Microcircuit Silvers
for Conductive Bonding in Microelectronics
One-part thermosetting silver epoxy systems for conductive bonding in microelectronic assembly operations.
MICROCIRCUIT SILVER – TYPE K
Low temperature, fast cure- automatic dispensing
MICROCIRCUIT SILVER – TYPE L
Low temperature, fast cure – screen print
MICROCIRCUIT SILVER – TYPE N
High bond strength – 100% solids
MICROCIRCUIT SILVER – TYPE O
High electrical conductivity – 100% solids
MICROCIRCUIT SILVERS
Microcircuit Silvers are one-part, thermosetting silver-epoxy compositions designed specifically for conductive bonding in microelectronic assembly operations. Recommended applications include the conductive bonding of integrated circuit chips, capacitors, and other active and passive components. Microcircuit Silvers meet Hi-Rel requirements for low outgassing, bond strength, and electrical conductivity.
Microcircuit Silvers withstand temperatures up to 350 °C, allowing ultrasonic and thermal compression bonding of interconnecting wires. Microcircuit Silvers Types K and L, will fully cure in 15 seconds at 300 °C; thus these silver compositions possess the unique ability to cure during thermal compression bonding operations.
Several modifications of Microcircuit Silvers are offered. Types K and L exhibit low temperatures and fast cures. Types N and O are 100% solid systems which provide high electrical conductivity. Microcircuit Silvers Type K,L,N, and O are designed for screen printing or automatic dispensing applications.
Properties of Microcircuit Silvers
Type K | Type L | Type N | Type O | |
Uncured | ||||
Per Cent Silver | 75 | 73 | 70 | 77 |
Solids (%) | 98 | 98 | 100 | 100 |
Viscosity cps | 60,000 | 80,000 | 100,000 | 125,000 |
Shelf Life-70 °F | > 6 months | > 6 months | 6 months | 6 months |
Application | Automatic dispense | Screen print/dispense | Screen print/dispense | Screen print |
Cured | ||||
Serv. Temp Range | -50 °C to + 175 °C (325 °C intermittent) | same | -60 °C to + 200 °C (325 °C intermittent) | same |
Electrical Resistivity ohm-cm |
5 x 10-4 | 5 x 10-4 | 2 x 10-3 | 6 x 10-4 |
Linear Coef. Therm Exp. (cm/cm°C) | 5 x 10-5 | same | same | same |
Thermal Conductivity (BTU hr/ft2/°F/in.) | 21 | 20 | 20 | 22 |
Outgassing | ||||
1000 hrs @ 100 °C | 0.05% | .05% | .09% | .08% |
1000 hrs @ 125 °C | 0.2% | .2% | .7% | .6% |
Bond Shear Strength(psi) after cure | 1500 | >1500 | 3500 | 1500 |
aged 200 hrs @ 175 °C | >1000 | >1000 | 2750 | 1000 |
Cure Schedule | (Select Temp.) | |||
115 °C | 1 1/2 hrs | 1 1/2 hrs | —- | —- |
125 °C | 1 hr. | 1 hr. | —- | —- |
135 °C | 30 min | 30 min | 5 hrs | 5 hrs. |
150 °C | 15 min | 15 min | 1 1/2 hrs. | 1 1/2 hrs. |
175 °C | 5 min | 5 min | 30 min | 30 min |
300 °C | 15 sec. | 15 sec. | —- | —- |