Disclosed is a battery pack configured such that a plurality of battery modules is connected to each other in series in a state in which the modules are in contact with each other or stacked adjacent to each other, the pack being fixed such that a stacked state of the modules is maintained even when volume of the modules is changed during charge and discharge, the pack including a cut-off portion connected in series to an electrical connection circuit between modules, a fixing member to fix a circuit breaker to at least one outer surface of the pack, and the breaker configured to be electrically conducted when an outer surface of at least one module expands by a reference volume value or more, the breaker being connected in series to the electrical connection circuit to short-circuit the cut-off portion when electric conduction is performed due to swelling of the modules.

The present disclosure relates to a technical field of cells, and discloses a protection device and a battery. The protection device includes: a first connecting member; a second connecting member; a first element; and an elastic sheet. When the elastic sheet has a temperature lower than a first temperature, the elastic sheet is connected to at least one of the first connecting member and the second connecting member; when the temperature of the elastic sheet is equal to the first temperature, the elastic sheet is deformed to allow the first connecting member, the second connecting member, the elastic sheet and the first element to form a series circuit. When the protection device is not triggered, the temperature of the elastic sheet is lower than the first temperature, and the elastic sheet is connected to at least one of the first connecting member and the second connecting member.

An attachment structure includes a housing and a plate-shaped cover attached to the housing. The cover has a locking portion to fix the cover to the housing. The housing has a locked portion engaged with the locking portion to regulate a movement of the cover in a direction separating from the housing. The attachment structure is configured to engage the locking portion and the locked portion at an engagement place while the cover and the housing are pressed each other in directions separating from each other at a pressing place distant from the engagement place, and to form a space between the cover and the housing in a region between the pressing place and the engagement place, when the cover is attached to the housing.

A method of making printed circuit board vias using a double drilling and plating method is disclosed. A first hole is drilled in a core, the first hole having a first diameter. The first hole is filled and/or plated with an electrically conductive material. A circuit pattern may be formed on one or two conductive layers of the core. A multilayer structure may then be formed including a plurality of cores that also include pre-drilled and plated via holes, wherein at least some of the pre-drilled and plated via holes are aligned with the first hole. A second hole is then drilled within the first hole and the aligned pre-drilled and plated holes, the second hole having a second diameter where the second diameter is smaller than the first diameter. A conductive material is then plated to an inner surface of the second hole.

An attachment structure includes a housing and a plate-shaped cover attached to the housing. The cover has a locking portion to fix the cover to the housing. The housing has a locked portion engaged with the locking portion to regulate a movement of the cover in a direction separating from the housing. The attachment structure is configured to engage the locking portion and the locked portion at an engagement place while the cover and the housing are pressed each other in directions separating from each other at a pressing place distant from the engagement place, and to form a space between the cover and the housing in a region between the pressing place and the engagement place, when the cover is attached to the housing.

An electromagnetic relay including: an electromagnet; a movable spring having a movable contact; a first terminal to which one end of the movable spring is connected; a second terminal having a fixed contact opposite to the movable contact; an actuator that rotates by excitation of the electromagnet, rotates the movable spring, and causes the movable contact to come in contact with the fixed contact or to separate from the fixed contact; a nonmagnetic card to be attached to the actuator; a plurality of magnetic members that sandwich the movable contact and the fixed contact, and apply a magnetic flux to the movable contact and the fixed contact to extend an arc; and a permanent magnet attached between the magnetic members.

A method of making printed circuit board vias using a double drilling and plating method is disclosed. A first hole is drilled in a core, the first hole having a first diameter. The first hole is filled and/or plated with an electrically conductive material. A circuit pattern may be formed on one or two conductive layers of the core. A multilayer structure may then be formed including a plurality of cores that also include pre-drilled and plated via holes, wherein at least some of the pre-drilled and plated via holes are aligned with the first hole. A second hole is then drilled within the first hole and the aligned pre-drilled and plated holes, the second hole having a second diameter where the second diameter is smaller than the first diameter. A conductive material is then plated to an inner surface of the second hole.

A method of making printed circuit board vias using a double drilling and plating method is disclosed. A first hole is drilled in a core, the first hole having a first diameter. The first hole is filled and/or plated with an electrically conductive material. A circuit pattern may be formed on one or two conductive layers of the core. A multilayer structure may then be formed including a plurality of cores that also include pre-drilled and plated via holes, wherein at least some of the pre-drilled and plated via holes are aligned with the first hole. A second hole is then drilled within the first hole and the aligned pre-drilled and plated holes, the second hole having a second diameter where the second diameter is smaller than the first diameter. A conductive material is then plated to an inner surface of the second hole.

The present disclosure relates to a technical field of cells, and discloses a protection device and a battery. The protection device includes: a first connecting member; a second connecting member; a first element; and an elastic sheet. When the elastic sheet has a temperature lower than a first temperature, the elastic sheet is connected to at least one of the first connecting member and the second connecting member; when the temperature of the elastic sheet is equal to the first temperature, the elastic sheet is deformed to allow the first connecting member, the second connecting member, the elastic sheet and the first element to form a series circuit. When the protection device is not triggered, the temperature of the elastic sheet is lower than the first temperature, and the elastic sheet is connected to at least one of the first connecting member and the second connecting member.

Fuse assemblies are disclosed. In one implementation, a fuse assembly may be disposed that includes a first portion of the second portion. The first portion may be formed of a first metal. The second portion may be formed of a second metal different from the first metal. The second metal may be copper, and the copper may be tin plated or silver plated.