Trying to learn advanced soldering techniques...

CZroe

Lifer
Jun 24, 2001
24,195
857
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http://www.psxcare.com/product.php?xProd=725

When tinning the contacts on a flexible PCB, the guy keeps moving his iron off the camea and a "pop" can be heard. When he returns, the bead of solder seems to be gone, so I can assume that it is a suction device. At work, they have suction irons that are operated with a foot pedal, but nothing desk-mounted to suck it off an iron. I only resort to my wet sponge.

He is able to grab the shaft of his iron for pencil-like precision. I can't do this on my adjustable-temp iron. Is it the coating I see him using or does he have some kind of precision iron that is meant to do this (thus, including the coating)? I don't know what that coating is called or where to look for it. I can't even find replacement tips that small for either of my adjustable temp solder station/irons... the only tips Fry's carries for my Elenco model are identical replacements and the chisle-tipped version of it, certainly nothing smaller meant for reworking SMT devices and soldering to IC legs. I have the same problem with my Velleman unit. I can't find tips for either anywhere else (not at Radio Shack).
 

BrownTown

Diamond Member
Dec 1, 2005
5,314
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0
Just out of curiosity, why exactly do you want to be able to solder such small components by hand? On another note, I have seen where people programmed a toaster oven to do solering like you might see in an industrial setting. So if you are doing alot of SMD solering and the like it might be easier to do something like that instead of hand soldering hundreds of tiny little pads.
 

CZroe

Lifer
Jun 24, 2001
24,195
857
126
So someone made a reflow oven from a toaster? Interesting. :) Probably wouldn't work too well with the RoHS Pb-Free stuff like reflowing an XBOX 360 GPU/CPU to fix the RLOD. Unfortunately, my intentions always include unofficial modification. That means few, if any solder pads and a lot of soldering to pins, sanded traces, etc.

I was impressed to see people at work reworking motherboards and such by desoldering and replacing motherboard chipsets by hand, but I'm just an outside observer there (security guard).

Basically, I want to do work VERY similar to what is seen in the video... if the device he was soldering wasn't out-dated, I'd be planning to do many of the exact same jobs. The flexible PCB is a tool for finishing the job much faster, but I'd like to be good enough to do it without first while still making it look nice and professional.
 

Modelworks

Lifer
Feb 22, 2007
16,240
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Yeah the reflow toaster ovens are great for hobby projects, but I wouldn't recommend doing things like a motherboard in them.

If you really want to work with smd, then a hot air rework station is a must.
I can't concieve using a soldering iron on something like a 144 pin chip.
 

JonB

Platinum Member
Oct 10, 1999
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All I could think of was how much better his eyesight is than mine. No lighted magnifier. Working in the shadow of his own hand.

The tiny soldering tip and superfine gauge solder sure helped. I was impressed how he controlled solder quantity by how much length he fed to the tip. Very precise. He was a lot less concerned about oil from fingertips that I am. He touched EVERYTHING with bare fingers.
 

Modelworks

Lifer
Feb 22, 2007
16,240
7
76
I've soldered for over 20 years and the best I can do is a 32 pin plcc chip with some very fine solder and an almost needle tipped iron.
Even then my eyes get the better of me.
Guess I'm getting old, noticed my hand shakes a bit now too.

 

bobsmith1492

Diamond Member
Feb 21, 2004
3,875
3
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Originally posted by: Modelworks
I've soldered for over 20 years and the best I can do is a 32 pin plcc chip with some very fine solder and an almost needle tipped iron.
Even then my eyes get the better of me.
Guess I'm getting old, noticed my hand shakes a bit now too.

Try a wave tip and flux - no need for point-to-point soldering. You just drag it across all the pins and the surface tension pulls it apart leaving just the right amount on each pin.
 

CZroe

Lifer
Jun 24, 2001
24,195
857
126
Originally posted by: JonB
All I could think of was how much better his eyesight is than mine. No lighted magnifier. Working in the shadow of his own hand.

The tiny soldering tip and superfine gauge solder sure helped. I was impressed how he controlled solder quantity by how much length he fed to the tip. Very precise. He was a lot less concerned about oil from fingertips that I am. He touched EVERYTHING with bare fingers.

Yeah, tell me about it. I'd be wearing latex gloves. Perhaps he's allergic to latex or needed to feel the solder to control it?

Originally posted by: PottedMeat
I asked on another forum and someone mentioned that it may be a Hakko. Browsing their site, I think the poster was right:

http://www.hakkousa.com/detail.asp?PID=4482&Page=1

Looks like a Hakko FX951-66 - a bit out of my price range.

