Hello, I am a bit confused ??? , how does momentum define the interface layers in the substrate definition? I though it was as follows:
If I have the following stack up:
Air
-------Strip cond2
Alumina2 Via via2
------- Strip cond1
Alumina1 Via via1
///////GND////////
and I define the thickness as follows:
Alumina1=100um
cond1=10um
Alumina2=100um
cond2=10um
how does momentum define the thickness
of Alumina2 layer? Is it from bottom of cond1 to bottom of cond2, or from top of cond1 to bottom of cond2? I thought it was from top of cond1 to bottom of cond2, but someone told me otherwise. Now I am not sure.
Depending how it is defined, the capacitance calculation will change.
If momentum defines this as from bottom of cond1 to bottom of cond2 then what I specified for alumina2 in this example will be actually 100um-10um=90um between cond1 and cond2.
If it specifies as from top of cond1 to bottom of cond2 then it will be as I specified in the example above.
Any clues?
If I have the following stack up:
Air
-------Strip cond2
Alumina2 Via via2
------- Strip cond1
Alumina1 Via via1
///////GND////////
and I define the thickness as follows:
Alumina1=100um
cond1=10um
Alumina2=100um
cond2=10um
how does momentum define the thickness
of Alumina2 layer? Is it from bottom of cond1 to bottom of cond2, or from top of cond1 to bottom of cond2? I thought it was from top of cond1 to bottom of cond2, but someone told me otherwise. Now I am not sure.
Depending how it is defined, the capacitance calculation will change.
If momentum defines this as from bottom of cond1 to bottom of cond2 then what I specified for alumina2 in this example will be actually 100um-10um=90um between cond1 and cond2.
If it specifies as from top of cond1 to bottom of cond2 then it will be as I specified in the example above.
Any clues?
There is an method using multiple conductor layers and vias to model the thickness of a conductor. The following documents does provide some more info:
Tech Info Session
Considering Metal Thickness in Momentum EM Simulations
Support Example
ADS MOM : Simulating lines with thickness
Support Document
How to model thick metal in Momentum
There will be a new feature in ADS 2003C (the upcoming release) which automates the somewhat tedious workaround described above.