MacDermid Alpha Electronics Solutions Underfill Materials for Printed Circuit Boards (PCBs) ALPHA ® HiTech ® CU31-3300

Product Overview ALPHA HiTech CU31-3300 is a one-component reworkable underfill that balances a moderately high Glass Transition Temperature (111 °C) with excellent reworkability to help manufacturers protect assemblies while maintaining repair and rework options. The material is easily removable without damaging the solder mask, which can reduce scrap risk and lower total cost of ownership while supporting waste-reduction goals. It offers a stable production window with 20-day pot life at 25 °C and mild storage conditions of 1 °C to 10 °C. CU31-3300 has demonstrated strong thermomechanical durability, passing a Thermal Cycling Test from -40 °C to 105 °C for at least 1,000 cycles. It is halogen-free (no halogens intentionally added) and complies with the Restriction of Hazardous Substances Directive EU/2015/863. Product Features Glass Transition Temperature (Tg) 111 °C to support applications from mobile and wearables to computing and automotive Pot life 20 days at 25 °C to support a stable processing window Typical uncured viscosity 2,800 ± 600 centipoise (Brookfield RVT, 20 revolutions per minute at 25 °C) Good adhesion strength Good adhesion strength to reinforce Ball Grid Array components and improve board-level reliability Halogen-free No halogens intentionally added Restriction of Hazardous Substances compliant Directive EU/2015/863 (amending Annex II to 2011/65/EU) Featured Applications Ball Grid Array reinforcement for high-density assemblies Supports reinforcement of Ball Grid Array packages where tight spacing and high interconnect density increase mechanical stress, helping improve board-level reliability. Mobile devices requiring rework-friendly reliability protection Provides underfill reinforcement for compact mobile assemblies while still enabling rework, helping manufacturers reduce scrap risk on high-value boards. Wearables with compact layouts and board-level reliability needs Fits space-constrained wearable designs where reliability is critical and rework capability matters due to tight tolerances and high assembly value. Computing assemblies exposed to repeated thermal stress Designed for assemblies that experience frequent temperature changes, with demonstrated thermal cycling performance to help protect interconnect reliability. Automotive electronics requiring thermomechanical durability Targets automotive environments where assemblies face wide temperature ranges and long-life reliability expectations, supported by thermal cycling performance data. High-value assemblies where scrap reduction and rework economics matter Helps lower total cost of ownership by enabling clean rework and recovery of expensive assemblies, reducing the impact of rework events on yield and waste.