They carry Hakko at Fry's Electronics and, IIRC, they sell a similar one for much less ($180 IIRC). Anyway, I see that he also has a YouTube vid where he identifies it as some JBC model in the comments section ("We use JBC advanced series with 0.3mm tip"). In that video, he demonstrates a wired install of an alternative product with fewer wires but no FlexPCB (so it takes a bit longer).

I'm still wondering what kind of hands-free device he is sucking the solder off his iron with.

Originally posted by: bobsmith1492
Originally posted by: Modelworks
I've soldered for over 20 years and the best I can do is a 32 pin plcc chip with some very fine solder and an almost needle tipped iron.
Even then my eyes get the better of me.
Guess I'm getting old, noticed my hand shakes a bit now too.

Try a wave tip and flux - no need for point-to-point soldering. You just drag it across all the pins and the surface tension pulls it apart leaving just the right amount on each pin.

I looked it up and it appears that a wave tip is hollowed out to hold a ball of solder and applies as you describe, but they don't seem to be available for most irons. How do you get the component to stay still as you apply heat and drag across? I doubt I'll be soldering/desoldering whole components often, but I will be soldering to them while installed and this looks like a great way to tin them.

 

bobsmith1492

Diamond Member
Feb 21, 2004
3,875
3
81
Originally posted by: CZroe
Originally posted by: JonB
All I could think of was how much better his eyesight is than mine. No lighted magnifier. Working in the shadow of his own hand.

The tiny soldering tip and superfine gauge solder sure helped. I was impressed how he controlled solder quantity by how much length he fed to the tip. Very precise. He was a lot less concerned about oil from fingertips that I am. He touched EVERYTHING with bare fingers.

Yeah, tell me about it. I'd be wearing latex gloves. Perhaps he's allergic to latex or needed to feel the solder to control it?

Originally posted by: PottedMeat
I asked on another forum and someone mentioned that it may be a Hakko. Browsing their site, I think the poster was right:

http://www.hakkousa.com/detail.asp?PID=4482&Page=1

Looks like a Hakko FX951-66 - a bit out of my price range.

They carry Hakko at Fry's Electronics and, IIRC, they sell a similar one for much less ($180 IIRC). Anyway, I see that he also has a YouTube vid where he identifies it as some JBC model in the comments section ("We use JBC advanced series with 0.3mm tip"). In that video, he demonstrates a wired install of an alternative product with fewer wires but no FlexPCB (so it takes a bit longer).

I'm still wondering what kind of hands-free device he is sucking the solder off his iron with.

Originally posted by: bobsmith1492
Originally posted by: Modelworks
I've soldered for over 20 years and the best I can do is a 32 pin plcc chip with some very fine solder and an almost needle tipped iron.
Even then my eyes get the better of me.
Guess I'm getting old, noticed my hand shakes a bit now too.

Try a wave tip and flux - no need for point-to-point soldering. You just drag it across all the pins and the surface tension pulls it apart leaving just the right amount on each pin.

I looked it up and it appears that a wave tip is hollowed out to hold a ball of solder and applies as you describe, but they don't seem to be available for most irons. How do you get the component to stay still as you apply heat and drag across? I doubt I'll be soldering/desoldering whole components often, but I will be soldering to them while installed and this looks like a great way to tin them.

Tap a bit of solder on a corner pin; line it up (the hardest part), put heat on that pin, then let it cool. Make sure everything is still lined up and tap a bit of solder on an opposite corner. Then wave each side.
 

Born2bwire

Diamond Member
Oct 28, 2005
9,840
6
71
Originally posted by: Modelworks
If you really want to work with smd, then a hot air rework station is a must.
I can't concieve using a soldering iron on something like a 144 pin chip.

Damn straight. The way I do small pinned packages is use soldering paste and a hot air station. I use a soldering braid to clean up any errant solder bridges but if I do things right it's unnecessary.
 

Kirby64

Golden Member
Apr 24, 2006
1,485
0
76
Pfft.. I've soldered 1mm pitch 256pin chips before with no issue with my soldering iron. Wave soldering is where it's at. No special tip, just my trusty Hakko 936, my 1.2mm screwdriver tip, and some delicate work.
It takes awhile to get used to, but just using massive amounts of flux (paint it on fairly thick) and a semi-large amount of solder causes everything to flow together easily. The issue is to line it up properly. Tack one edge pin, check alignment with a loupe, then tack the other side. If the alignment is right, then everything else will flow. The occasional bridge can be fixed with some desoldering braid.

