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℃
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 fiml hybrid microelectronic circuits. It bonds to glass, mica, plastic, graphite, quartz and other materials as well.
PROPERTIES
| System | One-Part |  |
| Composition | Silver filled epoxy |
| Rheology | Thixotropic paste |
| Viscosity | 90,000 cps ± 5% |
| Thinner | Butyl carbitol acetate |
| Cure Temperature | 150℃ (minimum) |
| Electrical Resistivity, nominal | 1 x 10-4 ohm-cm |
| Thermal Conductivity | 100 BTU/ft2/hr./℉./in. |
| Bond Shear Strength | 1500 PSI |
| Outgassing | 0.97% @100℃ (1250 hours) |
| | 0.7% @125℃ (1000 hours) |
| | 1.2% @160℃ (1000 hours) |
| Temperature Stability Range | -65℃ to +250℃ |
| Linear Coef. of Therm Expan. | 5 x 10-5 cm/cm/℃ |
| Storage | 40℉(4.4℃) or below |
| Shelf Life | 6 months @40℉(4.4℃) |
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℃ followed by at leat 1 hour at 200℃.
