If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #1806
Joined: Sun Nov 09 2008, 04:58AM
Location: USA
Posts: 136
I get it; the top pic is the LED on the board, the middle pic is the let led, and the final pic is the 1, 2, 5 second exposures. The high density of the intended array is for illuminating a board that is coated with photo resist, masked by the pcb artwork....
How am I doing... oh... no, wait.. were you going to literally "CNC" etch the board by selectively exposing the photoresist with the multiplexed leds?
Perhaps get a uv laser diode, and appropriateeba focusing lens, and drag it around the board to draw your pattern. Ah, here we go... Something like this in a 2 axis (at least) cnc might get the job done... ebay
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
He is trying to etch boards without makign a mask, thus the need for many small LEDS
he tried using a laser to expose it in an earlier thread, but didn't have much luck.
Although except for maybe etching the simplest of boards, it seems the resolution of this will be too low.
Heres my idea, take a black/white LCD panel and put a backlight of UV leds behind it. There will probably be a ton of loss from the uv being absorbed in the screen (but i wouldn't expect a whole ton, glass is pretty transparent under 380nm and plastic goes to about 350nm). Then just bring up a picture of the board you want and viola
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062
hmm.... i did try that with a damaged single line HD44780 panel but unfortunately the panel broke during removal of the backplate.
It might work, i've confirmed some light gets through. My latest idea is using a spare PCMCIA laptop edge connector (which has virtually identical pin spacing to 0603) and a spare LCD panel's STaB connector as a ground plane and interconnect. Plan is to use Charlieplexing (common +V and Gnd) to minimise the number of interconnects to sensible levels. Am up to 12 LED's soldered with no defects... :) pics soon.
Will need to use some sort of mask to prevent spurious PCB exposure, have an idea to use a sheet of acetate with pinholes at the correct spacing.
Registered Member #1131
Joined: Mon Nov 19 2007, 01:36PM
Location: Germany
Posts: 9
@cjk2 It depends on the setting of the laser-focus, from 0.05mm to 1mm but the mecanical resolution of the plotter is limited to 0,1mm. the best results are with 0,15mm laser and ~30mm/s pen speed.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
LED PCB etcher
