Developing A Quantitative Approach To Evaluating Soldering Stations

[SiBurning]

I've done a few reviews of soldering stations elsewhere and always wished there were a template to follow--a repeatable, quantitative approach for those things that could be quantified, as well as a list of qualitative issues to be considered. Between the two, a more useful compare & contrast could be done by different people.

There doesn't seem to be much in the way of quantitative reviews of soldering stations or a methodology for them. Here's the little bit of background I came up with.

• Evaluating Soldering Irons for Lead Free Assembly: A Quantitative Approach
  
• Evaluation of Hand Soldering Tools for Printed Wiring Board Application
  
• Evaluation of Hand Soldering Tools On Heavy Thermal Load
  
• Evaluation of Hand Soldering Tools for Terminal Connections
  
• Soldering Iron Evaluation (Draft)
  
• Evaluation of the Temperatures Attained by Electronic Components During Various Manual Soldering Operations
  

Here's a list of sample criteria I came up with:

• tip selection and quality
• features, ease of use
• heat: time to heat & cool, stability, recovery, temperature for various tips
• ergonomics
• maintenance: tip cleaning, changing tips, calibration
• cost: initial, tips, upgrades, warranty
• performance: fine pitch, heavy pitch, used in a variety of situations
• safety: sleep, auto-shutoff, cord heat resistance, alarms
• upgradeability: desolder/rework, tweezers

Another aspect of this is assigning weights to various criteria. For example, Evaluate Soldering Irons for Pb-Free Assembly - A Quantitative Approach contains the following sections, and assigns weights to each question. The difficulty here is that any assignment of weights is subjective.

Ergonomics

• Is it easier to work with this soldering iron?
• Is it easy to clean tip/replace tip?
• What features you don't like?
• What features you like?

Operational

• Does this soldering iron heat up faster than the other? Do you like that?
• While soldering fine pitch components, does this iron perform better than the previous soldering iron?
• Is it faster to solder using this iron than the earlier one?
• Does this soldering iron cool faster than the other? Do you like that?
• While changing the cartridge, does this soldering iron take a longer time to change than the earlier soldering iron?
• While soldering did you have issues like burning of boards or components, when you were least expecting it?
• Temperature control is easier than the previous soldering iron?

Does such a thing exist? If not, what do you think is important? What should be added or removed? Is it even useful at all to have something like a standard set of tests?

[saturation]

NICE!  Thanks for making this available, most excellent work.  Comments to follow, much to digest.

[saturation]

Hi SiBurning,

A great post with many items worth discussing; so I'll break my reply into multiple segments addressing each one, to make for easier reading.

I agree fully with your premise, but these studies require small labs to build standard test surfaces, and braze thermocouples to new test tips, so one need to sacrifice a new test tips.  Brazing equipment isn't common, so its less likely many users can perform these test such as:

http://www.ipc.org/4.0_Knowledge/4.1_Standards/test/2.4.37.2.pdf

You can buy a test tip from Hakko, IIRC, that does this for you, but again it would only work for Hakko and compatible models.

A practical approach could be to first eliminate non-players, then among players, we can devise ways to find ok, better and best.  Insure station meets minimum elements for electronics use by defining why such elements are needed and a simplest way to test for it.

In an older thread I posit that based on specifications made by IPC J-STD-001E for commercial requirements for soldering,  any station that meets IPC standards is a minimum: for practical application it reduces wear on soldering tips and minimizes risk from heat damage to soldered components, if its used properly.

These IPC elements for stations are simply:
accuracy requirement of ±15°C (±27°F)  [ i.e., dial setting vs thermocouple]
temperature stability of ± 5ºC (9ºF)  [i.e., variations of tip temp]

In addition, there are the tip to ground resistance of <= 2 0hms and potential of no more than 2mV for the ESD safe models.  Luckily one needn't think of these as most good stations meets these specs as 'standard issue'.

Users should know that an oft quoted stability of 1ºC for stations reflect just a IPC requirement of the station alone, not that of the iron.  The above specs are for the whole station.

This is for the unloaded standard tip [ these are what are shipped from say the basic Hakko FX888 and are matched to the calibration settings].
 
https://www.eevblog.com/forum/index.php?topic=4208.msg56121#msg56121

Among well known names like Oki, Weller, Hakko etc., one can have faith in the specs, but a simple tip thermometer can determine if the stations meet the criteria, even a well placed DMM thermocouple could work.  In addition, a user suggested testing measurements with eutectic solder to insure the station readouts are true and confirm thermocouple readings; I also found a good IR thermometer helps correlate readings within 5^oC.  These aren't ISO or IPC recommended test gear, but for home labs its practical and easy to do.

Its a good way to determine too whether the $20-30 you save buying a Quakko or Atten station isn't real money saved or great hidden value.   If your station meets the requirements, then the next phase begins: who is better and why, and should you spend money for those better features?

