Two Part Curable Gap Fillers

Shin-Etsu’s two-part Gap Fillers are silicone materials with fillers that provide high thermal conductivity while maintaining electrical isolation. The main application for these Thermal Interface Materials is to fill gaps between components and heat sinks. Applied in liquid form, they produce less stress on components during assembly. The material cures in place and remains a soft elastomer.  Shin-Etsu’s two-part Gap Fillers can be used on a larger range of gap thicknesses.  The liquid material can be applied in different thicknesses in adjacent areas to account for varied interface topography.  They provide a natural tack between mating surfaces but do not create a structurally adhesive connection.

Product Features:

  • Thermal interface materials that cure at room temperature when the two components are mixed.
  • The materials will hold shape even before curing, which makes “three-dimensional” application possible.
  • When applied, the materials have a grease-like consistency and get into the nooks and crannies of the substrate surface, which creates lower contact thermal resistance. The material cures in that shape, there is no danger of oil bleeding or pumping-out.
  • The materials have low hardness after curing, putting less stress on components.
  • The materials can be reworked because they do not adhere to substrates.
  • Owing to the addition reaction, curing time is shortened by heating.
  • All products have different thermal conductivity values.
ItemMain FillerAppearanceViscosity (Pa•s)Thermal conductivity (W/m•°K)Specific GravityCuring conditionHardness (Asker C)Elongation (%)Tensile strength (MPa)Dielectric strength
(kV/mm)
Volume resistivity (Ω•m)Bond Line Thickness (µm)
X23-8039-A/BAl2O3 InsulationWhite/ Sky BlueA:102/B:551.12.525° C × 24hrs104800.3192.3×10^1212
X23-8043-A/BAl2O3 InsulationWhite/ Sky BlueA:99/B:712.32.925° C × 24hrs25700.3182.3×10^12120
X23-8051-A/BAl2O3 InsulationWhite/ GrayA:103/B:723.53.125° C × 24hrs17400.1202.3×10^12120
X23-8068 A/BAl2O3 InsulationGrayish White/PinkA:181 / B:1625.13.325° C × 24hrs16300.1212.3×10^12120
X23-8098 A/BAl2O3 InsulationGrayish White/PinkA:282 / B:2886.53.225° C × 24hrs30200.1202.3×10^12-