Advice on double sided board

[odessa]

Hi guys,

Making a GLCD development board and quickly realised it's going to have to be double sided. I'm ok with actually producing the board but wonder how I'm going to handle soldering pins on the top side that are through hole , ie the GLCD and the Pic holder. resistors etc aren't a problem as the wire is visible same with the push switches

Is there anything available and easy ish to do that will connect the two sides ?

I was thinking of maybe a piece of copper wire soldered topside, through the hole then soldered to the component pin when pushed through ?

Any ideas ??

[brad]

I use these headers when soldering LCD's to a circuit board:



As for the pic holder, I am guessing that you will only have on track connecting to an individual pin. (I.E each pin will have a track connected to it either on the top OR the bottom)

If so, then you simply bend the pins that will solder to the top tracks on the board (so they don't go through a hole) and then leave the pins that connect to the underside of the board intact so they can fit through the hole.

[odessa]

Thats a really good idea thanks Brad

I should have it done over the weekend so will post some piccys. I'm using a 40 pin ZIF ( although if i bend the pins a 40 pin DIL socket would be easier) , a 128 x 64 GLCD, six buttons and a header for some A/D connectors.

It'll be my first proper double sided board so a bit of a challenge ...

Jay

[bitfogav]

I find when making your own double sided PCB, the heardest part is lining up both sides, if you use the press & peel stuff! hehe!

[odessa]

Yeh Gav I found that as well. I'm going to use photo resist so the lining up should be easy as its transparent, it's slipping the board between the 2 sheets thats tricky, still it'll be fun trying it out as I love making boards

[bitfogav]

Hope it goes well Jay

Using press & peel, I always do one side of the board first and then drill two pilot holes, either through the template holes for the PCB screws or through any component that is for a through hole component or for a via?, and use these two holes to line up the other side of the board.

[odessa]

Cheers Gav thats another good idea.

Got the board finished now in Eagle, I will print.etch it tomorrow.

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Thats pretty much final.

All the through hole devices are now connected to the bottom then to the top by via so I dont need to worry about soldering top
pins on the LCD or ZIF which I really wanted to keep so changing pics would be easy.

I have 6 switches, a 20Mhz crystal, voltage reg, and a header for AN0 and AN1. Should be enough to be getting on with

To think less than 1 year ago I could barely flash an LED is amazing to me .... hope it works now

Also I had the idea of using vero pins as vias ? You could use the flat side on the top and solder, then solder the bottom and cut the pin off ... sound feasible ?

Cheers Guys

Jay

[brad]

Hope it goes well Jay

Using press & peel, I always do one side of the board first and then drill two pilot holes, either through the template holes for the PCB screws or through any component that is for a through hole component or for a via?, and use these two holes to line up the other side of the board.

That's how i did it for my original 8x85 POV display, dare I say that great minds think alike?

[brad]

All the through hole devices are now connected to the bottom then to the top by via so I dont need to worry about soldering top
pins on the LCD or ZIF which I really wanted to keep so changing pics would be easy.

I have 6 switches, a 20Mhz crystal, voltage reg, and a header for AN0 and AN1. Should be enough to be getting on with

To think less than 1 year ago I could barely flash an LED is amazing to me .... hope it works now

Also I had the idea of using vero pins as vias ? You could use the flat side on the top and solder, then solder the bottom and cut the pin off ... sound feasible ?

Cheers Guys

Jay

Looking good there Odessa!

Do you know that if you're happy to freely give your PCB design away, you can get some PCB's made and sent to you for free? The PCB company will then make extra PCB's to sell to ther people online for around $3 each.

That's how I get my circuit boards now - all for free!

[odessa]

No Brad I didn't know that ....

How do I go about it ??


Jay

[odessa]

Overexposed the first 2 boards

Third time lucky perfect exposure but the back/front alignment was about 1mm out so useless ... doh

Tonight I will align by drilling as you guys suggested .. should have done that i the first place really .... lesson learnt .

I am going to recoat one of the first overexposed boards with photoresist and try again. Not tried that before but better than writing the board off.

Jay

Update:

Don't know if anyone else has ever tried using photoresist spray ?

My advice .... DONT BOTHER

Its almost impossible to get an even coat ... it stinks ( literally ! )

Have ordered some pre coated boards from rapid so will hopefully be etched tomorrow

Jay

[odessa]

Yay !!!!!


Finally built it and ... after debugging my total noob error it works

I couldn't work out why it didn't work at first, till I actually checked my schematic and in my rush
to assemble the board didn't notice I had connect up port D bit 4-7 to port C. I assumed that port D ran sequentially on the pic .... BIG lesson learn't. Still I managed to cut the faulty tracks and resolder jumper wires onto the correct pins and hey presto !!

Really pleased with it, now to get writing some proper code

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[bitfogav]

Great work Jay, the board looks good aswell

How did you find lining up both sides in the end? hehe!

[odessa]

Cheers Gav

Lining it up was quite easy...I Drilled the top left and bottom right pin through the transparancy then pushed a 1mm vero ping through to align both sides when exposing

Worked really well..If I hadn't noobed up the intitial schematic it would have been perfect

Still, wont make that mistake again

Jay

[brad]

I've been there and done that with PORTD

Very nice work by the way - I'm highly impressed! Look forward to what you will be doing with this new project board, it will certainly be of help to me when I get around to these cool displays.