patnor1011
Well-known member
After seeing this thread:
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=9131
I decided to do small research and found this:
Resistors
Most chip resistors are of the so-called ‘thick film’ construction, where patterns of inks containing glass frit and a mix of metals and oxides are printed onto a ceramic substrate and converted to adherent, stable films by firing at high temperature (typically 850ºC).
The usual substrate is a high purity alumina3 sheet which is first laser-scribed in two directions at right angles to provide crack lines for breaking out the individual resistors at a later stage in production. The internal metal electrodes, usually of palladium-silver, but sometimes of gold, are printed across the appropriate cracks and fired on.
3 Alumina (Al2O3) is produced from the bauxite ore which is also the source of metallic aluminium. The crushed ore is digested with hot caustic under pressure, the solution filtered, and aluminium hydroxide precipitated by passing carbon dioxide through the solution. The resulting pure hydroxide is dried and calcined at 1100°C where it decomposes to give pure alumina.
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source:
http://www.ami.ac.uk/courses/topics/0135_cc/index.html
Looks like nice small source of AgPd for patient people.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=9131
I decided to do small research and found this:
Resistors
Most chip resistors are of the so-called ‘thick film’ construction, where patterns of inks containing glass frit and a mix of metals and oxides are printed onto a ceramic substrate and converted to adherent, stable films by firing at high temperature (typically 850ºC).
The usual substrate is a high purity alumina3 sheet which is first laser-scribed in two directions at right angles to provide crack lines for breaking out the individual resistors at a later stage in production. The internal metal electrodes, usually of palladium-silver, but sometimes of gold, are printed across the appropriate cracks and fired on.
3 Alumina (Al2O3) is produced from the bauxite ore which is also the source of metallic aluminium. The crushed ore is digested with hot caustic under pressure, the solution filtered, and aluminium hydroxide precipitated by passing carbon dioxide through the solution. The resulting pure hydroxide is dried and calcined at 1100°C where it decomposes to give pure alumina.
**********************************************************************************************************************
source:
http://www.ami.ac.uk/courses/topics/0135_cc/index.html
Looks like nice small source of AgPd for patient people.
