Soldering Temperature and Thermometer Selection - Page 1
Forum section: electronics / general

author: PixieDust
author_rank: Frequent Contributor
timestamp: December 30, 2021, 04:29:48 am
content: In another thread:https://www.eevblog.com/forum/reviews/which-soldering-temperature-would-you/Dave says:Quote from: EEVblog on September 19, 2014, 12:21:26 pmReading other people's experiences on these forums, it seems that the digital readouts of their soldering stations aren't very reliable. Which for me suggests that perhaps JBC is soldering at lower temps because it's better calibrated than other brands?I'm a rookie when it comes to electronics, so I'm probably wasting my time worrying about this but I want to learn none the less.I've also seen the series:and people on these forums seem to suggest that adjusting temperatures until you get expected behaviour is better than setting a temperature and using it no matter what. For me, I don't know what the correct behaviour is yet, so all I can rely on is actual temperature, which basically means that I want to get a thermometer to test my soldering station temperatures. The stuff that I've done has mostly worked (I've had only 1 delaminated trace so far), but each time I solder it's a crapshoot right now, I have no idea what's going to happen.I've narrowed it down to two so far (if you know of others, I'm all ears):https://mektronics.com.au/products/fluke-t3000-fc-wireless-temperature-module?variant=41043707101340&currency=AUD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gclid=Cj0KCQiAq7COBhC2ARIsANsPATHOIjF_loKwmpZi4IofgdGR-p7A4fyKsm4JN12zzS9E3BaoJKl-18AaAi_3EALw_wcBhttps://mektronics.com.au/products/hakko-tip-thermometer?variant=41044122665116&currency=AUD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gclid=Cj0KCQiAq7COBhC2ARIsANsPATFE2ug4MCeYIp1QoqqMM7CgnOIr6kpW6cf6PzzY7_pdsA4cuWFDEAUaAtuFEALw_wcBI prefer the Fluke, it comes in a much nicer package. I saw videos on Youtube of knock off Hakko 191 and FG-100 and after watching Dave's video:Got the answer of everything wrong with the knock off thermometers that cost 10-20 dollars.Anyway, I was wondering if anyone has any suggestions as to which one would be better? The Hakko or the Fluke? The Hakko comes with those replaceable star shaped things that last up to 50 uses before they need to be thrown away, the Fluke on the other hand has a more traditional configuration with just two wires sticking out. Does anyone have any issues or comments?I have a Weller WESD51 soldering station and will run it through its paces to see whether Dave's experience has a simple explanation of JBC being better calibrated from the factory vs other brands!

author: ledtester
author_rank: Super Contributor
timestamp: December 30, 2021, 07:46:30 am
content: Quote$350 seems like a lot of money to spend to learn to solder.I think you're overly concerned about the whole temperature thing. My first soldering iron was a simple 25W Weller -- no temp controls and it took 5 minutes to heat up.Start with a temperature that easily melts the solder. Concentrate on the fundamentals -- a clean and tinned tip, make sure the tip is touching both surfaces to be soldered and strive for that shiny concave fillet. If you get cold joints try adjusting the temp and/or add flux. Another piece of advice I was given when starting out was to not spend more than two seconds on a joint. As they say, practice makes perfect.Edit: Ok, I guess that AU$ not USD -- still a lot of money though!

