Ultrasonic Spray Fluxing Process for Flip-Chip Bonding

Ultrasonic Spray Fluxing Process for Flip-Chip Bonding | High-Precision Selective Fluxing Solution

Process Overview: High-Precision Selective Ultrasonic Spray Fluxing Technology

Ultrasonic selective spray fluxing is a precision process designed for PCB and advanced packaging workflows. Its core advantage lies in the ability to deposit a highly uniform, ultra-thin flux film onto specific areas with minimal overspray and no risk of nozzle clogging. Leveraging mature precision deposition technology, this process is tailored for flip-chip mass production, delivering precise, repeatable, and controllable flux application for pads and solder bumps, thereby perfectly meeting the demands of large-scale flip-chip manufacturing.

Core Process Advantages: Addressing Traditional Flip-Chip Fluxing Challenges

In flip-chip packaging, the precision of flux application directly determines reflow soldering quality and package reliability. The ultrasonic spray process deposits an ultra-thin, uniform flux coating, fundamentally eliminating issues associated with excessive flux residue—such as poor underfill adhesion and post-reflow interconnection failures.

Precise control over film thickness completely prevents chip “float” (lift-off), avoids misalignment between the chip and substrate or poor connections, and significantly reduces production line downtime for adjustments and product scrap rates. Furthermore, the process minimizes overspray, preventing flux contamination of surrounding passive components and maintaining a clean, “no-clean” production environment that meets high-end precision packaging standards.

Compared to traditional methods—such as jetting, dip coating, solder paste printing, or pressure-nozzle spraying—ultrasonic spraying achieves ultra-thin, targeted, and uniform flux application, offering a high-precision solution that traditional methods cannot match. When integrated with fully automated XYZ motion control systems and conveyor lines, it enables high-speed mass production; the use of multiple atomizing nozzle configurations further boosts spraying efficiency, making it ideally suited for high-volume flip-chip packaging lines.

Key Advantages of Ultrasonic Spray Fluxing for Flip-Chip Applications

• Precise Spray Control for Cost Efficiency: Highly controllable spray areas eliminate overspray defects, significantly reducing rework costs and boosting production yields.
• Ultra-thin, Precisely Controlled Coating: Supports the creation of ultra-thin coatings at the micron level; achieves a uniform flux layer as thin as 20 microns to meet the demands of precision flip-chip processes.
• Optimized Soldering and Defect Elimination: A uniform flux coating significantly improves pad wettability, completely resolving issues like chip float and misalignment, thereby preventing chip and substrate scrap.
• Compatible with Diverse Mass-Production Carriers: Compatible with various JEDEC-standard trays and adaptable to batch spray production for different substrate structures, offering strong process versatility.
• Non-clogging and Highly Stable: Utilizes pressure-free ultrasonic atomization to eliminate the clogging issues common with traditional pressure nozzles; features low maintenance costs and excellent process repeatability and stability.
• Strong Material Compatibility: Perfectly compatible with various indium-based flip-chip flux materials and diverse high-end packaging process formulations.

About Cheersonic

Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.

Our coating solutions are environmentally-friendly, efficient and highly reliable, and enable dramatic reductions in overspray, savings in raw material, water and energy usage and provide improved process repeatability, transfer efficiency, high uniformity and reduced emissions.

If you have any technical questions, customization demands, or procurement inquiries about ultrasonic atomization nozzles, feel free to contact our professional sales and technical team for detailed parameters, customized solutions, and industry application support.
Email: market2@cheersonic.com