HDD GURU FORUMS

Hi,
I am having a fun time trying to solder to monoliths. By fun I mean painful. I know it is hard to show how to solder, as it is a task with many variables, and best learnt by practice.

I have done plenty of hardware hacking, electronics for quite a wile, but this is a different level of work.

I have a monolith as a task right now. the pads are around 0.20mm centres apart. There are 40 pads across the SD Card. They don't look too hard until I go and try to solder. I can get wires soldered to the pads after a lot of careful time. I was wondering if someone could either outline the way they do it, or offer some tips.

The issues I am having and the things I have tried are:

1. Bought thin wire that may not be thin enough, 0.25mm. I found it hard to get a small bead on the pad and the wire to stick.
2. Unwound a transformer from a power supply for some thinner wire, 0.17mm. I found the solder doesn't stick to it well, and even after scraping the end well and applying flux, the solder is not sticking well.
3. I am using 0.7mm 60% Tin 40% lead solder and a flux pen
4. I have a temperature controlled Iron on my hot air re-work station

I would love some tips on things like better wire, better solder etc

BTW, comments like "that's nothing, we solder smaller stuff all the time" etc not really helpful, I have seen some amazing jobs on some of these forums and sincerely, all due respect to the people that do it.

Before soldering wires to pads you need to tin both pads and the wire (all of them, it's very hard to tin with other wires in place)
Flux pen is not the best flux, something like this should work much better - http://www.vetco.net/catalog/images/MG-8341-10ML.jpg
If you cannot easily tin your wire that could mean that either your flux(most likely) or you wire is not good enough for this task
Wire from a transformer has enamel insulation, this wire is not good for the task - to hard to remove the insulation
There is a wire which is much better for the task - http://multimediacity.krasno.ru/mgtf007.jpg but unfortunately I cannot find non-Russian analog of it
You need iron with a thin tip

Thanks for the tips Doomer, I was wondering if that because the wire is "wrapping" wire, made for transformer and not designed to be specifically soldered to, that this is not a good choice.

I will look for some other options for wire and buy some different flux and give it a shot.

I have been looking for large magnifying rings that do more than 2x or 3x most arm type table clamped glasses are small res, with a 5x inset and not large enough.

will report back on progress.

Thanks.

The transformer wire with enamel/varnish insulation (yellow-brown colored thin layer of hard-to-remove stuff on a copper wire) is simply going to be very big PITA to work with, I wouldn't recommend using it at all

These wires look good and they are already tinned

http://www.ebay.com/itm/20-feet-32-AWG- ... 589d2873d0

http://www.ebay.com/itm/20-feet-32-AWG- ... 35c9ffded9

As with all things.... practice makes perfect... remember that flux is your friend and don't be afraid to use it. I prefer to use mine from a syringe with a small needle for accurate application, and although your soldering kit is temperature controlled, you will find yourself playing with the temp to get it just right... working quickly (to avoid component damage) comes with practice, good preparation and correct set-up.... it may take a while and some fails to achieve, but soldering and de soldering will soon become second nature...

For fine work, I use a stereo microscope with ring lamp attached, I have tried a USB microscope, but have found them far too fiddly and a bit awkward to use... you will be surprised what you can repair and re solder with a fine tip and correct magnification....

Enjoy the learning curve....and don't get too frustrated if at first you don't succeed.....just try again....

I always assumed the stereo microscopes were very expensive. Ive seen some that aren't all that bad. 20x and 40x seem good magnification. Thanks alot

You'll probably find that 10x will be ample..... I have 20x lenses, but have never had the need to use them....

This is the one I use... cheap, cheerful, and does the job.....

http://www.ebay.co.uk/itm/Stereo-Microscope-with-Binocular-Rotating-Observation-Head-Brand-NEW-LOW-PRICE-/140938461881?pt=UK_Collectables_Scientific_MJ&hash=item20d09642b9

Thanks for the advice, especially on the magnification x, these details are ones that make good/bad purchase decisions, and aren't always known in time

Doomer wrote:The transformer wire with enamel/varnish insulation (yellow-brown colored thin layer of hard-to-remove stuff on a copper wire) is simply going to be very big PITA to work with, I wouldn't recommend using it at all

Don't agree with you. This wire is excellent, just must know how to use it. It is matter of some tests.

HaQue wrote:I always assumed the stereo microscopes were very expensive. Ive seen some that aren't all that bad. 20x and 40x seem good magnification. Thanks alot

Come on... You want make hard things without good tools?
I use microscope wit 45x magnification. It is very good.
If you don't have a really GOOD solder station your work will be very hard.

