Printed circuit board, battery module, battery pack, and electrical device

A printed circuit board, comprising:

• a substrate;
• a pad above the substrate;
• a solder paste layer above the pad;
• a component body above the solder paste layer;
• and
• a support assembly between the pad and the component body to form a degassing space between the component body and the solder paste layer,
• wherein one end of the support assembly is connected to the component body, and another end of the support assembly extends into the solder paste layer to directly connect to the pad,
• the support assembly is soldering lug, which has a higher melting point than solder paste in the solder paste layer,
• the printed circuit board further comprises a fixing assembly for preventing an offset in a case of connecting the component body to the pad between the component body and the pad,
• the fixing assembly comprises a solder paste zone and a limiting post, the solder paste zone is disposed on the pad, one end of the limiting post is connected to the component body, and another end of the limiting post is connected to the solder paste zone,
• the limiting post is disposed at a flank of the component body, and
• a thickness of the solder paste zone is greater than a thickness of the solder paste layer.