Maker Pro
Maker Pro

Dielectric Constant Standards of Materials?

W

Wayne

Jan 1, 1970
0
Hi

I have searched the web and found many lists of dielectric constant lists.
However, non of them make ref. to where they acquired the information from.
1/ Can anyone tell me where I can find the dielectric constant tables for
different materials at dif. temps.
2/ What frequency do they use for measuring the dielectric constant value
for example if you look at the chemical datasheet for say IPA it says the
dielectric constant is equal to 18.3 @ 25 degC. However, they do not say
what the frequency is? What is the standard method for measuring dielectric
constants; as it value changes as frequency changes with some materials?


Cheers


Wayne
 
S

Spehro Pefhany

Jan 1, 1970
0
Hi

I have searched the web and found many lists of dielectric constant lists.
However, non of them make ref. to where they acquired the information from.
1/ Can anyone tell me where I can find the dielectric constant tables for
different materials at dif. temps.
2/ What frequency do they use for measuring the dielectric constant value
for example if you look at the chemical datasheet for say IPA it says the
dielectric constant is equal to 18.3 @ 25 degC. However, they do not say
what the frequency is? What is the standard method for measuring dielectric
constants; as it value changes as frequency changes with some materials?
Cheers


Yes, my Reference Data For Radio Engineers lists dielectric constant
at various frequencies from 60Hz to 25GHz. My CRC Handbook refers to
the values as "limiting values at low frequencies", and points you to
NBS Circular 514. They give the values at 20 and 25°C and give the
nominal tempco in the vicinity of room temperature. Internet sources
often omit references and other pertinent data that you'll find in
printed reference books.


Best regards,
Spehro Pefhany
 
W

Wayne

Jan 1, 1970
0
Is there a standard body that list them such a NIST (although I can not find
anything on NIST)?



Cheers

Wayne
 
J

Joerg

Jan 1, 1970
0
Hi Wayne,
Is there a standard body that list them such a NIST (although I can not find
anything on NIST)?
Standard bodies generally don't go as far as dealing with properties of
each individual material. They only deal with the fundamental units such
as time, weight, distance etc. Anything beyond that would require a
hiring spree on their part and a huge tax hike, something we all don't
want ;-)

Also, the formulation for certain materials is not under their control
but under that of companies such as Dupont who can change parameters at
any given time.

Take a mundane material most common to folks like us, FR4. I had boards
where a simple vendor change caused the dielectric constant to veer a
little bit while both vendors insisted it was FR4.

Regards, Joerg
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that Joerg <[email protected]
acbell.net> wrote (in <[email protected]>)
about 'Dielectric Constant Standards of Materials?', on Sun, 26 Sep
2004:
Standard bodies generally don't go as far as dealing with properties of
each individual material. They only deal with the fundamental units such
as time, weight, distance etc. Anything beyond that would require a
hiring spree on their part and a huge tax hike, something we all don't
want ;-)

I don't suppose too many people would object to the hiring spree, but
the tax hike is quite another matter.
 
Top