SEMICOSIL® 920 LT A/B is a pourable, addition-curing, two-part silicone rubber that cures to a soft silicone gel.


  • two-part, 1 : 1 mixing ratio
  • very low viscosity
  • fast cure
  • forms a soft gel on vulcanization
  • almost constant properties between -100 °C and +200 °C
  • low ion content

Encapsulation of sensitive electronic components such as hybrid elements with wire-bonded chips.

All surfaces must be clean and free of contaminants
that will inhibit the cure of SEMICOSIL® 920 LT A/B.
Examples of inhibiting contaminants are sulfur
containing materials, plasticizers, urethanes, amine
containing materials and organometallic compounds –
especially organotin compounds.
If a substrate’s ability to inhibit cure is unknown, a
small-scale test should be run to determine

Only components A and B with the same lot number
may be processed together!

Component A of SEMICOSIL® 920 LT A/B contains
the platinum catalyst, component B the crosslinker.
Even traces of the platinum catalyst may cause gelling
of the component containing the crosslinker.
To eliminate any air introduced during dispensing or
trapped under components or devices a vacuum encapsulation
is recommended.

The curing time of addition-curing silicone rubber is highly
dependent on temperature, size and heat sink properties
of the component being potted.


SEMICOSIL® 920 LT A/B should be stored between 5 °C and 30 °C in the tightly closed original container.


 The 'Best use before end' date of each batch is shown on the product label.


Storage beyond the date specified on the label does not necessarily mean that the product is no longer usable. In this case however, the properties required for the intended use must be checked for quality assurance reasons.

Sales and support

Wacker Chemical Corporation
3301 Sutton Road
Adrian, MI 49221-9397
United States
+1  888  922-5374 (Phone)

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