Chapter 5 - Introduction to Design for Manufacturing

Abstract

This chapter addresses the mechanical aspect of Printed Circuit Board (PCB) design—design for manufacturability. For a PCB to be manufacturable the bare board has to be able to be fabricated within standard fabrication allowances (SFAs), and the board has to be able to be assembled given the different component technologies. When a design is complete and submitted to a board house, the house must be able to perform the manufacturing steps that the design calls for. Whether a PCB is manufacturable or not really begins with and includes parts creation and schematic entry in Capture, padstack and footprint design, parts placement and trace routing, and artwork production in PCB Editor. The chapter explains where parts should be placed on the board, how far apart, and in what orientation from a manufacturing perspective. To aid in understanding the design issues, manufacturing processes such as reflow and wave soldering, pick-and-place assembly, and thermal management are discussed. A PCB assembly consists of the bare board, the attached components, and connectors. The board design can have a significant impact on how easily components can be placed on and attached to the board and how reliable the end product is. The information is then used as a guide in designing plated through holes, surface-mount lands, and PCB Editor footprints in general. Tables summarize the information and serve as a design guide during footprint design and PCB layout.