Multilayer ceramic substrate and manufacturing method therefor

A multilayer ceramic substrate comprising:

• a ceramic element body including a plurality of stacked ceramic layers;
• a resistor including a resistance film disposed between at least two of the ceramic layers;
• and
• a lead via conductor penetrating the ceramic layers in a thickness direction and connected at a first end portion to the resistance film;
• wherein
• the resistance film and the lead via conductor both contain at least a first metallic component and a second metallic component that constitute an alloy resistive material;
• and
• a concentration of the second metallic component in the lead via conductor has a gradient structure that is comparatively high in the first end portion connected to the resistance film and gradually decreases from the first end portion toward a second end portion opposite therefrom.

A manufacturing method for a multilayer ceramic substrate, comprising:

• a step of preparing a plurality of ceramic green sheets;
• a step of preparing a resistor paste including an alloy resistive material containing a first metallic component and a second metallic component, and a conductor paste mainly composed of at least the first metallic component;
• a step of forming a lead via conductor including the conductor paste in one of the ceramic green sheets;
• a step of forming a resistance film to be connected to an end portion of the lead via conductor by the resistor paste on a principal surface of the ceramic green sheet;
• a step of forming a laminated body by stacking the plurality of ceramic green sheets;
• and
• a step of firing the laminated body.