author: Shock
author_rank: Super Contributor
timestamp: December 30, 2021, 08:16:44 am
content: The JBCs T245 (CDB stations)They have an aggressive thermal profile and overshoot. It's why they perform so well, but it's sort of cheating if done deliberately. Still they are a high performance station regardless but seem to get a reduced tip life which is also consistent with a hotter average tip temperature (it directly affects tip life).Metcal MX-H1-AV (PS5200 stations)Have the best thermal response and shortest tip to grip, the downsides are that it's one of the more costly systems to run and as it's an RF powered station the tips are set temp. It's still a temp adjustable station but done by swapping tip series rather than turning a knob or button. Metcal has a good track record with tip life, I think this is mainly because they don't widely overshoot and have soft thermal profile near set temp.I went with the Pace ADS200, it's almost the opposite of the JBC and has a soft thermal profile. It's also the cheaper station and lowest cost of consumables. No problem with tip life and the tip to grip is slightly better than JBCs. Unfortunately though Pace has been unable to keep the station price low. In Australia as it's imported it doubles the cost, they are ridiculously expensive here now.Aesthetically I'd only ever buy the Pace or Metcal stations as they are metal construction. JBCs affordable stations are plastic compact all-in-one style, with a plastic handpiece. The Pace ADS200 is all metal (station, handpiece, stand). Metcal has ventured out into fully temp adjustable stations but in my opinion they need to rethink a few design decisions, the PS5200 remains their best performing station.I think what sets Pace apart for me is their handpiece compatibility. They make a good iron, tweezers and vacuum desoldering tool. They also have a low setup cost once you factor in consumables like tips, filters and maintenance parts (specific to vacuum desoldering).As for checking the tip temp, I suggest not spending hundreds on an expensive tip thermometer. You will only use it once or twice then it's just going to sit around. The cheap ones are within a few degrees so that is plenty accurate. There is also a trick to getting accurate measurements on the thermocouple. You need to have a very clean tip and apply a little fresh solder to get a consistent thermal bridge.You can use a standard multimeter thermocouple to perform the same function but unlike a tip thermometer you may need to check if it's rated for high temps, consider that soldering it directly may cause damage. So I suggest you use a cheap throwaway thermocouple also for this reason and it will allow you to practice your technique. Joe Smith (also a forum member here) shows how in this video.

author: Shock
author_rank: Super Contributor
timestamp: December 30, 2021, 09:44:51 am
content: As for the debate about temperature accuracy being required. It's not essential for hobbyists, but in business and manufacturing mistakes can have large consequences down the line. Therefore they focus more on maintaining process control which delivers predictable outcomes.The IPC standards in the past were about idle temp accuracy but are now focused the ability of the station to stay within an accurate temperature window. So you still need the station to be calibrated (reading within it's stated accuracy) but the standards encompass soldering performance. In other words you want temp accuracy and recovery/heating speed to best achieve that.

author: Microdoser
author_rank: Frequent Contributor
timestamp: December 30, 2021, 12:01:42 pm
content: Quote from: PixieDust on December 30, 2021, 04:29:48 amReally, the best way forward is to get used to using your equipment on different boards that have different thermal characteristics, so you gain enough experience that it does not become a crapshoot. You seem to be looking for a way to not have to do it, but there is no shortcut for this.If using the same style tip, someone with a lot of experience can get better and more consistent results from a cheap inaccurate base station than an inexperienced person using a very expensive calibrated base station. The number on the front of the machine does not matter, it does not matter if it is accurate or not (as long as the tip is kept to a stable temperature and does not vary wildly), you observe how the tip interacts with the solder and the work and adjust accordingly until things work as described in the pace video series you watched, or pretty much any other series on soldering.Some base stations, especially hot air ones, just have a dial that goes from 1-10, and you learn that 4.5 is good for small work, but 6-7 is needed for something with a large ground plane. No need for temperature, let alone accurate temperature. The reason some irons can solder at a cooler temperature is more to do with how much thermal energy they can supply to the tip and how quickly they respond to temperature changes than how accurately they measure that temperature.If you have watched the pace series then you have all the theoretical info you require, now get used to soldering until that theory becomes practice.

