Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

NASA's Through-Hole Workmanship Req (2002)

workmanship.nasa.gov

Post reply on HN
Print view View original

21–30 of 60 posts

Re: NASA's Through-Hole Workmanship Req (2002)

#21

Post by segfaultbuserr »

gte525u wrote: post #20
jcims wrote: post #8

Was curious what their treatment was going to be regarding tin whiskers. Not much there (of course this is point in time inspection so it kind of makes sense), but a quick google revealed quite a bit of study: https://nepp.nasa.gov/whisker/ I thought they were just one of those low probability items until a Sunday morning when I was running live audio for a church service. Singer was mid verse and BOOOOM! Huge boomin…

NASA and aviation in general are later adopters of lead-free. It definitely wouldn't have been reflected in older standards.

AFAIK, lead-free soldering is never enforced in space applications. An exemption is granted because of its extremely high reliability requirements.

Re: NASA's Through-Hole Workmanship Req (2002)

#22

Post by buescher »

The NASA handbooks are good. I like the one for rework that shows neatly staked wires. There are a couple of subtleties you could miss on this one though:

1) On page three, that exposed end of the lead is a defect if you're NOT going to conformally coat the board. If you don't know what a conformal coating is, it's a defect.

2) On page eleven, flux residue. Sure, for NASA's applications. For most commercial applications, the IPC rule is "excessive flux residue". For prototypes, one-offs, and hobby projects, my rule of thumb is, if you can't measure the difference removing flux makes, leave it there. Incompletely cleaned flux can be more corrosive than undisturbed flux. Also, no-clean flux should be called "never clean" flux. Never clean it with ordinary methods because you will never get it clean.

Re: NASA's Through-Hole Workmanship Req (2002)

#23

Post by buescher »

inamberclad wrote: post #16
shireboy wrote: post #9

Anybody have tips on how to get to this level of solder-fu?

Heat control. Cleanliness. High quality tools and solder.

Temperature control is so inexpensive these days you should not bother with heat control. Unless by heat control you mean the right size tip for the job, in which case we agree.

Re: NASA's Through-Hole Workmanship Req (2002)

#24

Post by buescher »

DanBC wrote: post #17
shireboy wrote: post #9

Anybody have tips on how to get to this level of solder-fu?

Basic soldering is easy to improve with practice. A couple of hours with a few hundred assorted components and some scrap PCBs will help to perfect the steps (tin the bit, hold the bit to the joint, apply the solder, pull the solder wire away, pull the bit away, inspect the joint). Things are a little bit trickier today because the alloy of the solder and the flux you use do make a difference, but lead-free solder to…

I wouldn't give up my Metcal for anything else I've seen, but if I were broke, I'd buy one of the Chinese Hakko clones and eventually replace the tips with Hakko tips.

Re: NASA's Through-Hole Workmanship Req (2002)

#26

Post by aerostable_slug »

konschubert wrote: post #5

I knew I was bad at soldering, I didn't know I was THAT bad. I need to take a course.

>course

I used to work with a developer whose second job was with HP back in the 70s. He was hired as a technician building lab equipment and had to be prequalified from an educational and trades/skill perspective to be hired.

Then they taught him to solder again. Their standards were apparently incredibly high.

Re: NASA's Through-Hole Workmanship Req (2002)

#28

Post by HeyLaughingBoy »

heyflyguy wrote: post #2

Every now and again this pops up on a different forum. I wonder how much is actually hand soldered any more vs. pick and place machines with SMT.

For low volume, it can cost more to set up the P&P machine, deal with alignments, check first articles, etc. than just soldering a few (dozen) board by hand. And there are a lot of small companies in niche markets whose annual production of a PC board might be in the single digits.

That and, people who hand solder stuff all day are fast.

Re: NASA's Through-Hole Workmanship Req (2002)

#29

Post by function_seven »

DanBC wrote: post #17
shireboy wrote: post #9

Anybody have tips on how to get to this level of solder-fu?

Basic soldering is easy to improve with practice. A couple of hours with a few hundred assorted components and some scrap PCBs will help to perfect the steps (tin the bit, hold the bit to the joint, apply the solder, pull the solder wire away, pull the bit away, inspect the joint). Things are a little bit trickier today because the alloy of the solder and the flux you use do make a difference, but lead-free solder to…

> Basic soldering is easy to improve with practice

If you're looking for a practical way to do this, consider hand-wiring your own keyboard. I did this a couple years back, with 75 keys or so. With the diodes on each key, it was about 225 solder joints plus whatever extra to land the matrix leads on the microcontroller.

Good variety, too. Some were wire-to-wire joints, others were wire wrapped around post, and a few where through-hole joints.

If I look at the underside of that keyboard, I can tell where I started and where I finished by how clean the solder joints look :)

Re: NASA's Through-Hole Workmanship Req (2002)

#30

Post by mcshicks »

shireboy wrote: post #9

Anybody have tips on how to get to this level of solder-fu?

I found these videos from eevblog extremely helpful when I setup my home lab after working as an EE for many years but never really learning to solder.

https://www.youtube.com/watch?v=J5Sb21qbpEQ

Post reply on HN