The trusted workhorse on every assembly/repair station, the well-known soldering station.
However, it occasionally (once per year at minimum) needs some care and attention (or TLC).
To do everything correctly, you must do at least three calibrations/tests:
- Electrical safety – NEN-3140*
- Solder tip to ground resistance – IPC-TM-650 & IPC-J-STD-001
- Solder tip temperature accuracy – IPC-J-STD-001
Where electrical safety check is mandatory by law, every soldering station (and other equipment) must regularly be checked for electrical safety. As an ESD safe soldering station must have a grounded solder tip, it is classified by NEN as a Class 1 device**.
*NEN-3140 applicable in Dutch environment, other countries have equivalent standards (like IEC – 50110 )
**NEN safety classification differs from IPC product classification
NEN-3140
For electrical safety, three (3) parameters are to be measured:
- Insulation resistance RISO ≥ 1 x 106Ω (1MΩ)
- Ground resistance RPE ≤ 1 Ω
- Leakage current IEA ≤ 1 x10-3A (1mA)
IPC-TM-650
IPC’s test procedure TM 2.5.33 has an outline of Measurement of Electrical Overstress from
Soldering Hand Tools. In this procedures you will be directed to following procedure TM 2.5.33.1. This describes measuring the tip to ground resistance.
As an extra, also apply procedure TM 2.5.33.2 on measuring tip transient voltage and procedure TM 2.5.33.3 on measuring current leakage.
These test methods are mainly intended for validation when buying a soldering station or after a soldering station has been repaired.
IPC-J-STD-001H
This standard for soldered electrical and electronic assemblies (aka. printed circuit assemblies) has §3.7 which states following “Soldering irons shall [D1D2D3] be chosen and employed to provide temperature control and electrical overstress or ESD”. From §3.7 J-STD-001 directs you to appendix A: “Guidelines for Soldering Tools and Equipment”. Bullet b. and e. have statements on temperature accuracy and tip to ground resistance.
- Temperature accuracy: Equipment should be able to maintain temperature (when idle)within ±10°C of the set temperature.
- Tip to ground resistance: Should not exceed 5 ohms at normal soldering temperature.
So, to takes this forward (driven by “shall” in §3.7):
If tip grounding and/or temperature are not accurately checked, not even IPC Class-1 equipment can be fabricated !!!
To summarize:
To be in line with mandatory requirements, everybody using a soldering station must perform safety and performance checks.
Check electrical safety to enable safe working for operators. Check ESD requirements to ensure reasonable protection against ESD related damages. Check temperature accuracy of the soldering station to ensure correct soldering.
Deducted from over 25 years of experience in the field of soldering, we are confident to state the mere part of soldering stations is not checked in any way or at max electrical safety (NEN-3140).
The smart approach:
Where it is clear quite a bit of maintenance is due for all soldering stations, a smart approach will make life a bit easier.
Perform all checks in one go. Do safety- and ESD requirements in one measurement. Most Portable Appliance Testers (PAT) check the protective ground resistance as well, select a measuring instrument that will return the exact measured resistance, not just a pass/fail indication. Use this value for electrical safety measurement as well as ESD requirements.
Interested, want to know more?
Get in touch with our department Business Support: +31-45-7112390 or info@etech.training
