Light emitting device and a method of making the same

Abstract

A light emitting device includes a heat sinking substrate, an electrically insulating layer, a circuit pattern layer, and at least one light emitting diode (LED) chip. The electrically insulating layer is partially formed on the heat sinking substrate so as to expose a portion of the heat sinking substrate. The circuit pattern layer is formed on the electrically insulating layer. The LED chip is electrically connected to the circuit pattern layer, and is indirectly and non-electrically mounted to the portion of the heat sinking substrate exposed from the electrically insulating layer and the circuit pattern layer. A method of making the light emitting device is also provided.

What is claimed is: 
     
         1 . A light emitting device, comprising:
 a heat sinking substrate;   an electrically insulating layer partially formed on said heat sinking substrate so as to expose a portion of said heat sinking substrate;   a circuit pattern layer formed on said electrically insulating layer; and   at least one light emitting diode (LED) chip electrically connected to said circuit pattern layer ant indirectly and non-electrically mounted to said portion of said heat sinking substrate exposed from said electrically insulating layer and said circuit pattern layer.   
     
     
         2 . The light emitting device of  claim 1 , further comprising an electrically insulating and thermally conductive interlayer interposed between said portion of said heat sinking substrate and said LED chip, said interlayer being made from a thermal interface material (TIM), said LED chip being electrically connected to said circuit pattern layer in a wire-bonding manner. 
     
     
         3 . The light emitting device of  claim 2 , wherein said TIM is selected from one of thermal grease, a thermal pad, and a thermal adhesive. 
     
     
         4 . The light emitting device of  claim 1 , further comprising at least one solder pad formed on said circuit pattern layer, said LED chip being electrically connected to said circuit pattern layer in a flip-chip manner. 
     
     
         5 . The light emitting device of  claim 1 , wherein said circuit pattern layer includes an active layer formed on said electrically insulating layer including a catalytic metal material and a first electroless-plated metal layer formed on said active layer. 
     
     
         6 . The light emitting device of  claim 5 , wherein said circuit pattern layer further includes a second electroless-plated metal layer formed on said first electroless-plated metal layer, which is made from a metal material selected from the group consisting of platinum (Pt), silver (Ag), tin (Sn), gold (Au), rhodium (Rh), palladium (Pd), and alloys thereof. 
     
     
         7 . The light emitting device of  claim 1 , wherein said heat sinking substrate is formed with a plurality of heat sinking fins opposite to said electrically insulating layer and said LED chip. 
     
     
         8 . A method of making a light emitting device, comprising:
 partially forming an electrically insulating layer on a heat sinking substrate so as to expose a portion of the heat sinking substrate;   forming a circuit pattern layer on the electrically insulating layer; and   electrically connecting at least one light emitting diode (LED) chip to the circuit pattern layer, and indirectly and non-electrically mounting the LED chip to the portion of the heat sinking substrate exposed from the electrically insulating layer and the circuit pattern layer.   
     
     
         9 . The method for making the light emitting device of  claim 8 , further comprising forming an electrically insulating and thermally conductive interlayer interposed between the portion of the heat sinking substrate and the LED chip. 
     
     
         10 . The method for making the light emitting device of  claim 9 , wherein the interlayer is made from a thermal interface material (TIM) selected from one of thermal grease, a thermal pad, and a thermal adhesive. 
     
     
         11 . The method for making the light emitting device of  claim 8 , wherein in electrical connection of the LED chip to the circuit pattern layer, the LED chip is connected to the circuit pattern layer by a wire bonding process. 
     
     
         12 . The method for making the light emitting device of  claim 8 , wherein in the electrical connection of the LED chip to the circuit pattern layer, at least one solder pad is formed on the circuit pattern layer and then the electrical connection of the LED chip is electrically connected to the circuit pattern layer by a flip-chip mounting process. 
     
     
         13 . The method for making the light emitting device of  claim 8 , wherein the step of forming the circuit pattern layer on the electrically insulating layer includes forming an active layer comprising a catalytic metal material on the electrically insulating layer, and then forming a first electroless-plated metal layer on the active layer. 
     
     
         14 . The method for making the light emitting device of  claim 13 , wherein the step of forming the circuit pattern layer on the electrically insulating layer further includes forming a second electroless-plated metal layer, which is made from a metal material selected from the group consisting of platinum (Pt), silver (Ag), tin (Sn), gold (Au), rhodium (Rh), palladium (Pd), and alloys thereof, on the first electroless-plated metal layer.