Soldering Subtopics

Reflow profiling has gained importance as SMT assemblers struggle to meet the lower-temperature reflow needs of components, and the higher-temperature needs of lead-free solder alloys. Profiling can involve a lot of guess work, wasted boards, and lost time. KIC, along with the Rochester Institute of Technology (RIT), studied the most accurate way to profile a BGA, and achieved nonlinear results. The methodology and design of experiment described here, from Brian O’Leary’s presentation to the SMTA Boston Chapter, can be applied to other profiling situations.

With PCBs becoming increasingly complex, unexpected assembly issues are inhibiting quality. Adding vacuum and nitrogen to reflow — whether in a new reflow oven or integrated onto an existing SMT line — offers benefits like higher quality with an economical cost and continuous operation. Raimund Faber, GM, sales & marketing, SMT Maschinen- und Vertriebs GmbH discusses the causes of voids and how these defects affect quality, and one method to eliminate them during reflow without sacrificing oven flexibility or throughput.

Advances in PCB and component technology have created higher demands on the equipment used to repair and rework array components. It is no longer possible for the operator to simply increase the reflow temperature and expect safe and controlled component removal. These uncontrolled operators can damage the latest lead-free assemblies by utilizing older and less-capable rework systems. Ed Zamborsky and Paul Wood, OK International, explain the new machine technologies for safe BGA rework.

Gail Flower, editor-at-large, SMT, surveyed soldering equipment manufacturers and solder material suppliers to learn more about the latest practices and requirements. In Part II, equipment suppliers explain what customers ask for on new machines and solder suppliers talk about environmental legislation and its effect on solder alloys.

Tin (Sn) whiskers are extremely thin metal filaments, 1 to 3 µm in diameter, that grow from tin metal surfaces as straight, kinked, or even spiral single crystals of Sn. Field failures due to tin whisker growth have occurred in the highest reliability applications, as well as high-volume consumer ones. Lead-free solder and finer pitches are increasing the risk of failures caused by tin whiskers. Laura Turbini, Ph.D., provides updates on the latest whiskers studies.

Research and Markets released “A Global Strategic Business Report: PCBs,” analyzing the global market for printed circuit boards (PCBs) in US$ million. The major markets analyzed include the US, Canada, Japan, Europe, Asia-Pacific, and rest of world (ROW), with forecasts through 2015. It identifies major geographical and technological changes coming for the PCB fab industry.

Express Manufacturing, Inc. (EMI), an electronics manufacturing services (EMS) provider, is building a line of products for OEMs to promote health. The company recently obtained ISO 13485 certification for medical device manufacturing and invested in Fuji XPF chip shooters for medical electronics production.

EPIC, the European Photonics Industry Consortium, released “LEDs: The 2009 Market Review.” The report, which is distributed exclusively to EPIC members, tracks the response of the lighting and display industries to one of the most difficult economic crises in recent years. HB-LED and OLED unit production figures as well as revenues have been summarized for major players around the world for the two-year period of 2008 and 2009.

Bob Willis, a consultant who has been providing electronics assembly training over 20 years, will launch a new Website-based training service.

Lightspeed Manufacturing has moved from its old factory in Methuen, Mass. to a new 60,000-sq-ft modern manufacturing facility at 135 Ward Hill Avenue in Haverhill, MA. Lightspeed is a contract manufacturer of printed circuit electronics assemblies that has experienced continued growth.