| 摘要 |
<p>A thermal fuse comprises a member (14) mounted on a ceramic substrate. The member comprises a fuse element and spring (M-shaped region) and is mounted locally with solder via connection pads (12, 21 and 13). The fuse element bridges opposing pads (12, 21) of conductors (17 and 19). Pad (13) constitutes an anchor point. Current flows via the tracks (17 and 19), formed on the surface of the substrate, and part of the element (14), the fuse element, connected between the pads (12 and 21). Under electrical overload the solder softens and releases the spring away from the conductive areas to break the electrical contact between the conductor pads (12 and 21). In this way the spring means is not heated directly by the effects of current flow and, thus, does not lose its springiness since current only flows through the fuse element.</p> |