With proper tools and skills, solder to monolith takes ~10-15 minutes.

Hi mate, just a few random points might be some use ...

If you haven't seen it already, maybe check out EEVblogs youtube soldering tutorial ... iirc its a small no-legs device soldered "dead bug" fashion on to a PIC development board. similar type to sticking a mono on the tsop adapter.
Some nice tips in there.

If you go for a scope be sure to check out the "working distance". this gives you an idea of whether you can get a soldering iron comfortably under the lens area.
Stereoscopic or binocular seemed to be best ebay keywords.
A cheap led pen torch can be blu-tacked on to the turret as a cheap alt to a Ring of LEDS, or even a despklamp tilted over.

Got an Olympus zoom 10-40 for under £100GBP on ebay. home brew stand. works a treat.

Maybe also check for the "long arm" variety. these usually have low magnification and long working distance as they are designed for lab bench type environemnts.

Zoom is a nice bonus if you can get it. low mag for finding stuff on board and general inspection, hi mag for checking shorts in close together pad work like you mentioned above.
Flux: bottle type, thin liquid rather than pen. Tiny artist brish.
i found the little square jar dispensers are good with the metal top. pop your brush on it and it floods the little saucer up top.

Another possbility is getting the solder balls and placing them on the pads with the end of a scalpel, then hot air to melt. saves dragging solder all over the place.

Finally, track dependent, you can also offset where you solder.
Trace the tracks away from the pad and space the tin blobs around the tracks leading to the pads. this sometimes used for dense trackwork where a bed of nails approach wouldnt work on the pads themselves: too close together.
-------------------------------[O]
------------------O------------[ ]
-----O-------------------------[ ]

sometimes helps to only clean the conformal coating off where you want to solder, rather than the entire board. Saves the solder adhering to adjacent tracks.

gl mate. makes my eyes hurt just thinking about it.

K

Thanks everyone, I think I can put bed to this thread now after all that great advice.

I have to go drive now for a few days, so I wanted to give it another shot before I went. I pulled apart a few cables looking for some wire with better soldering properties. I found some from a vga cable with stranded wire that is 0.10mm and can be tinned fairly easily. I would say that working under the magnifying glass of 2.5x - 3x is going around 40% improvement.

I looked at a heap of ways making a jig with pins and everything seemed harder than just biting the bullet and soldering.

BTW kern, is the zoom a lens to go on the scope or an actual camera? I had heaps of hits with Olympus zoom as keywords.

cheers

i have very thin wire for sell.

HaQue: the zoom is the actual microscope.
I used to seach for "stereo microscope" and then ebay will put a few suggestions underneath like nikon, olympus etc.

The benefit of the removable head mech is that i *think* i can remove the gear from the stand, invert the holding piece at the back and attach to a boom.

networkpc3000 wrote:i have very thin wire for sell.

Hi, can you tell me the width in mm? does it solder well? You can PM me some more details if you like.

Is there a there a theoretical minimum size of the wire, such as signal would cause data corruption if too small ? I already guess keeping wires as short as possible is a good idea.

Thanks for the details Kern, that looks like it has a pretty good viewing area and space under enough for soldering.

I spent a while before I had to go last night practicing on some 0.15 wire. I managed to solder 15 wires to a blank TSOP48 PCB side by side. The biggest issue I have at the moment is that I cant seem to get the solder to sit right on the tip of my iron in tiny amounts. If I put a lot on it will, but I need a tiny amount to tin the pad of the monolith. I probably need a new tip, though the one I have is quite small, but has been shaved to a point.

I used to think soldering in 8 pin 12c508 PICs into PSX was hard, then mastered that and along came PS2, they had some small points, and then the Wii even smaller. I actually thought I was a pretty good solderer

Anyway key point is I have made significant progress

This city Im in for the day is a lot larger than my own so I might checkout some electronics stores and see what toys they have.

It's 0.025

I got my Stereo Microscope wow, Pity I wont have time for 4 days to try out soldering now.

I also bought some good solder, some flux liquid and flux past and a LED Light ring for the scope.

I will research about different eyepieces and see how I can expand the scope a bit.

I am confident now I am better informed

Thanks to everyone who offered advice!

Here is some info about microscopes. Sorry, only in Polish language, but you can use google translator

http://www.elvikom.pl/forum/viewtopic.php?f=112&t=27203

Thanks, good to get more info