Soldering questions and opinions - Page 1
Forum section: electronics / beginners

author: alin_im
author_rank: Regular Contributor
timestamp: December 18, 2015, 06:11:40 pm
content: Hey guys,Quick questions:What is the temperature used for soldering (60/40 solder and lead free solder) ?What is the maximum time that you apply heat on the components so you do not damage them ? ( SMD and throw hole work)Do you think the heating element of the soldering iron will be damaged if it is used more then 2 hours ?How often do you change the soldering tip ? (Answer based on how much you use it)I know that are tones of articles about this on internet but I wanted your opinion !Alin I.

author: aaronhance
author_rank: Regular Contributor
timestamp: December 18, 2015, 06:32:59 pm
content: Quote from: alin_im on December 18, 2015, 06:11:40 pmRead the datasheets for the solder and for the components, not everything has the same specs. I have also noticed some components have a limit to the time they can be out of their packaging(moisture related?) before they can't be soldered.

author: mariush
author_rank: Super Contributor
timestamp: December 18, 2015, 07:39:25 pm
content: alin_im , watch at least the first few episodes of this series:https://www.youtube.com/playlist?list=PL926EC0F1F93C1837The videos look dated, but the information is still valid.Also see Dave's own soldering tutorial videos, here's part 1 and 2 :andhere's some answers to your questions.1. 60/40 melts at around 180c . the better 63/37 melts at 183c, exactly, as it's euctetic (doesn't have a semi-liquid state between liquid and solid like 60/40). Lead free solder has a melting temperature of around 217c.These temperature don't matter, as the temperature of your iron tip will depend on the thickness of the pcb and/or the thickness of the leads you solder, it depends on how much heat parts you want to solder will absorb. You would adjust the tip temperature at a higher value, I would say around 250c for small SMD stuff, 300-350 C for through hole parts, wires, DIP packages etc.2. the maximum time will depend on the parts and how sensitive they are. Some parts like LEDs , infrared sensors , optocouplers etc are more sensitive to heat, others are less sensitive. With some parts you have to be more careful as they absorb moisture in time and can blow up if you solder them with too much heat.Also, the first couple of videos in the Pace playlist I linked to above will explain how you're supposed to solder, how much time the tip is supposed to touch parts and other valuable things.3. it depends on the heating element and the soldering station and the temperature. Some stations "idle" the tip at much lower temperature as long as it sits in the iron holder and boost the temperature to preset temperature as soon as you lift the iron.In some factories, they run the soldering irons for the full work day without worrying about the tips, as they're cheap enough to be replaced when used too much, without decreasing their work efficiency.

author: Ian.M
author_rank: Super Contributor
timestamp: December 18, 2015, 08:54:50 pm
content: The Weller 50W Magnastat TCP series irons were supplied with a PTAA7 Sloped (chisel) Tip, 1.6 mm, 700° F (370° C),, as standard. Tens of thousands of TCP irons have been run all day, every day five or six days a week with a PTAA7 bit doing Sn/Pb assembly and rework on both SMD and through hole boards. If the iron is in frequent use, the tip stays in reasonably good condition till the iron plating wears through. However if its left hot and unused, it can oxidise badly in a few hours and be difficult to clean and re-tin. Turn it off if you go for lunch! Due to the Magnastat mechanism, the temperature could not significantly exceed the Curie point of the ferromagnetic alloy pellet on the shank end of the bit, (unless the switch failed) so the accuracy of the bit's fixed temperature was typically better than most uncalibrated variable solder stations.With skill and experience a hot iron (within reason) lets you get the joint made faster with less heat transfer to the component. I never had any issues except when trying to salvage the most delicate parts. Too cool an iron can actually cause worse heat damage, because there is less temperature differential across the very small contact area with the lead and track, so the joint heats up to soldering temperature more slowly and a greater length of the track and component lead inside the package heats up so the device spends more time above its maximum rated continuous storage temperature.PTAA6 600° F (315° C) bits were too cool for general through hole work, requiring excessive dwell time on each joint.

