Substrate unit

A substrate unit, comprising:

• an insulating substrate;
• a first pad provided on the insulating substrate;
• a second pad provided on the insulating substrate;
• a wiring provided on the insulating substrate;
• a solder resist layer including a first portion in contact with the insulating substrate and a second portion covering the wiring, and an opening exposing the first pad and the second pad;
• a first insulating portion provided between the first pad and the second pad in the opening;
• and
• an electronic part having a first terminal connected to the first pad across a joining material and a second terminal connected to the second pad across a joining material, wherein,
• a length in a first direction of the first insulating portion is less than a length in the first direction of the first portion of the solder resist layer, the first direction being a direction extending from the first pad toward the insulating substrate.

A substrate unit, comprising:

• an insulating substrate;
• a first pad provided on the insulating substrate;
• a second pad provided on the insulating substrate;
• a solder resist layer including a portion provided on the insulating substrate and an opening exposing the first pad and the second pad;
• an electronic part having a first terminal connected to the first pad across a joining material and a second terminal connected to the second pad across a joining material;
• and
• an insulating portion provided between one portion of an edge of the opening and the electronic part when viewed from a first direction extending from the first pad toward the insulating substrate, wherein
• the solder resist layer includes a first insulating material,
• the insulating portion includes a second insulating material different from the first insulating material, and
• a length in the first direction of the insulating portion is less than a length in the first direction of the solder resist layer.