Polyonics new XT-657 flame retardant bonding tape helps prevent the propagation of fire, provides dielectric separation between electrical circuits and eliminates mechanical fasteners in battery assemblies and packs. The halogen free UL94 VTM-0 tested tape provides a thin, conformal bond line and offers an adhesive strength of greater than 32 oz/in (> 35N/100 mm), The tape has been proven effective in bonding Li-ion batteries used in today’s space-constrained consumer electronics devices as well in industrial power and battery applications.
Li-ion battery bonded to PCB using Polyonics XT-657 double coated, flame retardant polyimide tape
XT-657 is a high temperature bonding system that is used to attach batteries and components to chassis, boards, other batteries, etc. The REACH and RoHS compliant tape includes a 1 mil (25 µm) polyimide film, two layers of 1 mil acrylic pressure sensitive adhesive (PSA) and a variety of liners that aid in handling, die cutting and auto application.
The Polyonics bonding tape remains dimensionally stable at high temperatures, is resistant to the chemicals used in PCB manufacturing and designed to remain effective throughout wave solder and reflow processes. The tape also provides a high dielectric strength of >7.6 kV/mil (>299kV/mm) that helps isolate electrical circuits and complies with the aerospace FAR 25.853 and BSS 7238/7239 smoke and toxicity standards.
Shown at right, a Li-ion battery is bonded to a PCB using the Polyonics XT-657 tape. The edges of the battery case are sealed using the Polyonics XT-708flame retardant single coated matte black polyimide tape while the PCM circuit is isolated with the single coated Polyonics XT-624 flame retardant amber polyimide masking tape.
The XT-657 double coated bonding tape is available in rolls of 9" x 1000' (230mm x 300M).