TABLE OF CONTENTS 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. As discussed in the previous chapters there are many steps to designing and fabricating a PCB. When a design is complete and submitted to a board house they 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 finally postprocessing in Layout.
But it does not end there. Once the board has been fabricated it is of little use without the functional parts. Those parts need to be able to be attached to the board without them or the board being damaged. Parts attachment encompasses positioning the parts (which depends on proper parts placement and orientation) and making the reliable solder joints between the component s leads and the board s mounting pads (which depends on good padstack and footprint design). This chapter provides the information necessary for padstack and footprint design and component placement for the design of manufacturable PCBs.
Printed circuit boards may be manually assembled or assembled by automated machinery. Assembly processes depend on the class of component technology (Classes A through Z as described earlier) and the number of boards to...
