Is a tiny IC chip easily destroyed by soldering? - Page 1
Forum section: electronics / repair

author: lame man
author_rank: Newbie
timestamp: March 16, 2021, 06:45:24 pm
content: I'm a novice to electronics. I have tried and failed to build an amplifier circuit using five new chips. I am trying to build a basic amplifier circuit around the Texas Instruments LM 4862 amplifier chip. It consistently fails to produce any output. Is it possible that each time I am burning out the LM 4862 chip while soldering? The soldering iron temperature is set at 510° Fahrenheit. The circuit schematic is found in my attachment "03_12_2021 Schematic LM4862..." Any reply would be appreciated.03_12_2021 Schematic LM4862 amp circuit.pdf(30.19 kB - downloaded 133 times.)

author: ataradov
author_rank: Super Contributor
timestamp: March 16, 2021, 07:17:49 pm
content: SOIC-8 is not that small. It all depends on your skill.Show us the pictures of the assembled board and how exactly you are testing it.

author: lame man
author_rank: Newbie
timestamp: March 16, 2021, 07:50:12 pm
content: It is assembled as faithfully as possible with the included schematic. My test was that it should do what an amplifier does. Music from the audio-In portion should be heard in the audio-Out portion - even better it should be amplified. There is no sound whatsoever coming out of the circuit.

author: ataradov
author_rank: Super Contributor
timestamp: March 16, 2021, 08:00:07 pm
content: It is hard to tell what "as faithfully as possible" means. May be your "possible" is not good enough.What other components did you use? Do you have a PCB or how was it assembled? How do you power the circuit?You need to provide more information to get a useful answer.

author: lame man
author_rank: Newbie
timestamp: March 16, 2021, 08:24:56 pm
content: You're long on attitude and short on useful information.

author: ataradov
author_rank: Super Contributor
timestamp: March 16, 2021, 08:25:37 pm
content: Are you serious? Ok, then. Seems like not every reply is appreciated.The answer to your question - no, those chips are not easily destroyed by soldering. I personally have not destroyed a single one and I have been soldering for a long time.

author: Microdoser
author_rank: Frequent Contributor
timestamp: March 16, 2021, 08:37:44 pm
content: Quote from: lame man on March 16, 2021, 08:24:56 pmActually, this seems to apply better to yourself.Ataradov simply asked you for the very minimum of information in an attempt to help you. It may well be that you have not connected something correctly or you failed to connect something important or you have not supplied the right sort of power to the circuit and have blown 5 chips that way. Posting a schematic does not help someone figure out what is wrong with your real world circuit.It is far more likely that something is wrong in how you have reproduced the schematic in the real world than exactly the same soldering issue happens to five chips in a row.If it is somehow the soldering, without seeing an image of that soldering it is almost impossible to say whether that is the problem or not.As you say, you're long on attitude and short on useful information.

author: bdunham7
author_rank: Super Contributor
timestamp: March 16, 2021, 08:39:41 pm
content: Quote from: lame man on March 16, 2021, 08:24:56 pmThat would be you!If you want help, we need information. A photo of both sides of your board (is there a board??) and an explanation of your power source, input source and output device would help. Is there a reason you can't provide that? A quick look and someone here may spot the problem.As for soldering, unless you are using a propane torch or an induction soldering gun, you are unlikely to have ruined 5 in a row...

author: Gyro
author_rank: Super Contributor
timestamp: March 16, 2021, 08:44:06 pm
content: Quote from: bdunham7 on March 16, 2021, 08:39:41 pmUnless you bought them from aliexpress - many sellers offer a pre-torching service.

author: BrokenYugo
author_rank: Super Contributor
timestamp: March 16, 2021, 09:20:25 pm
content: Not about the temp really, it's more about the time you sit on the joint soaking heat up the leads into the package, joints that fine should be made nearly instantly, under a second. 510/265 is kinda low really, depending on the iron/station and solder alloy in question. Are you using extra flux?

author: lame man
author_rank: Newbie
timestamp: March 16, 2021, 09:46:01 pm
content: Hey Microdoser. The same goes for you. Ya feel good that you are many?

author: lame man
author_rank: Newbie
timestamp: March 16, 2021, 09:47:22 pm
content: Hey bdunham7. The same goes for you. Ya feel good that you are many?