I've done a few reviews of soldering stations elsewhere and always wished there were a template to follow--a repeatable, quantitative approach for those things that could be quantified, as well as a list of qualitative issues to be considered. Between the two, a more useful compare & contrast could be done by different people.

[Wim_L]

Something you might also want to consider for ergonomics is if the handle becomes uncomfortably hot after having it powered on for a while.

[SiBurning]

Fixed that link to "Evaluation of Hand Soldering Tools for Terminal Connections"

I don't want to give away too much of my thoughts. Much better to have an open discussion. The links above should provide the background. Here's my basic line of thinking...

My preference is to use parts available to a hobbyist. They might not be perfectly repeatable if they come from different vendors, and they might not be as precisely specified as in those IPC tests, but I think they satisfy the needs of a review well enough. Aside from a nail, here's some of the parts I was considering using.

Known gauges of solid & stranded wire, 1/8 W resistors, short pin & wire wrap DIP, various terminal strips & blocks, PCB from known sources for through hole & SMD, etc... Perhaps even some of those heavy duty terminals used by the fancy tube amplifier folks. These kinds of things give a somewhat repeatable variety of things to solder. Having a lot of these would allow repeating specific soldering tasks many times, and the variety would provide... well, a variety of tests per review. In addition, a small, cheap kit, such as a portable stereo amplifier, would allow us to do a complete soldering project with each station. Of course it doesn't have to be the same kit for each review, but something small & useful to be given away as a gift is helpful if you don't have an actual project on hand.

Of course, the main idea is to find ways to quantify things to some extent. Using a more or less standard set of parts, and having a list of criteria would seem to go a long way towards that goal.

[saturation]

I agree fully Si, lets discuss it here.  BTW the image you attached is corrupted.

In your head-fi thread I noticed you used some nails to do a solder test, that would work.
However, it would be better to use something of copper that is well fluxed.

A long time ago I would test solder on US pennies, but increasing they are no longer made of copper and other countries no longer use such metal, many coins, such as Canadians, are actually steel alloys.

You can get a standard sized copper tube at most hardware stores used for plumbing reason that is very well defined.  It can then be cut precisely to size for a test thermal load.

 

[EEVblog]

I agree fully Si, lets discuss it here.  BTW the image you attached is corrupted.

All the forum attachments got corrupted in the sever move today (but nothing lost), they are re-uploading now.
Should take a few hours and then hopefully everything will ok again...

Dave.

[SiBurning]

Do they have small enough sizes of plumbing tubing that are appropriately sized for typical electronics projects? I used to use long pieces of square or rectangular copper for amplifier ground planes in point to point, on the theory that you want a "fat wire" for returns, but you also want to keep the higher current loads closer to the power supply. It worked out naturally and simply, if you just put the pre-amp stages further away from the supply, and I liked that exposed, dual railroad track look. They're good 99.x-100% copper, so just clean em up and flux em. They're more readily available--or rather accessible--at hobby shops, not so much at electronics stores which charge outrageous prices for them. Much better than nails, since nails usually don't specify an exact metal composition.

Dave,
Thanks for the all your hard work with the server issues, and getting me up and running here. Clearly, I picked just about the worst time to join to add to your pain. Murphy is vindicated. Thanks.

[saturation]

You can get copper tubes and sheets from Home Depot, and they can be cut to size for testing.  They are fairly easily obtained as its a common plumbing item.  They are generally soft, and can be cut with a snipper to the right standard size.  The one pictured below is $1.00 about 1" diameter, more than enough for many test surfaces.

Many of these pieces are brand names.  Also one can just use AWG electrical wire, std size, strip of the insulation and just use the solid copper wire as a test surface, cut to spec.

There are many premade copper surfaces that can be reshaped, the problem is which is most available, so everyone can get one and test it.  I think plumbing items are more widespread than electrical items even at the Home Depot or Lowes, and any size can be bought and cut to shape.  Specific premade items, like lugs, washers etc., may be out of stock at anyone time but less so copper tubes.

Do they have small enough sizes of plumbing tubing that are appropriately sized for typical electronics projects? I used to use long pieces of square or rectangular copper for amplifier ground planes in point to point, on the theory that you want a "fat wire" for returns, but you also want to keep the higher current loads closer to the power supply. It worked out naturally and simply, if you just put the pre-amp stages further away from the supply, and I liked that exposed, dual railroad track look. They're good 99.x-100% copper, so just clean em up and flux em. They're more readily available--or rather accessible--at hobby shops, not so much at electronics stores which charge outrageous prices for them. Much better than nails, since nails usually don't specify an exact metal composition.

Dave,
Thanks for the all your hard work with the server issues, and getting me up and running here. Clearly, I picked just about the worst time to join to add to your pain. Murphy is vindicated. Thanks.