My tiny single sided LM3886 PCB layout. :)

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My tip is to allow a bit more room around the zobel resistor, try not to bend the legs so close to the body. Doesn't need much more room though. You could also lose a bit of the ground plane around the backside of the chip which would allow you to bring the mute trace in a bit and the board smaller/chip closer to the heatsink/better clearance for the trace-heatsink. Do you have to bend the chip legs a bit as it is, to get it flat against the heatsink?
 
Here is my method(Thanks to GCollier and others):

1) Print out the copper side normally onto glossy inkjet photo paper with a laser printer on the darkest setting. I have had great luck with JetPrint premium glossy paper from walmart which is about $10.00US for 50 sheets.

2) Print the component side mirrored.

3) Place the copper laminate copper side up on a sturdy ironing surface. Place the copper printout toner side down onto the copper. Place a scrap wiece of plain paper over the photo paper as many photo papers have backing that turns sticky with heat.

4) Iron the paper to the copper laminate for about 5 minutes or so on medium to high temp (don't go too high as this can be detrimental to results).

5) While the laminate is still hot take it over to a sink and run warm(not cold) water over it to help cool it down to where the toner sticks, but still warm enough that the photo paper is still very workable.

6) Now the moment of truth, in a steady motion lift the backing paper and the photo paper off. You should see a nice black copper layer! :)

The etching part. Do this outside

7) Now I put 1/4 cup 30% muratic acid and 1 cup 3% hydrogen pyroxide in a disposable plastic container(the kind you get at the grocery store to store left-overs in). Be very carfeul with the stuff! Wear gloves and eye protection and clothes you don't care about. Don't get it on you period.

8) Now place you PCB in the acid bath a use a plastic spoon the agitate the solution gently.

9) In about 5 minutes when all the unwanted copper is gone pull the PCB out (I use plastic tongs for this, but any plastic utinsle should work) and rinse it very thoroughly with water.

10) Dispose of the acid safely (There are a couple of ways to this) and clean up.

11) Remove the toner from the copper using acetone in a well ventilated area using proper care.

12) Drill your PCBs. At the same time drill a couple of holes (I use the mounting holes) into your component side photo paper printout for use in aligning for ironing.

13) Take the PCB back in to your ironing surface. Place it copper side down.

14) Lay your component printout toner side down onto the component side (facing up) of the PCB using your drilled holes as a guide.

15) Place a piece of plain paper over the photo paper.

16) perform steps 4-6.

Done!
 
Hey Russ,

Great design, I'm going to make some tonight!

Quick question about your PCB making technique. My technique is very similar but without the extra piece of paper (just iron right onto the photo paper). I have a difficult time getting the paper off but keeping the toner on to the copper. Are you saying the toner will stick to the copper and the paper will stick to the photo paper and will pull off all at once? My current method takes hours of soaking and rubbing to get the paper off.

If so I will definitly attempt tonight with the second sheet.

Also you say medium heat, whereas I was using max (1200W iron). Maybe that will help.

Pete
 
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