Gold – Epoxy Paste
THERMOSETTING GOLD FOR OHMIC BONDING
Produces quality electrical and mechanical contacts for semiconductor and hybrid circuits applications.
GOLD-EPOXY PASTE, TYPE GE-10
One-part system, economical
GOLD-EPOXY PASTE, TYPE GE-20
Two-part system, low temperature cure
GOLD EPOXY PASTE, TYPE GE-30
Two-part system, fast cure
GOLD-EPOXY PASTE, TYPE GE-40
Two-part system, fast cure, long pot life
GOLD EPOXY PASTE
Gold-Epoxy Pastes are gold-filled conductive bonding preparations exhibiting high electrical conductivity and bond strength.
The Gold Pastes are easily applied by manual techniques, machine dispensing or screen printing and cured with relatively low applied heat in bonding operations. Gold-Epoxy Pastes are used to advantage in place of tin-lead solders to avoid flux contamination or exposure of components to excessive heat. The gold products are used in preference to silver-epoxy or other silver preparations to avoid silver migration problems.
Gold-Epoxy Pastes bond well to alumina ceramic substrates, phenolic circuit boards and transistor headers. They are useful in a variety of applications in solid state and hybrid circuits including:
- Attachment of discrete semiconductor devices and integrated circuits. Ohmic contacts are produced with diodes and transistors, in all package configurations, if the semiconductor surface is first metallized or the surface is highly “doped” and lapped.
- Bonding of other active devices, heat sinks and capacitor ships.
Top electrodes for crossovers and interconnections for parallel and multipurpose circuits.
Gold-Epoxy Paste, Type GE-10 is more economical to use since it is a one-part system with waste eliminated in actual use. Types GE-20 and GE-30 are two-part systems and cure more rapidly and at lower temperatures. Type GE-30 is especially recommended for repair of microcircuitry. Type GE-40 is formulated for long pot life and fast cure. It is recommended for screen print applications. All of the Gold-Epoxy Pastes are designed for low outgassing and for continuous use up to 175 °C.
Gold flake particle size: D50 = 4.5 micrometers; D90 = 9.5 micrometers
PROPERTIES OF GOLD-EPOXY PASTES
|Composition||88% Gold||88% Gold||88% Gold||88% Gold|
|System||One-part epoxy||Two-part epoxy||Two-part epoxy||Two-part epoxy|
|Rheology||Thixotropic paste||Thixotropic paste||Thixotropic paste||Thixotropic paste|
|Pot Life (25 °C)||6 months||6 hours||2 hours||2 days|
|Shelf Life||6 months||1 year||1 year||1year|
|Application||Screen printing or dispensing||Screen printing or dispensing||Dispensing||Screen printing or dispensing|
|Thinner||Butyl carbitol acetate or butyl cellosolve acetate||Butyl carbitol acetate or butyl cellosolve acetate||Butyl cellosolve acetate||Butyl carbitol acetate or butyl cellosolve acetate|
|Cure||15 hours. @ 150 °C, or 1 hr. @ 150 °C plus 2 hrs @ 200 °C||4 hrs @ 50 °C, or 2 1/2 hrs @ 75 °C or 2 hrs @ 100 °C||1/2 hr @ 50 °C or 15 min @ 75 °C or 5 min @ 125 °C.||10 min @ 100 °C or 5 min @ 125 °C or 2 min @ 150 °C|
|Elec. Resist,(Ohm-cm)||4 x 10-4||7 x 10-4||7 x 10-4||6 x 10-4|
|Bond Shear Str. (psi)||1000||1000||1000||1000|
|Outgassing (postcure) 1000 hrs @ 125 °C||0.70%||0.30%||0.35%||0.30%|
|Serv. Temp Range||-65 ° to + 200 °C||-65 ° to + 175 °C||-65 ° to + 175 °C||-65 ° to + 175 °C|
|Mixing Ratio (a/b)||————————||(100/1.8)||(100/1.3)||(100/2.7)|
|A : B
1.25 gm : 1 drop
10 gm : 7 drops
1 oz. : 22 drops
|A : B
2 gm : 1 drop
10gm : 5 drops
1 oz. : 16 drops
|A : B
2 gm : 2 drops
10gm : 9 drops
1 oz. : 24 drops
Gold-Epoxy Pastes are applied by screening using a 200 mesh stainless steel screen or by other methods of application such as dotting with a needle or by use of automatic dispensing equipment. Parts to be bonded are mounted and pressed lightly, then over-cured under the appropriate conditions of time and temperature.