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Ceramic matrix after firing, for core of SMT inductors

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w3pbs

Mechanical
Mar 17, 2023
5
I have very little understanding of chemistry, and I am quoting this from a materials declaration expert:

[pre]oxides of metals are combined and different metals give different properties
after combining the powders and firing at a high temperature and transform the
individual oxides of metals into glass or ceramic matrix as a glass frit.
The individual CAS Numbers that were present when they were a powder do not
exist as single substances anymore. The term UVCB now applies. (unknown or
variable composition of biological materials)[/pre]

What can be done to relate this to the purposes of REACH and other scrubbing lists?

More precisely, what are the chances that the UVCB now contains restricted substances, in ppm that exceeds the regulatory tolerances?

For example:
Will "combining" and "firing" any combination of "oxides of metals", none of which is Mercury, results in UVCB that all of the sudden contains Mercury?

By knowing what's NOT in the source mixtures is it becoming predicable what is not going to be in the resulting UVCB?
 
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"What can be done to relate this to the purposes of REACH and other scrubbing lists?"

Dunno, have not read up on those regulations.

"More precisely, what are the chances that the UVCB now contains restricted substances, in ppm that exceeds the regulatory tolerances?"

Should be pretty low chance as long as the manufacturer knows what they are doing.

For example:
Will "combining" and "firing" any combination of "oxides of metals", none of which is Mercury, results in UVCB that all of the sudden contains Mercury?


Possibly, if the firing is done with a fuel that has trace mercury in it and that gets deposited on the parts. All petroleum fuels (natural gas, oil, and coal) can have trace amounts of mercury.

By knowing what's NOT in the source mixtures is it becoming predicable what is not going to be in the resulting UVCB?

Unless you are a magician, it's not possible to create mercury out of thin air. If you have a sintered part with detectable mercury in it, then it had to be in the source materials or added to the parts during some part of the processing.
 
Thanks, this helps me with my assumptions.
I got it, the manufacturer may have many legitimate reasons not to share too much information regarding even non-critical parts of the design, such as the core holding the inductor coils.

I just need to be sure I did not miss an opportunity to deal with that, and that I do not assume one thing only to have someone prove me wrong.
It is a pain in the rear knowing the full 9% coil composition, but none of the 91% core which does not affect form or function.
 
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