MG Chemicals
AppGuide
One company. Many solutions.
Can I use sunlight to expose
your presensitized boards?
This is an excellent question. It is not a simple yes or no answer. There are
many cases where users have successfully exposed our boards using sunlight.
This does not surprise us because what is needed to expose our presensitized
boards is a UV light source.
Using sunlight however is not something we suggest. There is a relationship
between the intensity of the light and the amount of exposure time. To have
consistent quality every time, you must be able to control both variables. The
intensity of sunlight is not something we can control.
Not by an average user anyway.
Our
Exposure Kit (Cat. No. 416-X)
comes with a 15
watt daylight rated fluorescent light bulb (wave
length of approximately 400nm). At this intensity
and at a height of 5 inches above the board, we find
that the optimal exposure time is 12 minutes.
Other light sources will also work but tests will need
to be performed to find the optimal exposure time.
The following formula will be able to help you
determine a good starting point to test from:
X = r
2
/ P
Where,
X = Exposure time
r = distance of light source above the board (centimeters)
P = intensity of light in watts
Here is an example for our 600 series boards
using our own Exposure Kit (Cat. No. 416-X):
r = 5 inches
P = 15 watts
Therefore,
R = (5)(2.54)
= 12.7 cm
X = 12.72 / 15
= 161.29 / 15
= 10.75
Exposure Kit
Cat. No. 416-X
You can see that using this formula gives us 10.75 minutes of exposure time. As indicated
earlier, our optimal exposure time is 12 minutes. Keep in mind that the formula is only a guide
to get you close to the exposure time and not the optimal exposure time. You can now see why
using sunlight may work but not suggested because we are unable to control the P variable.
For complete photofabrication instructions, visit www.mgchemicals.com/techsupport.
E-mail
Phone
Fax
info@mgchemicals.com
1-800-201-8822
1-604-888-3084
1-800-708-9888
1-604-888-7754
For technical specifications,
MSDS, tech support and more
To customize this AppGuide
for your own use please email
www.mgchemicals.com
ISO 9001:2000
info@mgchemicals.com
Registered Quality System. QMI Certificate #004008 Burlington, Canada.
