Archive for April, 2011

Vendor Spotlight: A solution to pad cratering.

Saturday, April 30th, 2011

Lead-free assembly techniques and practices have pushed the envelope of printed circuit board technology for years. The industry has been forced to change and improve as a result of customer demands and regulatory compliance. Lead-free compliance has been a journey filled with advancement and disaster. The advancement comes in the form of new improved materials and surface finishes. The disaster came in the form of all of the manufacturing non-conformances found along the way and yet to come. Over the past six years the electronics industry has been one giant crucible. Within this crucible we have tested the limits of the process at the bare board and assembly levels.

Prior to lead-free assembly practices there was eutectic solder consisting of tin-lead (Sn63/Pb37). As the saying goes “Nothing solders like solder”. Eutectic solder wicks easily at relatively low temperatures. Solder joints have a unique property where the inter-metallic copper-tin alloy grows over time. There are decades of historical information and observation on the longevity and durability of eutectic solder joints and assembled materials. In a competitive industry where change introduces the potential of non-conformances, eutectic solders are a proven and safe technology.

Enter lead-free assembly. (more…)

Material Allocation

Wednesday, April 27th, 2011

What does it take to build a circuit board? For starters you can’t build a printed circuit board without materials. What types of materials to be used are defined by the customer supplied documentation and or by the methods/release engineer. If requirements are not specified by the customer the methods/release engineer shall default to IPC standards. The various manufacturing operations used are a series of added and subtractive processes. All of which are determined by the methods/release engineer. It takes many different types of chemicals and materials to fabricate the printed circuit board. The most important material is what we start with and that’s the base copper clad laminate.

Base laminate is typically copper clad FR4. FR4 is a composite material consisting of (more…)