Resizing this tiny PCB - Page 1
Forum section: electronics / beginners

author: recharged
author_rank: Contributor
timestamp: July 28, 2012, 04:26:36 pm
content: Hi guys, I need some assistant with getting a smaller size of this PCB printed to be used in a new project. I have never done any PCB printing or designing before so I could use some help with getting some printable layout together. I was hoping someone here with a spare time on their hands could help me out. I have included an image below to give you an idea of the shape I'm trying to get from the original PCB.

author: hlavac
author_rank: Frequent Contributor
timestamp: July 28, 2012, 07:20:10 pm
content: What is it? Conductive rubber buttons backplane? Or touch sensors?You will need some kind of coating to stop corrosion of the exposed copper contact patterns.Also two side board with vias like that is hard to make yourself.Does the front side have to be absolutely flat or can you have some solder joints on it somewhere?

author: recharged
author_rank: Contributor
timestamp: July 28, 2012, 08:17:53 pm
content: It's a conductive rubber buttons backplane. This is for prototype so I'm not too worried about corrosion. The front doesn't have to be flat - the side with the wires soldered on is not flat. It's the angle of the picture that makes it look like that. The solder joints can stick out to make soldering easy. The important thing is to have a smaller PCB that works.

author: hlavac
author_rank: Frequent Contributor
timestamp: July 28, 2012, 09:05:04 pm
content: In that case, it will be quite easy - go for single sided board.First you need to figure out the exact dimensions of the board to fit the enclosure.Once you have that I can draw you the board in Eagle and walk you thru the process of making it...You will need access to a printer and some supplies depending on the method you want to try.I recommend the photo transfer method.You will need:PrinterA few sheets of tracing paperPiece of single sided pcb with photoresistPiece of glass to hold the tracing paper with pcb pattern flat to the pcb during expositionSource of UV lightTwo flat plastic containersPlastic pliers to hold/move the pcb withDeveloper for the photoresistFerric chlorideacetone to clean the boardsmall drill for any holessomething to cut the pcb with (saw or score&snap off method)

author: recharged
author_rank: Contributor
timestamp: July 28, 2012, 10:16:49 pm
content: It will be difficult and probably expensive to get those materials in my area. My plan was to upload the completed diagram to one of those services that accept online order. That would be much cheaper in my opinion...

author: recharged
author_rank: Contributor
timestamp: July 29, 2012, 12:16:51 am
content: Here are the dimensions

author: PedroDiogo
author_rank: Regular Contributor
timestamp: July 29, 2012, 12:28:42 am
content: In my opinion the best way to do this is to download Eagle CAD, which is free and has great documentation online, and watch a few tutorials on youtube. In a few hours you will be able to design that pcb.

author: mariush
author_rank: Super Contributor
timestamp: July 29, 2012, 02:03:38 am
content: May I suggest cutting as much as you need from a board like this :http://uk.farnell.com/roth-elektronik/re315-hp/pcb-eurocard-fr2-2-54mm/dp/1172140http://uk.farnell.com/roth-elektronik/re310-s1/labor-card-cem3-3holepads/dp/1837352http://uk.farnell.com/roth-elektronik/re330-lf/labor-card-fr4-rm-2-54-mm/dp/1837356http://uk.farnell.com/roth-elektronik/re520-hp/pcb-eurocard-fr2-stripes-2-54mm/dp/1172154http://uk.farnell.com/roth-elektronik/re450-lf/pcb-eurocard-sop-w-o-holes/dp/1172110For a prototype pcb, I think you could easily cut a section suitable and use a bit of solder and wire to connect the odd rows to a wire, the even rows of pads with another wire, and you've got yourself those traces the button is supposed to short.At least it would be much faster than ordering a new pcb from China.

author: recharged
author_rank: Contributor
timestamp: July 29, 2012, 02:54:01 am
content: Quote from: PedroDiogo on July 29, 2012, 12:28:42 amI've looked at few other tutorials before coming here, but since I will be having this printed by a local manufacturer. I thought it might be better to get an experienced help instead making mistakes and then running into the problem of going back and forth.

author: recharged
author_rank: Contributor
timestamp: July 29, 2012, 02:56:36 am
content: Quote from: mariush on July 29, 2012, 02:03:38 amNo China for this one, this is too small of a project to go that far. I will be reaching out to a shop couple of hours away from where I live.