Silicone potting adhesives are widely used in new energy vehicle electronic controls, photovoltaic inverters, energy storage BMS, and other applications. However, bonding failure and curing abnormalities reported from production lines remain persistently high. Based on on-site technical service data collected over the past two years, Tensan has compiled a self-check reference checklist for potting process issues for industry reference.
I. Incomplete Curing: Three Questions for Rapid Diagnosis
|
Symptom |
Possible Cause |
Tensan Recommendation |
|
Tacky surface, insufficient hardness |
A:B mixing ratio deviation too large |
Switch to automatic metering equipment, control error within ±1% |
|
Localized flow-like state, uneven curing |
Static mixing tube too long or not replaced regularly |
Match tube diameter to flow rate; replace every shift |
|
Frequent non-curing in winter |
Ambient temperature <15°C, reaction rate drops sharply |
Heat work area to 23±3°C; preheat adhesive to 25°C before mixing |
|
Thin coating areas (<1mm) remain uncured for long periods |
Insufficient exothermic heat, rapid heat dissipation |
Apply post-curing in 80-100°C oven for 30-60 minutes |
II. Interfacial Delamination: Four Scenarios for Targeted Identification
|
Symptom |
Possible Cause |
Tensan Recommendation |
|
Complete peeling between adhesive layer and PCB board |
Residual fingerprints/flux/dust on board surface |
Add plasma cleaning step before production |
|
No adhesion at all on PP/PE housings |
Surface energy too low (<34 dynes/cm)Surface energy too low (<34 dynes/cm) |
Flame or corona treatment, increase to ≥38 dynes/cm |
|
Edge warping after curingEdge warping after curing |
Excessive shrinkage stress from fast-cure system |
Switch to low-shrinkage slow-cure formulation + stepwise heating process |
|
Cracks appearing after thermal shock testing |
Rapid cooling after curing, instantaneous release of thermal stress |
Allow slow cooling to room temperature after curing before transferring |
III. Tensan's "Three-Step" Closed-Loop Improvement Solution
For the high-frequency issues mentioned above, Tensan has established a standardized "Diagnose - Improve - Solidify" three-step service process:
IV. One Sentence Summary
The baseline of potting quality is not guaranteed by good adhesive alone — it's secured by good process discipline. Tensan: not just an adhesive supplier, but your potting process partner every step of the way.