Abstract: The present invention relates to a solder paste composition used for precoating an electrode surface with solder. A first solder paste composition is contains a solder powder and a flux, and a metallic powder made by metallic species different from metallic species constituting the solder powder and metallic species constituting the electrode surface in a rate of 0.1% by weight or more and 20% by weight or less based on a total amount of the solder powder. When these solder paste compositions are evenly applied onto an electronic circuit substrate for precoating, such a solder that does not generate any swollen portion, solder-lacking portion and variability in a height thereof can be formed irrespective of a shape of a pad.

Abstract: A solder paste composition used in a solder precoating method of forming solder bumps by forming a dam around electrodes on a substrate, filling a solder paste composition on the electrodes within opening parts surrounded by the dam, and heating the solder paste composition filled, so that solder is adhered to the surfaces of the electrodes. The solder paste composition contains solder powder, which is of a particle size distribution in which particles having a particle size of below 10 ?m are present 16% or more, and a sum of the particles having a particle size of below 10 ?m and particles having a particle size of 10 ?m or more and below 20 ?m is 90% or more. This enables to suppress occurrence of bump defects, and form solder bumps of a uniform height with a high yield by a solder precoating method using the dam.

Abstract: A solder paste composition used in a solder precoating method of forming solder bumps by forming a dam around electrodes on a substrate, filling a solder paste composition on the electrodes within opening parts surrounded by the dam, and heating the solder paste composition filled, so that solder is adhered to the surfaces of the electrodes. The solder paste composition contains solder powder, which is of a particle size distribution in which particles having a particle size of below 10 ?m are present 16% or more, and a sum of the particles having a particle size of below 10 ?m and particles having a particle size of 10 ?m or more and below 20 ?m is 90% or more. This enables to suppress occurrence of bump defects, and form solder bumps of a uniform height with a high yield by a solder precoating method using the dam.

Abstract: The present invention relates to a solder paste composition used for precoating an electrode surface with solder. A first solder paste composition is contains a solder powder and a flux, and a metallic powder made by metallic species different from metallic species constituting the solder powder and metallic species constituting the electrode surface in a rate of 0.1% by weight or more and 20% by weight or less based on a total amount of the solder powder. A second solder paste composition contains a deposition solder material which deposits the solder by heating and a flux, and a metallic powder comprising metallic species different from metallic species constituting a metallic component in the deposition solder material and metallic species constituting the electrode surface in a rate of 0.1% by weight or more and 20% by weight or less based on a total amount of the metallic component in the deposition solder material.