author: ataradov
author_rank: Super Contributor
timestamp: March 16, 2021, 09:47:40 pm
content: I don't get why are you insulting people that ask valid questions. What do you want from us?

author: m3vuv
author_rank: Super Contributor
timestamp: March 16, 2021, 09:55:18 pm
content: who is this ungratefull twat that asked the question,asks for help wont answer basic valid questions then insults people,what a prat!!

author: JohnnyMalaria
author_rank: Super Contributor
timestamp: March 16, 2021, 09:58:15 pm
content: Quote from: lame man on March 16, 2021, 06:45:24 pmPlease provide photos of your board.

author: DrG
author_rank: Super Contributor
timestamp: March 16, 2021, 10:39:45 pm
content: Quote from: lame man on March 16, 2021, 09:47:22 pmHey, chill out a bit eh? Nobody here feels good that a newcomer and a novice is having a hard time.The temperature of 510 F isNOT, IMO,so hot that it would burn out the chip [EDIT looking at the data sheet - assuming I looked correctly, it IS too hot,but it depends on whether you are holding the iron on the chip for a really long time (as was mentioned.There could be lots of other reasons why things are not working.So, for example, I have had novice friends solder a small chip like that and not even notice that the solder was bridging more than one pin...and when I say "friends", I mean that I have done it beforeYou could have made a mistake on how the pin is numbered - that has happened to many people at one time or another.Attaching the schematic was a really good idea.The reason folks want a picture is so that they can see if there are problems that you have not seen - that happens all the time.

author: GodIsRealUnless DefinedInt
author_rank: Contributor
timestamp: March 16, 2021, 10:44:58 pm
content: Might be a bit of an obvious to some, but have you actually downloaded the data sheet and looked for the Soldering information for the IC?

author: DrG
author_rank: Super Contributor
timestamp: March 16, 2021, 10:54:11 pm
content: Quote from: GodIsRealUnless DefinedInt on March 16, 2021, 10:44:58 pmI did just now:Vapor Phase (60 sec.) 215°CInfrared (15 sec.) 220°C220 is 428F and he was using 510F - now I want to change my answerMaybe he was burning them all up. Lame Man come back - I'm sorry....https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjnzav09LXvAhWfGFkFHcFFCy0QFjAAegQIARAD&url=https%3A%2F%2Fwww.ti.com%2Flit%2Fds%2Fsymlink%2Flm4862.pdf&usg=AOvVaw2ryYWJ1EgusRkQgocugJsv

author: james_s
author_rank: Super Contributor
timestamp: March 16, 2021, 11:05:49 pm
content: I wonder if the OP is someone who got banned previously and showed up just to troll people? Seems like an odd thing to do, but I'm having a hard time thinking of another explanation.

author: Microdoser
author_rank: Frequent Contributor
timestamp: March 17, 2021, 01:53:09 pm
content: Quote from: lame man on March 16, 2021, 09:46:01 pmSo, are you going to give us the information we need to help you or are you just going to give us attitude?It's totally up to you how things go forward from here.Pro Tip: If you get the same response from many people it is more likely a valid response to how you are being towards them than they all decided beforehand to respond in the same way...Post us an image of the constructed board, then we can see if there are any issues with it.If you made the board perfectly and soldered perfectly then your board works perfectly, problem fixed

author: DrG
author_rank: Super Contributor
timestamp: March 17, 2021, 02:27:18 pm
content: Quote from: james_s on March 16, 2021, 11:05:49 pmSpeculation. A set up...entrapmentI have no idea.I entered the thread late, but was suspicious. An admitted novice with a schematic and thorough resistance (especially to posting a pic)....and 5 IC losses (hey, I would have stopped at 3). What immediately came to mind was all of the novice mistakes - and everybody is or has been a novice.My two soldering irons are set at ~290-300C. The solder I use flows well there and I have not had any problems and, honestly, can't remember toasting a chip for that reason (or lifting a trace or anything like that). But, I am a hobbyist and I do a limited amount of soldering and with a limited amount of ICs. When I read his soldering iron temperature, I discounted it as the problem....because it was lower than what I was using..and that was an error.Speaking for myself only, I should have checked the data sheet....and here is the thing...before I posted, I did pull up the data sheet...and I went immediately to the end of the document where I have, so often, seen the graphs with the ramp time and hold time and so on - I didn't see them there, where I was expecting to see them. Also, I do not have an oven and have never made use of such graphs.It was not until it was explicitly mentioned that I went and looked again. The temperature of his soldering iron was above the maximum limits and I should have seen that earlier. So, for me, regardless of the OP's motivation, it was a lesson learned and, hopefully, remembered.

