What is BGA Assembly?

Ball Grid Array (BGA) assembly is an advanced PCB packaging technology where solder balls are arranged in a grid pattern beneath the component, enabling high-density interconnects for complex electronics. FanyPCB specializes in precision BGA soldering, rework, and X-ray inspection for reliable, high-performance circuit boards used in:

✔ Advanced computing (CPUs, GPUs)

✔ Telecommunications equipment

✔ Medical devices

✔ Automotive electronics

Our BGA Assembly Capabilities

Precision BGA Soldering

FanyPCB delivers unmatched precision in BGA soldering through our advanced assembly lines equipped with Europlacer EVO hybrid pick-and-place systems capable of handling components down to 0.3mm pitch. Our controlled environment soldering process utilizes nitrogen-assisted reflow ovens to achieve void rates below 5%, significantly outperforming industry averages. For challenging mixed-technology boards, we've developed specialized thermal profiles that accommodate BGAs alongside delicate 01005 passives and through-hole components without compromising joint integrity. Our engineering team particularly excels in high-density interconnects for applications like FPGA packaging and GPU substrates, where we routinely achieve placement accuracies of ±15µm through laser-aligned vision systems.

Comprehensive BGA Rework

When modifications or repairs are needed, our IPC-7711/7721-certified technicians perform precision BGA rework using the industry's most advanced equipment. The Jovy RE-8500 rework stations in our ESD-protected workstations allow for component-specific thermal profiling with real-time IR monitoring, enabling successful re-balling of 0.35mm CSP devices. Beyond basic rework, we offer design validation services where we thermally map prototype assemblies to identify potential manufacturing issues before volume production. This proactive approach has helped numerous clients avoid costly respins, particularly for aerospace and medical devices requiring absolute reliability.

Multilayer Quality Verification Process

Quality assurance at FanyPCB extends far beyond basic visual inspection. Our three-tiered verification system begins with high-resolution 5µm 3D X-ray tomography to examine every solder joint's internal structure, followed by automated optical inspection (AOI) for surface defects. For mission-critical applications, we perform destructive cross-sectioning to analyze intermetallic compound formation and microvia fill rates. This rigorous process catches potential failure points like solder bridging, non-wetting, or excessive voiding that conventional methods might miss, giving our clients confidence in their high-value assemblies.

Application-Specific BGA Innovations

Recognizing that one size doesn't fit all in advanced packaging, we've developed specialized BGA solutions for extreme environments. Our high-temperature assemblies use SnAgCu (SAC305) solder formulations tested to withstand 150°C continuous operation, ideal for automotive power modules. For RF and photonic applications, we offer low-CTE substrates that precisely match silicon and GaAs die characteristics, minimizing thermal stress. We also maintain an inventory of specialty underfill materials to address the unique mechanical demands of large-die BGAs in industrial vibration environments.

BGA Assembly Process Tips

Design Phase Preparation

Successful BGA assembly begins with thoughtful design considerations. We recommend allocating at least 0.5mm escape 

routing between BGA pads to ensure manufacturability, using dog-bone fanout patterns for standard BGAs with 0.8mm or 

larger pitch. For more advanced micro-BGAs below 0.5mm pitch, via-in-pad designs with copper filling typically yield better 

results while maintaining 10-15% solder mask expansion helps prevent bridging issues during soldering. These design 

choices significantly impact the assembly's success rate before production even begins.

Stencil Optimization

The right stencil configuration makes all the difference in BGA assembly quality. For 0.5mm pitch BGAs, we've found a 

0.1mm stencil thickness with 1:0.9 aperture ratio using round openings delivers the most consistent results, especially 

when using nano-coated stencils that reduce paste sticking by approximately 40%. When dealing with mixed-pitch designs, 

implementing step stencils with 0.08mm and 0.12mm zones combined with electropolishing creates smoother aperture wallsthat improve paste release characteristics.

Soldering Process Control

Precise temperature control forms the foundation of reliable BGA connections. Our proven method involves a gradual preheat 

phase at 1.5-2°C per second up to 150-180°C, followed by a 60-90 second soak at 180-200°C to activate the flux properly. The 

critical reflow stage should maintain temperatures above 220°C for 30-45 seconds, peaking at 235-245°C when using SAC305 

solder alloys. Implementing a nitrogen atmosphere with oxygen levels below 1000ppm can reduce voiding by 35% compared to 

standard air environments, significantly improving joint reliability.

Inspection Best Practices

Thorough inspection protocols catch potential issues before they become failures. We configure our X-ray systems at 90kV for 

examining 0.3mm pitch BGAs, always including 30° oblique angle views to detect head-in-pillow defects that straight overhead 

views might miss. Following IPC Class 3 standards, we maintain strict acceptance criteria including no more than 15% voiding per

joint, absolutely no bridging between adjacent balls, and verification that solder achieves full wetting across at least 80% of each 

pad's circumference.

Rework Protocol

Even with perfect processes, occasional rework becomes necessary. Our approach begins with carefully preheating the board to 

125°C on the bottom side before component removal, while limiting each pad to maximum of two rework cycles to prevent 

degradation. For site preparation, we use low-residue no-clean flux combined with copper braid wicking to achieve perfectly 

level pads. When replacing components, applying fresh Type 4 solder paste and verifying coplanarity with less than 0.05mm 

variation ensures the new connection matches original quality standards.

Reliability Enhancements

Long-term BGA reliability requires additional protective measures. Selecting the proper underfill material proves critical - 

capillary flow works best for standard BGAs while no-flow varieties suit high-density arrays, with both options capable of surviving 

1500+ thermal cycles between -40°C to +125°C. For environmental protection, acrylic conformal coatings serve well in general 

conditions while polyurethane formulations better withstand harsh operating environments with exposure to chemicals or 

extreme temperatures.