[SI-LIST] Re: Solder mask
- From: liuluping 41830 <liuluping@xxxxxxxxxx>
- To: umamaheswaruk@xxxxxx
- Date: Mon, 05 Jan 2009 10:34:11 +0800
Hi Umamaheswar:
You can find the answer at "Soldermask: It’s
NOT JUST GREEN Anymore" ,by JODY WILLIAMS,PRINTED CIRCUIT DESIGN AND
MANUFACTURE,
MARCH 2005.
...A number of years ago a there was a discussion about this issue on
IPC’s Technet forum. Here are some of the most interesting
quotes from that discussion. Which one ?C if any ?C is correct?
You decide.
“… it goes back to the old military requirements which
said that you could have any color soldermask as long as
it was green.”
“Soldermask is green because when it was originally
produced, the base resin was brownish yellow in color
and the hardener was very muddy brown and when you
mixed them together you got green. Also, laminates at
that time were mostly green so it was easy to accept the
idea of green soldermask as well.”
“The green color of soldermask was chosen after
extensive testing by the US military at the National Materials
and Procurement Center in Cedar Bluffs Virginia in
1954 … That particular shade of green produced the right
contrast with the white legend ink while being tested
under all types of adverse conditions. Every other color at
that time failed to produce the same contrast under the
same extensive testing.”
“Soldermask is green because green has been proven
to be the color most visible to the human eye. Individual
colors have specific wavelengths, but combinations of
wavelengths produce differences in hues and intensities.
Yellow and green colors are the easiest to see in normal
light. Thus green is the easiest color to see, the color easiest
on the eyes and so the color best suited for board
inspectors and assemblers.”
There you have it: just a few theories about why green
soldermask was the only choice for so many years. Do
you agree or disagree with these theories? Do you have a
different theory? If so I would love to hear from you.
Regards,
LIU Luping
Msg: #1 in digest
Subject: [SI-LIST] Solder mask
Date: Tue, 30 Dec 2008 19:22:39 +0530
From: "Umamaheswar U-TLS,Chennai" <umamaheswaruk@xxxxxx>
Hi all,
I have couple of questions/doubts on solder mask, please clarify.
1. Why green color solder mask is popular when compared to other
solder mask (RED, PURPLE, BLUE etc.).
2. Are there any performance issues with other solder mask if I use
them.
Please send me your valuable comments on the same.
Thanks in advance.
Thanks& Regards
U.K.UMAMAHESWAR
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