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 .
