Boards for electronic projects
There are many electronic circuits out there you can make yourself. And designing your own is not that hard either. But whatever you make you need to put it on something. Here there are multiple alternatives depending on both the complexity of the circuit and how permanent it is. I'll give you an overview:
The first thing is usually to place the components on a breadboard. A breadboard is really only a board with holes and connection in strips between the holes. It is very easy to build on these but circuits can very soon become very complex on hard to look at. It is also very easy to put a component in a wrong hole and get hell trying to find what is wrong with the circuit. A tip for those building on breadboards is to always cut the wires as short as possible and not let them become a big nest above the components. Otherwise it is quite easy to pull one out and not remember where it was supposed to go, or even seeing that it was out. They are great for prototyping but after that you really have to move on to something else.
If you need something a little bit more permanent than a breadboard, a stripboard is the way to go. It is a board with holes just like the breadboard. One of the differences here is that the holes are connected with copper tracks that you can break yourself. By breaking the copper tracks and creating new tracks with wire simple circuits can be made. The other difference is that the components need to be soldered into the holes. Since the tracks are very wide this is very easy. Just be careful so you don't connect two tracks that shouldn't be connected with solder. It can be a bitch removing, even if you have a solder sucker (a vacuum pump) or solder wick. If you have a cut close to where you are desoldering the track can very easily come loose.
The stripboard is the easiest method for building a permanent circuit. But after a while you will want to move on to more complex circuits that don't lend themselves easily to be transferred to a stripboard. Then you really need to move on to a custom made PCB. There are many ways to make these, all depending on how complex circuits you have.
The most common way to create your own PCB is through etching. When you get board made for etching it is made of three layers.
1. Photoresist
2. Copper
3. Glass fiber board
The first thing you have to do is cover the photeresist where you need to have copper tracks. If you have a very simple circuit this can be done with black tape. If it is more complex you can print out your circuit on a OH-transparency or through a laser toner transfer (have not tried this method but it looks promising). Then you subject the photoresist to UV-light. This removes all of the photoresist which wasn't covered and leaves clear copper. This copper can now be etched away with chemicals. You are then left with a glass fiber board with copper tracks just where you wanted them. After drilling holes to attach the components you are done.
There are some limitations here but basically it is a very good process that works with most circuits you are going to make yourself. Some cicuits though are too complex to make in this way. If you need very high accuracy, e.g. for surface mounted components, or if you need more than two layers (front and back) of tracks, you really need to send away for a professional firm to make the board.
This is not hard, there are multiple firms that do this. In the States you have Pad2Pad and ExpressPCB and back in Scandinavia, Elfa can take care of this through Elprint. There are of course many more, wherever you live.
Another way to make board are by milling away the copper. Companies or universities that want high quality PCBs without needing to send it away might have a PCB milling machine but unless you work in such a place you will probably not encounter this method though I can attest to it being very good (no need for drilling the holes yourself).
There you got it! Now you only need a CAD program for circuits too. Easy enough. Can recommend Eagle which have a freeware version of there program (maximum 100x80mm boardarea). Only remember that if you are sending it off, it should be able to handle Gerber-files since this is the standard for printed circuit board.
Tags: PCB, prototyping, breadboard, stripboard, etching, milling
The first thing is usually to place the components on a breadboard. A breadboard is really only a board with holes and connection in strips between the holes. It is very easy to build on these but circuits can very soon become very complex on hard to look at. It is also very easy to put a component in a wrong hole and get hell trying to find what is wrong with the circuit. A tip for those building on breadboards is to always cut the wires as short as possible and not let them become a big nest above the components. Otherwise it is quite easy to pull one out and not remember where it was supposed to go, or even seeing that it was out. They are great for prototyping but after that you really have to move on to something else.
If you need something a little bit more permanent than a breadboard, a stripboard is the way to go. It is a board with holes just like the breadboard. One of the differences here is that the holes are connected with copper tracks that you can break yourself. By breaking the copper tracks and creating new tracks with wire simple circuits can be made. The other difference is that the components need to be soldered into the holes. Since the tracks are very wide this is very easy. Just be careful so you don't connect two tracks that shouldn't be connected with solder. It can be a bitch removing, even if you have a solder sucker (a vacuum pump) or solder wick. If you have a cut close to where you are desoldering the track can very easily come loose.
The stripboard is the easiest method for building a permanent circuit. But after a while you will want to move on to more complex circuits that don't lend themselves easily to be transferred to a stripboard. Then you really need to move on to a custom made PCB. There are many ways to make these, all depending on how complex circuits you have.
The most common way to create your own PCB is through etching. When you get board made for etching it is made of three layers.
1. Photoresist
2. Copper
3. Glass fiber board
The first thing you have to do is cover the photeresist where you need to have copper tracks. If you have a very simple circuit this can be done with black tape. If it is more complex you can print out your circuit on a OH-transparency or through a laser toner transfer (have not tried this method but it looks promising). Then you subject the photoresist to UV-light. This removes all of the photoresist which wasn't covered and leaves clear copper. This copper can now be etched away with chemicals. You are then left with a glass fiber board with copper tracks just where you wanted them. After drilling holes to attach the components you are done.
There are some limitations here but basically it is a very good process that works with most circuits you are going to make yourself. Some cicuits though are too complex to make in this way. If you need very high accuracy, e.g. for surface mounted components, or if you need more than two layers (front and back) of tracks, you really need to send away for a professional firm to make the board.
This is not hard, there are multiple firms that do this. In the States you have Pad2Pad and ExpressPCB and back in Scandinavia, Elfa can take care of this through Elprint. There are of course many more, wherever you live.
Another way to make board are by milling away the copper. Companies or universities that want high quality PCBs without needing to send it away might have a PCB milling machine but unless you work in such a place you will probably not encounter this method though I can attest to it being very good (no need for drilling the holes yourself).
There you got it! Now you only need a CAD program for circuits too. Easy enough. Can recommend Eagle which have a freeware version of there program (maximum 100x80mm boardarea). Only remember that if you are sending it off, it should be able to handle Gerber-files since this is the standard for printed circuit board.
Tags: PCB, prototyping, breadboard, stripboard, etching, milling
posted by Tomas Björklund at 6:18 PM
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