Patent ID: 8072730

Claim:
A chip-type protection device having an enclosed micro-gap between electrodes, comprising: a substrate having two opposite surfaces made of poor conductor; plural sets of paired discharge electrodes, arranged in parallel to one another on either of the two opposite surfaces, wherein each set of the plural sets of paired discharge electrodes includes a pair of conductive portions connected to opposite edges of the substrate respectively and a pair of discharge portions extending from the respective conductive portions towards each other by a micro-gap; and a surrounding wall hermetically enclosing, together with the substrate, the micro-gaps to constitute a chamber having a predetermined gaseous environment, said surrounding wall comprising: an elevated portion formed on the plural sets of paired discharge electrodes in a manner spaced apart from the micro-gaps by a predetermined distance; and at least one cover portion disposed above the elevated portion in a straddling manner across the micro-gaps; wherein the elevated portion is a plurality of frames, each being formed on one of the discharge electrodes.