Abstract: The present disclosure relates to a device and a system for testing flatness. The device for testing flatness includes a base, a testing platform, and a ranging sensor. The testing platform is assembled on the base. The testing platform includes a supporting structure. The supporting structure is disposed on the side of the testing platform away from the base and is used to support a to-be-tested board. The structure matches the structure of the to-be-tested board. The ranging sensor is disposed on the side of the testing platform away from the base. After the to-be-tested board is placed on the testing platform, the ranging sensor is used to test distances between a number N of to-be-tested positions on the to-be-tested board and the ranging sensor, to obtain N pieces of distance information, and the N pieces of distance information are used to determine the flatness of the to-be-tested board, where N is an integer greater than 2.

Abstract: The present disclosure relates to a device and a system for testing flatness. The device for testing flatness includes a base, a testing platform, and a ranging sensor. The testing platform is assembled on the base. The testing platform includes a supporting structure. The supporting structure is disposed on the side of the testing platform away from the base and is used to support a to-be-tested board. The structure matches the structure of the to-be-tested board. The ranging sensor is disposed on the side of the testing platform away from the base. After the to-be-tested board is placed on the testing platform, the ranging sensor is used to test distances between a number N of to-be-tested positions on the to-be-tested board and the ranging sensor, to obtain N pieces of distance information, and the N pieces of distance information are used to determine the flatness of the to-be-tested board, where N is an integer greater than 2.

Abstract: The present disclosure discloses a vacuum adsorption unit and a vacuum adsorption carrier, wherein the vacuum adsorption unit comprises: a housing defining an air path through-hole therein, the air path through-hole provided with an upper abutting surface and a lower abutting surface; a piston movable provided in the air path through-hole and is located between the upper abutting surface and the lower abutting surface; an outer peripheral wall of the piston is slidably matched with an inner peripheral wall of the air path through-hole; an elastic member having both ends that respectively abut against the housing and the piston, to constantly drive the piston to abut on the upper abutting surface; and a pressure relief passage communicated with the air path through-hole, and is configured to be closed only when the piston moves to abut against the lower abutting surface.

Abstract: The present disclosure discloses a vacuum adsorption unit and a vacuum adsorption carrier, wherein the vacuum adsorption unit comprises: a housing defining an air path through-hole therein, the air path through-hole provided with an upper abutting surface and a lower abutting surface; a piston movable provided in the air path through-hole and is located between the upper abutting surface and the lower abutting surface; an outer peripheral wall of the piston is slidably matched with an inner peripheral wall of the air path through-hole; an elastic member having both ends that respectively abut against the housing and the piston, to constantly drive the piston to abut on the upper abutting surface; and a pressure relief passage communicated with the air path through-hole, and is configured to be closed only when the piston moves to abut against the lower abutting surface.