A number of LSI chips (9) are mounted on a wiring substrate (12). A cooling element (68) comprises a housing (1), a bellows (2) and a cooling plate (6) for introducing a cooling medium. The cooling element is connected to the LSI chip by low melting solder, at the same time, the cooling plate is connected to the wiring substrate through a skirt (5) which is connected to the cooling plate and also connected to the wiring substrate by a low melting solder.
