Do U know??? CHEAP, EASY and EFFICIENT technique for transfering layout from software to PCB?

Question

I've designed a layout for Pinited Circuit Board(PCB) on a software. Now i want to transfer it to Copper Board. Previously I've used tonner transfer method using TRANSPERENCY (transperent plastic sheet) and cloth iron. But it was not proved efficient, as it damaged the printed areas from copper board while etching. PLASE TELL ME SOME BETTER METHOD IF U KNOW!!!
THANKS.

Answer 1

If you are damaging traces by under cutting there are several causes.
1.) Over etching
2.) Leaving the board to long in the etch
3.) Poor resist coverage ( Try using a sharpie permanent marker to touch up any missed resist spots)
4.) attempting to make too narrow of a trace (Widen you min trace widths and pad sizes)

Under cutting maybe improved by increasing the etchant efficiency. Try warming the ferric chloride in a water bath (beware of fumes) this will increase the speed of the etching and minimize the time available to under cut the trace. Also you can agitate by rocking the tray to bring fresh etchant to the copper and wash away the disolved copper.

Under cutting is the etchant disolving the copper from the sides of the trace. The resist is on the top of the copper and when the adjacent copper is ecthed away is exposes the sides of the trace to the etchant. Slow etch speeds allow the etchant to eat away at the sides of some traces while other sections of the board are being developed.

I have used the toner transfer method and found it easier than Photo resist.

The older technique I have used is photo resist. There are two process types positive or negative, each require nasty chemicals and UV exposure lamps. The positive or negative referrs to the PCB art work transparencies. Each process works with its specific chemisrty and products. The good news is that most PCB programs allow for printing either Positive or Negative artwork.

Keeping in mind that a Positive image will make a negative image and visversa. You print a positive image to make a negative transparency which is then used to expose UV light to a photosensitive copper board to create a positive resist pattern.

Once the resist pattern is developed the board is etched as usuall in ferric chloride.


Really the Toner Transfer is Soooo simple in comparison for prototype PCB's . I would spend some time perfecting the TTF technique.

Heat and pressure are key in transferring toner. If you are using a regular IRON to heat try the following.

Use a 1 inch dowel under the PC board when applying heat . This allows you place more pressure onto the TTF paper while heating than if the PCB was flat.

One thing I do know about TTF is that it is very sensitive to the amount of toner available on the paper. You must boost the darkness and contrast to place a max amount of toner on the paper. The toner is remelted onto the copper to form a resist.

You may also use a secondary product (toner foils)which places additional resist on to the TTF toner on the copper.

I have toyed with the idea of buying an old Laser Printer and diabling the fuser heater. This would print unfused toner onto the TTF paper allowing me to melt even more Toner onto the PCB. The down side to this is the toner would smudge quite easily and I would have to have a dedicated Laser printer.

Remeber that modern laser printer are designed to conserve toner so you will have to try adjusting your printer settings or try another printer to get the most toner onto the TTF paper.


Good Luck

Answer 2

As long as Hawk doesn't make eye contact with me, I'd be up for it! Ace - Not PCB was suspended.

Answer 3

problematic task. search on google. that will may help!