Electronic component and mounting structure

An electronic component comprising:

• a component body;
• and
• an external electrode on a surface of the component body, wherein
• the external electrode includes a layer having an alloy of at least one first metal and at least one second metal,
• the at least one first metal is selected from the group consisting of metals of Group 9 to Group 11 of the Periodic Table of the Elements,
• the at least one second metal has a melting point higher than a melting point of the at least one first metal,
• in the layer having the alloy, a concentration of the at least one second metal continuously changes in a thickness direction of the external electrode, and at least one first portion of the layer having the alloy has the concentration of the at least one second metal increasing in the thickness direction, and at least one second portion of the layer having the alloy has the concentration of the at least one second metal decreasing in the thickness direction, and
• wherein there are 1 to 100, per 1 μm, of the at least one first portion where the concentration of the at least one second metal increases.

A mounting structure comprising:

• an electronic component comprising:
• a component body;
• and
• an external electrode on a surface of the component body, wherein
• the external electrode includes a layer having an alloy of at least one first metal and at least one second metal,
• the at least one first metal is selected from the group consisting of metals of Group 9 to Group 11 of the Periodic Table of the Elements,
• the at least one second metal has a melting point higher than a melting point of the at least one first metal,
• in the layer having the alloy, a concentration of the at least one second metal continuously changes in a thickness direction of the external electrode, and at least one first portion of the layer having the alloy has the concentration of the at least one second metal increasing in the thickness direction, and at least one second portion of the layer having the alloy has the concentration of the at least one second metal decreasing in the thickness direction;
• and
• a substrate having an electrode portion,
• wherein the external electrode of the electronic component is joined to the electrode portion of the substrate through a solder joint portion,
• wherein an intermetallic compound derived from the external electrode and derived from the solder joint portion is present proximal to an interface between the external electrode and the solder joint portion, and
• wherein the intermetallic compound is an FeSn2 based alloy.

A mounting structure comprising:

• an electronic component comprising:
• a component body;
• and
• an external electrode on a surface of the component body, wherein
• the external electrode includes a layer having an alloy of at least one first metal and at least one second metal,
• the at least one first metal is selected from the group consisting of metals of Group 9 to Group 11 of the Periodic Table of the Elements,
• the at least one second metal has a melting point higher than a melting point of the at least one first metal,
• in the layer having the alloy, a concentration of the at least one second metal continuously changes in a thickness direction of the external electrode, and at least one first portion of the layer having the alloy has the concentration of the at least one second metal increasing in the thickness direction, and at least one second portion of the layer having the alloy has the concentration of the at least one second metal decreasing in the thickness direction;
• and
• a substrate having an electrode portion,
• wherein the external electrode of the electronic component is joined to the electrode portion of the substrate through a solder joint portion, and
• wherein the layer having the alloy includes a plurality of layers laminated in the thickness direction of the external electrode, each of the plurality of layers having a different concentration of the at least one second metal.