Professional assembly mishaps

[tszaboo]

This things happen. The important is to have IPC-610 at hand to send back feedback, or pas this info for purchasing, so they can haggle.

[mikeselectricstuff]

We had panels with scorched AOI stickers on them.  I guess it tells you something.
Leo

Implying they did the AOI BEFORE reflow??

Or that they reworked it

If it was a mixed TH/SMD board it would be reasonable to AOI before flowsoldering the TH parts

[mc172]

I've yet to meet a CEM that shows any passion or enthusiasm for what they do, or any significant amount of imagination.

Exactly. Those that I've come across have just ended up in that field and hopelessly bumble around, somehow delivering product. A few I've come across have grand ideas about designing their own product but really have no idea about the work involved.

These places also tend to be "run" by a lot of managers and the like, whereas there are really only one or two really good people ensuring that the place runs.

Liaising with them is hard work as the people you're put into contact with don't have a clue.

[mikeselectricstuff]

I've yet to meet a CEM that shows any passion or enthusiasm for what they do, or any significant amount of imagination.

Exactly. Those that I've come across have just ended up in that field and hopelessly bumble around, somehow delivering product. A few I've come across have grand ideas about designing their own product but really have no idea about the work involved.


Liaising with them is hard work as the people you're put into contact with don't have a clue.

Lack of communication about their process is also a big issue - I think they regard it as a trade secret.
For example I always include fids in my pick/place data but I know at least one -place was still programming them manually from a sample board.

These places also tend to be "run" by a lot of managers and the like, whereas there are really only one or two really good people ensuring that the place runs.

And the only people/person who knows anything about electronics are in the test dept.

[Leo Bodnar]

One more from today. 
This is from the company that was (and still is) my favourite.  Not because it's the best but because the others are worse.
Leo

[bd139]

Ugh been wanting to get this off my chest for years ... seems like the right place!

I fell out of university into a dying industry in the UK so I did some time on a soldering line. I think I lasted a week before I was promoted to rework only because I wasn't a dumbass and the rework guys lasted about a month before they had a mental breakdown.

This was mid-1990s and they did everything in house because it was defence sector. The whole line was producing stacks of legacy TH replacement boards that were designed in the 1970's for a refurbishment programme. The people on the line had been there doing that line for 15+ years. All manual insertion and manual soldering. All old ladies chatting as they were working.

And you know what? Someone in inventory accidentally swapped a bin full of diodes and resistors around due to a "heavy pub lunch". They stuffed and soldered 80 boards before the QA guys noticed. They put the resistors in the diode holes and the diodes in the resistor holes. Orientation of diodes? Who cares, just stuff them in. What could possibly go wrong. Part 1 comes from bin 1 and goes in that hole. Part 2 comes from bin 2 and goes in that hole. Turns out that if you put them in the bin the wrong way round, all the diodes would have been soldered in the wrong way around. Silk screen? Nah that's for the design engineers to worry about.

So my job was to rework the fuck ups for about a month when they had come back from QA. One day I just flipped my shit like happy noodle boy [1]. Then I, as many before me had done, got reassigned to a different department which was just as bad.

GRADE F TO GRADE E STAFF PROMOTION ACHIEVED!

[1]

[Kean]

Lack of communication about their process is also a big issue - I think they regard it as a trade secret.

^ This!

For example I always include fids in my pick/place data but I know at least one -place was still programming them manually from a sample board.

I actually had one assembler specifically tell me not to bother providing the Pick and Place files (for about 10 designs being run at once, all in qty of about 50-100).  Surprisingly these guys did one of the best jobs of all the companies I've dealt with.  They've since closed down though

[AF6LJ]

The moral of the story is the Human Element is where the highest quality standards must exist in the overall system.

[AF6LJ]

Ugh been wanting to get this off my chest for years ... seems like the right place!

I fell out of university into a dying industry in the UK so I did some time on a soldering line. I think I lasted a week before I was promoted to rework only because I wasn't a dumbass and the rework guys lasted about a month before they had a mental breakdown.

This was mid-1990s and they did everything in house because it was defence sector. The whole line was producing stacks of legacy TH replacement boards that were designed in the 1970's for a refurbishment programme. The people on the line had been there doing that line for 15+ years. All manual insertion and manual soldering. All old ladies chatting as they were working.

And you know what? Someone in inventory accidentally swapped a bin full of diodes and resistors around due to a "heavy pub lunch". They stuffed and soldered 80 boards before the QA guys noticed. They put the resistors in the diode holes and the diodes in the resistor holes. Orientation of diodes? Who cares, just stuff them in. What could possibly go wrong. Part 1 comes from bin 1 and goes in that hole. Part 2 comes from bin 2 and goes in that hole. Turns out that if you put them in the bin the wrong way round, all the diodes would have been soldered in the wrong way around. Silk screen? Nah that's for the design engineers to worry about.

