Issue link: https://iconnect007.uberflip.com/i/1457913
MARCH 2022 I DESIGN007 MAGAZINE 59 tation is created when the router bit contacts the edge where the plating is removed and advances into the circuit to completely remove the plating. When the interruption of the plat- ing is a minimum of 0.200" the use of a tab to prevent the continuous plating can be used. When less than 0.200" the edge will be plated entirely across and subsequently removed by the routing process described. Edge plating typically involves the connec- tion of one or more of the internal planes in a board. ese planes extend to the edge of the board and are electrically connected by the plating process. ose layers are typically fab- ricated with a polarity border (ref. 0.050") to prevent exposed copper when they are routed and removed from a panel. Understanding the cost drivers in PCB fab- rication and early engagement between the designer and the fabricator are crucial ele- ments that lead to cost-effective design suc- cess. Following your fabricator's DFM guide- lines is the first place to start. DESIGN007 Anaya Vardya is president and CEO of American Standard Circuits; co-author of The Printed Circuit Designer's Guide to… Fundamentals of RF/ Microwave PCBs and Flex and Rigid-Flex Fundamentals; and author of Thermal Management: A Fabricator's Perspective. Visit I-007eBooks.com to download these and other free, educational titles. He also co-authored "Fundamentals of Printed Circuit Board Technologies" and provides a discussion of flex and rigid flex PCBs at RealTime with… American Standard Circuits. Figure 4: a) By placing a tab at the interruption, and subsequently removing it, the tab prevents the plating; b) the subsequent removal of the plating will leave a small tab or an indentation into the circuit. Figure 3: It is required that the plating not only encapsulate the edge of the panel, but that the plating also wrap around to the surface of the panel. a b