Soldering Iron Temperature Control

J

jepam

Is there any specific requirement by ISO for checking tha temp. of soldering irons. I know IPC suggests that the temp. is controlled to +/- 5c. If there is a requirement, how often should it be done, I think daily would be overkill. Thanks
 

AndyN

Moved On
Re: Soldering Iron Temp. Control

Is there any specific requirement by ISO for checking tha temp. of soldering irons. I know IPC suggests that the temp. is controlled to +/- 5c. If there is a requirement, how often should it be done, I think daily would be overkill. Thanks

You have to control your processes, that's the requirement. Since soldering is one where you cannot verify the quality of the soldered joint, by inspection, you have to control the things which affect quality, like temperature.

You control the flux, type of solder, training of operators etc. The temp of the iron is important to achieve the correct melt for the alloy, so check the irons. Without data, you/we can't say if daily is overkill or not...
 
T

tomvehoski

Re: Soldering Iron Temp. Control

ISO 9001 does not prescribe requirements for anything technical. It just requires that you (and your customer) determine requirements needed and implement them.

You need to determine, for your organization and customer requirements:
1. What is the cost of checking soldering irons.
2. What is the cost of the required calibration/checking equipment.
3. What is the risk (in cost) of using a soldering iron that is off by XX degrees.
4. What is the frequency of use of soldering irons, wear and tear, etc.
5. What check frequency and accuracy provides the best cost/benefit/risk minimization for you.

IPC is probably a good place to start.
 

BradM

Leader
Admin
Re: Soldering Iron Temp. Control

Tom and Andy has covered this pretty well.:agree1: I do know, firsthand, of instances where the solder temperature in Aerospace was a significant factor. They had to perform verifications quarterly. Also of interest was the heat guns, what setting they ran at, how far away to hold it, and how long to keep it on there.

I would suggest doing some investigation on it. Start by looking and seeing if you have any industry regulations that require it. Second, contact your customers, and also consult the vendor of the materials you are working with. They are typically knowledgable on temperature effects of their products.
 
J

jepam

Thank you. I spoke with tech. support at Wellar and they said most companies do this check quarterly.
 

AndyN

Moved On
Thank you. I spoke with tech. support at Wellar and they said most companies do this check quarterly.

Don't forget that YOU need data to support the frequency you choose. It's not sufficient to say quarterly and then ignore the data. I'd start off more frequently, say monthly, build up the data - like a study and then reset your frequency.
 
J

jepam

Good advise. Thank you. I will change the procedure to monthly until we have a good baseline and then adjust if possible.
 
G

George Weiss

The art of soldering iron calibration. OMG I love doing soldering iron calibrations!
I have had the true pleasure of worrying about this effort as a calibration technician. I have been asked to do the seemingly silly calibration of a glass ruler once a year, ( I might ask, "what could change").
A soldering iron is a simple item, but with varied applications deserving degrees of attention.
At a facility like Lockheed Martin, where space qualified and defense product is produced, attention to every detail is warranted.
The soldering iron has 2 features of interest.
1. Soldering tip temperature accuracy
2. Soldering tip residual mV AC/DC and ohms to GND, (0-5 expected)
These 2 items are related. A dirty soldering iron tip will cause intermittent performance
There are soldering irons with digital readouts and marked knobs with temperature values
Some soldering irons have no digital display or marked temperatures for the knob control
The temperature control feedback is within the soldering iron heating element, and there is some gradient loss between the control element and the actual tip. There are different types of tips, with the small fine tips having the most temperature loss to the tip. Developing a solder pool to measure the tip temperature is a wild estimate, which can with some skill be reduced. In many attempts it has become a written procedural practice to verify max temperature above 700 deg. F. in most cases to warrant range capability, and resistance to ground to comply with ESD issues standards. The effort required to achieve +/-5 deg. F. with a system which is best accurate with a digital display of +/-1 deg. or temperature marked knob with +/-3deg best setting ability exceeds reasonable efforts. The soldering iron would have to get a correction chart for tips used, (which some manufacturers actually supply), and a calibration conditional statement that the values achieved were with a tail-light warranty, because repeating the testing successfully is unlikely. Calibrating soldering irons in some cases is warranted, but should be restricted to only when really needed.
Recommended: I recommend a written procedure to include:
limits testing on all soldering irons to max temp. >700deg. F. and tip resistance <5 ohms.
Further efforts could be added to meet customer needs when requested or required.
This is a suggestion, and is in practice in the commercial calibration field.
IF regular testing is planned, then consider stocking a good collection of new tips, and heating elements to acheive good results. annual calibrations by service labs do little to better the soldering iron performance. The user of the tool is a very good source for awareness of tip issues in many cases.
I am offering a what if variance comment to relentless testing of a device which is user settable to desired performance. Similar to calibrating a garden hose shut-off valve. "ya just set it where you want it"
I am rambling, and sorry if this is off the track you desire. It is a good real world account. Thanks for reading it..........
 
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AndyN

Moved On
George - surely (and I apologize if this has been covered before) but a soldering iron isn't inspection, measuring and test equipment. It's process control equipment, isn't it? I understand that some fancy equipment has built in controllers etc., but since the iron (not the controller, if fitted) are the process equipment, going through the 'full monty' of calibration is unnecessary to establish they're working correctly. A simple check against a thermocouple is all that's required.
 
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