OBC Housing Leakage during Air Tightness Test? Sealing Troubleshooting with SIPA 1820 CIPG

If the on‑board charger (OBC) housing fails the air tightness test, distinguish leaks at housing joints, connectors and test fixtures first. Once the leak is localised to the flange joint, inspect the continuity of the adhesive bead, consistency of bead height after curing, and insufficient local compression after closure. For the CIPG process where the bead is cured prior to clamping and lid closure, ELAPLUS SIPA 1820 may be evaluated as a candidate for flange sealing. Final acceptance shall rely on repeated air tightness testing of the complete assembly. Leakage Symptom Priority Inspection Verification Method Recurring leaks at bead start/end across multiple units Missing adhesive, excess build‑up or stringing at overlap Compare dispensing trajectory and bead photos; adjust overlap and retest Leaks concentrated between two fasteners Flange gap, flatness and local compression Check physical gap and tightening sequence; retest after closure Passes initial test but leaks after environmental cycling Bead contact, interfacial adhesion and housing distortion Record leak points before and after testing; validate against control samples after disassembly Where Do Leaks Occur? Follow the full assembly inspection flow to separate housing seams, connectors and other sealing interfaces. If leakage originates from the housing joint, focus on bead overlap, corners, spans between screws and uneven flange areas. Map leak locations to the actual bead condition before deciding whether to modify dispensing, curing or closure parameters. Where Is SIPA 1820 Applied? Bonding between plastic housing and aluminium plate ELAPLUS recommends SIPA 1820 as a candidate CIPG sealant for OBC housings. It is a one‑component heat‑cure system. For evaluation, prepare test coupons using production‑representative housing flanges or grooves, surface treatments and mating components. Bead height, curing profile and target compression shall follow the product datasheet and assembly design respectively. How to Verify the Effectiveness of Modifications Record bead continuity, cross‑section dimensions and…