NOVEL TECHNIQUE OF THROUGH-HOLE LASER DRILLING IN TEFLON

In this manuscript, we report a novel technique in laser drilling of t eflon films. The new process surpasses the conventional techniques in simplicity, throughput and spatial resolution. The process consists of three simple steps. First, a thin absorbing layer (in this case 300 A ngstrom of gold) is deposited on the teflon to allow for the laser abs orption. Second, the drilling is laser induced at the rate of one hole per one-millisecond pulse. At this stage, the hole is not completely open and debris still fills the hole. Third, the ultrasonic cleaning i n water is used to remove the modified and weakly cleaning in water is used to remove the modified and weakly bound material inside the dril led holes. This new technique is desirable for packaging technique bec ause of its drilling: speed as high as 60 000 holes per minute and its low laser equipment cost. Copyright (C) 1996 Elsevier Science S.A.