Page 71 - PCMI December 2017 Journal

Advantages, Disadvantages and Comparisons of
Direct Image by Laser or LED Systems
Paolo Iellici |Sales Marke ng Director | Lasertech | IT
11/25/17
Or, even better - printing technology adapted...
For a really long time nothing changed - always the same concept: a mask made in different ways, a photosensitive layer and some kind of energy to transfer the image into the photosensitive layer.
So today the state of the art ”Old Style” comprises:
1) Print 2 layers, top and bottom, by laser photoplotter (+/-10 micron) 2) Develop (+/-50 micron each 500mm by Rh and °C)
3) Align and join the 2 films (+/-25 micron each 500mm)
4) Expose by UV on the right wavelengths and Rh and °C (+/-10%)
The complete process has a cumulative deviation of 75-120 micron for a phototool of 500x500mm.
That Is 50% of the total deviation in most etching jobs!!!
www.lasertechsrl.eu www.cm-italia.it 11/25/17
How to really change imaging practice?
Some companies started to think differently. Why not use higher energy
and print the image directly into the photosensitive layer? Why not print
the etch resist directly on the metal (PCB)?
I remember ETEC with the Digirite system for Direct Image, New System (today Orbotech) for Ink Jet, and others, but all of those pioneers in DI had in mind PCB not PCM, so those systems were virtually impossible for us to use, and for a long time limited to special production, or high-volume parts.
Also the initial investment was not affordable for most PCM companies. The main technical problems were,
•
•
•
(in the tests we did, 8 minutes were necessary for a 300x500mm sheet laminated with 25 micron dry film, a capacity of 60 sheets day.....)
So we forgot Direct Imaging for 15 long years...
www.lasertechsrl.eu www.cm-italia.it 11/25/17
single sided imaging,
alignment of top and bottom layers,
time needed to image a standard dry film or PCMetching resist,
Issue 130
December 2017
PCMI Journal Page 70
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