Solder strength on Monolith PCBS too weak.

[jeremyb]

This one was a challenge to solder But finally with success. The worst thing if you solder all pins, and must find short somewhere
http://www.odzyskiwanie-danych.com.pl/i ... arvika.jpg

Now that one looks like fun, I'd love to try it out..

[HaQue]

I had fun taking those pictures but sergey changed the forum so I couldn't post new ones..
For those pictures I used a $500 DSLR camera, nothing special. I still love when people rub the traces off the PCB and ask for support..

I think the bigger question was how you cleaned it so well, chemicals, rubbing/sanding, other.. but seemingly not touching the copper!
Yes, I rubbed off a trace from a MicroSD a while back, the trace went down the side almost on the edge. Very fine and fiddly.

But, you gotta love Monoliths, such fun !

[arvika]

Next challenge will be: http://www.odzyskiwanie-danych.com.pl/i ... arvika.jpg



Haque: i try chemicals, but not good result and it is not so save for health. So i prefer mechanical way, but you must be very carefully. JeremyB as I see on photos probably find good substance to remove the layer - looks perfect

[jeremyb]

My wish list is a good high res camera/microscope combo to around 100x, a wire bonding machine and an X-Ray machine.

X-ray sounds nice but the resolution on all the pictures I see looks so poor. I can see traces but it's fuzzy or not obvious where the via is in some cases. On eBay I've seen some x-ray sensors for $1200 and the xray generator for $300 but I've seen mixed results with that too, the picture will be mostly black because the generator is too strong.

Also the scale seems wrong so aligning it perfectly to the pcb to make a connection looks unreliable.

Those are my general thoughts on x-ray for monolithics.. Anyone have different results?

[Sasha Sheremetov]

We have not bad results with Xray analysis of pinouts, quality is perfect, but that's not xxxx$ device...
But yes, you can break your eyes trying to trace all tracks But it works.

[arvika]

Sasha was faster than me

You can use very very veeeery expensive x-ray machine with good resolution - first photo.
You can use chip dentist X-ray machine (cost about 4000-8000 euro) but quality is poor - second photo.

It can help but i think not for all cases.

Attachments

[Arthur]

.. but seemingly not touching the copper!

There is only one method to do that ..

[jeremyb]

Yes, dentist xray is bad, maybe what I'm trying to say is the focus looks poor going from one layer to another. That said the quality on some of those is pretty good, #2 is pretty impressive but it makes me go blind looking at all those traces.. Maybe zoomed in at high resolution is better.

[jeremyb]

.. but seemingly not touching the copper!

The copper is touched, it's just difficult to see, it's very soft. Although noticeable if you know the marks.

[Matiw]

Thank you everyone for all the priceless information.

I have bought a very thin soldering Iron (Weller from Amazon). Now, using a Microscope and the soldering Iron, I can precisely locate and put the soldering Iron on the PCB Pads of monolith Flash drives, no more problem with messing up adjacent Pads or Traces. But, I still having problem sticking the solder to the pads. I have sanded the PCB to remove any protective material, I have used flux paste, and then flux pen, I have heated the pads first and then put the solder next to the soldering Iron (as shown in some Youtube Videos), but I still have a problem, the solder would rather stick on the soldering Iron than the Pads. This thing is really pissing me off ! Help is desperately needed.

Thanks.

[HaQue]

you have to make sure the solder pad is clean copper. if you have a bit of solder on the soldering iron, dab the blob onto the pad.
are you using good 5 core solder? I am using 5core, .45mm 60/40 alloy.

You must be pretty close!

[Matiw]

Thank you HaQue,

Let me buy the Solder type you recommended and try.

you have to make sure the solder pad is clean copper. if you have a bit of solder on the soldering iron, dab the blob onto the pad.
are you using good 5 core solder? I am using 5core, .45mm 60/40 alloy.

You must be pretty close!

[Matiw]

You are right; the main culprit was the Epoxy covering the PCB traces. The solder sticks easily to a bare copper trace (Pad). Using Sand paper to remove the Epoxy seems a futile attempt. Sanding removes the Epoxy from all places (traces) less the required places, the Pads, it just leaves the Pads untouched, very strange and annoying. My next step is to get a chemical agent that removes the Epoxy. Any recommendation is greatly appreciated.

Thanks HaQue.

you have to make sure the solder pad is clean copper. if you have a bit of solder on the soldering iron, dab the blob onto the pad.
are you using good 5 core solder? I am using 5core, .45mm 60/40 alloy.

You must be pretty close!