Soldering this specific FPC connector and heatgun safety question - Page 1
Forum section: electronics / beginners

author: __stdcall
author_rank: Newbie
timestamp: December 21, 2023, 07:41:25 pm
content: Hey there!I want to solder this specific FPC connectorhttps://www.digikey.com/en/products/detail/jae-electronics/WP7B-S050VA1-R8000/7917434I have no prior experience with SMD soldering and always bought myself out of it by using more expensive and bigger through hole parts, but this time I can't.I still can use youtube though and studied some videos about soldering those connectors.Now I get the feeling this one is different than the common Samsung/Apple FPC connector type as its legs are shorter than in those videos - or I'm holding my microscope wrong. (I have attached a photo of it)They barely reach behind the plastic enclosure and are basically not exposed to the PCB anywhere reachable where I could get a soldering iron positioned. What is this - 0.1mm?Also almost everyone uses a heat gun to solder this in those videos.So I guess I will need a heat gun?I did search for some and the 858D was mentioned a lot here. I was looking through Amazon, but the results were pretty devastating.Here in the Forums and in the Amazon Reviews they were torn apart because they were not properly shielded/grounded or they fry themselves at too hot temperatures or simply start to melt inside the station.I honestly don't really want to spend 100-250$ to solder a connector. And I don't want to die yet.30-50$ would be fine for me if I can use this for a longer time, but I don't have the knowledge to fix a bad connected heatgun.What are my options? Is a small soldering iron tip still a possibility, or should I rather get a hot air gun? What about a heat plate instead?I know starting SMD soldering with this connector is maybe not a great start, but I have enough patience with me (and 10 connectors to try).Solder paste, Flux, Microscope, Pinecil (with different tips) is what I have right now.Thanks a lot in advance!

author: u666sa
author_rank: Frequent Contributor
timestamp: December 21, 2023, 08:46:42 pm
content: STS Telecomhas videos on how to solder this connector. Also,NorthridgeFix. But the way I understand it, you have bare PCB, no solder on contact on PCB. I would do it using solder iron.You would apply some, very little flux to contacts on PCB. Place connector. Apply it on each side so it is straight. Then do the rest. All under microscope.

author: __stdcall
author_rank: Newbie
timestamp: December 21, 2023, 09:10:59 pm
content: Thanks a lot for the swift response!Do you mean this video here?I have seen this video already, but maybe it's simply the camera angle why the legs look longer on this connector for me. He does indeed also use the iron to solder.I will try to use the iron first and if I can't get it done I might get the TOOLCRAFT ZD-8908 which is available in a store very close to me. 55$ is bearable.At least according to the ratings, it does not kill me for no reason, and maybe I can use it for other things in the future such as shrink tubing or desoldering components.What do you mean with "no solder on contact on PCB"?It's a two layered PCB I designed myself, but built by a pcb manufacturer. Ordered it without a stencil as it looked pretty easy to tin the pins myself with added Flux.It's simply a breakout board for the connector, leading to 2.54mm headers.

author: u666sa
author_rank: Frequent Contributor
timestamp: December 21, 2023, 09:15:16 pm
content: Quote from: __stdcall on December 21, 2023, 09:10:59 pmLook at NorthridgeFix shop, he has cordless mini iron. His shop is BS, aliexpress resale. I've seen this same iron, only not red, for 2000 rubles, about $20 USD. So look for youtube video on teardowns and review of his iron and aliexpress. Idea is that it has smaller about 1/2 cartridges. Plus you often need a cordless iron. Good thing to get.But yea, I would add, no special Iron is needed. Regular iron, smallest cartridge. Flux. Pin by pin. If they stick, use solder wick. It's doable. In fact I prefer this method to heat gun.If you want to use heat gun. You should add solder to pads, then heat the board before placing connector. Then add flux. Then place connector and "touch it" so it would float into solder. But keep in mind Apple has chips and stuff that can stick balls or kill baseband. I never user this method. Ever. Only to take things off from donors.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: December 21, 2023, 09:58:28 pm
content: Hot air will be your best friend one day. Go ahead and get a decent hot air rework station.I like a bevel tip for doing my touchup work. Do not go with the "smallest tip". These don't heat up well. The large bevel can still work on small components. To make it easier, make the pads longer than they need to be. This will allow you to touch the bevel to the pad and melt the solder under the component.The advantage of the heat gun is that your component will float on the solder and the surface tension of the solder will help align the component. Lightly tin the pads before you start. The bevel iron is real good for this. The a light layer of flux (as suggested). Be very careful with the "float touch" but it will help you know when everything is melted properly. The component will "snap back" into alignment. Tap it too hand and no bueno. Be very careful not to dislodge neighboring components when working with hot air.These things are designed to be hot air soldered. Just don't linger too long. Don't use too low of a temperature. Hotter is better in many cases. This way you don't linger too long. Try to preheat your work area a bit.

author: __stdcall
author_rank: Newbie
timestamp: December 22, 2023, 02:42:56 am
content: Alright, thanks a lot for the very helpful and extensive answers!I think I'm more confident now and properly equipped to get it done.I guess the small size of those components scared me off a bit, but I think I will gain a lot in the future by learning it.

author: __stdcall
author_rank: Newbie
timestamp: December 29, 2023, 01:43:13 pm
content: Success!I've failed miserably with the iron, got a heat gun and this worked after a few retries (300°C, ~20% air).I think it's a bit rotated, but the pins seem to have contact, so I'm fine with it.Thanks a lot again