LED Chip On Board (COB) Packaging Process

LED chip board (Chip On Board, COB) packaging process is first surface of the substrate with a thermally conductive epoxy ( usually with silver particles doped epoxy ) covered wafers placed points , and then placed under indirect silicon substrate surface , Heat treatment is firmly fixed to the silicon substrate as a line , and then re -wire welding methods are indirect establish electrical connection between the silicon and the substrate. Its closure demolition process is as follows :

The first step: expanding the use of extended crystal machine zero film LED chip manufacturers to provide uniform expansion Chi, so closely attached to the film surface display is off the LED die opened to facilitate thorn crystal .

Step two: gum will expand good crystal crystal ring expansion is not scraping gum machine to put a good face silver layer , back silver paste. Silver Point . Apply to bulk demolition LED chips. Using the right amount of paste dispensing points are on the printed circuit board PCB .

The third step: down into the thorn crystal holder will prepare silver crystal ring expansion into the thorn crystal frame , the member is being done by the operating microscope LED chip crystal pen with barbed spines are on the printed circuit board PCB .

Step Four : Put oven will stab good thermal cycling crystal PCB printed circuit board placed outside the thermal cycle oven thermostat quiet place for some time , until the paste cured removed ( not long put , or the coating will be roasted yellow LED chips , which oxidized to form bonding difficulties ) . If there is no LED chip bonding , you need more than a few steps ; If the IC chip bonding as long as you cancel the above steps.

Step Five: stick chip PCB printed circuit board with IC dispenser is placed right amount of red plastic bits ( or vinyl ) , and then the anti-static equipment ( real suction pen or female ) to put the IC die is accurate red plastic or vinyl on .

Step Six: drying the good die stick into the thermal cycle oven is putting large flat heating plate thermostat quiet place for some time , and can naturally cure ( longer ) .

Step Seven: bonding ( wire ) wafers using aluminum wire bonders (LED grains or IC chips ) take on the PCB pads for when aluminum wire bridging that COB 's inner lead bonding .

Step eight: pretest using public inspection tools ( COB different purposes by different devices without simple is the high -precision current regulator ) detection COB board , the board failed female Shen repair.

 Step nine: dispensing dispenser will be deployed using a good amount of AB glue good place to bonding the LED bulb, IC is sealed with vinyl split , then the appearance of split seal according to customer requirements .

Step ten: Curing the sealed plastic PCB printed circuit board placed outside the thermal cycle oven thermostat static discharge , upon request, can set different drying time .

Step eleven: After the test will be sealed and then split the common good PCB printed circuit board testing tools for electrical performance test to distinguish between good and bad bad bad . With the advancement of technology, encapsulated aluminum plate COB packaging , COB COB packaging ceramics , aluminum plate MCOB package form .