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The High Cost of
Wave Solder Defects
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touch up operator. This, of course, is a total fallacy brought about by incorrect
calculations of the true cost of faulty wave soldering. Wave solder defects are
the most expensive process deficiencies in the electronics packaging industry. When
the cost of wave soldering is considered, the evaluation must stretch further than
the actual wave soldering itself. The cost of assuring reliable PCBs - the cost
of inspection, touch up and rework - and, of course, the ultimate expenditure of
making right field failures, must be included in the final figure.
The Real Cost of Defects
When all factors are put together and the calculation correctly done, even a very
tiny increase in yield will result in important cost savings. Wave solder defects
are very, very expensive. Anything that will reduce the number of defects will show
a cost savings.
The problem is not only with "poor quality" wave soldering, but also with wave solder
results that are generally considered "satisfactory" and even "excellent".
Since a defect rate of 0.5% is considered good, the overall cost of "acceptable"
wave soldering in the electronics industry is nothing short of astronomical. A major
problem is that normal accounting procedures usually put field failures into a separate
budget from that of the factory, and so the true costs are never articulated.
Your own data will provide compelling evidence that new steps are not only necessary
but also extremely cost effective even when only a part of the overall figures are
considered.
Improved Process = Fast Results
In company after company, the prevailing defect rate now considered "acceptable"
causes annual costs many, many times more than the implementation of sound procedures.
Even worse, it can result in a field failure rate that can only damage the reputation
of the product and eventually confidence in the assembly plant.
This is so completely unacceptable in this era of contract manufacturing, so damaging
to the competitive posture and profitability of the assembly facility, it is astonishing
that the vast
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More than any other cost element, the cost of wave solder defects is misunderstood.
The problem is not only with "poor quality" wave soldering, but also with wave solder
results that are generally considered "satisfactory" and even "excellent".
Wave solder defects are the most expensive process deficiencies in the electronics
packaging industry.
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C ost alone - cost of inspection, cost of touch up and
the cost of a company's reputation for quality and reliability - are forcing every
organization to review its wave solder methods. The cost of reducing wave solder
defects is much lower than any other method of improving PCB assembly results and
the most direct approach to measurably reducing operating budgets.
When wave soldering replaced hand soldering it produced an enormous improvement
in productivity. The fact that the machines and materials were not perfect did not
outweigh the spectacular reduction in labor expenditure. Thus was born the use of
personnel for inspection and rework. Early on, small boards with simple circuitry
were the order of the day, making inspection and rework quite feasible.
Machines improved, better solder and fluxes were developed, devices for thermal
control were introduced, and even some broad mechanical measurements of the solder
wave, such as those from a glass plate, were implemented. Still, the solder joint
inspector and touch up operator continued as significant and inevitable parts of
operation.
However, with the increasing complexity of PCBs, they have come to be used not as
backup for deficiencies in materials or machines, but to cover a lack of process
control, inept accounting when the cost of the soldering process is calculated,
poor training of operators and frequently a lack of understanding by management
of the nature of the wave solder process.
More than any other cost element, the cost of wave solder defects is misunderstood.
A common assumption is that wave soldering is a relatively cheap process and if
there are problems it only means putting on another
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