Control of Soldering Irons and Soldering Stations

[BradM]

Dear all,

thank you very much for your comments and advice. Yes, during the interview the auditor stated it clearly that soldering is a special process and should be validated as such; this particular NC - about controlling the soldering station - is part of bigger issue which we will have to address.
As for the question whether the stations maintain proper temperature - the answer is, alas - WE ARE NOT SURE. The stations are equipped with temperature indicator and the indications are within limits - but whether this indication is proper, we cannot know without calibrating these thermocouples.
In current circumstances, the soldering stations just exist, without any control - and I believe taht total lack of any control was the direct cause for NC.

Thank you for the explanation.

There are many auditors here, with many different approaches. Again, this is my opinion....

So the auditor goes to the lunchroom, and all the vending machines are empty and the cord on the microwave appears frayed. That's a complete failure on the part of management: NC. Looks like there are some chemical drums not stored like they should. Another NC. Why don't those flourescent lights have plastic protectors? Someone could get hurt. NC....

An auditor should be a person welcomed by the organization. A fresh, independent set of eyes to view their process. Hopefully they deserve parts of the process that do not conform to the stated Quality Management System or requlatory requirements. They issue a non-conformance, because something needs to be fixed.

Auditors (again, IMHO) should make observations for their client. Suggestions of areas that appear that improvement could be made and improve the process. The client can accept the observations, act or ignore them, but always be appreciative.

If the auditor cannot cite from your document system, regulatory requirement, or an industry standard that is a requirement for you, what section you are not complying with, then it is not a non-conformance, but an observation. As such, you can choose to take their good advice or not.

But now... they said "Oh big problem... NC". Yet... you legitimately have no idea what needs to be corrected, so confusion and frustration ensue. Then, typically a bunch of things are thrown into place, many that are not needed.

Again, I'm a calibration guy, so everything down to the stapler should be calibrated! Seriously, if you're soldering iron has a temperature indicator, I would at least verify its accuracy like Andy mentioned. But in the end, you need to do the things that are required to better your process.

My opinion? I would take the NC and use it to improve your process. Find out what soldering requirements you have for what you are doing. If you have some, then implement them. I would bet somewhere you have some requirements.

One of my customers wanted me to certify a heat gun. OK, "what are your requirement?" They did not know. OK, so I basically measured temperature at different distances, and wrote it up as a verification of sorts. After asking multiple times, they finally dig some digging. Guess what??:mg: They had the heat gun way way too close to the shrinking area (too big of a hurry). This led to fixing another big problem they had: the heat was damaging some of the solder joints. Now the solder joints were yet another matter (gun temperature, exposure, solder diameter, etc.)

Talk to the mfg. of the material that you are working with, the parts you solder, customers, etc. I bet there are some requirements that may not yet be realized.

 

[AgnieszkaSz]

Brad, thank you a lot, once again. Now I have an idea what we should concentrate on, and still not to kill ourselves with some exaggerated means of control. THANKS!

 

[themuss]

Re: Control of soldering irons

This is an opportunity for improvement.

I'm sure the reason why it was highlighted was due to the fact that the soldering irons are used in manufacturing - bad joints may present themselves later on in life and may not be picked up on during test.

What I would do is specify that you follow the best industry standards i.e the IPC specs as well as employ competent staff who can solder and identify faults. You probably also carry out testing on a number of units to check for build quality and life.

You may want to specify the temperature range of the soldering iron as not to damage components but in my life i have not seen a soldering policy. I have however, seen work instructions detailing where/how to solder and specifying solder temp ranges and the use of a particular flux and solder.

You may also want to include teh irons in the calibration process but i'm sure this is not required.

 

[e006823]

Hello everybody,

Can anybody please help me and redirect to any document that suggest WHAT actually must be controlled?
A bit of explanation - the process is soft soldering and its aim is to create electrical connection in wire harness (between wires in multicore cable and legs of a connector); no pull force testing is required, the connection must just hold.

Thanks in advance - Agnieszka

IPC J-STD-001 addresses the control of soldering tools and equipment.

 

[sowmya]

our company is doing wire harness manufacturing and soldering is a special process for us. We use temperature controlled irons (as different temperatures are required based on different connectors and AWG of wire).

less temperature may lead to improper soldering and higher temperature might melt the wire insulation.We have internal calibration for our soldering irons. We use hakko FG-100 for calibrating the iron. We concentrate on selection of bit diameter, solder wire sizes and flux for soldering different connectors. But it is based on your type of soldering.

you need to do operator qualification, training IPC 620 requirements

hope it helps!

 

[Pistonbroke]

A Somewhat late reply, but hopefully I can add some value

Control of soldering irons is required because:

Irons that are not hot enough cause bad joints and can cause damage to the wires - increased dwell time can cause heat to conduct up the wire and melt insulation rather than applying the right amount of heat locally for a short time

Irons that are too hot can cause surface oxidisation, and again damage to surrounding materials such as connectors.

The right sized tip, and tip condition is also important for getting the right heat to the right place.

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You can purchase soldering iron "calibration" equipment which uses a pyrometer to check the output of the irons (I think weller do one, and Pace may also do something similar) - this sort of equipment has been developed to give control over processes to comply with the requirements of (for example) DOD-STD-200 and MIL-STD-2000.

The process is rapid, relatively simple and permits soldering stations to be incorporated into your existing processes as a calibrated item as per other measurement and validation equipment.

"Recal" may vary from weekly to half-yearly depending on the equipment and its usage but this should give you greater control over your soldering stations - when combined with a modicum of training to make sure your operators know how to select the right tip for the job, keep the soldering surface wetted and look after their tips.

Make sure you buy some Cal seals to seal off the adjuster on the stations - too many time I've seen operators jacking up the temperature to MAXIMUM becasue they cannot get a joint due to an oxidized tip, a too small tip, or failing to wet the tip to help with heat transfer prior to application of solder.

 

[somashekar]

Re: Control of soldering irons

you may have to validate the soldering process .. may be the attach helps if you can modify and use.
good luck

 

[raybor]

In reference to his comments concerning soldering irons, he was most probably referring to the ESD requirements. This is an important requirement for the electronics assembly industry. There is a max leakage voltage permitted on the soldering head, to prevent electrostatic damage.

For cable and harness assemblies this is not relevant. In regards to workmanship standards, companies should conform to the industry standards, such as IPC 620, IPSC 610, J-STD, etc. But if not noted as a requirement in the contract, need not be applied. Note; there is good reasoning behind the industry standards. Improper assembly of cables will lead to eventual and even short time failure.

The important question is not; "How to get through the survey", but "How to make a reliable product and satisfy my customer".

 

[AgnieszkaSz]

Re: Control of soldering irons

Thank you very much for the attachment - I am a complete greenhorn in area of process validation, so this will give me an idea about consistent and systematic approach. The soldering validation is not the only gap in this area for us. The temporary measure we applied was to introduce calibration for soldering station - but I like your approach better. Thanks a lot.