Converter fill for LED array
An optical isolation material may be applied to walls of a first cavity and a second cavity in a wafer mesh. A wavelength converting layer may be deposited into the first cavity to create a first segment and into the second cavity to create a second segment. The first segment may be attached to a first light emitting device to create a first pixel and the second segment to a second light emitting device to create a second pixel. The wafer mesh may be removed.
1. A method comprising:
providing, on a release film, a bi-layer wavelength converting layer comprising a phosphor layer and an optical material layer, by coating the phosphor layer and the optical material layer on the release film;
after providing the bi-layer wavelength converting layer on the release film, laminating the phosphor layer and the optical material layer together to form a laminated bi-layer wavelength converting layer;
after forming the laminated bi-layer wavelength converting layer, disposing the laminated bi-layer wavelength converting layer on a tape;
after disposing the laminated bi-layer wavelength converting layer on a tape, cutting the laminated bi-layer wavelength converting layer on the tape to create gaps of a first spacing in the laminated bi-layer wavelength converting layer such that the laminated bi-layer wavelength converting layer forms a plurality of bi-layer wavelength layer converting elements in an array pattern, the bi-layer wavelength converting layer elements including the phosphor layer and the optical material layer in the array pattern;
inserting an unfilled wafer mesh having an array of cavities separated by intersecting cavity walls into the gaps of the first spacing to form a wafer mesh surrounding bi-layer wavelength converting layer elements and covering sidewalls of the phosphor layer and sidewalls of the optical material layer;
providing an array of semiconductor light emitting devices (LED array) having a plurality of light emitting devices spaced apart from each other at a second spacing greater than the first spacing;
positioning the wafer mesh relative to the LED array so that each of the light emitting devices of the LED array is aligned with a bi-layer wavelength converting layer element surrounded by the wafer mesh;
after positioning the wafer mesh with the LED array, attaching each of the light emitting devices to the aligned bi-layer wavelength converting layer element so that the phosphor layer is between the optical material layer and the light emitting device, and
removing at least some of the wafer mesh.
2. The method of claim 1 , comprising after attaching the light emitting devices, cutting the wafer mesh.
3. The method of claim 1 , comprising after removing at least some of the wafer mesh, filling channels created by removing at least some of the wafer mesh with optical isolation material.
4. The method of claim 1 , wherein the cavity walls of the wafer mesh are coated with optical isolation material.
5. The method of claim 1 , wherein the phosphor layer is one selected from a phosphor in glass, a phosphor in silicone, and a phosphor ceramic.
6. The method of claim 1 , wherein, after attaching each of the light emitting devices to the aligned bi-layer wavelength converting layer element, the optical material layer is not in direct contact with the light emitting device.
7. The method of claim 1 , wherein the phosphor layer and the optical material layer comprise a silicone binder that is solid at room temperature, flows at 80-140° C., and cures at 150° C.
8. The method of claim 1 comprising after inserting the wafer mesh into the gaps, annealing the wafer mesh and bi-layer wavelength converting layer elements causing the bi-layer wavelength converting layer elements to flow.
9. The method of claim 1 , wherein the optical material layer is a scattering layer.
10. The method of claim 1 , comprising applying an optical isolation material on the unfilled wafer mesh before inserting the unfilled wafer mesh into the gaps.
11. The method of claim 10 , wherein the unfilled wafer mesh applied with the optical isolation material has a width greater than the second spacing of the light emitting devices.
12. The method of claim 10 , wherein the optical isolation material is applied onto the unfilled wafer mesh by ALD.
13. The method of claim 10 , wherein after removing at least some of the wafer mesh, the optical isolation material remains on the bi-layer wavelength converting layer element.
14. The method of claim 1 , wherein the wafer mesh is removed after the bi-layer wavelength converting layer elements are aligned with the light emitting devices of the LED array.
15. The method of claim 1 , wherein removing at least some of the wafer mesh comprises one of etching, scraping, lasering, and chemical treatment.
16. The method of claim 1 comprising, after removing at least some of the wafer mesh, disposing a second optical isolation material in channels created by removing at least some of the wafer mesh.
17. The method of claim 1 comprising, after positioning the wafer mesh and before removing at least some of the wafer mesh, curing the bi-layer wavelength converting layer elements.
18. The method of claim 17 , wherein the curing is done at a range from 150°-180° C.