Warning: long
I am sort of surprised to see the amount of activity on this thread. I have this harbor freight
shear/brake and like it.
**broken link removed**
I have nothing against photo transfer PCB making. I use the pulsar system. Which is better for you depends on a few things.
First you wanted to see a real PCB. This
work in progress is the 44 pin TQFP board. I did a shitty job on the 805 parts (
do not work when angry). The processor chip is spot on. The unpopulated pads are for a serial EEPROM.
Note: If I cared about what people think I would not post this image. This my first shot at this board. The next time I will do a solder mask and everything will be beautiful. I will even clean off the flux
**broken link removed**
Some of the header pins are soldered top and bottom. The bread board holds the loose pins in alignment during soldering. For vias I used .025 in holes stuffed with header pins that are held in by friction. Again ugly but faster than messing with wire. The plastic on the 2x5 header is above the PCB because the pins are soldered on both side.
The following is about the two methods. It has more toner transfer detail because that is what I have been using for the past few years. I have tried to be fair to both.
It used to be that you could get more resolution from the photo method. I do not think that is true anymore. Pulsar Toner transfer puts the toner on the copper. Photo relies on contact print.
I am not including P&P here.
Resolution is limited by the printer and the ability of the PCB to hold a narrow trace. Now all PCBs are created equal.
Both methods have steps you have to get right. With photo you need to get the exposure and developing correct. With photo transfer you have to get the toner to stick to the PCB and enough of it.
If you do this on the cheap I would have to say you are more apt to have success with the photo method. Toner transfer using an iron is an art, and a lot of work.
Will I get flack for saying that?
One problem with photo is that the photo resist chemicals/coatings age. If you make a board or two a year, or a board every two years this could be an issue.
With photo you need lights to expose the resist. With toner you need the laminator. You can go cheap on either with
mixed results. There are people who can and do do it on the cheap, but do not expect it to be easy to master.
Next is the cost. The pulsar paper and foil cost under 3 cents a square inch. How much you pay for the PCB stock depends on where you go.
I have not used the photo method recently enough to speak about the cost.
Alignment for 2 sides PCBs is always an issue. There are several solutions. It can always be done.
I drill my holes first then apply toner to one side and mask the other side. Then I mask the etch sided and apply the toner to the other. For masking I use common/cheap (not scotch or UPS) box tape. Some people apply toner to both sides and etch once.
If you do not have predrilled holes you can align the 2 toner images to form a pouch. I have not tried it.
Regarding fine lines with the Pulsar system. As I said earlier the limitation is not the paper but the printer and the PCB. I like to stay at .010 and larger. It is possible to put finer traces on the PCB but you can easily lift them when soldering. There is a greater possibility that that printer will not print the line well enough to etch.
Note that the starch coating on Pulsar paper does not absorb liquid toner. If an insufficient amount of toner is present it will tend to bead up rather than make a line. With a good toner cartridge this is not a problem.
When doing toner transfer use a brand name toner cartridge. There has been a report (here) of a refill brand that works but I do not recall the name. It is best to use a fresh cartridge for printing PCBs and then move it on to regular use when it gets somewhat used up. I do not do that but it would not hurt. It is all about delivering maximum toner.
3v0