Home made PCB's

[canyon]

I have been making all my own pcb's for the last 10 years with this method. I can easily and consistently reproduce traces down to .015" wide.

http://www.qrpbuilder.com/downloads/homemade%20pc%20boards.mp4

ken - wa4mnt
www.qrpbuilder.com

[ikrel]

Video Link is broken.

[BravoV]

Upload to youtube please.

[poorchava]

15 mils is not a brilliant result - it's ok, but not brilliant. Most people are able to reliably do 10mils traces with occasional 8 mils trace here and there with toner transfer method.

[Dave]

I have managed to successfully (and reliably) etch 6 mil traces with toner transfer. The key is to thoroughly clean the copper clad boards before laminating toner onto them. I use a kitchen sponge and some abrasive paste, commonly used to clean kitchen sinks, to clean the copper to a shine, wash everything off and finally wipe the whole board with paint thinner. Make sure not to touch the copper with bare fingers after cleaning - you don't want the oils from your fingers on the board.

I also suggest using ground pours when designing boards like that, as that minimizes the surface of copper that needs to be etched. The water-hydrochloric acid-hydrogen peroxide mix tends to start chewing copper at the edges and before the centers of large surfaces of copper are etched, you can lose traces due to under-etching.

[akis]

Is "toner transfer" where you use a household iron to heat-transfer a laser printed circuit onto the PCB effectively copying the (plastic) toner onto the PCB?

I have tried that in the past and could not get a good quality transfer. Some areas would be OK, but some areas would be fuzzy. In some places the paper would not come off easily and when pulled it would also pull the toner with it. You would not know how much you'd need to iron over until trying to peel the paper off, and then it would be almost impossible to iron over it again because it would not land on the same place. And then you have two sided boards as well to consider.

I wonder, aren't there automatic machines that can do this, even with a few manual steps, I'd pay even $2000 to get such a machine that could make two sided boards!

Also someone advised me that using the older type of PCBs (those made out of paper not out of fibreglass) makes it much easier to cut and drill into. Cutting through a fibreglass board I was going through lots of jigsaw blades, the teeth almost melted off with every inch or two of a straight cut.

[Rerouter]

to easily make a two sided board, get a hot plate press, similar to the one in frans videos, print out both sides with alignment marks,  and flipped to the correct side,

sandwitch the bare and cleaned pcb in the middle of the 2 transfer sheets and tape the corners to maintain alignment, (better if the board is sligtly larger than the design to begin with)

place the sucker in the heat press and bam, double sided board done in a few minutes when you get the hang of it,

otherwise look into UV, you print out boath sides on a transparency, and either do similar (using a UV treated board and a UV light box instead of a heat press) though you have one benefit in that you can drill 2 alignment holes and physically secure the pcb before exposure but loose out on it being a bit more involved a process with more chemicals,

[poorchava]

My process for doublesided pcb is following:
-clean the laminate
-export drill pattern and pcb outline to dxf
-drill and cut on cnc mill
-align first layer carafully, then GENTLY place a cloth iron on it for a few seconds so that the paper sticks to pcb
-do the same thing with the other side
-pass multiple time through hacked laminator
-remove the paper by soaking in vinegar
-etch

As for 6 mil traces: this is hard. I have bee occasionally able to achieve this feature size, not repeatably. Even high-tech, uber-quality pcb manufacturers (automotive, aerospace, medical etc) usually consider anything below 7mils "special" and charge you extra.

[nctnico]

Sorry but those are old standards. 0.15mm (6mil) is common nowadays and 0.1mm isn't something PCB makers are afraid of. If you go below 0.1mm the story gets different. I once tried to have a 0.06mm trace / 0.04mm clearance PCB made and that caused some frowning.

[Dave]

Is "toner transfer" where you use a household iron to heat-transfer a laser printed circuit onto the PCB effectively copying the (plastic) toner onto the PCB?

Yes, this method, however instead of using an iron, I use a cheap laminator (similar to this one) to heat-transfer the printed PCB design to the copper clad board. These laminators have two silicone rollers spinning in opposite directions and you put your board between them. Unlike the iron, the laminator applies pressure very evenly across the whole board and the results are much better.
The trouble with these laminators is their temperature: It's often too low to properly melt the toner (the rollers are in contact with a relatively small surface at a given moment and the large copper surface dissipates a lot of the supplied heat). I have modified my laminator by replacing the 110°C thermostat with a 155°C one. I also added many holes to the case to improve ventilation. Needless to say, I never leave it unattended, in case something goes wrong.