author: dom0
author_rank: Super Contributor
timestamp: December 18, 2015, 09:10:30 pm
content: Quote1 REALLY depends on the iron (and the tip). You'll need higher temperatures with cheaper systems (larger thermal mass), because you basically "discharge" the thermal energy from the tip into the joint and "recharge" the tip while not making a joint. For leaded work with one of these irons you'll want to use ~300 °C, for leadfree work ~350-400(!) °C. But with a better iron and station you can go much lower. I use 63/37 solder and a Weller WSP80 (DIY station) and my normal working temperature is just ~250 °C.2 Typically <1 second per pin at a time. Most parts have an exact spec on this. Most parts also don't really care. With precision parts and LEDs you want to take care, these two don't really like heat3 Absolutely not.4 Every few years maybe? I exchange more often, different tips and so on, but replacing a tip... yeah, definitely years. Daily or every other day use between maybe an hour up to day-long sessions.

author: janoc
author_rank: Super Contributor
timestamp: December 18, 2015, 09:38:18 pm
content: Quote from: alin_im on December 18, 2015, 06:11:40 pmI am using around 280-320C for the 60/40, depending on the size of the part I am working on. However, take those temperatures with a large grain of salt - few soldering stations are precisely calibrated.Quote from: alin_im on December 18, 2015, 06:11:40 pmDepends on the component - usually 1-2 seconds max. 3 seconds is commonly considered a maximum soldering time. For through-hole components you can always hold the leads in tweezers or clip a crocodile clip/forceps on them, that will help to act as a heatsink and take the heat away from the die. However, better learn to solder properly - you shouldn't need more than a 1-1.5s per joint.Quote from: alin_im on December 18, 2015, 06:11:40 pmNo. Unless it is some sort of el-cheapo Asia/eBay crap or you have the temperature turned up to the maximum.Quote from: alin_im on December 18, 2015, 06:11:40 pmI swap tips quite often - but not because they are worn out. I sometimes need a different size for different tasks. I am a hobbyist using leaded solder and not soldering for many hours every day - and I haven't worn out a tip on my irons yet despite having them for years now. Good quality tips will last you a very long time.With lead-free solder it is worse, lead-free can literally "eat" tips. But you should still expect at least a few months of use, even with very heavy use for many hours every day.Of course, it also depends on the type/shape of the tip - very fine tips will wear out faster than larger ones, obviously

author: Alfons
author_rank: Regular Contributor
timestamp: December 18, 2015, 10:13:07 pm
content: As already mentioned, the whole very dependent on the components used, and especially from the PCB. 1-3 seconds might apply to very fine conductors or SMD chip, but it is impossible to solder at this time components in a multi-layer PCB when to come even ground surfaces. That could in that short time only at a very high temperature and then the flux would evaporate too quickly. For soldering it needs some experience, because too different are the conditions. But you learn that quickly. To put it briefly: I have not yet managed to destroy a component by soldering. And the soldering tip: I have that here, who are 10 years old and still OK.

author: alin_im
author_rank: Regular Contributor
timestamp: December 18, 2015, 11:08:11 pm
content: My soldering iron model is a HAKKO 888D, I use the stock tip for through hole and I have another one that is fine for SMDs. I was thinking about buying an WEP 858D hot air rework station (now I am looking at Dave's video review) for SMDs instead of using the iron, because I am at the beginning with the SMD work and I tend to leave the iron tip on the component too long ( about 3 seconds).Thanks for the reply, I usually have my iron at 320 degrees and I usually work with lead free solder.If I leave my iron on and I do not use it ( I check continuity or something- 5 minutes ) I always leave a blob of solder on the tip, and when I need to used it I clean the blob.My usual working time with the iron is about 1 - 1:30 h.

author: janoc
author_rank: Super Contributor
timestamp: December 20, 2015, 12:26:23 pm
content: Quote from: alin_im on December 18, 2015, 11:08:11 pmBlob of lead-free solder to eat the surface of the tip faster?The blob will help only against oxidization, but I think a better precaution is having a sleep mode on the iron when you put the handle down for a while. E.g. my iConn Nano will reduce the temperature to 250C after a few minutes and after 10min or so it goes down to 50C. The sleep in 250C is basically completely unnoticeable during normal use because the iron heats up almost instantaneously as soon as you pick the handle up and before you arrive to the place where the soldering is to be done.

author: KL27x
author_rank: Super Contributor
timestamp: December 20, 2015, 07:25:40 pm
content: QuoteToo cold, and it takes too long to flow a joint. Too hot, and the solder on the tip dries out faster than necessary. The right temp for a given job depends on what kind of soldering. For assembly, you might want the minimum temperature where you are making fast joints without waiting for the solder to melt. For repair work or experimenting you might do with even lower temp, where a bit of waiting for the solder to flow is ok, because your solder duty cycle is like 1% soldering and 99% testing/trouble-shooting.