Napsal: 14 led 2011, 22:11
GeorgeB: Já do toho teda moc nevidím, ale není tvůj problém v tom, že sis tam dal "diskotékové" UV-A, ale měl bys tam mít "solárkové" UV-B?
Vše, co potřebujete vědět o elektronice :-)
http://elektrobastlirna.cz/
jezevec píše:Rozostřené plochy, to nasvědčuje nedokonalému přitlačení předlohy desce cuprextitu
My vacuum frame was constructed using a 20x24" sheet of 3/4" plywood with a matching piece of pegboard laminated to it. I used a router to cut a series of shallow interconnecting grooves (air channels) into the plywood prior to glueing the pegboard on. The grooves lie directly underneath the holes in the pegboard. A tube glued into the edge of the plywood intersects the air channel, providing an easy way to attach a vacuum. I used thick construction adhesive (available in a tube and applied with a caulking gun) to ensure a tight seal between pegboard and plywood. The pegboard was sanded smooth and painted flat black. A 20x24" sheet of polyester is taped to one edge of the frame. To use, I lift up the polyester, place the neg/paper underneath and turn on the vacuum. Within seconds, the polyester is pulled tight against the pegboard, providing intimate contact between
negative and paper. The vacuum frame is hinged onto the edge of a wooden box that contains a bank of UV fluorescent lights. The exposure unit is bolted vertically onto a wall in a position that's very convenient for loading and use, without taking up valuable counter space.
I haven't had problems with the pegboard holes being too large. An insert
of stiff, open-cell foam might be a good alternative to using pegboard. If
you think about it, there are many different ways to construct a vacuum frame. All it takes is a good design and skill using power tools. The question of whether the polyester overlay degrades image quality has come up in the past. It does not. I'm using "Kleerbase", a product marketed to the graphic arts industry.
http://www.electro-tech-online.com/gene ... ocess.htmlExposure Frame
For best results, the emulsion side of the master film should be held in close contact with the resist surface. I use a home-made vacuum frame. It consists of 2 sheets of 1/8" Plexiglas. One sheet has a 1/8" NPT angle pipe fitting threaded into it, for the vacuum hose. The other sheet has a ring of .060" plexiglas strips glued around the edge. Just outside this ring is a piece of very thin (about 1/8" OD) Tygon plastic tube, used as an O-ring. The ends are glued together, and it is tacked down in a few spots with contact cement. The vacuum pump is a small diaphragm-type pump. it really doesn't need to provide much suction, due to the large area of the sheets. Mine is about 12 x 18", large enough to do just about anything I'd be likely to do. Right now, I expose one side at a time, but the films are aligned, so I can flip the vacuum frame over without risking that the board will slip out of alignment with the side already exposed.
Note that the dry film resist should be exposed with the cover sheets on, and then held in a dark place for 15 minutes before removing the cover sheets and developing.
jezevec píše:
Teď jsem přešel na negativní fotorezist, je to vlastně nalaminovaná fotocitlivá fólie. Výsledný spoj má ostřejší hrany a nejsou zde mikrotrhlinky. http://www.dioda.cz/index.php/vyroba-dps.html