Need help with making a double sided PCB

I need some help for this

1. What is the best transparant sheet for printing the pcb layout.
i have a deskjet 970 and a laserjet 5L

Which printer is the beter choice ?
and what type ( manufacture ) of transparantcy film is the best.

2. How can i align the upper and the bottom layer ( output on sheet ), so that the pads of the components are exactly align with the upper and bottom side of the print

Please hlp

Hi!

In my opinion should be the Laserjet the better way.
I think the Laserjet has a resolution of 600dpi. That's just enough for structures down to 200microns.
And furthermore the laserjet foils are much cheaper than this on you can use for an inkjet. The only thing you have to keep in mind, is that the foils must not distort while printing. So I made the best experiences with that special foils that are sold for pcb layout applications.

I made a few experiences with inkjet foils, but they mostly are not fully covered and because of that the structures had scratches.

I'm doing the aligning in a quite simple way...
I take the printouts and lay them over each other.
After that i take some glue and glue them together. Nowyou have a bag where you can put your board in. Take some tesa strips and fix the board in this bag... Now you can do the rest.

I think it's not the best way.. but the cheapest.

I hope i chould help you! Please excuse my bad english
Ciao reiniheini

Hi,

One hint.... if you look the printed image with lens, you'll see that the black is not good - it's more strong near the ends of the lines and it's more transparent in big areas. It's some electrostatic effect of disattraction the charged ink.

Some firms sell speciall sprays that make colours dark and dense - you just spray over the printed sheet and you get extreme dark and dense print.

I saw that some people use one other way, that gives better results.

Just put some disolver for nitro paints in flat plate. Put your image over the vapours for several minuts, until the colors become dense and dark enough. It's good to put the disolver for nitro paints into some closed box, to avoid evaporating and smells.

Best regards
Luben

Hi The Puma,

I also use a laser printer. But take care, the printed picture ratio is not exactly 1:1. In y-direction (long side) you will get a magnification of about 1-2%. This could give problems if you have large pin arrays (IC's or connectors). Perhaps it's better to arrange them in X-direction. I tested several (HP) lasers, all had this 'problem'.

Bye

Hi,

You can solve the problem with magnification is you:
- print to file (post script PS) the PCB
- import in CorelDraw
- set some correction in the dimensions

I succeeded to print PCB for calipper on Linotronix by resizing one of the sides with 1mm on 1 m. I got perfect PCB with excellent punctuality for calipper.

best regards
Luben

I use a stapler to stick the two films together after aligning them up, and sellotape to stick the board down.
Results are ok.

and how do you implement the vias ??

Hello, The Puma

There is much to say about the subject.
Try this link:
https://groups.yahoo.com/group/Homebrew_PCBs/messages/
You should get most of the answers.

Good luck
777*

Hello, luben111

A long time ago I saw a copier that used aceton to stabilize or enhance the images.

777*

printers

hello folks,

some time ago I've this distortion problem when printing the files to PS and then handling the files to a bureau to be print. All got distortion. Is there any program where I can inspect the file to see if the aspec ratio is ok? or dimensions... corel draw makes this possible???
regards,
2000

Hi,

CorelDraw can operate with 0.000001 mm resolution (if set correctly).

You can measure any objects and resize them easy.

In addition you can add to the PCB any graphics and messages - the design could become really cool.

Thanks all for replys

corel

hello friends,

one more questio, after editing the ps file at corel, I'll need to print it again in PS file, does it will get distortion again??? is it better to print it in a eps or ps to send to the bureu?

regards,
2000