Problem

A semiconductor assembly house in Penang, Malaysia faced capacity and yield challenges moving fan-out wafer-level packaging (FoWLP) from pilot to volume production. Key pain points included inconsistent underfill dispensing across full 8–12" wafers, limited equipment capable of coping with wafer warpage, and high cost/lead time for foreign dispensing systems. The customer required a reliable, high-throughput dispensing solution for underfill, coating, flux spray and Dam & Fill processes that could handle wafer-scale variability while meeting automotive and consumer reliability targets.

Cause

FoWLP underfill and related processes demand precise volumetric dispensing over large wafer areas. Traditional benchtop dispensers lack the throughput, warpage compensation and process repeatability required for wafer-level mass production. Inconsistent bead profiles and voids arise from poor nozzle control, inadequate compensation for wafer bow (warpage), and systems not designed for continuous wafer handling. Importing turnkey systems added long lead times and support complexity for local engineers.

Solution

SS101 — the first domestically produced dispensing platform specifically certified for FoWLP underfill mass production. Key capabilities applied for the Penang line:

• Wafer compatibility: supports both 8" and 12" wafers without hardware changeover, enabling mixed-line production and future capacity scaling.
• Warpage compensation: active pick-and-place stage with ±3 mm warpage handling ensures consistent nozzle-to-surface distance across bowed wafers, preventing nozzle crashes and variable bead geometry.
• Multi-process support: configurable modules for Underfill, Coating, Flux Spray and Dam & Fill allow the same cell to perform sequential process steps or be integrated into a clustered line.
• High-precision volumetric control: servo-driven screw and advanced motion control deliver repeatable bead profiles and volumetric accuracy suitable for void-free underfill filling.
• Domestic service and fast spares: local manufacture reduces lead time for spare parts and supports rapid on-site tuning with local application engineers.

Integration and Process Implementation

SS101 units were installed in a cluster with automated wafer loaders and inline pre-bake ovens. For underfill, the system used a synchronized dispense-robot profile: nozzle start/stop points and Z-compensation were programmed per wafer map. Flux spray and coating modules were configured with recipe-controlled spray patterns and flow rates. Dam & Fill sequences used dual-path dispense heads to form containment dams and complete bulk fill, minimizing capillary voids. The system controller provided centralized recipe management and traceability, logging dispense mass, nozzle temperature and pressure for each wafer lot.

Results and Benefits

• Yield improvement: void incidence in underfill drops by over 70% due to precise Z-compensation and volumetric control, improving thermal fatigue reliability in subsequent testing.
• Throughput increase: SS101’s wafer-level continuous dispensing reduced cycle time per wafer versus die-level dispensing, enabling higher line capacity without adding operators.
• Lower TCO and faster support: local manufacturing reduced capital lead time and cut spare-part replacement time from weeks to days, increasing equipment uptime.
• Process flexibility: single platform performing underfill, coating, flux spray and Dam & Fill simplifies line layout and reduces integration cost.
• Robustness to warpage: ±3 mm warpage handling removed the need for pre-sorting bowed wafers, saving upstream handling steps.

Recommendations for Malaysian FoWLP Lines

• Run initial wafer qualification across representative bow profiles and materials to fine-tune Z-compensation maps.
• Use inline X-ray or acoustic inspection after underfill to validate void reduction and close the process loop.
• Standardize recipes for wafer sizes and material families to speed changeovers between 8" and 12" runs.
• Leverage local support for preventive maintenance schedules and rapid nozzle replacement.

Conclusion 

For Penang-based FoWLP manufacturers moving to volume underfill production, the SS101 provides a domestically produced, high-precision solution that addresses warpage, throughput and serviceability challenges. By combining wafer-level handling, ±3 mm warpage compensation and multi-process flexibility, SS101 enables reliable, scalable FoWLP underfill, coating and Dam & Fill production — reducing defects and shortening time to market. Contact Mingseal’s regional team for a pilot deployment and process qualification tailored to your assemblies.