Achieving efficiency, reliability, and exceptional thermal performance is crucial in package-attach soldering applications for power modules. However, the high reflow temperatures required by conventional solder alloys present significant challenges. From risking mold delamination to compromising substrate integrity, the need for a low-temperature solder with superior reliability has become increasingly urgent.
Introducing Indalloy®301LT, a next-generation low-temperature solder alloy engineered specifically for package-attach applications. With a focus on reduced processing temperatures and enhanced performance, this cutting-edge solution addresses the key challenges in modern power module soldering.
The Challenges of Traditional Alloys in Power Module Soldering
Traditional solder alloys like SnSb5 or SAC305 are widely used but come with inherent challenges, particularly in package-attach soldering processes:
- Mold Delamination Risks: High peak reflow temperatures can exceed the glass transition temperature (Tg) of module molds, leading to warping and reduced reliability.
- Substrate Stress: High temperatures can cause thermal stress on substrates, shortening the lifespan of the components.
The growing demand for reliable low-temperature soldering solutions across industries like automotive, e-mobility, and renewable energy underscores the need for advancements in soldering alloys.
Given these limitations, the demand for high reliability alloys with low processing temperatures has grown significantly in industries like automotive, e-mobility, and renewable energy.
A Game Changer: Indalloy®301LT Alloy
The innovative Indalloy®301LT low temperature alloy has been developed to meet the challenges of low-temperature soldering without compromising mechanical or thermal performance. This SAC-In alloy sets itself apart through the following key advantages:
1. Low-Temperature Processing
Indalloy®301LT achieves a significant reduction in reflow temperature, operating at a peak reflow temperature nearly 50°C lower than conventional Pb-free alloys like SnSb5 and SAC305. Lower processing temperatures help protect molds and substrates, preventing delamination and extending the lifecycle of molded power modules.
2. Enhanced Mechanical Strength
Unlike bismuth-based alloys prone to brittleness, the SAC-In alloy provides robust mechanical properties, essential for applications requiring thermal shock tolerance and reliability. Indalloy®301LT demonstrated comparable reliability to SnSb5 and SAC305 in thermal shock testing under -40°C to +125°C operating conditions.
3. Thermal and Electrical Performance
Indalloy®301LT excels as a thermomechanical interface between power modules and heat sinks. Its superior thermal conductivity ensures optimal heat dissipation, a critical requirement in high-demand applications like automotive power electronics and water-cooled systems. This advantage makes it well-suited for next-generation efficiency requirements driven by SiC and GaN technologies.
4. Versatility in Processing
This alloy is adaptable to various assembly conditions. It’s compatible with conventional air/N2 reflow processes and flux-free environments, like formic acid reflow. Additionally, Indalloy®301LT can be integrated into innovative configurations, such as InFORMS®, for enhanced bond line control and reliability.
Performance Insights
During rigorous testing, including thermal shock testing over 1,000 cycles (-40°C to +125°C), Indalloy®301LT outperformed traditional low-temperature alloys like SnAgIn. These tests revealed:
- No significant degradation or voiding in solder joints, even after extensive thermal cycling.
- Enhanced mechanical reliability, significantly reducing risks of cracking or void formation.
- Consistent performance in protecting against common failure modes of SnSb and SnAgIn alloys.
By ensuring robust thermal and mechanical integrity, SAC-In alloys such as Indalloy®301LT have established themselves as a superior alternative in power module soldering.
Applications of Indalloy®301LT in Power Modules
This low temperature solder alloy has clear advantages across various applications. Specifically, it addresses the critical thermal management requirements in:
- Automotive Power Electronics: Enables highly compact SiC and GaN power modules with enhanced efficiency and thermal reliability.
- E-Mobility Systems: Provides reliable thermal and mechanical performance, supporting lightweight, high-performance designs in e-mobility applications.
- Renewable Energy Systems: Ensures long-term reliability in high-temperature environments, supporting the transition to greener energy solutions.
Why Choose Low Temperature Soldering Alloy Technology?
The choice to adopt Indalloy®301LT represents a forward-thinking approach to meeting evolving industry demands. Here’s why:
- Reduced Costs: Lower processing temperatures translate to reduced energy consumption, reduced yield losses, and lower costs compared to sintering alternatives.
- Enhanced System Reliability: By overcoming the limitations of traditional alloys, SAC-In alloys ensure long-term operational excellence in high-stress, high-performance environments.
- Future-Readiness: The environmentally friendly, Pb-free design positions manufacturers to meet stringent global regulations while staying ahead in a competitive landscape.
A Step Towards the Future
The electronics and automotive industries are rapidly evolving, driven by demands for higher performance, smaller sizes, and greener technologies. Indalloy®301LT stands as a unique innovation, demonstrating that low temperature solder alloys can meet the rigorous demands of modern assembly processes without compromising long-term reliability.
At Indium Corporation, we are committed to supporting engineers, technicians, and designers in harnessing the true potential of solder preform technology. Whether you’re redesigning thermal interfaces or exploring new possibilities with SAC-In alloys, our team is here to assist you.
Curious to Know More?
Indium Corporation team members Joseph Hertline, Ryan Mayberry, and Andreas Karch co-authored a whitepaper titled "Solder Preform Technology for Improved Thermomechanical Performance in Molded Power Module Package-Attach", which expands on the capabilities of Indalloy®301LT. Request access to read this paper here!
Contact our experts at Indium Corporation to learn how Indalloy®301LT can enhance your operations or stay tuned for our upcoming advances in flux-free tacking agents for formic acid reflow.
Refine your designs. Reduce your risks. Choose innovation with low temperature solder technology.