In many occasions, the self-recovery fuse needs to be externally packaged to protect the core and control the heat transfer. So can the self-recovery fuse be "packaged"? And what is the impact of "packaging"? Please follow the small series to find out.
Answer: Packaging will have an impact on the self-healing fuse, because it will affect the normal exothermic process of the product after the fuse packaging is restored, resulting in unstable working state of the product. Secondly, too tight or too hard packaging will affect the physical shrinkage of PTC materials, resulting in product failure.
Packaging of self-recovery fuse products is generally not recommended. If packaging is needed, pay attention to the selection of packaging materials. If the packaging material is too hard, it will hinder the expansion of the thermistor, thus affecting the normal use of the thermistor. Even if the soft sealing material is used, its heat dissipation performance will be affected.
Self-recovery fuse is characterized by eliminating abnormal current after shut-off action. The temperature of the fuse drops rapidly and returns to the low resistance conductor. At this time, if the heat dissipation capacity is strong, the fuse will cool quickly and the recovery time will be short.
Therefore, action time and recovery time are a pair of contradictions, which need to be well balanced and optimized. Therefore, the matching of thermal expansion coefficient, low thermal capacity and proper thermal conductivity should be considered in the selection of packaging materials. Choosing modified epoxy resin as packaging material can meet the requirements.
