For theapplication of mini LED,the requirement on the reflectance rate of the printed circuit board(PCB)is becoming higher and higher,while the cost needs to be as low as possible.At first this article proposes a method of using white solder mask twice to save the consumption of high value printing ink.Then,it is proposed to use green solder mask to print the reverse side of LED,and a scheme to prevent the fake copper leakage is given.At last,for the undercut of solder mask ink,the laser window opening scheme is adopted to guarantee the yield and save costs.
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