majority have not already taken advantage of new, production- oriented tools which can near instantly address these issues.
  Fortunately, throughout the world manufacturing managers and engineers are waking up to this absolute necessity - pulled by the vision of moving forward and upward and pushed by the fear of being left behind to forever battle with their current wave solder saga.

Figure 1: Use of the Wave Solder Optimizer is an opportunity for immediate improvement of wave solder quality. Direct measurement of the solder wave is key. Production costs and defects will decrease.

Inspection and Rework are Futile
  Regarding inspection, at normal levels of solder joint inspection the inspector is at best sampling the quality of the joints on each board and, from the external appearance of the joints, assessing the chances that a satisfactory result has been achieved on all of them. This assessment of each and every joint is obviously ridiculous. The responsibility for high quality PCBs lies with the process, not with the inspector.
  Likewise for rework. There is general agreement that rework of defects results in joints with shorter lives than those successfully made in the wave solder environment.

Conclusion
  The real solution is to ensure that the wave solder process produces the highest portion of joints possible that are correctly soldered from the start. Direct data on board-wave interaction - parallelism, dwell time and immersion depth - are essential for the achievement of real repeatability and true optimization. Fortunately, this is now easily attainable.

Ralph W. Woodgate is the author of The Handbook of Machine Soldering, John Wiley & Sons, New York City, from which this article was adapted.