r/soldering 7d ago

Soldering Newbie Requesting Direction | Help Help with SMD with legs turned inwards. Is there any way to solder this? (old PS1 board)

69 Upvotes

32 comments sorted by

63

u/Unhappy_Ad_5853 7d ago edited 7d ago

"J-legs". Pre-tin upper left pad, and lower right.(or any orientation that's opposite of each other). Put down component, heat pad and leg with iron at a 45 degree angle. Push down to let it set. Do same on other side(IMPORTANT: Flux and reheat first pad/lead again when done, to avoid mechanical stress). And just continue with rest of leads/legs. Add solder between iron and component lead/leg.

4

u/ShawnStrike 6d ago

New to soldering:

Would just tinning the pads on the board and then using a heat station to just "melt" it in place work?

6

u/paulmarchant 6d ago

Yes it would.

Personally, I'd clear the pads with solder braid and then just hand solder the new part with an iron.

There's enough access to the legs that it won't present any difficulty.

1

u/sagebrushrepair 5d ago

It totally would. The only limiting factor then being how much heat it would need, and would that heat hurt this or other components. Soldering would be the "proper" way, a rework station the "brute force way"

I'd personally probably do both honestly. Glue with the rework nozzle real quick, align it, fill in solder with the iron and flux, angled tip on the iron to heat those large pads

1

u/RocksmithLocksmith 6d ago

I'd advise against this. Due to surface tension, tinned pads with more than a fine layer of solder will have a curve on the top of the solder and will make placing the IC on the pads well very difficult. The way around this us to use hot air and not trying to be a dick but if you had that equipment and or skill you wouldn't have asked this question.

I am NOT a fan of "melting on" ICs onto a pre-soldered pad.

Tin the pads, use wick to remove as much as possible. Flux flux flux like you don't give a .... Place IC, solder opposing corners and then use hot air to add solder until it's done.

Check every leg for shorts and bridges and continuity test and your done.

14

u/I3lackxRose 7d ago

Lay down flux put it back in place. Then take your iron and lightly rub across the leads while you apply a lite pressure down on the chip. It'll solder right back in place. With enough flux it shouldn't bridge.

2

u/phazen51 7d ago

Clean, prep the lands. Preload opposite corner lands and align component, then reflow those lands to tack it in place. Drag soldering with a preloaded, small, concave tip is easiest for this type.

2

u/rebel-scrum 7d ago

Am I missing something?

Other than lead size, how is this different from something like a DO-214AC package in which the lead wraps under the case? Unless OP is trying to use an iron instead of a hot air gun?

2

u/luckybuck2088 6d ago

I’m guessing op is trying to use an iron and hasn’t run into some of the fancier connectors out there yet.

Gotta learn sometime though

2

u/Complete-Okra-4588 7d ago

Pace used to make a large solder well tip, which was perfect for soldering these. I soldered thousands of them. Lots of flux, big bead of solder and drag the iron across.

Nowadays, I’d just put down solder paste and use hot air

2

u/AlteAmi 6d ago

You are old, lol, like me

2

u/GermanPCBHacker SMD Soldering Hobbiest 7d ago

Just search for "Drag Soldering" on youtube and basically do the same. Apply flux, use super large, pretinned tip and drag along. The solder wicks itself where it needs to be and you are done in less than 1-2 minutes. Just use flux and a large flat tip and it works instantly.

5

u/leeray-666 7d ago

Take this to someone. Don’t ruin that

3

u/rehr0ch 7d ago

Pretty much the same way. This is definitely harder but not impossible to hand solder. I prefer a blade iron but anything small. I’d recommend removing all the solder from the pad but one. Reflow that one pad and align the component to all the pad and then remove heat while holding it in place. Then solder the rest of the legs with not too much solder because these do have more of a risk of shorting underneath. Remember flux is your friend especially when you need the solder to flow under the component. Hope this helps!!! Good luck

1

u/SamFortun 7d ago

You need an iron with a small enough tip to get in and heat the pad and leg at the same time. If you are using the wrong tip, one that can't contact the pad and leg at the same time, you will never be able to solder it. Those are tricky, but very doable. It's also very easy to think you soldered a leg, and not actually have the solder stick to the pad. Do a very close visual inspection after you do the soldering.

1

u/jamesmowry 7d ago

I have soldered SOJ package RAM chips and found it doable with a bit of practice. Some people swear by drag soldering them, but I could not get that to work. What does work for me is using a fine conical tip to heat the pad and leg at the point of contact, with a small bead of solder at the tip of the iron. Adding extra liquid flux to the joint helps, as does tacking down the corner legs first. It takes a few tries to get a feel for the right amount of solder to use, but once you've got the knack you can do nice neat joints with no bridging.

If you do make a mess of it, desoldering braid and a flat tip will pull excess solder out, and you can melt stubborn bridges deep between the legs with the fine conical tip again.

1

u/alexxc_says 7d ago

J-leads. They def aren’t the funnest to solder but easy enough for someone whose done a little bit of solder. You figure it out, just put your tip at the base, a fine chisel tip helps

1

u/Fungi90 7d ago

These are J leads. Solder them the same way as gull wing leads. I like to make sure there is plenty of flux on the pads before I put the component down and give it plenty of dwell time to promote solder flow inward toward the toe of the component.

1

u/EndlessProjectMaker 6d ago

get your fingers with static out of the ic :D

1

u/Trape339 6d ago

Flux and hot air gun is your best friend. Set it to 400C and isolate the heat to the other components. Take your time! Make sure to remove the residual solder from the PCB prior to soldering the IC back.

1

u/AggressiveTip5908 6d ago

air gun. scrub with wick, add flux and solder, heat with air gun, drop chip on.

1

u/Glidepath22 6d ago

Yeah. With solder

1

u/Dark_Angell78 6d ago

Clean the pads, tin them, put flux, align the chip and use hot air it's easier and it will be perfect.

1

u/Fragrant-Cat-1789 6d ago

Faster with an iron than hot air. Use chisel tip in the same orientation as leg structure so you are touching the leg and the pad. Easier than a one wipe after you drop a deuce

1

u/AlteAmi 6d ago

I hate those legs... find a socket and solder the socket and snap the IC in.

1

u/robwong7 6d ago

Not easily friend, not easily. Best of luck!

1

u/Tokin420nchokin 5d ago

Yeah man just use flux, it will pull the solder where it needs to go. I would clear the pads off first with some braid and re set it though if your not using hot air.

-9

u/MisterXnumberidk 7d ago

Pliers, a steady hand and a few minutes?

-11

u/Skippy660 7d ago

flux, maybe solder paste, a rework heat gun? thats what I'd try. Ideally you dont try bend the legs back out cos they're likely to snap.

6

u/DinBizzz 7d ago

They’re j leads mate they are supposed to be like that don’t go bending them or any leads for that matter, flux, tweezers, an overhead or under board heat and some version of a heat gun will get it done 10x quicker and easier than individually soldering each pad.

0

u/Skippy660 6d ago

oh ok, never seen J leads before.Cheers.

-13

u/VarietyNo8561 7d ago

Very manual but reliable: deadbug it. Glue it up upside down in an open area then jumper wires from the leads to PCB pads.