The grid format heat exchanger was designed and manufactured by the Dutch company Philips in 1968, and was first used in the Philips type helium liquefier. It consists of a copper wire mesh of 25-250 mesh/square inch punched out in a square shape and then combined with a partition made of synthetic resin. The partition has several square holes punched on it, and the partition and copper wire mesh are alternately stacked together, placed between the air distribution heads at both ends, and then pressed in a mold and heated to 150 ℃ to bond the copper wire mesh to the softened resin until it solidifies. Its square holes are connected in series to form gas channels, with each gas channel surrounded by four opposing flow channels around it. The two gas streams exchange heat through a copper wire mesh. It has good thermal contact and uses a large number of narrow channels instead of other types of large channels, resulting in high heat transfer efficiency. Its heat transfer area per unit volume can reach over 3000m2/m3, and its longitudinal thermal conductivity is small, overcoming the disadvantages of plate fin type.