User's Manual Part 3

following precautions must be observed:
• Minimize exposure to ESD Events. If the M.O.L.E. Profiler or one of the thermocouples receives an 8kV
electrostatic discharge during the data collection sequence, the M.O.L.E. Profiler may switch itself “OFF”.
To retrieve the data, simply upload the data that was recorded prior to the event. If a new data collection
sequence is started without uploading first, the existing data stored in the M.O.L.E. Profiler will be lost.
•
Keep strong electromagnetic fields away.
The thermocouple wires serve as an antenna for
electromagnetic radiation. If field strength of 3 volts per meter is present (usually due to close proximity
of
radio transmitters) while the M.O.L.E. Profiler is collecting data, the accuracy of the data may be
compromised. This interference is compounded by using long thermocouple wires, as well as the effect of
the thermocouple wires acting as a “tuned” antenna.
8.2. B: Statistical Process Control (SPC) Background Information
This appendix deals with the subset of SPC that is incorporated into M.O.L.E.® MAP
Software. It does not address general SPC principals. A working knowledge of general
statistical principals and SPC terms is assumed and is not addressed here. There are
many good basic SPC books where this information may be obtained.
Reflow and Wave Solder operators, engineers and production managers are expected to
understand their soldering process so as to deliver quality products cost effectively. This
is a continuous process.
First, the machine must be checked for consistency. A standard or typical set up should
be routinely checked prior to any process set point determinations, or actual production
run machine checks. Only after the machine has been determined to be operating
correctly and not experiencing abnormal variation, should data from the machine be
utilized. SPC is all about identifying common or normal variation from abnormal variation.
Second, the correct process set points must be determined for a particular product.
Utilizing the M.O.L.E. Profiler, the correct set points for a particular product may be
determined. These set points, if selected correctly and followed, should deliver the
maximum throughput of quality product.
Third, the machine must consistently deliver the correctly determined set points. SPC will
help identify common or normal variation from abnormal variation. Checking the machine
using your M.O.L.E. Profiler and the M.O.L.E.® MAP Software with its SPC capability will
help ensure that the machine is consistently performing to its set points and your
expectations.
Fourth, repeat the above three steps. Continuous improvement is a never-ending cycle.
Check the long-term variation of the machine by graphing typical set point samples. Using
the M.O.L.E. Profiler, recheck/adjust part number specific set points to maximize your
quality throughput. Check the machine during a part number run to control the machine
variation from that part number’s actual ideal set points.
While SPC had its start in high volume repetitive operations, SPC is applicable to many
other types of operations as well. However, SPC can be difficult to apply to short runs.