Bonding structure, head module, head device, and liquid discharge apparatus

A head module comprising:

• a liquid discharge head configured to discharge a liquid;
• and
• a nozzle cover, to which the liquid discharge head is bonded,
• wherein the liquid discharge head includes:
• a nozzle plate, including a nozzle, through which the liquid is discharged;
• and
• an actuator substrate, including an actuator, configured to generate energy to discharge the liquid from the nozzle and a first bonding surface, and
• wherein the nozzle cover includes an opening, configured to expose the nozzle in the nozzle plate, and a second bonding surface, to be bonded to the first bonding surface of the actuator substrate with a first adhesive and a second adhesive, different from the first adhesive, and
• wherein at least one of the first bonding surface and the second bonding surface includes:
• a first region on which the first adhesive is applied;
• a second region on which the second adhesive is applied;
• and
• a third region, disposed between the first region and the second region, the third region having a water repellency relatively higher than a water repellency of the first region and a water repellency of the second region.