Solder Alloys

Durafuse® LT – Low-Temperature Alloy System

The tough choice that is easy to make.

Durafuse® LT

Durafuse® LT is a patented low-temperature alloy system designed to provide high-reliability in low-temperature applications that require a reflow temperature below 210°C.

Durafuse® LT provides improved drop shock resilience, outclassing bismuth-tin (BiSn) or bismuth-tin-silver (BiSnAg) alloys, and performing better than SAC305 with optimum process setup. Durafuse® LT is made up of a low-melting indium-containing alloy and a higher-melting SAC alloy. The SnInAg alloy initiates joint fusion while the SAC alloy provides enhanced strength and durability. Durafuse® LT is ideal for high-reliability applications, which utilize thermally sensitive components or boards and/or have a requirement for step soldering.

Durafuse® LT Features & Benefits

  • Drop Shock – Performance is more than two orders of magnitude better than Bi-containing low-temperature materials
  • Drop Shock - Performance is equal or better than SAC305 with proper process optimization
  • Ideal for step soldering and low temperature requirements

Durafuse® LT

Obtains the benefits of low-temperature processing reduced warpage and other negative effects on substrates and components without sacrificing reliability.
Dropping electronics is a fact of life. Durafuse<sup>®</sup> LT allows for end-product durability.

Low-Temperature Solder

Durafuse® LT and the Low- to Mid-Temperature Solder Space
Low-Temperature Solder Innovation Webinar screenshot

Improving Drop Shock Resistance

Drop Shock

44g ball at 500mm drop height

Drop Shock (44g ball at 500mm drop height)

Fusion Time vs. Drop Shock Performace

Peak temperature and time at peak can be used to optimize for drop shock resilience

Fusion Time vs. Drop Shock Performance: Depending on peak temperature, time at peak can be used to optimize for drop-shock resilience.

Low Temp Alloy Technology

Durafuse® LT contains a low-melting indium-based alloy which initiates joint fusion, while the high-melting SAC alloy provides enhanced strength and durability

Solder Joint Fusion

Step Soldering

  • Meeting requirements for step soldering, particularly in RF shield attachment and rework applications
    • Peak reflow temperature between 200°C and 210°C
    • Shear strength retained above 150°C

Durafuse® LT Recommended Reflow

Optimization of the reflow profile with a plateau at peak temperature is essential for maximizing drop shock reliability

  • A 200°C peak reflow temperature requires a longer plateau region
  • Increasing peak temperature to 205 or 210°C allows for reduced reflow time
  • This profile is a general guideline in establishing a reflow profile for Durafuse® LT in Indium5.7LT-1

Related Applications

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