Burr Control for Removal of Metal Coating from Plastics Substrate by Micro-Milling

Manufacturing of miniaturized circuits on the surface of plastic substrate plays an important role for the industrial application. Many of these kinds of parts cannot be fabricated by conventional processing methods due to the manufacturing requirements are improved continuously and the plastic substrate presents 3D structure. Since the superior advantages of the micro-milling, graphically removal of metal coating from plastic substrate by micro-milling has led the way in manufacturing of high-accuracy circuits. In order to improve the edge quality of the circuits, the effect of processing parameters on burr sizes is quantitatively analyzed and a control model of burr formation is established based on the experiments. Furthermore, aiming at the problem that surface of the polyimide (PI) substrate often shows free-form state due to the machining error, the technology that removal of constant material from free-form substrate surface is proposed. With the optimized parameters and compensation technology of milling depth, a typical antenna circuit is machined via micro-milling at last. The experimental results indicate that the edge of the pattern is smooth, and there are almost no burrs. The achievements in this study could be applicable to industrial production.