Thermoset Ovemolding

[sreeraj.muralidharan]

I am trying to simulate a PCB overmolding with an EMC material.

The intent of the simulation are the follows
-To check the core shift of the PCB
-To check the influence of the heaters and the mold temp. on the filling and PCB movement.

I imported and the part, part inserts, mold inserts, mold and heaters.
I wanted to use the Reactive Molding module. But Core-shift was not available in that module.
So I used the Reactive Compression Molding module. This module was able to check for the Core-Shift.

As we have Cool FEM in Thermoplastics, where we can see the temperature distribution on the mold, can we do something similar for Thermosets?

I had imported the Heaters from CAD and had defined them as Heaters 3D
In the Reactive Compression Molding module we have Cool FEM. But i cannot analyse Cool FEM without cooling lines and as it is known there are no cooling for thermoset tools. The tools are usually heated with heaters.

Can anyone please suggest how this can be done?

Regards
Sreeraj

[mason.myers · Accepted solution]

Hello @sreeraj.muralidharan!

Yes, you can use Cool(FEM) for Reactive Molding.  In fact, you have to run Cool(FEM) since Cool is not supported with Reactive Molding processes.

If you model your cooling lines as beams, you should be able to change property type to Cartridge Heaters. For Cool(FEM) would also need a 3D mold mesh

If you are in 3D, you can change your analysis type to Microchip Encapulsation - you should be able to run a Fill+Pack+Paddle Shift or Fill+Pack+Dynamic Paddle Shift.  This will allow you to get the core shift results.  Please be sure to go to the Advance Process Settings - Solver Parameters - and turn on Paddle/Core Shift.

Mason

[sreeraj.muralidharan]

Hello @mason.myers .

Thank you for your advice. 

While I have tested the Paddle Shift in Microchip encapsulation (it works). I still have to check the Cool FEM in Reactive Molding. This I will do this week.

One observation related to the Core shift / Paddle shift. 

As mentioned in my earlier post, I used the Reactive Compression Molding (RCM) module for the Core shift initially.

For the Microchip Encapsulation (MCE) I used the

same study file,

same plastic material,

same melt temp.

same mold temp. 

same cold runner and gate,

same one sided/fixed constraints,

same part and insert properties, 

The injection time for the RCM module was 7.75s and for the MCE module was 7.98s.

When I compared the core shift results 

for RCM the first "Shift analysis performed" happened at 2.205s 

while for MCE the  first "Shift analysis performed" happened at 7.565s

for RCM the Maximum core-deflection = 3.0788 mm

while for MCE the  Maximum core-deflection  = 1.0784 mm

I am wondering why this difference. 

any thoughts?

With best regards

Sreeraj

[mason.myers]

Hello @sreeraj.muralidharan

I believe the difference in fill times would be causing a difference in pressure.  Can you evaluate the Pressure or Pressure at VP switchover?  

Are your core materials set correctly for both studies?

Sometimes the maximum core shift could be seen during packing as well.  I would suggest solving the core shift during filling and packing.  You can also adjust the frequency of the core shift calculations on the core shift page in the Advanced Options - Solver Parameters - Edit.

Mason

[sreeraj.muralidharan]

Hello @mason.myers 

I hope you are doing well. 

The Cool FEM worked. 

Thank you for your support. 

[adevadkar]

Hello @mason.myers ,
I am trying to simulate the thermoset process for Silicon mold, is there any guideline /Procedure to follow the simulation? and what important results need to be checked for this type of analysis.
Do you any correlation document for thermoset if have please share.

Thanks in advance.

[mason.myers]

Hello @adevadkar ,

I do not have any correlation documents that I can share publicly with thermoset materials. You can purchase our Reactive training materials from the Ascent website:

https://www.ascented.com/courseware/product/autodesk-moldflow-insight-2021-reactive-molding

Conversion at Node and Cured Layer Fraction are two new plots that I would suggest you evaluate to check cure times.

Mason