Screw up the alignment, and wave soldering won't work worth a crap. It's almost as simple as that.
 

CZroe

Lifer
Jun 24, 2001
24,195
857
126
Originally posted by: Born2bwire
Originally posted by: Modelworks
If you really want to work with smd, then a hot air rework station is a must.
I can't concieve using a soldering iron on something like a 144 pin chip.

Damn straight. The way I do small pinned packages is use soldering paste and a hot air station. I use a soldering braid to clean up any errant solder bridges but if I do things right it's unnecessary.

Where can I find tutorials for this? They have paste with needle applicators here and they are cleaning up and throwing out stuff, so I might be able to get a tube + applicator. Would I need a heat gun with a tube tip? How do I avoid overheating the package? How do I get it to stay on the PCB while I'm blowing on it? After hours, I used the hot air station here to remove a couple warranty stickers without leaving "VOID" marks with semi-success... the plastic grain texture was smoothened out around the sticker making it still possible to tell.

Now, as far as flux, I've always used liquid flux with a needle dispensor, but contextual clues in the things I read online make it appear that most people use a different kind. Even at Radio Shack and Fry's, I can't find it. I turn my tip around in "Tip Tinner" to remove oxidation pretty often, but that's not labeled "flux" (leaves a ding solder on my tip). I often use the rosin flux in the core of my solder to remove oxidation too. If I don't know the basics of what people do and what they call what, I can't go forward. Perhaps I should just take a class.

Anyway, how would you go about making a proto PCB for these kind of components? I have etchant kits from when I was a kid, but that would never work for SOIC and other surface-mount kits. I assume that I'd need to use a laser printer transfer method and some kind of software. Where should I start?
 

Born2bwire

Diamond Member
Oct 28, 2005
9,840
6
71
Originally posted by: CZroe
Originally posted by: Born2bwire
Originally posted by: Modelworks
If you really want to work with smd, then a hot air rework station is a must.
I can't concieve using a soldering iron on something like a 144 pin chip.

Damn straight. The way I do small pinned packages is use soldering paste and a hot air station. I use a soldering braid to clean up any errant solder bridges but if I do things right it's unnecessary.

Where can I find tutorials for this? They have paste with needle applicators here and they are cleaning up and throwing out stuff, so I might be able to get a tube + applicator. Would I need a heat gun with a tube tip? How do I avoid overheating the package? How do I get it to stay on the PCB while I'm blowing on it? After hours, I used the hot air station here to remove a couple warranty stickers without leaving "VOID" marks with semi-success... the plastic grain texture was smoothened out around the sticker making it still possible to tell.

Now, as far as flux, I've always used liquid flux with a needle dispensor, but contextual clues in the things I read online make it appear that most people use a different kind. Even at Radio Shack and Fry's, I can't find it. I turn my tip around in "Tip Tinner" to remove oxidation pretty often, but that's not labeled "flux" (leaves a ding solder on my tip). I often use the rosin flux in the core of my solder to remove oxidation too. If I don't know the basics of what people do and what they call what, I can't go forward. Perhaps I should just take a class.

Anyway, how would you go about making a proto PCB for these kind of components? I have etchant kits from when I was a kid, but that would never work for SOIC and other surface-mount kits. I assume that I'd need to use a laser printer transfer method and some kind of software. Where should I start?

I just learned by doing for the most part. I was given a quick lesson in how it was done in the lab. The solder paste is really just a bunch of solder particulates in liquid flux. For coarser IC's, I would apply a line of paste along the length of each pad. For very fine pin pitches, I would lay down a single line perpendicular to the run of the pins so that it crosses all the pins. Using proper magnification to see my work (we had a camcorder with a macro lens, truly high tech), I placed the IC down and held it in place via tweezers and used the hot air thingy to tack down a corner pin. Then I just systematically move down and heat each pin until the solder and flux melt and flow onto a pin. Once I've done all the pins, I do a quick visual check and then a continuity check using a multimeter on adjacent pins to check for bridges. If there is a bridge, I use a regular soldering iron to heat a piece of soldering braid placed over the bridge to suck up the solder. Then I reapply a small amount of soldering paste (preferably to one pin at a time) and resolder with the hot air. For the most part, I've never really used flux but that was pretty much negated by using the soldering paste and hot air station. If I was to use a very fine tipped soldering iron and wire solder then I would imagine that it would be more useful.