Optimization of S-curve intensity control model for laser direct writing

An optimization method of S-curve intensity control model was proposed for further improvement of joint quality during laser direct writing. On the basis of analyzing the effect of the S-curve parameter variation on the joint quality, the optimized interrelationship of the radian θ and the radius R used in the control model was established considering it to be optimal when the exposure dose distribution got an extremum at one point. The joint length after optimization can be simply determined by the radian θ, and is just twice as long as that of using slope line control method. The experimental results are consistent with the theoretical analysis, and indicate that the proposed optimization method can further increase the valid transition area length and can reduce the variation rate of exposure dose distribution at the joint area. Therefore the proposed method improves the joint quality as well as guarantees the writing efficiency.