Q
qe2008
Are soldering irons considered "monitoring and measuring equipment that needs to be calibrated or verified at specified intervals, or prior to use" under Clause 7.6?
Thanks,
Juneau
Thanks,
Juneau
In aerospace products, most soldering processes would fall under the so called "special processes". AS9100B 7.5.2.c statesAre soldering irons considered "monitoring and measuring equipment that needs to be calibrated or verified at specified intervals, or prior to use" under Clause 7.6?
Thanks,
Juneau
So, if the soldering process spec calls for specific temperature settings and was validated accordingly, the soldering iron associated instrumentation needs to be calibrated/verified. Otherwise, you have no confidence that the process is being performed in accordance with the approved specification for the process.- control of the significant operations and parameters of special processes in accordance with documented process specifications and changes thereto,
That does not agree withI've been through this *many * times. NO.
The answer is "It depends".
Since the OP mentioned AS9100, which is meant for aviation, space & defense product lines, I believe there is a high criticality issue.This is typically the case in high reliability electronics (military grade).
2. Solder quality. The tip temperature accuracy affects proper application of solder, and subsequently solder joint reliability. For example, an insufficient temperature may cause 'cold' solder joints, and will perhaps not allow adequate whetting of the solder through the circuit assembly (along with other variables).
Too hot a soldering temperature will measle the board, damage the solder, lift the bond pads, heat stress or damage components, cause an undesired flow, and other issues. Overall, poor control of solder application (which is a factor of the tin/lead composition, solder purity, cleanliness of the circuit board, temperature and time of solder application, among other things) will cause relibility problems in the circuit boards.
If your soldering temperatures are varying by as much as 100 Deg F, there is a definite reliability issue. MIL-STD-2000, as I recall, was developed as a "high reliability soldering" standard. If you desire high solder joint reliability, then the parameters which have now transitioned to the ANSI spec, are most definitely important. Plus or minus 5 deg C is in my view a quite reasonable allowable limit for high reliability soldering applications. The good soldering equipment available on the market is quite adequate to meet those needs. When I was in charge of soldering reliability and ESD at a former employer, I literally threw away a small trash can full of old "soldering irons" whch were not temperature controlled, and replaced them with variable temp solder stations.
After replacement of this equipment alone, I saw a first pass yield on a large circuit board (part of a digital antenna coupler assembly) go from 0% to more than 90%, simply because the soldering operators were assuring that they got consistent flow of the solder through the circuit board. The temperature control was a great part of that.