ETFE release films are mainly applied to high-temperature packaging processes, including semiconductor EMC epoxy transfer molding, Fan-out packaging, automotive-grade IGBT power device molding, and Mini LED COB dam forming. Distinct from PET films, silicone-coated release films and PTFE films, they are specialized packaging consumables balancing high thermal stability, ultra-high cleanliness, low stress and long reusable service life. Their core application characteristics fall into eight categories:
Capable of continuous long-term exposure to 180℃; melting point reaches 260℃. No softening, melting or mold adhesion occurs under molding high temperatures, whereas PET films deform at 120℃ and silicone films turn sticky after high-temperature aging. Thermal shrinkage rate <0.1% after 2 hours at 180℃, with uniform transverse and longitudinal shrinkage. During molding of 300mm large wafers and large-area IGBT substrates, it eliminates die offset, substrate warpage and molding flash burrs, ensuring micron-level packaging alignment precision. No creep elongation during the high-pressure molding dwell stage, maintaining consistent mold cavity flatness and drastically reducing packaging defects such as voids and delamination.
Inherent surface energy only 20~22 mN/m; no silicone release coating required, fundamentally preventing migration and precipitation of silicone small molecules. It is a mandatory preferred material for RF chips, Chiplets and automotive-grade IGBTs. Silicone contamination causes micro-bump contact failure, high-voltage leakage and wire bond detachment. High-purity substrate formulation with metal ion precipitation (Na, K, Fe, Cu) below 10 ppb and zero small-molecule outgassing, meeting Class 100 cleanroom production standards for semiconductors. No residual adhesive or film debris after peeling; plasma cleaning procedures can be omitted for most scenarios to streamline production workflows.
High tensile strength with elongation at break >300%; ultra-thin specifications ranging from 6 to 75μm resist tearing easily. PTFE films feature soft texture and low strength, prone to breakage during high-speed feeding of ultra-thin sheets. Moderate flexibility enables tight lamination to DBC ceramic substrates and uneven wafer surfaces. No fracture of fine aluminum or copper bonding wires during peeling, cutting scrap rates of cracked chips and ceramic substrates. Excellent adaptability to slitting, rewinding and continuous molding feeding; existing domestic and imported full-automatic plastic packaging equipment can adopt the film directly without modification.
Dielectric constant of 2.12.2 with extremely low dissipation factor, delivering stable electrical performance across wide temperature ranges without interfering with signal transmission of 5G RF and millimeter-wave chips. Volume resistivity >10¹⁶ Ω·cm and high breakdown voltage, providing temporary insulation protection during molding. Compatible with 6001700V automotive-grade IGBT and SiC power modules, restraining high-voltage creepage and excessive leakage current.
Water absorption rate <0.03%; no water vapor release during high-temperature molding to avoid internal packaging voids and delamination. No obvious performance degradation after long-term Double 85 damp-heat aging. No chemical reaction with epoxy EMC, curing agents or acidic/alkaline mold cleaning agents; release force remains nearly unchanged after repeated high-temperature cycles. PET films are susceptible to epoxy corrosion and hydrolysis, losing efficacy within dozens of cycles. A single film roll can be reused over 500 times, far exceeding PET (less than 50 cycles) and silicone-coated films (less than 100 cycles), significantly cutting downtime for film replacement.
Plasma or corona modification enables precise adjustment of release force within a range of 550 g/in, matching tailored peel strength for EMC of varying hardness and different packaged devices. No instantaneous impact stress during peeling. For ultra-thin chips, fragile ceramic substrates and fine bonding wires, it drastically reduces die cracking and wire breakage defects, lifting packaging yield by 5%12%.
Visible light transmittance ranges from 90% to 95%. Post-molding AOI inspection for packaging voids, flash and material shortage defects can be conducted without film peeling, boosting in-line inspection efficiency. Resists yellowing under prolonged high-temperature and damp-heat environments with stable optical performance, suitable for optical packaging of optical sensors, VCSELs and Mini LEDs.
ETFE release film is currently the only packaging release substrate that simultaneously satisfies high-temperature molding above 170℃, silicone-free ultra-high cleanliness, ultra-low thermal shrinkage, high insulation & low dielectric constant, and reusability for hundreds of cycles. It resolves mass production pain points of traditional PET, silicone-coated and PTFE films in high-end semiconductor and automotive power device manufacturing, including contamination, poor precision, short service life and easy breakage.
Ruikeda is one of the few domestic enterprises capable of developing high-end domestically produced ETFE films for electronic packaging as direct substitutes for imported counterparts. Shandong Dongyue and Zhejiang Juhua are leading domestic suppliers of ETFE raw materials.
