Another Newbie Question

[ddrecovery]

I have been in DR for a few years and now finding my feet with Flash (have VNR). Couple of questions.

1. How do you remove claw foot NAND chips? I have experimented with a hot air gun (280 degrees) which seems to work pretty well. I also know of adding solder to each side and using a chisel bit to remove the solder(or using ChipQuick). I also have a IR station, but I am afraid of overheating the chip as you have no choice but to heat the whole area but does make removing the chip easier. Which methods so you use?

2. Whats the best way to remove the coating from a Monolith? I have experimented with a scalpel (X ACTO) which seems to work. I have also tried sandpaper and a dremel (not on live chips of course) but found then to be too aggressive.

Would appreciate your comments.

[HaQue]

1. if you are talking about standard TSOP48, I just use hot air. I have a cheap satioon that has ben working flawlessly for over 2 years, maybe more (I think I posted when I bought it, so a search may turn up price, details) It is a YIHUA 862D. anything with 862D in the name is probably exact same thing with different clothes on. The soldering Iron I wasn't concerned about, as I have a good Micron, but actually once I bought some needle point tips is really a good iron... well it does the job nicely but I have never used what an industry guy might call a "good iron" that costs a lot!

2. I use 1200grit wet&dry sand paper (no water) and take it really easy. It is a bit slow and takes a while but works fine. I am hesitant to get into it with a dremel and sandpaper or buff bit.. Be especially careful with some microSD cards that have a circuit trace running along the edge. if you rub/sand through it, you could be breaking a needed circuit.

If you have a pinout, you don't need to remove all the coating. most times I do it if it is a new pinout, or I want to photograph it. But a customers monolith, it is just unnecessary work and added time and abuse for something to go wrong.

I would NOT use a scalpel. I understand how you could do it, but 1 slip and it is all over. some circuit traces are remarkably easy to pull off the board.

tips were posted a while ago and went into detail for this I think under "soldering monoliths"

things like a good microscope, good solder and flux, and above all - practice.

trying out methods on customers devices is not practice, it is recklessness

[Sasha Sheremetov]

The best tool for coating removal is fiberglass pen or fiberglass sticks (we just recently discovered by occassion), it's much better and safier that scalpel or sandpaper.
It doesn't scratch metal, but perfectly remove plastic. Tested many times under microscope. A bit slow sometimes but result is ideal.
We used flexible scalpels before, sometimes it damage edges as HaQue said (though it's mostly GND zone)

I don't like dremel or sandpaper, but it's a matter of taste



Result

[LarrySabo]

With the fibreglass pencil, keep the exposed bristles very short or you tend to get fibreglass slivers in your hands that are difficult to find but very aggravating.

[digitalferret]

Using them here, and brass on occasion.
Fabulous for removing conformal coating, but I too am hyper aware about the micro-shards that pop off.
Maybe not for a home electronics workshop if there a chance of kids or pets wandering through.

Many years ago the older fibre optic novelty lamps had similar long and very fragile strands.
They broke easily and shed everywhere. You got even the tiniest one stuck in you and you knew about it.

SafetyFirst: always.

[HaQue]

well you learn something every day. nice, I like the result Sasha! maybe another forum member's secret is out?

[Sasha Sheremetov]

There's another way to get better result - laser. The one that is used in companies who do carving on plastic, wood, etc (ads agencies). It's cheap because they count meters of work. Just too much efforts for one device, IMHO.

[ddrecovery]

Thanks Guys

[Amarbir[CDR-Labs]]

There's another way to get better result - laser. The one that is used in companies who do carving on plastic, wood, etc (ads agencies). It's cheap because they count meters of work. Just too much efforts for one device, IMHO.

Sir ,
I Do Have This Tool .IMHO The Best Result Would Be If The Fiber Is Chisel Type Or Converted To This Type Manually By Rubbing It On Something .