Author Topic: PC board  (Read 1110 times)

Offline Steve Smith

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PC board
« on: January 20, 2016, 05:36:36 PM »
Hi guys,

I was fiddling around the past week end and decided to try my hand at manufacturing PC boards for detectors for my hidden staging yards, both ambient light for those in the open and IR for my 5 track hidden staging.

The photo is of PC board for a dual IR detector, which will have LED's indicating when the sensor is covered / dark.  All I need now is a decent fine point marker pen so I can get the trace lines thinned out.


I will spare you photo's of the first attempt, which although functional, look like c#@p.

Cheers,
Steve

Offline Freightcars

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Re: PC board
« Reply #1 on: January 20, 2016, 05:53:42 PM »
Hey Steve,

That's some nice work.  Good Job  :thumb:

Could you share some details on how you "make" the PC boards?

Cheers,

Niel

Offline Steve Smith

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Re: PC board
« Reply #2 on: January 20, 2016, 06:42:49 PM »
Hi Niel,

I have a PCB design freeware program I downloaded some time ago, but am too lazy to learn it.   I designed the PCB layout in Excel, from a diagram taken off the internet, sizing the columns/rows to give the correct dimensions for components when printed on paper.   Make sure all the traces in the diagram are drawn in (ask me how I know !)

I used single sided PC board cut to the required size.   Double sided boards are available which allows traces to be made on both side for more complex designs.

I cut the paper design to size and glue it (Pritt) to the copper clad side of the board.  I marked all of the holes for components using a sharp centre punch, before removing the paper and cleaning the glue off.   I drilled 1 mm holes for all the components and cleaned the board with methylated spirits to remove grease residue. 

I marked the traces using an ordinary bullet tip permanent marker, taking care not to touch the copper board.   Initially I draw the design by freehand, but the one in the photo was done with a ruler which makes it look a lot more professional.  Make sure that the trace is fairly thick (thick, not wide) and there are no missed areas.

The board was immersed in a shallow dish of Ferric Cloride solution (available at most electronics component stores either as a solution or crystals), enough to just cover the board, and left for around 15-20 minutes, agitating regularly, until the copper had etched away, leaving the traces untouched.  I used around 35ml of Ferric Chloride in a small container to do the board in the photo.

After the etching was complete, I washed the board in cold water, dried it, and cleaned it with meths to remove the marker ink.

Take extreme care and use rubber gloves when using Ferric Chloride, as it is highly toxic and very corrosive.   It dissolves all metals so use plastic or glass containers for etching.   I disposed of the used Ferric Chloride down the drain, flushing with large volumes of water.

I reused the Ferric Chloride once only, and it markedly lengthened the etching time of the second board.

Also, if going the route of making multiple boards of the same design, do one first to try out and make sure it works first  (don't ask how I know)

Cheers,
Steve

Online ColWer

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Re: PC board
« Reply #3 on: January 20, 2016, 06:52:05 PM »
Hi Steve,

Very interesting!

Do you have schematic diagram for your IR detection project? Looking forward to turn everything orange.  ;D
Cheers
Werner

Online capeklr

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Re: PC board
« Reply #4 on: January 20, 2016, 09:27:14 PM »
Hi,
I've made lots of circuit boards, I have a PC board design program, but it does not work with windows 7  :bluduh:
So now I have downloaded a free program and managed to get it to work to design a layout, but (there always seems to be a "but") when printing out on special clear plastic sheets I can't get the settings right to print it 100% light proof so that I can place it over a copper board with photo resist covering to expose it to a strong light and then develop the board before etching.
I also use Ferric Cloride to etch, but I heat it to 45C for a much quicker etch and you can also reuse the solution many times.
Cheers.

Online ColWer

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Re: PC board
« Reply #5 on: January 21, 2016, 06:16:39 PM »
Hi there,

What would be great is to get a laboratory stirrer. It has a heated pad (variable temp settings) and a liltle magnet you pop into the bowl. The magnet turns and then agitate the Cl3Fe. Yes, and there is a but, they only R6000 plus.

Capeklr has fine tuned his process. ;D Would a laser printer sort the track quality issue?

Cheers
W

Offline Steve Smith

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Re: PC board
« Reply #6 on: January 22, 2016, 07:29:17 AM »
Hi Steve,

Very interesting!

Do you have schematic diagram for your IR detection project? Looking forward to turn everything orange.  ;D
Cheers
Werner

Hi Werner,

The schematic is from Rob Paisleys website (http://home.cogeco.ca/~rpaisley4/CircuitIndex.html)



The diagram is for a single detector section, but I modified the PC board to make use of the second set of contacts on the LM393 IC for another detector set.

Cheers,
Steve

Online ColWer

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Re: PC board
« Reply #7 on: January 22, 2016, 03:09:17 PM »
Awesome. Thanks Steve!  :thumb:

Offline BigEd

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Re: PC board
« Reply #8 on: January 25, 2016, 01:08:48 PM »
Looking good Steve. Need to pop in for a visit again...
For long you live and high you fly
And smiles you'll give and tears you'll cry
And all you touch and all you see
Is all your life will ever be

BREATHE
Dark side of the moon
Pink Floyd 1973

Offline GlynnC

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Re: PC board
« Reply #9 on: January 25, 2016, 02:29:02 PM »
Hey Ed,

When you do pop in, please get some photos for us?

 :rant:

 :)

Glynn

Offline BigEd

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Re: PC board
« Reply #10 on: January 25, 2016, 02:53:04 PM »
Of Steve ??? :stir: :peep:
For long you live and high you fly
And smiles you'll give and tears you'll cry
And all you touch and all you see
Is all your life will ever be

BREATHE
Dark side of the moon
Pink Floyd 1973

Offline Freightcars

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Re: PC board
« Reply #11 on: January 25, 2016, 03:56:22 PM »
Hi Steve,

Thanks for the detailed description.  I need to try this out sometime.

Thanks,

Niel

Offline GlynnC

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Re: PC board
« Reply #12 on: January 25, 2016, 05:36:03 PM »
Hell no.

His layout  :biggrin:

Offline Steve Smith

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Re: PC board
« Reply #13 on: January 26, 2016, 10:46:08 AM »
Hell no.

His layout  :biggrin:

You sayin' I'm ugly ?  :rant:

Offline GlynnC

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Re: PC board
« Reply #14 on: February 01, 2016, 07:55:13 PM »
Hi Steve,

LOL, No

I have seen you though. However, I have never seen your current layout...  :innocent:

I keep hearing about it from certain people...

BTW Steve,

I hope you and the family are well.  ;)