Substrate for ink ejection heads, ink ejection head, method ofmanufacturing substrate, and method of manufacturing ink ejection head

A substrate for liquid ejection heads, comprising:

• an element generating energy used to eject a liquid;
• a first electrode layer disposed in contact with the element;
• an insulating layer extending over the first electrode layer and the element;
• and
• a second electrode layer including a first portion extending through the insulating layer to the first electrode layer and a second portion positioned differently from that of the first portion in the direction perpendicular to a thickness direction of the insulating layer and which is not in contact with the insulating layer,
• wherein the second portion has a piece of resin disposed between the second electrode layer and the insulating layer.

A method of manufacturing a substrate, including an element generating energy used to eject a liquid, for liquid ejection heads, the method comprising:

• preparing a base plate including the element, a first electrode layer disposed in contact with the element, and an insulating layer extending over the first electrode layer and the element;
• providing a mask member on a first portion of the insulating layer;
• forming a through-hole in a second portion of the insulating layer and then providing a second electrode layer over the mask member and a portion of the first electrode layer that is exposed through the through-hole, the position of the second portion being different from that of the first portion in the direction perpendicular to a thickness direction of the insulating layer;
• and
• removing the mask member to form a space between the second electrode layer and the insulating layer.

A method of manufacturing a substrate, including an element generating energy used to eject a liquid, for liquid ejection heads, the method comprising:

• preparing a base plate including the element, a first electrode layer disposed in contact with the element, and an insulating layer extending over the first electrode layer and the element;
• providing a mask member made of resin on a first portion of the insulating layer;
• and
• forming a through-hole in a second portion of the insulating layer and then providing a second electrode layer over the mask member and a portion of the first electrode layer that is exposed through the through-hole, the position of the second portion being different from that of the first portion in the direction perpendicular to a thickness direction of the insulating layer.