Substrate, liquid ejection head, and method of manufacturing substrate

A substrate for a liquid ejection head, comprising:

• a first substrate that includes a front surface provided with an element generating energy to eject liquid while a first supply flow channel supplying the liquid ejected by the element is formed penetrating the first substrate;
• and
• a second substrate that includes a silicon base material having a crystal orientation of <110> and is adhered to a back surface of the first substrate opposite the front surface, wherein
• in the second substrate, a second supply flow channel that is opened in a first surface of the second substrate and communicates with the first supply flow channel and a third supply flow channel that is opened in a second surface of the second substrate opposite the first surface are formed to communicate with each other,
• the third supply flow channel has an opening width narrower than an opening width of the second supply flow channel, and
• a groove portion shallower than a depth of the third supply flow channel is formed close to the third supply flow channel in a region that is inside the opening of the second supply flow channel and outside the opening of the third supply flow channel in the second surface of the second substrate.

A liquid ejection head, comprising:

• a substrate for the liquid ejection head including a first substrate that includes a front surface provided with an element generating energy to eject liquid while a first supply flow channel supplying the liquid ejected by the element is formed penetrating the first substrate, and a second substrate that includes a silicon base material having a crystal orientation of <110> and is adhered to a back surface of the first substrate opposite the front surface, wherein, in the second substrate, a second supply flow channel that is opened in a first surface of the second substrate and communicates with the first supply flow channel and a third supply flow channel that is opened in a second surface of the second substrate opposite the first surface are formed to communicate with each other, the third supply flow channel has an opening width narrower than an opening width of the second supply flow channel, and a groove portion shallower than a depth of the third supply flow channel is formed close to the third supply flow channel in a region that is inside the opening of the second supply flow channel and outside the opening of the third supply flow channel in the second surface of the second substrate;
• and
• a flow channel formation member that is formed on one side of the substrate for the liquid ejection head, wherein
• a pressure chamber that communicates with the first supply flow channel of the substrate for the liquid ejection head is formed between the substrate tor the liquid ejection head and the flow channel formation member, and
• an ejection port that ejects the liquid supplied to the pressure chamber is formed in the flow channel formation member.

A method of manufacturing a substrate, comprising:

• forming a first flow channel that is opened in a first surface of a silicon base material having a crystal orientation of <110>;
• forming a second flow channel that has an opening narrower than an opening width of the opening of the first flow channel in a second surface of the silicon base material opposite the first surface so as to communicate with the first flow channel;
• and
• forming a groove portion that is shallower than a depth of the second flow channel close to the second flow channel in a region that is inside the opening of the first flow channel and outside the opening of the second flow channel in the second surface.