Detailed Introduction

This multi-cavity injection mold is customized for multi-size orange UV-shielding PFA photomask storage enclosures, fully optimized for PFA’s high chemical inertness, low particle emission and light-blocking property to eliminate PFA molding defects such as surface flow streaks, box body warpage and buckle flash that may contaminate precision photomasks.

The split fixed-moving two-plate mold adopts symmetrical multi-row cavity layout to realize mass production of three different sizes photomask boxes shown in the picture, each set composed of upper cover, bottom base and integrated snap buckles. Each square box cavity is an independent embedded insert for quick disassembly, residue-free deep cleaning and size switching. All molding surfaces undergo multi-stage particle-free high-gloss polishing to remove micro burrs and internal dust accumulation blind corners, eliminating post-molding secondary polishing that may generate tiny particles.

Independent distributed cooling pipelines are laid out for every single cavity to precisely control mold temperature during continuous high-temperature PFA injection molding, effectively restraining uneven wall shrinkage, large-size box bending and snap buckle deformation. Built-in precision interlock slide locking blocks maintain stable clamping force under long-cycle cleanroom mass production, preventing micro flash on thin-wall box edges and buckle contact surfaces to avoid scratching precision photomask glass substrates, and extending mold service life under cyclic fluoropolymer high-temperature processing.

Complete Precision Machining Workflow

1. 5-axis CNC rough milling for mold base outline and square multi-size box cavity rough forming
2. Vacuum stress relief heat treatment to stabilize steel hardness and reduce thermal deformation under long-run high-temp PFA molding
3. Precision surface grinding to control mold plate flatness & parallelism within ±0.002mm
4. Sinker EDM & Wire Cut WEDM for ultra-fine snap buckle, stepped box wall and positioning boss contours
5. Multi-stage particle-free high-temperature resistant polishing matched with PFA melt fluidity
6. Optional ultra-clean anti-corrosion surface coating compatible with semiconductor grade PFA raw materials

All mold core, cavity and structural components complete full 3D coordinate measuring inspection to satisfy strict semiconductor photomask packaging drawing tolerance standards. Full customization is supported based on photomask box samples or engineering drawings: cavity quantity, mold steel grade, cooling circuit layout and polishing grade can be adjusted according to semiconductor PFA purity grade, cleanroom Class 100/1000 standards and daily production capacity. The symmetrical multi-cavity layout greatly improves molding efficiency while unifying UV shielding consistency, box flatness and particle-free surface performance of all PFA photomask storage casings.

Specification Table