The Art Of Soldering

Started by PRR, April 10, 2022, 11:46:23 PM

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PRR

"I'm of the old school that believes there's a right and a wrong way of doing everything, and I think it's worth the effort to learn the right way. I know this applies to making a solder joint. Good soldering is an art,....."


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stallik

You're never too old to improve your soldering skills. I posted this elsewhere last night because it taught  me things I'd never realised after playing with the stuff for 20 years

Quote from: stallik on April 10, 2022, 04:47:58 PM
I found this video about soldering very educational - FF past the intro

Insanity: doing the same thing over and over again and expecting different results. Albert Einstein

Rob Strand

Back in the day US companies really knew their stuff and produced training videos and training books in many many fields.

These training videos from PACE on soldering and rework are a good example,
https://www.youtube.com/channel/UCT5e-XjqHPfA3_9wF3CgY1w

Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

soggybag

#3
Too much of an art to be called a science, too much of a science to be called an art!

Mechanical wire strippers should be exactly the size of the wire and calibrated daily!

pacealot

"Never mind checking the temperature or cleaning your iron. Go on your merry way! That does it. You managed to do just about everything wrong."

Funny, I don't remember being in this film...  :icon_surprised:
"When a man assumes, he makes an ass out of some part of you and me."

amptramp

You could always follow the NASA NHB 5300.4 soldering spec but it is designed for the lightest weight and therefore, the least solder usage:

http://everyspec.com/NASA/NASA-General/NHB_5300--4(3A-1)_7148/

We had three women doing all our soldering back when I worked on spacecraft and their work was something I couldn't believe a human could do.  Our parts reliability man called me over one day and asked what I thought of the soldering on a particular board.  I looked at it and said it looked like a lot of dry and insufficient solder connections.  He told me to look at it under an eye loupe.  He said it was the best soldering I would ever see in my life.  He was right.  That was in 1976 and I still haven't seen anything as good.  The board had flatpack digital IC's on it with gullwing leads and the solder fillet went halfway up the vertical part of the leads everywhere.  All of the connections were good but never excessive and this is important when you are lifting something into synchronous orbit.

Processaurus

I love the bit of philosophy about assuming because someone is good at one thing, they're likely good at everything. It happens with musicians as well! We ask famous entertainers to weigh in on all aspects of life.

One of the sad parts of beginners learning to solder is their $20 soldering iron sucks, making the job twice as hard- lots of cold solder joints with underpowered irons and crummy tips.

Ice-9

Quote from: amptramp on April 12, 2022, 10:22:24 AM
You could always follow the NASA NHB 5300.4 soldering spec but it is designed for the lightest weight and therefore, the least solder usage:

http://everyspec.com/NASA/NASA-General/NHB_5300--4(3A-1)_7148/

We had three women doing all our soldering back when I worked on spacecraft and their work was something I couldn't believe a human could do.  Our parts reliability man called me over one day and asked what I thought of the soldering on a particular board.  I looked at it and said it looked like a lot of dry and insufficient solder connections.  He told me to look at it under an eye loupe.  He said it was the best soldering I would ever see in my life.  He was right.  That was in 1976 and I still haven't seen anything as good.  The board had flatpack digital IC's on it with gullwing leads and the solder fillet went halfway up the vertical part of the leads everywhere.  All of the connections were good but never excessive and this is important when you are lifting something into synchronous orbit.

I have seen video's of the NASA lady's soldering with the need to to use the least possible solder but best possible joint for weight saving. I doubt if anyone could hand solder like this these days giving the lead free horrible stuff used now.
www.stanleyfx.co.uk

Sanity: doing the same thing over and over again and expecting the same result. Mick Taylor

Please at least have 1 forum post before sending me a PM demanding something.

EBK

Quote from: Processaurus on April 12, 2022, 03:55:32 PM
I love the bit of philosophy about assuming because someone is good at one thing, they're likely good at everything. It happens with musicians as well! We ask famous entertainers to weigh in on all aspects of life.

One of the sad parts of beginners learning to solder is their $20 soldering iron sucks, making the job twice as hard- lots of cold solder joints with underpowered irons and crummy tips.
I have occasionally told people that they'd do more damage with an underpowered soldering iron than they would with an overpowered soldering iron.  Then, Paul R. holds up his giant iron that could weld ships, and I sit back down, less proud of my "wisdom".   :icon_razz:

A temperature-controlled soldering station is a life changing investment.  Soldering becomes so much easier.
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Technical difficulties.  Please stand by.

Toy Sun

Love that film!
Two takeaways (one merits discussion)
1.  Trim leads before soldering? Discuss.
2.  I have to calibrate my wire strippers EVERY DAY

Rob Strand

Quote1.  Trim leads before soldering? Discuss.
The general reasoning is cutting afterwards can cause a mechanical shock at the joint and compromise the connection.

For DIY level soldering it's fine to cut afterwards.