So my job was to rework the fuck ups for about a month when they had come back from QA. One day I just flipped my shit like happy noodle boy [1]. Then I, as many before me had done, got reassigned to a different department which was just as bad.

GRADE F TO GRADE E STAFF PROMOTION ACHIEVED!

[1]

Wow, just WoW!

[tszaboo]

Turns out that if you put them in the bin the wrong way round, all the diodes would have been soldered in the wrong way around. Silk screen? Nah that's for the design engineers to worry about.

I've worked in a PCBA factory for internship, back in the day. It was Japanese run.It was run by the Japanese. (this is more english, right?) They had rigorous QC requirements for component orientation. And leaflets, telling the workers:
1) If a cap is placed backwards, it blows up.
2) If it blows up only later, we need to recall the boards
3) If we need to recall, we loose a bunch of money, and we have to close down
4) And YOU WILL LOSE YOUR JOB, and everyone working with you will loose your job

Engineers were sometimes running around with stopwatches, measuring how much time each assembly steps took. Not to grade workers but to optimize the assembly process for higher throughput. Didn't matter, it still scared them. Workers were told, that if we "have to let them go", there is a dozen other to take their places. It was actually true.
"Fear will keep the local systems in line. Fear of this battle station."

[bd139]

If only that place was Japanese run. I'd have loved that. That's how I run my software team.

That lot on that line ended up working in McDonalds when Six Sigma came in. Mainly because they had to fire them to pay for the consultants. You couldn't hire anyone now to do that in that locality.

[Gribo]

Dead bugs happen, especially on low pin count SOIC. Good (semi-competent) manufacturers usually catch those errors in production, mainly because the cost of repair rises logarithmically with each step of the process.

[Cerebus]

All manual insertion and manual soldering. All old ladies chatting as they were working.

Was this M_____ in West London? Sounds like them.

[Yellofriend]

To ask a factory to buy parts for you is always extreme high risk. Buy everything yourself from Mouser etc., that is the safest way.

Depends on who you're asking.

Sure! If you work with me I only buy from Digikey etc. I do lots of assembly in China. Would I let the factory buy parts - no way!

BTW, for the testing, the bad thing was that the fake ICs had full function, we we tested them 'good'. The client made an extended function test -20°C to +70°C for 24 hours - that's where 90% failed.

[bd139]

All manual insertion and manual soldering. All old ladies chatting as they were working.

Was this M_____ in West London? Sounds like them.

No not them actually. I don't wish to name the company in question as they are still active and all hail corporate now. But they're Essex side of London in the badlands.

[Leo Bodnar]

Dead bugs happen, especially on low pin count SOIC. Good (semi-competent) manufacturers usually catch those errors in production, mainly because the cost of repair rises logarithmically with each step of the process.

Surely you meant to say exponentially?
Leo

[8086]

All manual insertion and manual soldering. All old ladies chatting as they were working.

Was this M_____ in West London? Sounds like them.

No not them actually. I don't wish to name the company in question as they are still active and all hail corporate now. But they're Essex side of London in the badlands.

Does the name start with a "T"? 

[bd139]

Nope

[Nusa]

What keeps upside down packages from falling off the board? Is there an adhesive?

[Leo Bodnar]

What keeps upside down packages from falling off the board? Is there an adhesive?

Flux seeps underneath and solidifies after cooling down.
Leo

[mikeselectricstuff]

All manual insertion and manual soldering. All old ladies chatting as they were working.

Was this M_____ in West London? Sounds like them.

No not them actually. I don't wish to name the company in question as they are still active and all hail corporate now. But they're Essex side of London in the badlands.

Does the name start with a "T"? 

"D" ?

[Gribo]

Yes, I did. Meh. It always gets more expansive, faster than you can blink.

[jmelson]

Well, classic tombstone.  Not real common with modern processes, but it can happen.  It might actually be an undetected mis-pick on the P&P machine.  If the part drags on the side of the component tape, it can tumble into this position and show enough vacuum that the machine doesn't reject it.

Jon

[wraper]

Well, classic tombstone.  Not real common with modern processes, but it can happen.  It might actually be an undetected mis-pick on the P&P machine.  If the part drags on the side of the component tape, it can tumble into this position and show enough vacuum that the machine doesn't reject it.

Jon

It is not tombstoning at all. Component was placed between 2 pads vertically and produced dead short after reflowing. Tombstoning is when part is soldered on one side and lifted on another.

[M4trix]

One more from today. 
This is from the company that was (and still is) my favourite.  Not because it's the best but because the others are worse.
Leo

Hmm, that's actually a brilliant solution when you don't have jumpers, zero ohm resistors ! Just flip the cap vertically !