to much heat when soldering - Page 1
Forum section: electronics / beginners

author: honken
author_rank: Newbie
timestamp: November 04, 2012, 04:00:36 am
content: Hello.Is it possible when using a cheat soldering iron to damage ICs (mainly pic 555 and 4017).Reason why i ask is that im trying to finishhttp://www.555-timer-circuits.com/knight-rider.htmlthis project.I have it working on a breadboard, but when soldering it with my cheat soldering iron it never works.So them im thinking if its the heat of the soldering iron that may be damaging the ICs and/or the resistors/capacitator.If needed i can take a picture of the soldering i made and show, perhaps i forgot something.Cheershonken

author: fazz33
author_rank: Newbie
timestamp: November 04, 2012, 04:14:34 am
content: Hmm if your not practised in the art of soldering your solder joints may just not be connecting (I believe the term is a cold solder joint) grab a multimeter and check continuity between connections. Otherwise I a good rule is to not have the iron on for no more than a 2 or 4 after you got your solder flowing. But if for some reason the parts are super sensitive I'm going to suggest buying IC holders for your chips.But nothing beats practice so if you feel up for it make a very simple LED lighting circuit and practice soldering that. I doubt it's your cheap iron. I'm using a 20 dollar iron it's not great but it's not destructive. I have burned parts on it but I was being stupid and I left the heat on for way too long.

author: psycho0815
author_rank: Regular Contributor
timestamp: November 04, 2012, 03:00:37 pm
content: Most ics can actually withstand quite a bit of heat. So unless your frying the thing for 20 secs or so you should be ok. If unsure, just solder only 1-2 pins at a time, andCAREFULLYtouch the chip in between. If it gets to hot too touch, let it cool before you continue.Just to be clear, i wont be held responsible for any burns. I f your skin peels off, your way past a comfortable temperature.

author: sacherjj
author_rank: Frequent Contributor
timestamp: November 04, 2012, 03:10:41 pm
content: The 555 and 4017 should be able to handle some heat. I would worry about cold solder joints as others have said and also solder bridges (joining two things that shouldn't be with using too much solder).

author: G7PSK
author_rank: Super Contributor
timestamp: November 04, 2012, 03:38:50 pm
content: If you are worried abot the chips use a socket, but the problem is far more likely to be a cold joint or wrong connections. I know that I have misplaced wires when going from a bread board or prototype to the final circuit, I don't suppose there is any one on this forum that has not done something like that at some time,as they say to ere is human.

author: Jeff1946
author_rank: Regular Contributor
timestamp: November 04, 2012, 10:30:33 pm
content: If you soldering technique is ok, maybe your soldering iron is leaking AC to the tip and zapping (most likely the 4017) a chip. I would connect a 10k resistor between ground and the iron tip and measure ac voltage across it Try just wiring up the 555 and see if it is pulsing.

author: ejeffrey
author_rank: Super Contributor
timestamp: November 04, 2012, 11:05:11 pm
content: Overheating is also generally cause by a too cold/weak soldering iron, reason being it takes so long to melt the solder the rest of the chip has time to get hot. In general, overheating is more of a problem for degrading performance of things like precision resistors and plastic film capacitors. Most ICs can handle heat pretty well. If your circuit is completely not working I would suspect cold solder joints or leakage current frying the CMOS device.

author: ejeffrey
author_rank: Super Contributor
timestamp: November 04, 2012, 11:10:55 pm
content: One more thing, the worst are those cheap low power unregulated direct plug-in irons. When idle they can get plenty hot: hot enough to oxidized the tip badly and keep it from making good thermal contact. As soon as you start to work with them, they cool down because they don't have enough power to melt the solder quickly. It is a sure-fire way to get cold solder joints.

author: SLJ
author_rank: Frequent Contributor
timestamp: November 04, 2012, 11:53:10 pm
content: If you are new to soldering here's a quick 6 minute how to video:http://store.curiousinventor.com/guides/How_to_Solder

author: george graves
author_rank: Super Contributor
timestamp: November 05, 2012, 09:53:56 pm
content: Sometimes I take a paper towel, place it on my workbench, and add a few drops of distilled water to it. Then I place the board on it, with the chip on the wet paper towel. Haven't had any issues with that.But as someone above said, a hotter iron means less heat soak to the chip.