author: Ian.M
author_rank: Super Contributor
timestamp: December 30, 2021, 01:28:55 pm
content: For a simple 'spot check' of a variable temperature soldering station's temperature calibration, get a small quantity of 99.9% (or better) purity Lead, which should only cost you a few bucks for a 1g sample. Pure Lead melts at 327.5 °C, which is very close to the typical bit temperature used for Sn/Pb solder and not much under Pb-free soldering temperatures. You'll also need flux and wooden toothpicks.First thoroughly clean your bit, wiping off as much solder as possible. Next 'tin' the bit with a sliver of Lead, using plenty of flux, then wipe it all off again. Repeat twice more, (to dilute any residual traces of solder to below 0.1%) then melt a blob of lead on the working face of the bit, and prod it with a fluxed toothpick to check if its still molten, while reducing the temperature. When it goes solid, note the readout, and increase it slightly till it just melts. If there's more than a couple of degrees difference between the two readouts, let it cool again more slowly to refine the reading. You should be able to determine the accuracy of the temperature readout to within a few °C. Afterwards, thoroughly clean the bit, and re-tin it with your usual solder. If you use Pb-free solder, repeat cleaning and re-tinning it three times to reduce residual Lead contamination to below the ROHS limit. Finally, clean up all Lead residue safely!The same process can be used to check the temperature calibration at the melting point of pure Tin (231.9°C) and any known Eutectic solder alloy you have available.

author: PixieDust
author_rank: Frequent Contributor
timestamp: December 30, 2021, 02:27:23 pm
content: Thanks guys, words of reason and wisdom. I think I just got excited by Dave's video having learned a cool new thing and wanted the device to play around with. Apart from soldering iron tip temperature measurement, are there any common thermometer uses around the lab? In other words, how useful is a thermometer in electronics work?I haven't studied JBC very much at all, but what strikes me as odd is that their irons are 40W (whereas my Weller is 50W) yet they apparently warm up faster than anything else. To me that suggests their irons have low heat store volume? But then how do they maintain their temperatures better when soldering as well? Something doesn't make sense. I'm sure they do what the label says, I just don't understand how. But having said all that, I spent probably the whole of 5 minutes looking through their website. I think I'll make do with my Weller for some time to come. May not be the best thing out there but you don't know what you don't know right?

author: tooki
author_rank: Super Contributor
timestamp: December 30, 2021, 02:44:47 pm
content: Quote from: PixieDust on December 30, 2021, 04:29:48 amI wouldn't draw that conclusion at all. If anything, using my $20 el-cheapo tip thermometer, I found the JBCs I tested to be calibratedworsethan the others I tested (like my Ersa).Quote from: PixieDust on December 30, 2021, 04:29:48 amAbsolutely, becausetiptemperature isn't the end goal in soldering: the end goal (aside from producing a good joint) of the process is to get thejointto the needed temperature quickly, without damaging adjacent structures. Tip temperature is but one aspect in achieving that goal.Quote from: PixieDust on December 30, 2021, 04:29:48 amNot at all! IMHO one of the best nuggets of info from that Pace soldering series is the concept of what they call "workpiece indicators" or WPIs. It's teaching you to know what to look for in the process. Watch those videos again with that in mind. They tell you what indicators to look for, and what they mean, so you can figure out how to react.It's exactly like one of my favorite cooking Youtubers, Maangchi, who is very, very good at explaining to viewers what to look for in the cooking process. For example, she'll explain (and write onomatopoeic invented words) what the right temperature of oil looks and sounds like. (As opposed to saying "let your oil reach medium heat", which might be OK for a very experienced cook like me, but not for a novice.) Without using the word, she's explaining workpiece indicators.Quote from: PixieDust on December 30, 2021, 04:29:48 amAnd a thermometer isn't going to help you with that, not one tiny bit.Ian.M's suggestion of melting a metal of known melting point onto your tip is more than enough for determining whether your iron is reasonably well calibrated; a precise calibration is pointless most of the time, since it's generally tip-dependent, and the joint itself dictates at least as much about the temperatures needed as the tip! However, instead of seeking out pure lead, just use aeutectic(single melting point) solder of known melting point. For example, 63/37 leaded solder melts at (and solidifies below) exactly 183C. (Whereas non-eutectic 60/40 begins to melt at around 183C, but doesn't fully melt till around 190C, and vice versa.) SAC305 lead-free solder melts at 217C.But realistically, what will help you is lots of practice with different scrap boards, to see what works, what doesn't, etc. See what happens when you add more solder to an old joint. Add flux to learn its effect. Use a heat gun to preheat a board. Use different tips. Experiment to experience how too high a tip temperature can damage things by overheating or burning them, but that toolowa temperature canalsoresult in damage, because it takes much too long to heat the joint. (This mistake is often made with connectors, where worry of melting the plastic leads people to err low, not realizing that it's much worse to heat the connector for 30 seconds at a low temperature, allowing the plastic to turn to goo, than to use a high temperature to quickly get in and get out, heating the pin before the plastic has time to heat up.)Quote from: PixieDust on December 30, 2021, 02:27:23 pmQuite useful now and then, for example, to characterize how hot a component gets under load. Many multimeters these days have built-in thermometers (for external thermocouples) which are adequate for most purposes.Quote from: PixieDust on December 30, 2021, 02:27:23 pmJBC's standard T245 handpiece is 130W, not 40W. Much of JBC's performance is by a) using thin iron plating on their tips, which allows for better heat transfer and a tighter control loop, but at the expense of shorter tip life than many competitors, and b) allowing more overshoot than some other brands.Quote from: PixieDust on December 30, 2021, 02:27:23 pmTheir tips have reasonably high mass, and it's the 130W that makes them heat so quickly.

