Silver Epoxy Paste

Screenable Thermosetting Silver for Ohmic Bonding

A screenable silver epoxy preparation for developing high quality electrical and mechanical contacts – used in bonding semiconductors and other devices in hybrid microelectronic circuits.

SILVER EPOXY PASTE – TYPE I
Standard screenable conductive epoxy

SILVER EPOXY PASTE – TYPE II
Screenable conductive compliant epoxy

FEATURES

  • One component system
  • Excellent screening characteristics
  • Develops high bond strength
  • Low contact resistance
  • Very low thermal stress
  • Low thermal impedance
  • Temperature -65 ° to +250 °C

SILVER EPOXY PASTE
DESCRIPTION

Silver Epoxy Paste is a one component system designed as a conductive thermosetting silver preparation for screen printing applications. Its composition is unique, providing high electrical and thermal conductivity with excellent bond strength after appropriate cure. Silver Epoxy Paste is used to advantage in place of lead-tin solders to avoid flux contamination or exposure to excessive temperature and for process simplification by screening on contacts.

Silver Epoxy Paste forms ohmic bonds with semiconductors if the surface of the semiconductor is metallized, or if the surface is highly “doped” and lapped. The product finds extensive use in bonding semiconductor chips, integrated monolithic circuits, diodes, transistors and other components in thin film and thick film hybrid microelectronic circuits. It bonds to glass, mica, plastic, graphite, quartz and other materials as well.

PROPERTIES
Silver Epoxy Paste Type I & Type II

System One-Part
Composition Silver filled epoxy
Rheology Thixotropic paste
Viscosity 90,000 cps.± 5%
Thinner Butyl carbitol acetate
Cure Temp. 150 °C (minimum)
Electrical Resistivity, nominal 1 x 10-4 ohm-cm
Thermal Conductivity 100 BTU/ft2/hr./°F./in.
Bond Shear Strength 1500 PSI
Outgassing 0.097% @ 100 °C (1250 hours)
0.7% @ 125 °C (1000 hours)
1.2% @ 160 °C (1000 hours)
Temperature Stability Range -65 °C to + 250 °C
Linear Coef. of Therm Expan. 5 x 10-5 cm/cm/°C
Storage 40 °F or below
Shelf Life 6 months @ 40 °F

APPLICATION

Follow standard thick film procedures and screen Silver Epoxy Paste onto substrate using 165 or 200 mesh stainless steel screen. Mount parts to be bonded within one half hour and press lightly. Then oven cure at 150 °C followed by at least 1 hour at 200 °C.