Custom Adapter for Tiny Connectors or IC

It happens that you find interesting pieces at local fairies. In this case I bought some LCD displays for 1€ each. 
Since I wanted to connect them to a breadboard to make prototypes or test some features or codes, I needed to solder many wires to the tiny LCD contacts, or making a PCB to connect those contacts to larger pins. I went for the second way and I managed to be very accurate to avoid short circuits between the thin pads, I'll show you the entire process.

Step 1: References

With a fast research I discovered that the LCDs are very common 16 characters 2 lines MC1602X serie display. They are also compatible with the Hitachi HD44780 driver, so I can easily control them with Arduino libraries.
The 15 pins have a spacing of 1/20 inch, half the distance between common through-hole components and breadboards holes. To know the pins labels I've found this datasheet by Everbouchet/Wayton in internet, which is more likely referring this exact display module.

Step 2: Pcb Layout

In Diptrace I created two custom pad arrays and I connected them with regular tracks. I tried to keep the bigger the pads I could, because I noticed that sometimes very little pads detached from the board during solder process or due to a mechanical stress of the component. For the same reason I drew the pads with an elliptical shape. Free space between little pads is very thin, to be exact is about 0.2 mm, and it will probably be unsuitable for higher current, but it works good in this projects where LCD needs very low currents.
I attach the pdf file with PCB layout and also the file for Diptrace, so you can modify it if needed.

Step 3: Copper Board

Print the layout on a glossy paper with a laser printer (turn off toner saving option).
It's crucial find the right paper type, make more prints and check that edges are very sharp.
Set up the copper board cutting it with right size, then clean it very hard with a metal sponge and soap. This will make a good base to attach the toner with heat.
You can find more about ironing technique here.

Step 4: Transferring Traces

Use now the iron to transfer the traces on the copper board. Set the iron at 90-100% power, put the printed sheet in contact with the board, then push the head of the hot iron over the back of the sheet, only a bit to make it adhere with the copper side. Then insert the board with sheet on the upper side into a dish cloth, so to avoid ruin the iron, and pass more and more times especially on the board edges.
When you're satisfied dip it into water, wait a few minutes, and begin to scratch away the paper. To do that don't pull the edges, but scratch the center of the sheet, trying to not cut the toner traces. Use a soft toothbrush to remove entirely the paper from the board.

Step 5: Check

Now you have to check carefully each trace. If you're not satisfied take a metal sponge and scratch away the paper, clean the board with soap, and transfer with iron another layout, or cut another copper board to engrave both of them, as I did.
I had a problem with the transfer of the vector layout in a graphic software, it resulted into a pixelated image. Try always to print the original vector image.

Step 6: Etching

This is the second board, with toner traces already transferred, this time with a better print (the one I attached on this instructable of course). As you notice, the trace are very good, and no pixelation is visible.
Dip the pcb in acid (usually ferric chloride) and shake a bit the liquid to speed up the process. After about half an hour the pcb will be ready. The pcb comes out yellow, because the acid left this colour on everything it touch. It's easily removed with water, but beware to not dirty your clothes because acid consumes fabric.
Read more about etching technique here.

Step 7: Clean From Toner

PCB is etched now. Clean it from toner with the metal sponge, and check minutely the copper layout with the help of a magnifying glass.

Step 8: Drill

Time to drill the holes. Unfortunately my narrow bit is only 0.8mm and in this case a smaller bit would be better. I suggest to try with a 0.6 mm. However I was able to not cut the pads in half.

Step 9: Check Again

If the pads touch one each other, you can scratch the space between them with a cutter, so to remove the copper in excess. Test all the traces with a multimeter, you should obtain than no trace is connected with the other ones.

Step 10: Solder One..

You can now solder the pins row in the bigger holes. To do that raise the plastic holder and reveal a bigger space to solder. When pins are soldered you can lower the holder to hide the tin.

Step 11: Attach

Apply some double tape on the rear of the display board to attach the pcb. When this is in position you can solder the thin pins on it.

Step 12: ...solder Two

Pins are soldered now. You can refine the pin heads with a file, so to check again there are no connections between traces.

