Related Gold Paste Blog Articles
SPIE Photonics West 2023!
Indium Corporation to promote new specialty product offerings: AuLTRA™75, AuLTRA™ ThInFORMS™, and AuLTRA™ Fine Ribbon, at SPIE Photonics West in San Francisco, CA (January 22-27).
Read MoreSPIE Photonics West 2022
Indium Corporation to promote new specialty prodict offerings: AuLTRA™75, AuLTRA™ ThInFORMS™, and AuLTRA™ Fine Ribbon, at SPIE Photonics West in San Francisco, CA (January 22-27).
Read MoreBack to Basics: Au-Based Alloys
Indium's “Gold Standard” refers to the overall reliability and quality you can expect from our gold-based solder materials. Gold-based alloys offer strong solder joints, excellent corrosion and oxidation resistance, and good thermal and electrical transfer. Our gold-based alloy library includes a wide variety of gold-based solders suitable for any application at hand, such as 80Au20Sn, 88Au12Ge, 96.8Au3.2Si, 82Au18In, and 100Au.
Read MoreSolder in Medical Devices: Wait, There's Solder There?
Shielding the RF waves generated by an MRI machine is mandatory. Soldered copper is one the metals used for RF shielding because it absorbs radio and other electromagnetic waves and easily conforms to any odd angles, while not requiring much maintenance.
Read MoreSolder in Medical Devices: That Solder’s Going Where?
Cardiac pacemakers generally use 99.99% Au preforms as the solder material in the assembly. Pure gold is highly pure, inert, biocompatible, has a high resistance to corrosion, and works excellently to provide a hermetic seal in the device. All of these properties provide the perfect solder material required for the high quality and performance needed for implantable medical devices.
Read MoreFeatures & Benefits
- Highest tensile strength of any solder
- High melting point is compatible with subsequent reflow processes
- Pb-free
- Superior thermal conductivity
- Resistance to corrosion
- Superior thermal fatigue resistance
- Good joint strength
- Excellent wetting properties
- Resistance to oxidation
- AuSn is compatible with precious metals
- AuSn is RoHS compliant
Gold-Tin Solder Paste
AuSn Alloys:
- 80Au20Sn
- 79Au21Sn
- 78Au22Sn
- 77Au23Sn
Powder Sizes:
- Type 2 (-200/+325)
- Type 3 (-325/+500)
- Type 4 (-400/+635)
- Type 5 (-500/+635)
- Type 6 (-635)
- Type 6 SGS (5–15μm w/less than 10% overs/unders)
- Type 7 SGS (2–11μm w/less than 10% overs/unders)
No-Clean Flux:
- AuLTRA™ 5.1 (used in high-power LED and MEMS applications)
- Indium10.8HF (accommodates higher processing temperatures required by the electronics industry)
- RMA-SMQ51A (for difficult to solder surfaces in die-attach)
- NC-SMQ75 (halogen-free and low-residue; requires <10ppm oxygen)
Water-Wash Flux:
- AuLTRA™ 3.2 (used in high-power LED applications)
- Indium3.2HF
Low-Volume Packaging:
- Jars (10g per jar)
- Syringes (5cc syringes)

Gold-Tin (AuSn) Solder Paste
Gold-Tin (AuSn) Solder Paste is generally used in applications that require a high-melting temperature (80Au20Sn has a melting point of 280°C / 556°F). It can be made into a variety of solder paste forms with various options to address specific applications. It exhibits good thermal fatigue properties and is used in many applications that require high tensile strength and high corrosive resistance. In step soldering applications,Gold-tin (AuSn) Solder Paste will not melt during a subsequent low-temperature reflow process.