Is it possible to make PTH (Plated Thorugh Hole) at home?
Can somebody explain the procedure?
Best Answer
As Majenko says, a few folk have tried the conductive liquid route. From what I have read it seems to work okay but requires fine tuning and experimentation (but then so do the rest of the home brew PCB techniques if you want the best possible results)
I like the idea of conductive liquid/vacuum followed by copper electroplating to make them more reliable.
In general I agree with Mike - if you are doing this at all seriously etching your own is simply not worth it given the speed/price/ease of obtaining great quality boards. However if you need a quick hack or are in a rush to try something out though I find it certainly can come in handy to have a little etch tank sitting there.
Anyway, another suggestion is to use through hole rivets. I have used these (the 0.6mm and 1.0mm ones) with great success on my etched boards. I didn't bother getting the press as it was too expensive to use for something I only do occasionally when in a hurry, but it works fine without if you can cope with a little bit sticking out on one end (~0.4mm) and having to solder them. If you are planning to do this a lot grabbing the press would probably be worth it (or hacking one together yourself with e.g. a hole punch and pin)
Here is a picture of them in use (e.g. there are 2 next to the light brown capacitors pads just below the top IC)
Resistors are 0603, traces from ~0.25mm to ~0.8mm, rivets 0.4mm hole, 0.6mm diameter.
No, you don't want just a oversized via. Step back and think about the problem a bit. You don't just want a mounting hole, but rather a genuine electrical part. This part should show up in the schematic, be something you place on the board, have a pin connected to a net, and a pad that connection can be routed to, just like other electrical parts.
The correct answer is therefore to use such a part. This would have a schematic symbol with one connection. The package would be a thru-hole pad with the hole size matching your mounting screw and the pad diameter a little larger than the screw head diameter. If you want this to be a ground connection, connect it in the schematic to your ground net.
I have done this before and have a few such mounting hole parts in my library, including one for a #4-40 machine screw.
Use a via to a track and set via pad size to whatever you wish.
There will be a minimum size to obtain reliability.
Your PCB supplier will (or should) have design rules covering this.
Best Answer
As Majenko says, a few folk have tried the conductive liquid route. From what I have read it seems to work okay but requires fine tuning and experimentation (but then so do the rest of the home brew PCB techniques if you want the best possible results) I like the idea of conductive liquid/vacuum followed by copper electroplating to make them more reliable.
In general I agree with Mike - if you are doing this at all seriously etching your own is simply not worth it given the speed/price/ease of obtaining great quality boards. However if you need a quick hack or are in a rush to try something out though I find it certainly can come in handy to have a little etch tank sitting there.
Anyway, another suggestion is to use through hole rivets. I have used these (the 0.6mm and 1.0mm ones) with great success on my etched boards. I didn't bother getting the press as it was too expensive to use for something I only do occasionally when in a hurry, but it works fine without if you can cope with a little bit sticking out on one end (~0.4mm) and having to solder them. If you are planning to do this a lot grabbing the press would probably be worth it (or hacking one together yourself with e.g. a hole punch and pin)
Here is a picture of them in use (e.g. there are 2 next to the light brown capacitors pads just below the top IC)
Resistors are 0603, traces from ~0.25mm to ~0.8mm, rivets 0.4mm hole, 0.6mm diameter.