An ESD protection device includes a multilayer body including base material layers, a hollow portion inside the multilayer body, a ground electrode exposed at the hollow portion, first and second discharge electrodes exposed at the shared hollow portion and opposing the common ground electrode, and an auxiliary discharge electrode including conductive particles dispersed in the base material layer and extending along an inner surface of the hollow portion. At least the auxiliary discharge electrode in an adjacent region between the first discharge electrode and the second discharge electrode is divided into a portion on the first discharge electrode side and a portion on the second discharge electrode side by a non-formation section where the auxiliary discharge electrode is not provided in the hollow portion.

There is provided an ESD protection device capable of lowering a discharge starting voltage. An ESD protection device 1 includes a ceramic multilayer substrate 2, a first discharge electrode 4 and a second discharge electrode 5 arranged at a height position of the ceramic multilayer substrate, an end 4a of the first discharge electrode 4 and an end 5a of the second discharge electrode 5 facing each other, in which each of the first discharge electrode 4 and the second discharge electrode 5 contains a metal and a shrinkage suppression material having a lower rate of shrinkage than that of the metal at a temperature at which firing for the production of the ceramic multilayer substrate 2 is performed.

An air gap metal tip structure is provided for ESD protection that includes a lower substrate and an upper substrate disposed above the lower substrate. The air gap metal tip structure includes a first and a second metal tip disposed along at least one horizontal axis that is parallel to the upper substrate and the lower substrate. The air gap metal tip structure includes an air chamber formed between the upper and lower substrates within which the first and second metal tips are disposed. The air chamber includes a portion between points of the metal tips. Oxygen trapped in the air chamber is converted into ozone responsive to an occurrence of an arc between the tips to dissipate the arc, and the ozone is decomposed back into the oxygen responsive to an absence of the arc between the tips to maintain the ESD protection for subsequent arcs.

An air gap metal tip structure is provided for ESD protection that includes a lower substrate and an upper substrate disposed above the lower substrate. The air gap metal tip structure includes a first and a second metal tip disposed along at least one horizontal axis that is parallel to the upper substrate and the lower substrate. The air gap metal tip structure includes an air chamber formed between the upper and lower substrates within which the first and second metal tips are disposed. The air chamber includes a portion between points of the metal tips. Oxygen trapped in the air chamber is converted into ozone responsive to an occurrence of an arc between the tips to dissipate the arc, and the ozone is decomposed back into the oxygen responsive to an absence of the arc between the tips to maintain the ESD protection for subsequent arcs.

An ESD protection device includes a multilayer substrate, first and second discharge electrodes, and a discharge auxiliary electrode. Discharge portions of the first and second discharge electrodes are opposed to each other in a lamination direction of insulating layers with the discharge auxiliary electrode interposed between both the discharge portions. A cavity is provided within the multilayer substrate in at least one of a region positioned adjacent to or in a vicinity of the discharge portion of the first discharge electrode on an opposite side to the discharge auxiliary electrode and a region positioned adjacent to or in a vicinity of the discharge portion of the second discharge electrode on an opposite side to the discharge auxiliary electrode.

An ESD protection device includes: a first insulating layer (2a); a second insulating layer (2b) stacked on the first insulating layer (2a); a first via conductor (6a) extending through the first insulating layer (2a) in a thickness direction; a discharge gap portion (10) provided so as to be in contact with the first via conductor (6a), between the first insulating layer (2a) and the second insulating layer (2b); a first wiring line (7a) that is arranged on a surface of the first insulating layer (2a) opposite to the discharge gap portion (10) and that is electrically connected to the first via conductor (6a); and a second wiring line (7b) that is arranged on one surface of the second insulating layer (2b) and that includes a portion facing the first via conductor (6a) with at least the discharge gap portion (10) interposed therebetween.

An ESD protection device 1 has a ceramic insulating material 10, first and second discharge electrodes 21 and 22, and a discharge-assisting section 51. The first and second discharge electrodes 21 and 22 are disposed somewhere of the ceramic insulating material 10. The discharge-assisting section 51 is located between the distal end portion of the first discharge electrode 21 and the distal end portion of the second discharge electrode 22. The discharge-assisting section 51 is an electrode configured to reduce the discharge starting voltage between the first discharge electrode 21 and the second discharge electrode 22. The discharge-assisting section 51 is made from a sintered body containing conductive particles and at least one of semiconductor particles and insulating particles. The first and second discharge electrodes contain at least one of the semiconductor material constituting the semiconductor particles and the insulating material constituting the insulating particles.

It is common for a power tool system from a manufacturer to include a battery pack that is designed and configured to mate and operate with at least one power tool and a battery charger. However, as systems have evolved it has become desirable to provide a battery pack that is designed and configured to mate and operate with at least one power tool and a first battery charger but not a second battery charger. The present disclosure provides a battery pack including a housing, a terminal block, a plurality of terminals, and a mechanical lockout for allowing engagement with a power tool and a first battery charger while preventing engagement with a second battery charger.

An ESD protective device includes an element assembly with a hollow portion that includes inner surfaces including a first inner surface, a second inner surface, and a third inner surface inclined to a Z direction in a cross section including the Z direction. Accordingly, a surface area of the inner surfaces of the hollow portion is increased, the heat load on an auxiliary discharge electrode is reduced, and the deterioration of the auxiliary discharge electrode is significantly reduced or prevented.

A battery pack including a housing, a terminal block, a printed circuit board electrically connected to the terminal block, at least one battery cell, and a spark gap device on the printed circuit board to provide electrostatic discharge protection and disposed between the printed circuit board and the terminal block.