Quote
2.  I have to calibrate my wire strippers EVERY DAY

This whole calibration concept is outside of most people's experience.  When you make equipment
to certain standards you have to follow the rules.   If later on you find you have been making
product with equipment that isn't calibrated, or not conforming to the rules, then that can cause a
recall of all product back to the last time it was calibrated - if that was a year ago it could be a lot
of product.   There is scope to evaluate or monitor the extent of the problem, however, for NASA you
have one shot to get it right and there is zero tolerance for not following the procedures.

FYI there's also PCB standards (more rules to follow) which limit how far leads can extend
below the bottom of the PCB.   Quite often connectors similar to this will hang too far down,


Cutting such large short pins with cutters can compromise the connection. A machine with
a cutting disc is often used to cut everything off below a certain level.  Even that
can cause unnecessary issues with larger pins.
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

Phend

#11
The soldering hog leg (gun) is a good investment


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Do you know what you're doing?

Mark Hammer

More and more these days, I find the need to scrape the leads of whatever I'm about to solder.  Not just passive components but sometimes chips and transistors as well.  Maybe it's the air in my house.  Maybe it's just the age of the components I'm using.  But unless the leads or pins are nice and shiny, I'm suspicious of the solder joint.

Jarno

I do have that too, on some components, but in principle that's what the flux should also do, remove the oxide layer.
But there are some older components which perhaps have too thick an oxide layer, or maybe different oxides. And then there are cheap components, where sometimes the materials do not lend themselves to soldering (bought a batch of cheap jacks and RCA's on Aliexpress, dreadful), in a pinch I'll take a bit of sandpaper to those, but if I also have stock of proper ones, I just bin them.

Mark Hammer

A sharp (and nearby) utility knife blade is my friend in these instances.  I've seen too many attempted solder joints where the solder sits on the pad, like a donut at the base of the component lead, rather than sloping up from the pad to the lead.

r080

Quote from: Toy Sun on April 12, 2022, 06:00:53 PM
1.  Trim leads before soldering? Discuss.

I started trimming leads before soldering once I got cut and clinch pliers. Hakko has a reasonably priced one. It made a big difference in my speed. However, it definitely slows modding and fixing mistakes.

One thing from that video I didn't quite get was the short discussion changing iron temperature for different size leads. I was wondering if the iron in the film could control heat output, and not temperature. I would assume that if you have a solder that melts well at a specific temperature, as long as your iron has capacity to get the work up to that temp, you could leave a temperature controlled iron at that temp.
Rob

Rob Strand

#16
Quote from: Mark Hammer on April 12, 2022, 08:49:00 PM
More and more these days, I find the need to scrape the leads of whatever I'm about to solder.  Not just passive components but sometimes chips and transistors as well.  Maybe it's the air in my house.  Maybe it's just the age of the components I'm using.  But unless the leads or pins are nice and shiny, I'm suspicious of the solder joint.
A lot of my old parts are the same.   The parts I've pulled from old equipment are fair a bit better since they have residual solder on the leads (in most cases lead-tin solder).

I've got a separate stash of parts I use for bread-boarding.   Some of those need to be binned as the leads are getting corrosion from all the handing over the years.

With the amount of skimping that goes on these days and cost of copper increasing you have to start thinking how much lead scraping you can do before you hit the wire core (which isn't solderable).
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

amptramp

We had a problem on the Hermes satellite where a number of 2N2222A and 2N229A transistors could not be soldered.  The leads were gold-plated but the leads themselves were kovar, a nickel-iron alloy with the same coefficient of expansion as the glass insulators used to ensure the transistors could withstand soldering heat.  The gold plating was porous and allowed the kovar to rust underneath the gold because of the electrochemical couple between the gold and kovar, which behaved as a sacrificial anode.  There was no way out of this one - we had to scrap a number of transistors and replace them with newer ones.

Rob Strand

#18
QuoteWe had a problem on the Hermes satellite where a number of 2N2222A and 2N229A transistors could not be soldered.  The leads were gold-plated but the leads themselves were kovar, a nickel-iron alloy with the same coefficient of expansion as the glass insulators used to ensure the transistors could withstand soldering heat.  The gold plating was porous and allowed the kovar to rust underneath the gold because of the electrochemical couple between the gold and kovar, which behaved as a sacrificial anode.  There was no way out of this one - we had to scrap a number of transistors and replace them with newer ones.
It's hard to pickup on that stuff until you get stung, then there's no solution!

We had a PCB with a gold-plated switch contact.  To simplify the manufacture of the small PCB we gold plated the whole side of the board (back then gold was cheaper).  However, the manufacturers put gold on copper (IIRC) and the parts would not bond reliably through the gold.   Some parts would even pop off.  The solution was the copper was silvered first then gold was put on top of that.  When soldering gold is dissolved into the solder and it solders correctly.  The unsoldered  switch contact didn't oxidize (probably not as well as before though).

https://www.pcbway.com/blog/PCB_Basic_Information/Gold__Silver_and_Copper_in_PCB.html

Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

amptramp

^^^

It sounds like you ended up with the "purple plague", intermetallic compounds of gold and solder that do not have much strength and mechanically break down, causing open circuits.  If you had 150 microinches of gold, you could probably solder the component leads with no problem but if it was 50 microinches, you would be better off leaving the gold off entirely.