Packaged leds with phosphor films, and associated systems and methods

Abstract

Packaged LEDs with phosphor films, and associated systems and methods are disclosed. A system in accordance with a particular embodiment of the disclosure includes a support member having a support member bond site, an LED carried by the support member and having an LED bond site, and a wire bond electrically connected between the support member bond site and the LED bond site. The system can further include a phosphor film carried by the LED and the support member, the phosphor film being positioned to receive light from the LED at a first wavelength and emit light at a second wavelength different than the first. The phosphor film can be positioned in direct contact with the wire bond at the LED bond site.

1 . An LED system, comprising:
 a support member having a support member bond site;   an LED carried by the support member and having an LED bond site;   a wire bond electrically connected between the support member bond site and the LED site; and   a phosphor film carried by the LED and the support member, the phosphor film being positioned to receive light from the LED at a first wavelength and emit light at a second wavelength different than the first, the phosphor film being positioned in direct contact with the wire bond at the LED bond site.   
     
     
         2 . The system of  claim 1  wherein the support member has a generally flat surface on which the LED is carried, and wherein the surface does not include a feature to contain the phosphor film. 
     
     
         3 . The system of  claim 1  wherein the support member has a generally flat surface on which the LED is carried, and wherein the surface does not include a cavity in which the LED is positioned. 
     
     
         4 . The system of  claim 1  wherein the phosphor film is bonded to the LED and the support member. 
     
     
         5 . The system of  claim 1  wherein the phosphor film includes a matrix material and multiple phosphor elements, and wherein the phosphor elements are generally uniformly distributed in the matrix material. 
     
     
         6 . The system of  claim 5  wherein the matrix material is generally transparent to light emitted by the LED. 
     
     
         7 . The system of  claim 1  wherein the phosphor film has a first surface in contact with the LED and a second surface facing away from the first surface, and wherein a concentration of phosphor elements in the film is greater toward the first surface than toward the second surface. 
     
     
         8 . The system of  claim 1 , further comprising a rigid or semi-rigid carrier attached to the phosphor film, the carrier being transparent to light at the second wavelength. 
     
     
         9 . The system of  claim 8  wherein the carrier includes a lens portion positioned to affect radiation emitted by the LED. 
     
     
         10 . The system of  claim 1  wherein the LED includes an LED bond pad, and wherein the film is positioned in direct contact with the LED and with a portion of the wire bond at the LED bond pad. 
     
     
         11 . The system of  claim 1  wherein the film entirely surrounds an outer surface of the wire bond at least one position along a length of the wire bond. 
     
     
         12 . The system of  claim 1  wherein the wire bond is encapsulated by the film at a location spaced apart from the LED bond site. 
     
     
         13 . The system of  claim 1  wherein the LED has an active surface positioned to pass light emitted by the LED, and wherein the phosphor film is in direct contact with the active surface. 
     
     
         14 . An LED system, comprising:
 a support member having a support member bond pad;   an LED carried by the support member and having an LED bond pad;   a wire bond electrically connected between the support member bond pad and the LED bond pad;   a carrier; and   a phosphor film positioned between the LED and the carrier to receive light from the LED at a first wavelength and emit light at a second wavelength different than the first, the phosphor film conforming to and encapsulating at least a portion of the wire bond, the carrier being transparent to light at the second wavelength.   
     
     
         15 . The system of  claim 14  wherein a concentration of phosphor in the phosphor film is greater than a phosphor concentration, if any, in the transparent rigid carrier. 
     
     
         16 . The system of  claim 14  wherein the phosphor film has a first surface in contact with the LED and a second surface in contact with the carrier, and wherein a concentration of phosphor elements in the film is greater toward the first surface than toward the second surface. 
     
     
         17 . The system of  claim 14  wherein the carrier includes a lens positioned to collect and affect light emitted by the LED. 
     
     
         18 . The system of  claim 14  wherein carrier has a first composition that includes glass and the phosphor film has a second composition that includes epoxy. 
     
     
         19 . A phosphor film system, comprising:
 a compliant, generally transparent matrix material film forming a first layer; and   a distribution of phosphor elements forming a second layer, the second layer being in surface-to-surface contact with the first layer.   
     
     
         20 . The system of  claim 19  wherein a concentration of phosphor in the second layer is greater than a phosphor concentration, if any, in the first layer. 
     
     
         21 . The system of  claim 19 , further comprising a generally rigid, generally transparent carrier attached to the film. 
     
     
         22 . The system of  claim 21  wherein the second layer is positioned between the first layer and the carrier. 
     
