Opto-electronic assembly having an encapsulant with at least two different functional zones

Abstract

A radiation emitting device of the present invention includes at least one radiation emitter, first and second electrical leads electrically coupled to the radiation emitter, and an integral encapsulant configured to encapsulate the radiation emitter and a portion of the first and second electrical leads. The encapsulant has at least a first zone and a second zone, where the second zone exhibits at least one different characteristic from the first zone. Such different characteristics may be a physical, structural, and/or compositional characteristic. Preferably, the at least one different characteristic includes at least one of the following: mechanical strength, thermal conductivity, thermal capacity, coefficient of thermal expansion, specific heat, oxygen and moisture impermeability, adhesion, and transmittance with respect to radiation emitted from the radiation emitter. The radiation emitter may be in a form of an emitter, and is preferably an LED.

1 . An apparatus comprising: 
 a plurality of opto-electronic devices each comprising: 
 a lead frame comprising a plurality of electrical leads;  
 at least one opto-electronic component mounted on said lead frame and electrically coupled to said plurality of leads; and  
 an encapsulant encapsulating said opto-electronic components and a portion of said electrical leads, said encapsulant comprising a first zone made of a first material that is transparent to optical radiation and a second zone made of a second material a higher thermal conductivity than said first material, wherein both said first and second materials have a relatively high electrical resistivity,  
   wherein each of said plurality of opto-electronic devices are physically joined together.    
     
     
         2 . The apparatus of  claim 1 , wherein each of the plurality of opto-electronic devices are physically joined to each other by said lead frame of each of said plurality of opto-electronic devices.  
     
     
         3 . The apparatus of  claim 2 , wherein each of said plurality of opto-electronic devices are joined by tie bars extending between leads of said lead frames.  
     
     
         4 . The apparatus of  claim 1 , wherein each opto-electronic device comprises a plurality of opto-electronic components.  
     
     
         5 . The apparatus of  claim 1 , wherein said at least one opto-electronic component is an optical radiation emitter.  
     
     
         6 . The apparatus of  claim 5 , wherein said optical radiation emitter is an LED chip.  
     
     
         7 . The apparatus of  claim 1 , wherein a region of said encapsulant is configured to function as a lens.  
     
     
         8 . The apparatus of  claim 7 , wherein a region of said first zone of said encapsulant is configured to function as a lens.  
     
     
         9 . The apparatus of  claim 8 , wherein said second zone of said encapsulant is configured to retain said electrical leads.  
     
     
         10 . The apparatus of  claim 1 , wherein said second zone of said encapsulant is configured to retain said electrical leads.  
     
     
         11 . An apparatus comprising: 
 a plurality of opto-electronic devices each comprising: 
 a lead frame comprising a plurality of electrical leads;  
 at least one opto-electronic component mounted on said lead frame and electrically coupled to said plurality of leads; and  
 an encapsulant encapsulating said opto-electronic components, said encapsulant comprising a first zone made of a first material that is transparent to optical radiation and a second zone made of a second material having at least one different characteristic than the first material, the at least one different characteristic is selected from the group consisting of: cohesion, mechanical compression strength, mechanical tensile strength, thermal conductivity, specific heat, coefficient of thermal expansion, adhesion, oxygen permeability, gas permeability, moisture permeability, transmittance, glass transition temperature and microcrystalline structure,  
   wherein each of the plurality of opto-electronic devices are physically joined to each other by said lead frame of each of said plurality of opto-electronic devices.    
     
     
         12 . The apparatus of  claim 11 , wherein said at least one different characteristic is thermal conductivity.  
     
     
         13 . The apparatus of  claim 11 , wherein each of said plurality of opto-electronic devices are joined by tie bars extending between leads of said lead frames.  
     
     
         14 . The apparatus of  claim 11 , wherein each opto-electronic device comprises a plurality of opto-electronic components.  
     
     
         15 . The apparatus of  claim 11 , wherein said at least one opto-electronic component is an LED chip.  
     
     
         16 . The apparatus of  claim 11 , wherein a region of said first zone of said encapsulant is configured to function as a lens.  
     
     
         17 . The apparatus of  claim 11 , wherein said second zone of said encapsulant is configured to retain said electrical leads.  
     
     
         18 . An apparatus comprising: 
 a lead frame assembly having a plurality of electrical leads;    a plurality of opto-electronic components mounted to said lead frame assembly and coupled to said plurality of leads; and    an encapsulant for encapsulating said plurality of opto-electronic components and a portion of said electrical leads, said encapsulant comprised of at least a first material and a second material, wherein said first material is transparent to optical radiation, said second material having a higher thermal conductivity than said first material, both said first and second materials have a relatively high electrical resistivity.    
     
     
         19 . The apparatus of  claim 18 , wherein said lead frame assembly comprises a plurality of mounting locations on which said plurality of opto-electronic components are mounted.  
     
     
         20 . The apparatus of  claim 19 , wherein said mounting locations on said lead frame assembly are reflective cups.  
     
     
         21 . The apparatus of  claim 19 , wherein at least two opto-electronic components are mounted at each of said plurality of mounting locations.  
     
     
         22 . The apparatus of  claim 19 , wherein said opto-electronic components comprise LED chips.  
     
     
         23 . The apparatus of  claim 22 , wherein at least two LED chips are mounted at each of said plurality of mounting locations.  
     
     
         24 . The apparatus of  claim 23 , wherein said at least two LED chips emit light of different hues that together mix to form white light.  
     
     
         25 . The apparatus of  claim 18 , wherein a region of said encapsulant is configured to function as a lens.  
     
     
         26 . The apparatus of  claim 18 , wherein a region of said first material of said encapsulant is configured to function as a plurality of lenses.  
     
     
         27 . The apparatus of  claim 26 , wherein said second material of said encapsulant is configured to retain said electrical leads.  
     
     
         28 . The apparatus of  claim 18 , wherein said second material of said encapsulant is configured to retain said electrical leads.