Solder material, junctioning method, junction material, and semiconductor device

A solder material comprises a first solder plate and a second solder plate having a thickness equal to or larger than 1 micron provided at the both surfaces of the first solder plate comprising material-having a lower melting point than the first solder or material which reacts with the first solder to produce an alloy having a lower melting point than the first solder. A junctioning method comprise putting the above-described solder material inserted between two objects to be junctioned to each other; heating the solder material to a temperature higher than the melting point of the second solder or the alloy and lower than the melting point of said first solder thereby to melt the second solder or the alloy; and thereafter cooling or keeping the solder material at a temperature in the vicinity of the melting point thereby to junction the objects to be junctioned to each other. The second solder plate has preferably a thickness less than 5 microns and the first solder plate has preferably a thickness equal to or larger than 30 microns. By this construction, the interval between the objects to be junctioned can be controlled to a predetermined thickness and the stress functioning to the objects can be relaxed as well as there arises no positional deviation between the objects.