author: ataradov
author_rank: Super Contributor
timestamp: March 17, 2021, 03:55:04 pm
content: Those temperatures don't really matter for hand soldering.I think it was just a troll. People have all sorts of mental issues.

author: bdunham7
author_rank: Super Contributor
timestamp: March 17, 2021, 04:11:26 pm
content: Quote from: DrG on March 17, 2021, 02:27:18 pmThere's a lot of difference between irons and ovens. My iron is typically set at 350C and I like to be quick, but I also like my work to look nice so I usually go for a thorough flowing--and I don't burn up any chips. Even the few times I use hot air, I pretty much just roast them on until they look nice.

author: DrG
author_rank: Super Contributor
timestamp: March 17, 2021, 04:38:14 pm
content: I don't know what is going on with the OP and I don't much care - if he wants to come back and has an interest in getting help, that would be great. If not, that is his choice....and it would be hard to get help if you are that "autoreactive".I don't want to start a big argument, but here is the problem I have with the situation.My own experience is that I never hold the iron on there for 60 seconds or even 15 seconds. Plenty of flux, tin the tip, soldering tip on the pad, hit it with the solder and it flows right away, and that's it - maybe 3-5 seconds. As I said, I don't ever recall toasting a chip for over heating - if it gets bricked, it is because I did something else wrong and that I, eventually, figured out what it was that I did wrong. I am usually using a carrier board for smt and have hand soldered several SOIC8 and even a few smaller.These are the 'Absolute Maximum Ratings' from the data sheet.Now, I am not saying, speak to me like I am a 5 year old, or whatever that ^%$#ing acronym is, but instead, speak to me like I am not an EE (I'm not). But, I just looked at some chips that I did solder and I don't see one with a soldering temp AMR that low.Do you really want to say that Absolute Maximum Ratings can simply be ignored? Do they just make up crap and put it in there - of course not and I don't think that you would say as much.Nevertheless, he reported using a soldering iron temp significantly higher than the AMR. Granted, I may not appreciate the qualifications of "vapor phase" and "infra red", but I can see when one temperature is above another.

author: bdunham7
author_rank: Super Contributor
timestamp: March 17, 2021, 05:09:57 pm
content: It's ELI5--Explain Like I'm 5.Vapor phase for 60 seconds @215C is going to heat up the whole thing to 215C. If you solder 1 pin for 5 seconds with a 350C soldering iron, the thermal resistance between the iron and the pin as well as the heat-absorption of the melting solder will probably limit the pin temperature to 250C or so. That heat would then have to travel up the bond wire or through the package to heat up the chip. So the whole thing doesn't get anywhere near the iron temperature unless your technique is extraordinarily poor.215C does seem low for a ROHS-compatible process, but this chip is probably old enough that the original version was non-ROHS. Perhaps nobody thought to update that section of the datasheet. I doubt the OP using lead-free solder with an iron set to 510F.

author: ogdento
author_rank: Regular Contributor
timestamp: March 17, 2021, 07:01:30 pm
content: Regardless of the impetus for the initial post... I've wondered how much heat the chips I work with can tolerate during soldering/desoldering - with air or an iron - so the information you guys provided was very helpful. Thank you!...and I really like DrG's avatar.

author: TheMG
author_rank: Frequent Contributor
timestamp: March 17, 2021, 07:03:37 pm
content: Please post a clear detailed picture of your circuit as assembled!Pretty difficult to kill a chip such as this while soldering, you'd have to really keep the soldering iron on it for quite a long time, and/or have a very excessively hot iron.

author: Gyro
author_rank: Super Contributor
timestamp: March 17, 2021, 07:13:06 pm
content: Quote from: TheMG on March 17, 2021, 07:03:37 pmIf you check the OP's status, that's not going to happen.

author: DrG
author_rank: Super Contributor
timestamp: March 17, 2021, 10:36:12 pm
content: Quote from: bdunham7 on March 17, 2021, 05:09:57 pmThanks much. Good explanation as far as I can tell. You have some estimation and speculation but it seems completely reasonable. - I appreciate it.