Production method for joined body, and joined body

1. A method for manufacturing a joined body composed of a first substrate and a second substrate joined together by resin material attached to a predetermined area of the first substrate, the method comprising:

attaching a sheet material to the first substrate so as to cover the predetermined area, the sheet material including a sheet base material and the resin material provided on one main surface of the sheet base material;

forming, after the attaching, in the sheet material, a slit by reducing a thickness of the resin material along an outline of the predetermined area; and

separating, after the forming, part of the resin material inside the slit from the sheet base material to keep the part of the resin material inside the slit on the predetermined area of the first substrate and not to keep the rest of the resin material outside the slit on the first substrate.

2. The method of claim 1 , wherein

in the forming, the slit is formed by irradiating the resin material with a laser beam to remove the resin material to the extent that the thickness of the irradiated resin material partially remains.

3. The method of claim 2 , wherein

owing to irradiation with the laser beam, at least part of the resin material that remains in a bottom part of the slit is higher in reaction rate than the resin material before irradiation with the laser beam.

4. The method of claim 3 , wherein

owing to irradiation with the laser beam, part of the resin material constituting a sidewall of the slit is higher in reaction rate than the resin material before irradiation with the laser beam.

5. The method of claim 2 , wherein

a wavelength of the laser beam is a wavelength at which the resin material and the sheet base material absorb the laser beam, and

a power of the laser beam is a power that causes the resin material to disperse heat, evaporate, or sublime.

6. The method of claim 2 , wherein

the laser beam has a light intensity distribution with a top hat shape.

7. The method of claim 1 , wherein

the sheet material has a layer structure of at least the sheet base material and the resin material.

8. The method of claim 1 , wherein

the first substrate includes a first functional unit used for a display panel that is formed on a first base material, and

the slit is formed in an area of the first functional unit in which no image is to be displayed.

9. The method of claim 1 , wherein

the joined body is a display panel,

the first substrate includes a first functional unit that is formed on a first base material,

the second substrate includes a second functional unit that is formed on a second base material,

the predetermined area of the first substrate is on a surface of the first substrate facing the second functional unit,

in the attaching, the sheet material is attached while the resin material faces the first functional unit, and

the method further comprises:

uniting, after the separating, the first substrate and the second substrate while the first functional unit and the second functional unit correspond to each other; and

curing, after the uniting, the resin material remaining on the predetermined area of the first substrate united with the second base material, wherein

the forming is performed before the uniting.

10. The method of claim 9 , wherein

the first functional unit formed on the first base material is provided in a plurality, and

the second functional unit formed on the second base material is provided in a plurality.

11. The method of claim 9 , wherein

the first functional unit is a color filter element, and

the second functional unit is an EL element.

12. The method of claim 9 , further comprising

forming, before the attaching, a release film outside the predetermined area of the first substrate.