claim 4 , wherein the transparent matrix is directly deposited on the conformal reflective layer.
6. The solid state lighting package of claim 1 , wherein the height of the at least one side surface of the metal contact or pad is equal to the thickness of the conformal reflective layer.
7. The solid state lighting package of claim 1 , wherein the plurality of LED elements are post die attached and wire bonded to the substrate or the submount.
8. The solid state lighting package of claim 4 , wherein the transparent matrix has an index of refraction of between about 1.4 and about 1.5.
9. The solid state lighting package of claim 4 , wherein the transparent matrix further comprises a highly reflective material.