Display device and fabrication method for display device

1. A display device comprising

a two-dimensional array of a plurality of display pixels each having a display element layer and a drive circuit layer stacked, the drive circuit layer being for driving the display element layer,

wherein the drive circuit layer includes

a parallel-plate capacitor unit having a first electrode layer, a second electrode layer, and an insulating layer, the first electrode layer and the second electrode layer being arranged opposite to each other in a stacking direction, and the insulating layer being provided between the first electrode layer and the second electrode layer,

the parallel-plate capacitor unit includes:

a capacitor element having a first capacitor electrode and a second capacitor electrode, the first capacitor electrode being electrically connected to a first line and provided in the first electrode layer, the second capacitor electrode being electrically connected to a second line and provided in the second electrode layer opposite to the first capacitor electrode in the stacking direction;

a backup capacitor element having a first backup capacitor electrode provided in the first electrode layer and a second backup capacitor electrode electrically connected to the first line and provided in the second electrode layer opposite to the first backup capacitor electrode in the stacking direction;

a disconnect-able portion at which an electric connection between the second capacitor electrode and the second line can be disconnected; and

a connectable portion at which the first backup capacitor electrode and the second line can be electrically connected, and

the disconnect-able portion and the connectable portion are arranged at a position in which the disconnect-able portion and the connectable portion overlap in the stacking direction.

2. The display device according to claim 1 ,

wherein the disconnect-able portion is provided on a line connecting the second capacitor electrode and the second line, and has a shape that allows fusion-cutting of the connection between the second capacitor electrode and the second line by laser irradiation, and

the connectable portion includes a line for connection extended from the first backup capacitor electrode to a position overlapping with the disconnect-able portion, and has a shape that allows welding, by laser irradiation, of the line for connection and the second line disconnected from the second capacitor electrode.

3. The display device according to claim 2 ,

wherein the line for connection has an end surface in parallel with the stacking direction above the disconnect-able portion.

4. The display device according to claim 1 ,

wherein the parallel-plate capacitor unit includes two of the capacitor elements and one of the backup capacitor element.

5. The display device according to claim 1 ,

wherein the second backup capacitor electrode is electrically connected to the first line via a contact hole provided in the insulating layer.

6. The display device according to claim 1 ,

wherein the capacitor element is a holding capacitor element which holds, as a hold voltage, a voltage according to a signal voltage applied to each of the display pixels,

the drive circuit layer includes a drive transistor having a gate electrode connected to one of the terminals of the capacitor element, and converts the hold voltage to a signal current which is a current between a source electrode and a drain electrode through an application of the hold voltage to the gate electrode, and

the display element layer includes a light-emitting element which emits light when the signal current flows.

7. The display device according to claim 6 ,

wherein one of the first electrode layer and the second electrode layer is provided in one of a source-drain electrode layer and a gate electrode layer of the drive transistor, and

the other of the first electrode layer and the second electrode layer is provided in the other of the source-drain electrode layer and the gate electrode layer of the drive transistor.

8. A fabrication method for a display device which includes a two-dimensional array of a plurality of display pixels each having a display element layer and a drive circuit layer stacked, the drive circuit layer being for driving the display element layer, said fabrication method comprising:

forming the drive circuit layer including

a parallel-plate capacitor unit having a first electrode layer, a second electrode layer, and an insulating layer, the first electrode layer and the second electrode layer being arranged opposite to each other in a stacking direction, and the insulating layer being provided between the first electrode layer and the second electrode layer,

the parallel-plate capacitor unit including:

a capacitor element having a first capacitor electrode and a second capacitor electrode, the first capacitor electrode electrically connected to a first line and provided in the first electrode layer, the second capacitor electrode electrically connected to a second line and provided in the second electrode layer opposite to the first capacitor electrode in the stacking direction;

a backup capacitor element having a first backup capacitor electrode provided in the first electrode layer and a second backup capacitor electrode electrically connected to the first line and provided in the second electrode layer opposite to the first backup capacitor electrode in the stacking direction;

a disconnect-able portion at which an electric connection between the second capacitor electrode and the second line can be disconnected; and

a connectable portion at which the first backup capacitor electrode and the second line can be electrically connected, and

the disconnect-able portion and the connectable portion arranged at a position in which the disconnect-able portion and the connectable portion overlap in the stacking direction,

forming the display element layer;

testing the capacitor element formed in the drive circuit layer forming; and

repairing the capacitor unit having a capacitor element determined to be malfunctioning in the testing, by disconnecting the electric connection between the second capacitor electrode and the second line at the disconnect-able portion and connecting the first backup capacitor electrode and the second line at the connectable portion.

9. The fabrication method for the display device according to claim 8 ,

wherein the disconnect-able portion and the connectable portion are irradiated with laser at the same time in the repairing.

10. The fabrication method for the display device according to claim 9 , further comprising

reinforcing connection with the connectable portion by attaching low-resistance metal material on the connectable portion after the repairing.