making pc boards

[PChi]

Hello,

I have an Ultra Violet light box that hasn't been used for a long time. The specifications are:-
Model: Decon 415, Type: UVL-415
Exposure area = 470 x 255 mm, 4 off 15 W tubes, total power 60 W.
Overall dimensions = 625 x 290 x 130 mm excluding hinges and catches
Clockwork adjustable timer, 0 to 6 minutes.
A quick, not recommended, glance at the Ultra Violet light shows that it's working.
The foam on the lid has gone all crunchy and is turning to dust.
It's made of chip board so it's heavy and will need to be collected.
It's free to anyone who can make use of it.

[KatieandDad]

Crunchy foam is no probs. Scrape it off and replace with egg box foam.

Tubes need to be replaced regularly though.

[KatieandDad]

I'm still trying to get Toner Transfer method right.

Too long under the Iron and the Toner spreads. Too short and it doesn't stick.

This is OK for audio boards with big tracks and plenty of space between tracks.

I wouldn't trust it for high density boards.

[zdr]

I wish someone could design flatbed laser printer that could print directly on PCBs...

[jkuetemann]

Originally Posted by KatieandDad

For those foraying into UV board production.
...
3. The print must be completely opaque.

I had problems getting a completely BLACK - SOLID - OPAQUE print using an Inkjet printer and Inkjet transparencies. Every time I tried UV exposure I would get pin pricks through the black areas of print.

A Laser printer does a better job because the toner particles are FUSED together.

Having gone to a Laser Printer why not just print on magazine glossy paper and use toner transfer.

I go to a local printer and have them print my film on an 'Imagesetter'. This is the device they use to make the films for photo process printing plates. The print is absolutely opaque and pin hole free, everytime. If the design is small I have several printed in a letter size film and save these as spares should I damage my working film. They charge me about $10CAD for the pleasure.

[BFNY]

Originally Posted by anatech

I bought an IBM 5150 for my shop (no HDs, then the horrid Seagate ST-225 dead things). I also had to buy the $5K luggable, no HD in that either. Dos 2.0, then upgraded to DOS 2.1. Remember DOS 3.0? It had a habit of linking a sub-directory to the root. Instant "sorry about your data" situation.
-Chris

Geez, you are taking me backkk...My first PC a was a dual floppy Compaq, luggable (sewing machine white case) circa late '82 or early '83.
Then I joined HP, and entered the world of HP computers - HP85 w/ tape drive, HP9836, HP9816, and of course, the real time HP1000's. This was 1984. Microsoft was a tiny blip of a company.
Hard drives of say, 100MB were the size and weight of a small dishwasher.
This was back when floppy disks were single sided or dual sided, and only HP had the cool little 3.5" floppies, again, all single sided to start.

Getting back to PC boards, I played around with many toner transfer products for a long time, and ended up using the Pulsar stuff, with great results. Their toner transfer paper is excellent, but the real key is the very inexpensive TRF foil.

This TRF foil is applied over the toner image once it is on the copper side of the PC board. It is also "ironed on". It bleeds, seals, and fill in gaps on the toner, to make a better image. See the blurb here
PCB "Fab-In-A-Box" ... The 8min circuit board system

I've made a LOT of boards with this stuff, it works. I have no affiliation to them.
Bob

[PB2]

Remember the Fujitsu Eagle drive?
10.5" platters, 600W, 30 seconds to spin up, lol!

Fujitsu Eagle - Wikipedia, the free encyclopedia

http://museum.ipsj.or.jp/computer/de...es/0013_02.gif

We used a Xylogics 440 disk controller that was 2 Multibus 1
boards that included a microcoded bit slice processor.

[roline]

Still at it with the next project, RIAA preamp. Toner transfer method as my previous post. The last pic is after soaking the pcb in cold water to allow the paper to disolve and lift from the melted toner on the copper. All that is left on the top of the toner is a layer of the clay from the paper. If there are any small voids, I use a paint brush with modeling enamel and do a little touch up. The top of the PCB is black toner with the white clay layer removed. If you scrub too hard, you can remove the toner as well.

Also working on a hybrid tube Mosfet headphone amp with boxandall tone section and a couple of power supply pcbs.
I use green stiff floral foam to mock up the pcb to verify component count and lead spacings. When the PCB is etched and drilled, I just transfer the parts to the PCB.