Novel alloy claims top lead-free performance

The transition from tin/lead to lead free soldering is not as straightforward as engineers would prefer, as there are no "drop in" replacement alloys.

However, Cookson Electronics has developed and patented a new wave-soldering alloy which is claimed to outperform the standard lead free solder bars currently available and so ease the trauma of transition to lead-free assembly.

Alpha Vaculoy SACX0307 is a high yield alloy which in trials has given better performance than any Sn/Cu-based products currently available.

It is a high purity alloy, which gives low maintenance with high reliability.

Its wetting speed is faster than all popular Sn/Cu-based products and characteristics include low levels of both dross generation and copper dissolution.

Cookson's proprietary Vaculoy alloying process is used to remove impurities, particularly oxides.

The product is further enhanced with the addition of elements to reduce dross formation and subsequent waste, and improve joint cosmetics.

Alpha Vaculoy SACX0307 is recommended for use as best replacement for standard Sn63/37Pb wave solder alloy.

It creates strong, mechanically sound joints, which have excellent long term reliability (mechanical pull and shear tests demonstrate joint strengths equivalent to tin-lead and SAC305).

The new alloy is said to be particularly economical for lead-free soldering due to the lower material cost, high yields and low dross generation coupled with low pot maintenance.

It has very good solderability due to the fast wetting speed and very good drainage and hence low bridging.

Alpha Vaculoy SACX0307 delivers good performance across a range of both conventional and VOC-free flux technologies, and solders well without the need for nitrogen inerting.

A solder pot temperature of 255-265C is recommended with a contact time of 2.3-3.5s.

Alpha Vaculoy SACX0307 is available in 1kg solder bars, 3.5kg feeder bars with chunks and wire solders available on request.