Manufacturing, assembly and production qualifications of high density, high reliability POL DC-DC converters

In this paper, a set of consistent methods of design for manufacturing and assembly techniques, which are used to minimize product cost and increase reliability through design and process improvements for high density, high reliability Point-of-Load DC-DC converters are discussed. The Pin-in-Paste process, also called through-hole reflow technology, along with consideration for component packaging in tape and reel, the pick-up cap design for automatic handling, PCB hole size selections and solder heating profile are also discussed in details as the preferred assembly techniques. Furthermore, a detailed production qualification procedure is introduced to ensure methods and process used in production are validated, and the process consistently produces a product that meets its specifications, reduces production costs, and meets quality and regulatory requirements. Finally, selection and design of automated testing equipment system to complete the manufacturing of these high reliability products are discussed. Several examples of POL modules manufactured in different current level and module orientation and pin style, i.e. vertical, horizontal through-hole and surface mount are given to verify the proof of concept and improvements reported.