Deposition of phosphor on die top by stencil printing
A method for depositing a layer of phosphor-containing material on a plurality of LED dies includes disposing a template with a plurality of openings on an adhesive tape and disposing each of a plurality of LED dies in one of the plurality of openings of the template. The method also includes disposing a stencil over the template and the plurality of LED dies. The stencil has a plurality of openings configured to expose a top surface of each of the LED dies. Next, a phosphor-containing material is disposed on the exposed top surface of each the LED dies. The method further includes removing the stencil and the template.
1. A method for depositing a layer of phosphor-containing material on a plurality of LED (light-emitting diode) dies, the method comprising:
disposing a template with a plurality of openings on an adhesive tape;
after disposing the template on the adhesive tape, disposing each of the plurality of LED dies directly on the adhesive tape through a respective one of the plurality of openings of the template;
after disposing the LED dies on the adhesive tape, disposing a stencil over the template and the plurality of LED dies, the stencil having a plurality of openings configured to expose a top surface of each of the LED dies;
after disposing the stencil, depositing the phosphor-containing material on the exposed top surface of each of the LED dies;
after depositing the phosphor-containing material, removing the stencil; and
removing the template from the adhesive tape.
2. The method of claim 1 , wherein the adhesive tape is placed on a glass plate.
3. The method of claim 1 , wherein the adhesive tape is a heat release tape.
4. The method of claim 1 , wherein the adhesive tape is a UV release tape.
5. The method of claim 1 , wherein an area of one of the openings in the template is approximately equal to the size of a respective one of the LED dies.
6. The method of claim 1 , wherein a thickness of one of the openings in the template is substantially equal to a thickness of a respective one of the LED dies.
7. The method of claim 1 , wherein the stencil is configured to cover bond pad areas on each of the LED dies.
8. The method of claim 1 , wherein a depth of each of the openings in the stencil is equal to a desired thickness of the phosphor-containing material.
9. The method of claim 1 , wherein the stencil is coated with Polytetrafluoroethylene (PTFE) under the trademark of TEFLON®.
10. The method of claim 1 , wherein the stencil is made of metal.
11. The method of claim 1 , wherein the stencil is made of an insulator material.
12. A method for depositing a layer of phosphor-containing material on a plurality of LED (light-emitting diode) dies, the method comprising:
disposing a template with a plurality of openings on an adhesive tape;
after disposing the template on the adhesive tape, disposing each of the plurality of LED dies directly on the adhesive tape through a respective one of the plurality of openings of the template;
after disposing the LED dies on the adhesive tape, disposing a metal stencil over the template and the plurality of LED dies, the stencil having a plurality of openings configured to expose a top surface of each of the LED dies;
after disposing the stencil, depositing the phosphor-containing material on the exposed top surface of each of the LED dies;
after depositing the phosphor-containing material, removing the metal stencil; and
removing the template.