Advanced Packaging
World Leader in Reflow Ovens for Advanced Packaging
Flip Chip • 2.5D • CoWoS • Panel Packaging • Co-packaged Optics
BTU reflow ovens pack the performance needed to tackle the demand of advanced packaging processes where requirements for the highest process yields drive the process requirements:
Lowest O2 levels in the reflow zone
Low oxygen levels are critical during the reflow process in advanced packaging because they help prevent oxidation of sensitive materials, particularly solder joints and exposed metal surfaces. Oxidation can degrade solderability, reduce joint reliability, and compromise electrical performance. In advanced packaging technologies—such as flip-chip, wafer-level packaging, and heterogeneous integration—components often feature fine-pitch interconnects and materials like copper that are highly susceptible to oxidation. Maintaining a low-oxygen environment, ensures cleaner solder joints, better wetting, and improved mechanical and electrical integrity of the final package. This control is essential for achieving high yields and long-term reliability in high-performance electronic devices. BTU’s reflow ovens are specially configured for minimization of O2 levels in the reflow zone, with ppm levels in the single digits above source for the most sensitive processes.
Tightest thermal uniformity
Thermal uniformity—often measured as delta T across the substrate—is essential in reflow processes for advanced packaging because it directly impacts solder joint quality, component alignment, and overall process reliability. In heterogeneous assemblies with varying thermal masses and fine-pitch interconnects, uneven heating can lead to incomplete solder reflow, bridging, tombstoning, or cold joints. A tightly controlled delta T ensures that all regions of the package reach the target reflow temperature simultaneously, promoting consistent wetting and solidification. This is especially critical in advanced packaging formats like 2.5D/3D ICs, where thermal gradients can be more pronounced due to complex geometries and material stacks. Achieving optimal thermal uniformity minimizes defects, improves yield, and supports the mechanical and electrical integrity required for high-performance applications. BTU’s high convection rates and optimized convection technology ensure the most uniform heating and cooling throughout the entire process – delivering tightly controlled Cpk’s and high process yields.
Adjustable heating and cooling rates
Slow cooling rates during the reflow process in advanced packaging are crucial for mitigating the effects of coefficient of thermal expansion (CTE) mismatch between different materials in the package. Advanced packages often integrate diverse materials—such as silicon dies, organic substrates, and underfill compounds—each with distinct thermal expansion behaviors. Rapid cooling can induce thermal stress due to abrupt contraction, leading to warpage, delamination, or microcracking at interfaces. By controlling the cooling rate, thermal gradients are minimized, allowing materials to contract more uniformly and reducing mechanical strain. This is especially important in high-density interconnects and 2.5D/3D architectures, where structural integrity and long-term reliability are paramount. A gradual cooldown helps preserve solder joint quality and ensures robust mechanical performance across temperature cycles. BTU’s Pyramax and Aurora reflow ovens feature slow cooling configuration options. The Aurora platform can accommodate even the slowest cooling at high volume due to the availability of longer ovens with configurable heating and cooling zones.
TrueFlat technology to eliminate warpage for thin substrates
Key features for advanced packaging
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Ultra-Low Oxygen Reflow
Maintain O₂ levels in the single-digit ppm range above source to prevent oxidation of sensitive solder joints and exposed copper in flip-chip, WLP, and 2.5D/3D applications.
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Exceptional Thermal Uniformity
High convection rates and optimized airflow deliver tight delta T across the board—ensuring consistent reflow, reduced defects, and higher yields.
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Controlled Cooling Rates
Mitigate CTE mismatch and prevent warpage, delamination, or microcracks with slow, programmable cooling—ideal for advanced substrate assemblies.
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Configurable Zone Architecture
Aurora’s flexible design allows longer ovens with customized heating/cooling zones to support the most demanding packaging requirements at high volume.
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TrueFlat Warpage Control
Optional vacuum hold-down system flattens thin substrates throughout the reflow process—eliminating die tilt and improving yield.
Explore BTU technologies purpose-built for the most advanced packaging applications. Talk to our experts about reflow solutions purpose-built for high-yield, advanced packaging.
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