In flip chip and chip scale package (CSP) assembly, flux is jetted on the solder bumps before die placement to hold the die to the substrate prior to reflow. During the reflow process, flux removes oxides from metal surfaces to be soldered, enhances wetting, and protects against re-oxidation. Special high-tack phase change flux materials can be jetted in thin layers for added holding power.
Today’s flip chip and CSP devices with dense arrays of small bumps make jetting preferable to stencil printing and dipping. For example, the dipping process performed in component placement equipment is difficult to control for thinner flux coating requirements below 25 μm. Too much flux can cause the die to “float,” resulting in misalignment between die bumps and substrate bumps, and can also impede underfill flow. Too little flux can result in insufficient soldering.
A thin coating is also jetted on wafers prior to laser dicing to reduce contamination or dust caused by ablation fall-out from the dicing process.
Configured with Asymtek’s DJ-2200 DispenseJet® valve with coaxial air technology, the S-930N is the ideal system for high-speed jetting of thin film coatings as low as 5 μm (material dependent). The system is capable of jetting virtually any pattern while maintaining good edge definition (0.5 to 1.5 mm) and minimizing overspray associated with other spraying techniques.
The fully enclosed, vented system includes safety interlocks and an emergency stop. An optional external feed system and dual lane configuration are available for high-volume production. ASYMTEK’s MH-900 series loaders/unloaders can also be added to create an island of automation or for inline production capability.
Comprehensive process solutions from Nordson ASYMTEK ensure a maximum return on investment and low cost of ownership. From initial process development through full scale production, you are supported by our experienced worldwide engineering, applications development and technical service network.
- Selective flux jetting improves package reliability, production throughput and material utilization
- Nordson ASYMTEK’s DJ-2200 DispenseJet® valve with coaxial air technology enables thin flux coatings as low as 5 μm
- Selective flux jetting provides excellent edge definition (0.5 to 1 mm), minimizes flux residue and reduces or eliminates cleaning
- FmXP software controls the amount of flux jetted to accommodate different height flip chips
- MH-900 series loaders/unloaders can be added to create an island of automation or for inline production capability
Optional Features and Accessories
- Calibrated Process Jetting (CPJ) or Mass Flow Calibration (MFC) for automatically ensuring volumetric repeatability during long production runs
- Dual Valves: dual action and dual simultaneous capability
- Dual lane configuration
- Laser height sensor
- MH-900 Series material handlers for reliable magazine loading and unloading of a wide range of carriers, from thin strips to large heavy pallets
- Pre- and post-queue stations
- Programmable fluid and valve pressure
- SECS/GEM interface software