final measurements are tremendous. It is
summary
(+49) 3528-4149-12.
obvious that the final state of the machine
The main idea of SPC is to measure the
will produce much less failure during
quality characteristics of a process based
daily production, which reduces long-term
on random samples instead of 100 percent
failure and repair costs.
testing on a regular basis, and to use statis-
This example also shows a typical be-
tical methods to analyze them. The analysis
havior experienced by performing an MCA
results are used to control and adjust the
on SMT equipment over the last 12 years:
process if necessary. In the end, this helps
running an OEM calibration of a SMT
to locate and repair weak points in a pro-
production machine does not necessarily
cess before they cause decreased yield rates
and increased failure and repair costs.
mean that the machine performs in speci-
SPC is the key to combining high qual-
fication afterwards, even if the calibration
ity with low cost.
went through without showing any errors.
It is always a good idea to verify the result
Mathias Keil is managing director of
with an independent measurement tool.
CeTaQ. He may be contacted by email at

m.keil@cetaq.com or by phone at
!
Figure 7. Results after calibration.
!
Figure 8. Final measurements show the machine performing inside the specification limits.
www.globalsmt.net
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