The Navy's Best Manufacturing Practices (BMP) Program office has been conducting industry surveys since late 1985. These surveys focus on identifying the best practices being used in industry and common design and manufacturing problems. Throughout the surveys, the electronics industry consistently revealed that the most serious and prevalent problem with electronics manufacturing is solderability.
When the Navy hosted its first BMP workshop in May 1987, a portion of the workshop was devoted to discussing industry-wide problems and potential solutions. These discussions and a survey of the attendees substantiated that solderability is the number one concern within the electronics industry. It was also clear from the discussions that different companies were using different practices to address the solderability problem. An industry representative recommended that the Navy compile the best known practices for controlling solderability into a single guideline document. This document could then be used to supplement existing specifications and standards and provide the defense electronics industry with a common set of proven solderability guidelines.
Following the May 1987 workshop, the Navy established a Navy/lndustry Solderability Ad Hoc Committee staffed by technical experts to identify the best design practices and manufacturing processes for improved solderability. This committee met several times over the course of a year and provided most of the information contained in this publication. Comments on the first draft were also solicited from other major manufacturers of defense electronics.
Purpose of this Document
This document provides best practices for improving component and Printed Wiring Board (PWB) solderability. It includes recommended guidelines for termination finishes, solderability tests, incoming inspection practices, en- vironmental controls and storage containers. The recommendations are based on current research supported by practices that have been proven to yield high quality products. Ongoing research may shed new light on the soldering process, but the procedures recommended here represent best practices at this time. The committee also recommended areas requiring further research to better understand and control the soldering process.
This document is directed to all personnel in the electronics design, manufacturing and procurement process. Readers who have direct responsibility for planning, initiation, and monitoring the soldering process will find valuable information and guidance in this publication as well as general information. The guidelines are intended to be used as a reference to supplement requirements where existing specifications are known to be insufficient and are not intended to supersede contractual requirements.