Step 13: Ready for the Prototype!

You can now insert your new LCD display into a breadboard to connect it on Arduino for your custom watch or any other project!

Comments

[AJMansfield]

You can buy specialized drill bits for drilling PCBs; they really don't cost that much, either, under $1 each.

[andrea biffi]

I didn't knew that... thanks!

[rpswift]

I recently purchased a set of ten 0.8-mm re-pointed carbide bits from Drill Bit City for $8.65. I've been very happy with the performance, they are 'Made in USA' if that makes a difference to anyone (i.e., not drop-shipped from China), they offer new bits as well as a lot of other carbide drilling/routing tools, and shipped the same day as ordered. I use them in my Dremel tool, and use Dremel's plunge router as a drill press (it's what I have/don't want to buy the drill press). I have had trouble with dulling of HSS bits followed by ripping-out my etched pads.
And no - I don't work there - I'm just saying... drillcity.stores.yahoo.net/

[AJMansfield]

NOOO! That's ALL WRONG! That type of drill bits should never, ever be used with a hand tool. They need to be held very steady, and need to be almost exactly perpendicular to the surface drilled. A drill press is needed in order to use that type of bit correctly. I am surprised they haven't snapped yet from the abuse; if you continue doing it that way I guarantee that they will.

[rpswift]

A year later - two bits have broken, just returned 8 for re-tipping after around 1,000 holes drilled... Notice that I indicated I'm using a plunge router as a simple press, secure the work appropriately, and run the Dremel at a suitable rotation rate.

As with any fine machine work, it's important to learn the "feel" of your tools and how they respond to the work. I typically drill holes freehand these days, against your best advice:

I am surprised they haven't snapped yet from the abuse

A craftsman does not abuse his/her tools or work.

[oppie]

What program opens your .dip file that was in the Zip archive? I've been using Eagle CAD for my pwb work.

[andrea biffi]

I also tested Eagle, but then I tried DipTrace, after a good review by www.eevblog.com and I like it more, so I've used that software.

[Raphango]

Whoa!
Great ible!
Congratulations!

[WinstonP]

That, Sir, is excellent workmanship. I wish my hands were that steady.

[Aeon Junophor]

Hi Andrea

I am really impressed about your instructable
This will help me very much with my projects. I just try the iron technique with a lot of different papers -as you suggested too- and experienced that siliconized paper works best to transform the toner to copper. You can find this paper at the backside of self adhesive paper labels e. g. parcel labels

Yours Aeon Junophor

[andrea biffi]

Aeon, I will never get tired to repeating how much your steampunk projects are AWESOME! I really LOVE the plasmabeam lamp, the plasmabeam generator, the nixie tube cryptographer, the plasma bulbs... and many others! Being helpful to your works is an huge gratification, and thanks for the hint, I will try that paper.

[rpotts2]

very cool! my problem goes one stage beyond that. I have to make a controller board. Yikes!

[paolochiarlone]

Bravo Andrea!

[andrea biffi]

An essential trick to solder trough-hole components: heat the pin and the trace, not the tin! Push hard the soldering iron head against the pin and the pad, then approach with tin wire from the opposite side, try to wait the right time to heat both pin and pad, and be fast to cover them with welded tin. It's not essential you cover the pad all around, only one side is good, it's essential that tin is glossy and it adheres on both pin and pad.

Another trick: use a flux core tin wire and apply soldering paste on old or dirty pins, this will help you a lot!

[Dartag]

Can you do an instructable on how you solder those tiny connections so perfectly? I've never been able to get that part right, no matter how many hours I spend practicing...it always ends up shorting across when the connections are so close.

[andrea biffi]

Granted that I don't think to have made a perfect work, and I'm sure I could have done better, yes I can certainly write an ible about the technique I learnt from other instructables members and from many video on internet. I'll pm you meantime, so to make practice for the ible ;-)

[andrea biffi]

That's great, I'll try certainly! Thanks!

[andrea biffi]

Thanks! Can you explain how to use oily thinner? Between toner and copper?