Indium Corporation® has released a new, bismuth-based low-temperature alloy developed for low-temperature reflow processes which require enhanced thermal cycling reliability.

Indalloy®303, also known as Bi+, is an innovative alloy that retains the low reflow temperatures required for temperature-sensitive processes while enhancing the lifetime reliability of the solder joint beyond that of traditional low-temperature solders.

As a low-temperature, Pb-free solution, Indalloy®303 offers:

  • A reflow temperature as low as 170℃
  • Excellent thermal cycling performance
  • Resistance to hot tearing
  • Compatibility with SAC in hybrid BGA joints
  • Low voiding

Indalloy®303’s flux vehicle, Indium5.7LT-1, is an air-reflow, halogen-free, no-clean solder paste designed for assembly processes using Bi-based and In-containing low-temperature alloys. It delivers:

  • Superior print transfer efficiency
  • Clear post-reflow flux residue
  • Solder bead and solder ball minimization
  • Exceptional wetting on OSP, Immersion Ag, Immersion Sn, and ENIG
  • Excellent coalescence of small deposits
  • Outstanding SIR performance under challenging low-temperature reflow conditions

For more information about Indium Corporation’s high-reliability alloy products, visit

About Indium Corporation

Indium Corporation® is a premier materials refiner, smelter, manufacturer, and supplier to the global electronics, semiconductor, thin-film, and thermal management markets. Products include solders and fluxes; brazes; thermal interface materials; sputtering targets; indium, gallium, germanium, and tin metals and inorganic compounds; and NanoFoil®. Founded in 1934, the company has global technical support and factories located in China, Germany, India, Malaysia, Singapore, South Korea, the United Kingdom, and the U.S.

For more information about Indium Corporation, visit or email You can also follow our experts, From One Engineer To Another® (#FOETA), at or @IndiumCorp.