Abstract: In a semiconductor device (1), semiconductor elements (2) and (3) are mounted on a lead frame (5) having leads (4). The semiconductor elements (2) and (3) are connected with the leads (4) by metallic wires (6) and (7). The semiconductor device (1) also has a heat sink (8). The members (2) to (8) are sealed with a plastic package (10). The leads (4) are exposed outward. Each of the end leads (4a) to (4d) has a wide first lead portion, a narrow second lead portion, a third lead portion to be inserted into an external substrate, and a protruding gap-controlling portion (9) for keeping the gap between the semiconductor device (1) and the external substrate constant. Because the heat resistance from the leads (4) to the plastic package (10) increases, the temperature-rise property of the lead is improved so that the solderability is improved.

Abstract: A solder alloy is provided in which generation of an oxide film of Zn—Sn based or Zn—In based solder alloy, which can be easily oxidized, can be restrained without deteriorating the mechanical characteristics, and a soldering method that causes less joining defects is provided. Soldering is performed in an inert atmosphere or reductive atmosphere, using a solder alloy containing one or more of Sn and In at a maximum of 50% by weight and containing P at 0.0005% by weight or more and less than 0.001% by weight, with the remaining part made of Zn and unavoidable impurities.

Abstract: In a semiconductor device (1), semiconductor elements (2) and (3) are mounted on a lead frame (5) having leads (4). The semiconductor elements (2) and (3) are connected with the leads (4) by metallic wires (6) and (7). The semiconductor device (1) also has a heat sink (8). The members (2) to (8) are sealed with a plastic package (10). The leads (4) are exposed outward. Each of the end leads (4a) to (4d) has a wide first lead portion, a narrow second lead portion, a third lead portion to be inserted into an external substrate, and a protruding gap-controlling portion (9) for keeping the gap between the semiconductor device (1) and the external substrate constant. Because the heat resistance from the leads (4) to the plastic package (10) increases, the temperature-rise property of the lead is improved so that the solderability is improved.

Abstract: A method of depositing solder paste includes the steps of: superimposing a masking member having a plurality of through-holes and a supporting member on each other so that the supporting member covers the plurality of through-holes; filling cavity portions formed by the plurality of through-holes and the supporting member with solder paste; disposing an LSI chip and the masking member so that electrodes and the cavity portions are superimposed on each other respectively; and heating the solder paste so as to make the solder paste deposit on the electrodes.

Abstract: A high-speed, high-density, small-sized, low-cost semiconductor device wherein the feeder substrate 2 for supplying power to the semiconductor elements 3 as a bare chip has the containers 2a for containing the semiconductor elements 3, the semiconductor elements 3 are bonded to the wiring layer 1b of the signal transmission substrate 1 for transmitting signals to the semiconductor elements 3 and contained in the containers 2a, the containers 2a are covered with the signal transmission substrate 1, and the signal transmission substrate 1 is superposed upon and bonded to the feeder substrate 2.

Abstract: 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.