Surge protection module

A surge protection module, comprising:

• an upper cover;
• a lower cover, configured for connecting with the upper cover, and for forming an accommodation space together with the upper cover, wherein each of the upper cover and the lower cover has four side walls, and each of two side walls of at least one of the upper cover and the lower cover has a notch, so that a first through hole and a second through hole are formed at the junction of the lower cover and the upper cover;
• a printed circuit board assembly (PCBA), having a plurality of copper traces, and being equipped with at least one surge protection device, the PCBA further having a plurality of welding structures, the welding structures being electrically coupled to the surge protection devices through the copper traces, the PCBA being disposed in the accommodation space, wherein the welding structures are distributed on a first end and a second end of the PCBA, and the first end and the second end pass through the first through hole and the second through hole respectively to expose the welding structures;
• and
• a flame-retardant filler, being filled in a gap of the accommodation space.