Don't be afraid of lead-free soldering!

July 1, 2006 will be the day when lead-free soldering finally becomes law for the manufacturers and suppliers of electronic components in Europe.

Time is running short and many small and medium sized companies but also large industrial producers feel left alone with the changes to come.

It's true that many committees, a lot of them renowned institutes, have been discussing and researching the issue for years - but where is the support when it comes to the real problems, the daily grind?

Ersa GmbH, the European soldering systems supplier, is known to confront the problems of lead-free soldering and supports the user by answering process-related questions.

It considers the influence and interaction of various parameters:

• Solder alloy;
• Flux;
• PCB material;
• Coating;
• Component types;
• Layout, topology.

The company's products range from reflow machines for high-volume production over wave soldering and selective soldering to repair and hand soldering tools and inspection systems.

Each area has its very own questions with regard to lead-free soldering and each area needs its very own solution.

Ersascope inspection systems are being used for monitoring and analysing hidden, lead-free solder joints. Non-wetting problems, a significant problem with lead-free soldering, can be detected just as easily as irregularities on PCB soldering globules due to too high or too low temperatures.

The optical inspection system identifies bridging or solder squirts even beneath flip chips. It is necessary to find out about the surface structure of a good lead-free joint to ensure its quality.

One method of doing this is to use ImageDoc EXP 2.0 software that has a data bank of solutions to known problems of lead-free soldering.

As the process window for lead-free produced PCBs is narrower, defects will most likely increase during the changeover phase from lead to lead-free. Until now, unknown defects may show up at this time particularly where older production equipment is involved that might not be able to cope with the narrow process window.

In this case, the software along with the Erascope are helpful in resolving problems.

For many years, the most important tools in defect elimination and rework in electronics have been soldering stations and, since the adoption of surface mount technology, also IR reworked systems.

Both systems already meet the requirements of lead-free soldering. The defect rate caused by defective soldering joints is minimised with these tools.

Ersa's soldering stations for professional use have very precise temperature control at the iron tip due to good heat transfer from heating element to tip and heat recovery. The joint receives just the right amount of heat to form a good joint.

Ersa IR rework systems are in 4000 installations worldwide. The controlled and mild radiation heat, with no-touch temperature measurement on the PCB, works well in many lead-free applications.

The tool's visual process control and its capability of being calibrated to the melting point temperature of every solder alloy, makes the selective lead-free reflow process particularly safe.

The closed loop system makes the repair of lead-free components safe even for inexperienced users. Components and substrates receive no more heat than is needed by the process and ensures that defects caused by hot process gas or imprecise measurements due to aged thermocouples are eliminated.

Again all rework press results can be documented in detail using IR Soft 2.1 software that serves as a basis for the final control of the lead-free process.