Soldering Irons - Calibration Requirements

[johnnybegood]

Is soldering iron required to be calibrated? It is use to solder components on the product. Some of my colleague says that solder iron falls under tools category as such does not required calibration. But my concern is that the solder iron has to be set at certain temperature for example 200 degree plus minus 10 degree. Pls. advised.

[Claes Gefvenberg]

johnnybegood said:

Is soldering iron required to be calibrated? It is use to solder components on the product. Some of my colleague says that solder iron falls under tools category as such does not required calibration. But my concern is that the solder iron has to be set at certain temperature for example 200 degree plus minus 10 degree. Pls. advised.

I'd find it hard to regard a soldering iron as a measuring or monitoring device. However, if it's important for your product this could be taken care of via a maintenance schedule or something.
6.3b and / or 7.5.1c would be relevant in that case.

/Claes

[Marc]

Originally Posted by johnnybegood

Is soldering iron required to be calibrated?

This is an oldie, but I figured what the heck when I was wading through the past here.

Soldering irons may or may not have to be calibrated. It depends upon the work being done and the 'effect' on quality. A parallel is that some people who solder have to be certified (in the US the military had a soldering certification course they gave at China Lake for the old Mil-Std-1000 {DoD-Std-1000} if I remember the number correctly). One client of mine made bomb fuses. All soldering 'technicians' were certified by China Lake and all soldering irons were calibrated.

I ran into this at Motorola where some operations on some products had requirements for specific operator training and calibrated soldering irons, whilst others did not. The QS-9000 auditor questioned this. We explained why some were and some weren't and showed data from field returns and internal nonconformances which proved that in the 'un-calibrated' devices solder joint failure was never an issue.

So - It depends upon what you're soldering and how critical it is. You have to make that determination and be ready to explain to the auditor why you calibrate your soldering irons (or why not).

[Jim Howe]

Originally Posted by Marc

This is an oldie, but I figured what the heck when I was wading through the past here.

Soldering irons may or may not have to be calibrated. It depends upon the work being done and the 'effect' on quality. A parallel is that some people who solder have to be certified (in the US the military had a soldering certification course they gave at China Lake for the old Mil-Std-1000 {DoD-Std-1000} if I remember the number correctly). One client of mine made bomb fuses. All soldering 'technicians' were certified by China Lake and all soldering irons were calibrated.

I ran into this at Motorola where some operations on some products had requirements for specific operator training and calibrated soldering irons, whilst others did not. The QS-9000 auditor questioned this. We explained why some were and some weren't and showed data from field returns and internal nonconformances which proved that in the 'un-calibrated' devices solder joint failure was never an issue.

So - It depends upon what you're soldering and how critical it is. You have to make that determination and be ready to explain to the auditor why you calibrate your soldering irons (or why not).

Ah yes Marc, This rings a bell for me as I can recall calibrating many a soldering iron used on PCB's. We had a black box that checked for grounded tips and a few other things but as I recall it stemmed from ESD requirements. some components being extra sensitive to electrostatic discharge would be zapped during the soldering process if the iron was not maintained and calibrated. I do not recall the ESD spec but it was military, today i would suspect it can be found in an IPC spec.
Funny how memory seems to fade as age creeps up!

[Al Rosen]

Originally Posted by Jim Howe

Ah yes Marc, This rings a bell for me as I can recall calibrating many a soldering iron used on PCB's. We had a black box that checked for grounded tips and a few other things but as I recall it stemmed from ESD requirements. some components being extra sensitive to electrostatic discharge would be zapped during the soldering process if the iron was not maintained and calibrated. I do not recall the ESD spec but it was military, today i would suspect it can be found in an IPC spec.
Funny how memory seems to fade as age creeps up!

Ref:ANSI/ESD-S20.20-1999

6.2.6.1. AC Powered Tools
The working part of AC powered tools should be capable of providing a conductive path to ground. New powered hand tools such as soldering irons typically should have a tip to ground resistance of less than 1.0 ohm.

Note - This resistance may increase with use but should be less than 20.0 ohms for verification purposes.

If you are interested the standard is available free of charge (no pun intended) at http://www.esda.org/

[Hershal]

This is an interesting question.

I would have to take the position that if the iron had to be as tight as the original posts suggests, then calibration is basically unavoidable. The same may/may not be true for applications like NASA soldering.

Aside from special considerations like that, my personal opinion is that calibrating soldering irons is like calibrating a wooden ruler - a silly waste of money.

Hershal

[e006823]

The temperature of the soldering iron should be verified by some method if you want to call this calibration or maintenance tit doesn’t matter. I believe the reasoning behind this is to prevent damage to the board/substrate and components caused by excessive application of heat, and degradation of the solder joint. Heat causes metal to oxidize at a very rapid rate. The higher the heat, the faster the metal oxidizes. Oxidation creates an insulating barrier that will not allow the solder to flow easily, preventing the good wetting action needed. Flux in the wire-cored solder is intended to remove the surface oxides from the joint being soldered. If the iron/joint are overheated the flux forms carbon-type material on the tip of the iron and never does what is it is intended to do. In addition it can flow into the joint causing a poor joint due to contamination.

The following is from the NASA workmanship standard for "SOLDERED ELECTRICAL CONNECTIONS" 8739.3:

"3. Conductive-Type Irons. Soldering irons shall be of the temperature controlled type, controllable within ±5.5°C (±10°F) of the preselected idling temperature."

The following is from IPC/EIA J-STD-001C "Requirements for Soldered Electrical
and Electronic Assemblies":

"3.7 Soldering Tools and Equipment Tools and equipment used shall be selected and maintained such that nodamage or degradation that would be detrimental to the designed function of parts or assemblies result from their
use. Soldering irons, equipment, and systems shall be chosen and employed to provide temperature control and isolation from electrical overstress or ESD (see 3.5). A tool used to cut leads shall not impart shock that damages a component lead seal or internal connection. See Appendix A for guidelines on tool selection and maintenance."

A-2 BENCHTOP AND HAND SOLDERING SYSTEMS
Selection criteria of benchtop and hand soldering systems
include:
a. soldering systems are selected for their capacity to heat the connection area rapidly and maintain sufficient soldering temperature range at the connection throughout the soldering operation.

b. Temperature controlled soldering equipment (at rest) should be controlled within (5°C [± 9°F] of the idle tip temperature. Constant output (steady output) tools in compliance with A-2a, d, e, & f may also be used.

c. Operator selected or rated temperatures of soldering systems at idle/standby should be within ± 5°C [± 9°F] of actual measured tip temperature.

d. Resistance between the tip of soldering systems and the workstation common point ground should not exceed 5 ohms. Heated element and tips are measured when at their normal operating temperature.
Note: Current limiting soldering equipment manufactured
to EN 00015-1:1992 may not meet this requirement.



Bob