High Performance Silver Paste

High performance silver paste is a dispersion of 20µm silver flakes in an inorganic silicate aqueous solution. It is specially formulated for applications demanding high, continuous service temperature and/or low VOCs for high vacuum applications, but it also performs at cryogenic temperatures. It provides both high electrical and thermal conductivity. Its sheet resistance is 0.08 ohms/sq/mil (25µm). Its thermal conductivity is 9.1 W/m°K. Surfaces to be coated should be clean and dry.

Advantages

• One component system. No mixing required.
• Inorganic system ‐ no hydrocarbons no VOC's.
• High service temperature. ‐ Up to 927 °C, strength improves with temperature.
• Low temperature capability. Not affected by cryogenic temperatures, but bond integrity will depend on joint design and differential thermal expansion between substrate, sample and paste.
• Electrically and thermally conductive.
• Suitable for high vacuum applications.
• Refrigeration not required.
• High viscosity paste ‐ viscosity can be reduced by adding water.
• Water soluble after cure ‐ solubility is reduced, the higher the temperature it is exposed to.

Typical properties (as supplied)

Pigment: silver
Binder: inorganic silicate
Diluent: water
Consistency: smooth, flowing paste ‐ viscosity can be reduced by adding water.
Silver content by weight: >60%
Density: 2.3 g/cc
Shelf life: 6 months minimum after receipt of paste ‐ can be increased by adding water and/or removing skin that can form on the top layer.
Storage: at room temperature in tightly sealed container. Do not freeze.

Cure schedule

(bond time/temperature)
Achieves good mechanical strength with low conductivity in a matter of minutes at room temperature, but requires a 2 hour cure at 93°C to achieve stated high conductivity and a strong bond.
Strength improves with temperature and it becomes almost insoluble if exposed to temperatures above 260°C.
Must be cured before use at cryogenic temperatures.

Typical properties (when dried)

Recommended thickness: 0.581.5 mils dried (12.5 ‐ 37.5µm.)
Sheet resistance: 0.08 ohms/sq/mil (25µm).
Thermal conductivity: 9.1 W/m°K.
Soluble in water: up to 260°C exposure. Will still soften in water but may require abrasion to remove.
Bond strength: moderate but brittle.