     
         23 . The system of  claim 19  wherein the matrix material includes a solid state, partially cured thermoset adhesive material. 
     
     
         24 . A phosphor film system, comprising:
 a film having a compliant, light-transparent matrix material and a distribution of phosphor elements; and   a rigid or semi-rigid, light-transparent carrier attached to the film.   
     
     
         25 . The phosphor film system of  claim 24  wherein the matrix materials has a first composition and the carrier has a second composition different than the first composition. 
     
     
         26 . The phosphor film system of  claim 25  wherein the first composition includes glass and the second composition includes a partially cured epoxy. 
     
     
         27 . The phosphor film system of  claim 24  wherein a concentration of phosphor in the film is greater than a phosphor concentration, if any, in the generally rigid carrier. 
     
     
         28 . The phosphor film system of  claim 24  wherein the phosphor elements actively respond to radiation at a first wavelength and emit radiation at a second wavelength different than the first wavelength, and wherein the carrier is generally transparent to both the first and second wavelengths. 
     
     
         29 . The phosphor film system of  claim 24  wherein the film has a first stiffness and wherein the carrier has a second stiffness greater than the first stiffness. 
     
     
         30 . The phosphor film system of  claim 24  wherein the film includes a first layer of matrix material, and a second layer of phosphor elements disposed in surface-to-surface contact with the first layer of matrix material. 
     
     
         31 . The phosphor film system of  claim 19  wherein the matrix material and the carrier are transparent to visible light. 
     
     
         32 . A method for manufacturing an LED system, comprising:
 mounting an LED to a support member;   electrically connecting the LED to the support member with a wire bond;   conforming a pre-formed phosphor film to the wire bond over at least a portion of the wire bond between the LED and the support member; and   attaching the phosphor film to the LED and the support member.   
     
     
         33 . The method of  claim 32  wherein conforming a pre-formed phosphor film includes heating a partially cured phosphor film and surrounding at least a portion of the wire bond with the phosphor film, and wherein attaching the phosphor film includes further curing the phosphor film. 
     
     
         34 . The method of  claim 32  wherein the LED is one of multiple LED dies forming at least a portion of an LED wafer, and wherein attaching the phosphor film to the LED includes attaching the film to multiple dies of the wafer prior to dicing the dies from the wafer. 
     
     
         35 . The method of  claim 32  wherein the phosphor film includes a first layer of matrix material, and a second layer of phosphor elements disposed in surface-to-surface contact with the first layer of matrix material when the phosphor film is conformed to the wire bond. 
     
     
         36 . The method of  claim 32  wherein conforming a pre-formed phosphor film includes conforming the preformed phosphor film after the LED has been singulated from an LED wafer. 
     
     
         37 . The method of  claim 32  wherein conforming a pre-formed phosphor film includes conforming the preformed phosphor film before the LED has been singulated from an LED wafer. 
     
     
         38 . The method of  claim 32  wherein conforming a pre-formed phosphor film includes conforming the phosphor film while it is attached to a carrier having a stiffness greater than a stiffness of the phosphor film, and a composition different than a composition of the phosphor film. 
     
     
         39 . The method of  claim 38  wherein the carrier includes a lens portion positioned to redirect light emitted by the LED. 
     
     
         40 . The method of  claim 32  wherein attaching the phosphor film includes attaching the phosphor film without containing a flow of phosphor elements with a containment structure at the LED. 
     
     
         41 . The method of  claim 32 , further comprising forming the phosphor film by:
 mixing phosphor elements with a matrix material; and   at least partially curing the matrix material.   
     
     
         42 . The method of  claim 32  wherein the LED is a first LED having a first output characteristic, the support member is a first support member, the wire bond is a first wire bond and the phosphor film is a first phosphor film having first phosphor characteristics, and wherein the method further comprises:
 mounting a second LED to a second support member, the second LED having a second output characteristic different than the first; 
 electronically connecting the second LED to the second support member with a second wire bond; 
 conforming a second pre-formed phosphor film to the second wire bond over at least a portion of the wire bond between the second LED and the second support member, the second phosphor film having a second phosphor characteristic different than the first phosphor characteristic to at least partially compensate for the difference between the first output characteristic and the second output characteristic; and 
 attaching the second phosphor film to the second LED and the second support member. 
 
     
     
         43 . The method of  claim 42  wherein the first output characteristic is a first color characteristic and wherein the second output characteristic is a second color characteristic different than the first color characteristic. 
     
     
         44 . The method of  claim 43  wherein the first color characteristic is a first wavelength and the second color characteristic is a second wavelength different than the first wavelength.