Au78Sn22 Solder Paste
Features:
- High temperature solder, melting temperature 280ºC
- High strength and stable performance at high temperature
- Excellent wettability and soldering performance
- Anti-corrosion, anti-oxidation
- Excellent electrical and thermal conductivity
- Lead-free, RoHS compliant
Description:
Gold-Tin eutectic solder has a melting temperature of 280ºC. It has been widely used in aerospace, meidcal and other fields with high reliability due to excellent thermal and electrical conductivity, high corrosion resistance and good mechanical properties. The gold-tin eutectic alloy can be made into solder paste to meet various application requirements. The solder joints formed with gold-tin solder paste are generally used in applications that required a high operating temperature (over 150ºC), good thermal fatigue properties, high strength and good capacity of resisting corrosion and oxidation. It is also used in step soldering applications where the paste will not melt during a subsequent low-temperature reflow process. In comparison with gold-tin solder preforms, gold-tin solder paste shows an apparent advantage in convenience, whichmakes it suitable for high reliability packaging of micro-photoelectric devices and high thermal conductivity packaging of high power devices.
Products List:
| Product type |
Composition |
Viscosity (Pa ·s) |
Melting temperature (ºC) |
Powder particle size (μm) |
Metal(Wt%) |
XY-ASP-001 |
Au80Sn20 |
180~300 |
280 |
3#:25-45μm 4#:20-38μm 5#:15-25μm |
85~94 |
XY-ASP-002 |
Au78Sn22 |
180~300 |
280 |
3#:25-45μm 4#:20-38μm 5#:15-25μm |
85~94 |
XY-ASP-003 |
Au80Sn20 |
10~ 130 |
280 |
3#:25-45μm 4#:20-38μm 5#:15-25μm 6#: 5-15μm |
85~94 |
XY-ASP-004 |
Au78Sn22 |
10~ 130 |
280 |
3#:25-45μm 4#:20-38μm 5#:15-25μm 6#: 5-15μm |
85~94 |
*Other particle sizes for fine pitch applications are available upon request.
Physical Properties:
Products |
Melting point |
Density |
Resistivity |
Thermal
Conductivity |
Thermal expansion
coefficient |
Tensile strength |
| Au80Sn20 |
280ºC |
14.52 g/cm3 |
0.224µΩ·m |
57W/m·K |
16×10-6/ºC |
276 MPa |
| Au78Sn22 |
280ºC |
14.31 g/cm3 |
0. 166µΩ·m |
57W/m·K |
14×10-6/ºC |
276 MPa |
Solder Composition:
| Composition |
Au80Sn20 (wt%) |
Au78Sn22 (wt%) |
| Gold (Au) |
Margin |
Margin |
| Tin (Sn) |
20.0 ± 0.5 |
22.0 ± 0.5 |
Particle Morphology: 
SEM image of AuSn particles
Flux Vehicles for Au/Sn Solder Paste:
Flux types can be adjusted according to different application needs, in the welding process to remove the base metal surface oxide, forming a protective film to isolate air oxidation of liquid solder; At the same time reduce solder and base material surface tension, improve wettability.
Type Selection:
Related to particle size, viscosity and process, subject to customer requirements.
For printing, the powder particle size is less than 1/5 of the opening size of the template and less than 1/5 of the thickness of the template.
Reference Reflux curve:
(Only applicable to hot air reflux furnace, should be adjusted according to the actual welding process curve)
Recommended Profile:
The heating rate of 1-2 ºC/second allows gradual evaporation of volatiles and helps minimize defects such as solder balling/beading and bridging as a result of hot slump. A minimum peak temperature of 30-50 ºC above the melting point of the solder alloy is usually needed to achieve excellent wetting joint. The peak temperature is generally 30-50ºC above the melting point to obtain excellent wetting effect. And the time above liquidus should be 30-70 seconds, to avoid overlong residence of liquid and discoloration of resin. The process curve should be adjusted according to the actual situation in the specific application. The recommended range of reflux heating factor Q is:
450ºC·s < Q < 1750ºC·s
The heating factor Q is defined as the area occupied by the reflux curve above the melting point, approximately: Q=ΔT×Δt/2
Welding Atmosphere Requirement:
It is recommended to conduct welding in inert or reducing atmosphere to avoid coking of organic residues at high temperature and facilitate subsequent cleaning and removal of organic residues.
Packaging:
| Packaging Form |
Net Weight |
| Syringes |
2g ,5g ,10g ,20g |
| Jars |
100g ,200g |
Storage and Handling Precedure:
- Keep sealed and sore at 0-10 ºC
- Shelf life: six months
- Solder paste should be allowed to reach ambient working temperature prior to use. Actual time to reach thermal equilibrium will vary with container size.
- Re-seal if it is not needed after opening. If it is used for many times, please confirm the quality before use.
- Post solder cleaning can be accomplished using a recognized flux removal system.
Safety:
- Please use this product with sufficient ventilation and certain personal protection.
- Please do not mix with other toxic chemicals.
){kind=link}