Abstract: A button-type secondary battery includes a lower can having a bottom surface; an upper can having a top, the upper can and the lower can being coupled to define a space therein; an electrolyte in the space; an electrode assembly in the space and including a negative electrode, a separator, and a positive electrode wound together; a gasket between the upper can and the lower can to electrically insulate the upper and lower cans; a top insulator that is electrically insulating and covering a top surface of the electrode assembly; and a bottom insulator that is electrically insulating and covering a bottom surface of the electrode assembly. The top and bottom insulators are each configured to expand in volume by absorbing the electrolyte. Surfaces of at least one of the top insulator and the bottom insulator are coated with a protective layer to prevent thermal shrinkage from occurring.

Abstract: A button type secondary battery includes a wound electrode assembly; a lower can with the electrode assembly and an electrolyte in the lower can; a top plate to close the lower can; a positive electrode terminal coupled to the top plate through a gasket to be electrically insulated from the top plate with a portion of the positive electrode terminal passing through a hole in the top plate to be bonded to a positive electrode tab; a top insulator covering a top surface of the electrode assembly; and a bottom insulator covering a bottom surface of the electrode assembly. The top insulator and the bottom insulator are each configured to expand in volume by absorbing the electrolyte. Surfaces of at least one or more of the top insulator and the bottom insulator are coated with a protective layer configured to prevent thermal shrinkage from occurring.

Abstract: A vertical probe pin that includes: an elastic beam part which is disposed between a lower contact portion in contact with a device to be tested and an upper contact point spaced apart at a predetermined distance from the lower contact point and in contact with a test device. The vertical probe pin is composed of a pair of elastic beams having a predetermined gap in order to be elastically deformed by an external force; and a separation prevention protrusion part provided with separation prevention protrusions protruding from at least one of the pair of elastic beams in order to prevent the elastic beam part from being separated through an upper guide hole.