author: PixieDust
author_rank: Frequent Contributor
timestamp: December 30, 2021, 03:42:42 pm
content: I guess I'll buy some pure lead to figure out how well calibrated the station is at around the most widely used 330C to be happy and start practicing soldering. I don't think I'll need temp characterisation any time soon but at least I know what to get if or when I need it.

author: Ian.M
author_rank: Super Contributor
timestamp: December 30, 2021, 03:54:19 pm
content: I suggested pure Lead to get a calibration point near the usual working temperature. Pure Tin would be around 2/3 of that relative to room temperature), and most Eutectic alloys even lower, which is less than ideal as if the slope of the transfer function (between sensor and readout) is incorrect the absolute error will vary with temperature. Ideally you'd do a two point calibration, and would hope to find the same error at both temperatures. However the cost and inconvenience of obtaining pure metal samples may put you off the idea.As Tooki pointed out, even a single melting point check with whatever near-eutectic solder alloy of known composition you have on hand, will easily tell you if the temperature readout is 'in the ballpark', which is likely to be good enough for most purposes.A further question if you invest in a budget soldering tip thermometer, is how do you check your new gadget is properly calibrated? Precision high temperature thermometry can be a world class metrology rabbit hole!

author: Shock
author_rank: Super Contributor
timestamp: December 30, 2021, 05:46:22 pm
content: A well regulated station and you can compare thermocouples to a couple of degrees celsius. It's a lot of messing about though as Joes video shows.I've wasted a bit of time getting repeatable measurements so I know my clone tip thermometer is accurate (well enough for me) but only if you use a stable technique. When I got my Pace stations a few years later, again got comparable and reproducible measurements.

author: Shock
author_rank: Super Contributor
timestamp: December 30, 2021, 06:38:27 pm
content: Forgot to mention thermocouples give off their thermoelectric voltage so a decent multimeter with mV and uV can compare thermocouples, and if dissimilar type you can cross reference their charts. To check if the tip thermometers are in cal they are likely feeding in a few reference voltages.But anyway, just pointing out it can be done fairly cheaply, ghetto lab style.

author: PixieDust
author_rank: Frequent Contributor
timestamp: December 31, 2021, 04:12:39 am
content: From what I've seen, the errors at various points in the soldering iron temperature range aren't the same, but yes, a two point measurement would better than just a single with pure lead.My multimeter doesn't have a temperature function unfortunately, but measuring thecurrentvoltage and comparing to tables is a good idea! Why didn't I think of this?

author: PixieDust
author_rank: Frequent Contributor
timestamp: December 31, 2021, 04:49:18 am
content: Quote from: Ian.M on December 30, 2021, 03:54:19 pmI think for the purposes of measuring a soldering iron tip, going down the rabbit hole is unnecessary.