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got an error in the bigger size copper deposition

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Hi

I'm trying to use and modify the copper deposition model then I get an error when solve as below.
the model works well in the micron size but the error was found when I make it's wider between anode and cathode about 5 centimeter but the cavity is still 40 micrometer
In the error log, dependent variables, lm1 and lm2 what do they do in equation of Moving mesh(ALE)?

Error 7248
Exception:
com.femlab.jni.FlNativeException: Undefined value found Solvermodel
Messages:
Undefined value found Solvermodel

Stack trace:
at solvermodel.cpp, row 1837, (Undefined value found in the stiffness matrix.
There are 21 equations giving NaN/Inf in the matrix rows for the variable V
at coordinates: (-0.005,0.05), (-0.0045,0.05), (-0.004,0.05), (-0.0035,0.05), (0.005,0.05), ...
There are 21 equations giving NaN/Inf in the matrix rows for the variable lm1
at coordinates: (-0.005,0.05), (-0.0045,0.05), (-0.004,0.05), (-0.0035,0.05), (0.005,0.05), ...
There are 21 equations giving NaN/Inf in the matrix rows for the variable lm2
at coordinates: (-0.005,0.05), (-0.0045,0.05), (-0.004,0.05), (-0.0035,0.05), (0.005,0.05), ...
and similarly for the degrees of freedom, NaN/Inf in the matrix columns)
at com.femlab.solver.FlSolver.femTime(Native Method)
at com.femlab.solver.FemTime.run(Unknown Source)
at com.femlab.server.FlRunner.run(Unknown Source)
at com.femlab.util.i.run(Unknown Source)
at com.femlab.util.aa.run(Unknown Source)

and I dont understand the constant phi_s_anode and phi_s_cathode, from butler-volmer equation, are they standard electrode potential or supply voltage? and how would I change the electrode such as use Platinum for anode an Copper for cathode? because in the example model does not clear what the electrode is.

Thank you very much for your help

--
Pardon for my bad english

1 Reply Last Post Dec 23, 2010, 3:24 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Dec 23, 2010, 3:24 a.m. EST
HI

I do not have the electrochemical module, but in all generality the NaN errors are typically when your model is missing BC's to make it unique. So something must have changed, if you modify your geometry you must recheck all BC's and physics as the renumbering of the domains and boundaries might change and COMSOl cannot always reorder correctly, some human intervention is required ;)

the lm1 lm2 are the Langrangian Multipliers from a weak formulation, they are probably there from the particular BC's you are using, so the lack of boundary values are linked to V the voltage and to the two lm's and these are again linked to some variable that you need to identify first

If you have very small features (microns in a large structure cm-m) then the size ration is becoming large and you might need to reduce the geometrical relative tolerance from its default 1E-5 to 1E-7 or even 1E-9, the same for the import repair tolerance if you are importing the CAD geometry

--
Good luck
Ivar
HI I do not have the electrochemical module, but in all generality the NaN errors are typically when your model is missing BC's to make it unique. So something must have changed, if you modify your geometry you must recheck all BC's and physics as the renumbering of the domains and boundaries might change and COMSOl cannot always reorder correctly, some human intervention is required ;) the lm1 lm2 are the Langrangian Multipliers from a weak formulation, they are probably there from the particular BC's you are using, so the lack of boundary values are linked to V the voltage and to the two lm's and these are again linked to some variable that you need to identify first If you have very small features (microns in a large structure cm-m) then the size ration is becoming large and you might need to reduce the geometrical relative tolerance from its default 1E-5 to 1E-7 or even 1E-9, the same for the import repair tolerance if you are importing the CAD geometry -- Good luck Ivar

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