Silicone rubber outgassing and silicone migration

[homoly]

Hello,

I would like to get information if there are some differences from the point of view of outgassing and the silicone migration between different electrically graded silicone rubbers. Are there various techniques for manufacturing silicone rubbers and are there some major differences in parameters mentioned above?

I would like to get some suggestions for some links where I can get further information on this subject ( especially silicone migration - flow of silicone from the areas with higher mechanical pressure to areas with lower pressure after some time ).

Are there any standards related to outgassing ( or migration ) in the case of silicone rubbers ?

Any help will be appreciated.

Gabriel.

 

[gatech74]

Hi Gabriel,

In my experience fully cured silicone will not migrate, however if the silicone is not fully cross linked and there is a carrier for silicone (oil/ fluid), and it is under a high enough temp and pressure, then the silicone may be able to migrate. From the sound of your note it sounds like you have two different compounds in close proximity to each other. Why do you thinck the silicone is migrating? As far as outgassing goes, it is dependant on the formulation and the amount of volitiles as well as other components in the silicone. Again state of cure will play a part, as well as temp and pressure of application. There are definitely some differences in the manufacturing of silicone which can effect outgassing. Hope that helps.

Gatech74

 

[homoly]

Hello Gatech74,

Thanks you for the answer, it is helpful. I have observed the migration of silicone oil when it was a part of the thermally conductive pad for semiconductor devices. After a long period ( few years ) the silicon oil migrated from area with high pressure ( semiconductor pad ) to the area with lower mechanical pressure what could be seen as a bump on the edges of the semiconductor pad.