Successful Darkroom Management

The 5 most important points

ICT Evening SeminarHayling Island

September 2011

Topics•Housekeeping•Maintenance•Environmental Control•Process Control•When it all goes wrong !

Why control the darkroom ?

Minimizing defects to maximize quality

The phototool is the master film – every circuit produced should mimic the film perfectly.

Therefore, problems on tools = problems on boards

If the images are wrong, it’s likely that the printed circuit boards made from those images will be rejected.

Rejected boards can’t be sold. They cost you money.

Remaking them wastes time and resources.

Your productivity suffers.

You lose capacity.

Inside the Darkroom – General Housekeeping

•Keep people out•No food, no drinks•No unnecessary items•No cardboard boxes•Cover up when inside

The darkroom must be spotlessly clean. Not only do we have to check for contaminates from dust and particles that can affect the image on the film and cause defects, we also have to check for liquid contaminates inside processing and imaging equipment.

.

Upto 5 million particles a minute can leave the human

body whilst walking !

Maintenance of Equipment

photo-plotter

Silver Recovery

Film Processor

The humidity and temperature control in a production environment is crucial .

Photographic film is made up of polyester base with a thin layer of gelatine on its surface, and the film absorbs moisture and ambient temperature from the air . So, a simple biology lesson - the colder it gets, the smaller it gets and inversely, the warmer it is, then the bigger it is. It’s the same with humidity, the more water it absorbs, the more it swells (size increases). Equally as it dries out, it shrinks.

So, if we have too humid a darkroom, the film is longer than it should be. Once it is imaged and processed and taken to another place in the factory, the humidity may be lower and therefore the film will shrink - you now have films that do not align to a drilled panel because they are too small.

Temperature has almost the same affect as humidity. However, natural temperature fluctuations are much smaller than humidity fluctuations, and are generally easier to control.

Natural Film Enlarger

Gain 1-3 Inches Totally Natural Harmful Side-

Affects

Humidity & Temperature

Temperature & Humidity

Process Control

Get the balance right !

Exposure & Development go hand in hand. Successful films means getting aperfect balance of the two, and maintaining it !

Development Control

Correct chemical dilution.

Set the replenishment rates correctly.

Set the development conditions correctly.

Set drying conditions correctly.

Maintain the processor properly.

The important goal of this stage is to expose your film correctly so that with optimal processing, you obtain high quality photo-tools that give the correct line widths when used for imaging .

Exposure control can be maintained by using a checkplot.

Check the Density with a densitometer.

Check linewidths

Do not change any processing condistions whilst changing exposures .

Continue until the density and line/gapsettings are correct , and then fully measure all the dimensions on the filmTo ensure it’s overall accuracy.

Exposure Control

Just Ask !

Technical support is very important..speak to your film supplier, your equipment manufacturers and perhaps audit your current procedures and setup.

It’s all gone wrong – what do I do ?!

Thank You !