The ball attach process involves placing solder balls onto the pads of a semiconductor package (typically BGA or CSP) to create electrical and mechanical connections between the chip and the PCB. These solder balls are reflowed to form solid joints.

Ball attach ensures reliable electrical connectivity and mechanical stability in fine-pitch semiconductor packages. It’s essential for flip-chip packaging, BGA rework, and wafer-level packaging. Consistent ball quality and flux selection are critical for yield.

Tacky flux and liquid flux are both used in ball attach. Tacky flux helps hold the solder balls in place prior to reflow, while liquid flux can be used for dipping or spraying. INVENTEC provides specialized fluxes designed for high-reliability ball attach applications.

Wafer-level ball attach is performed on entire wafers before dicing, often using flux dipping or printing methods. Package-level ball attach is done after individual chip packaging, typically with tacky flux application. Both processes require precise flux control and solder ball placement.

Common solder alloys include lead-free compositions such as SAC305 and SnAgCu, as well as SnPb for legacy applications. INVENTEC supports a range of RoHS-compliant solder materials optimized for semiconductor packaging reliability and joint performance.

Solder balls are typically applied by screen printing, ball placement machines, or ball transfer methods using tacky flux as an adhesive layer. Uniform ball height and alignment are essential to ensure successful reflow and joint formation.

Reflow profiles are carefully tuned to match the solder alloy and flux used. Profiles typically include a preheat, soak, and controlled peak temperature phase to ensure proper wetting, minimal voiding, and ball collapse. INVENTEC provides reflow guidance based on your materials.

It depends on the flux type. No-clean fluxes may leave minimal residue suitable for high-reliability environments. Water-soluble or rosin-based fluxes typically require post-reflow cleaning to prevent corrosion or contamination. INVENTEC offers both no-clean and cleanable fluxes for ball attach.

Common defects include ball misalignment, non-wet opens, head-in-pillow (HIP), voiding, and insufficient collapse. These can result from improper flux selection, solder ball contamination, or suboptimal reflow conditions. Proper process control is essential.

Yes. INVENTEC Performance Chemicals provides high-performance tacky and liquid fluxes tailored for semiconductor ball attach processes. These materials support both wafer-level and package-level operations with excellent wetting, low voiding, and minimal residue.