Design for Manufacturing (DFM) Guidelines （设计制造(DFM)的指导方针）.pdfVIP

Design for Manufacturing (DFM) Guidelines Why DFM? The purpose of designing a part for manufacturing is to improve the product along three dimensions: quality, delivery, and cost. Utilizing sound DFM practices will ensure quality, reduce delivery lead-times and provide a reduction in the product cost by carefully selecting the best components for your application. In this day of global competition where cost, quality and speed to market are the key to a successful product, too often we witness very simple mistakes that are costly for our customers that could have been easily corrected during the design stage. Many errors are systemic across different customers and industries. Some of the most common errors we see in a regular basis are:  Missing or invalid manufacturing part numbers  Selection of components that are at the end of life or not available through distributors  No allowances for alternates on components  Selection of components that cannot withstand process temperatures (reflow)  The design requires unnecessary “extra” manual assembly effort  Distance between plated through hole parts (PTH) and surface mount technology (SMT) components is inadequate  Connectors or other components too close or overhanging edge of board  Incorrect pad size for the part geometry  PCB specifications not adequately detailed (e.g. board material, thickness)  PCB layout provides poor access for testing  Via holes board pad proximity too close  Pin spacing on PTH components wrong for machine placement, PTH holes incorrectly sized for part This document and its contents are property of Quik Tek Assembly. Any unauthorized use if this document is not permitted as it may violate confidentiality contracts. Its use can only be approved in writing by Quik Tek Assembly management. Our general guidelines for PCB development: Bill of Material (BOM) c