Ink jet head and ink jet printer

1. An ink jet head, comprising:

a first substrate including a first wiring;

a second substrate coupled to the first substrate, the second substrate including a second wiring overlaid on the first wiring at a connection region;

a plurality of ink jet elements configured to cause ink to be ejected from a plurality of nozzles; and

a drive circuit provided on the first substrate and configured to drive the plurality of ink jet elements,

a thickness of the first wiring at the connection region being less than a thickness of the second wiring at the connection region, and a width of the first wiring at the connection region being greater than a width of the second wiring at the connection region.

2. The ink jet head according to claim 1 , wherein the first wiring and the second wiring are electrically connected by an anisotropic conductive film at the connection region.

3. The ink jet head according to claim 1 , wherein the thickness of the second wiring at the connection region is at least 20 times greater than the thickness of the first wiring at the connection region.

4. The ink jet head according to claim 1 , wherein the first substrate is a printed substrate.

5. The ink jet head according to claim 1 , wherein

the first wiring is one of a plurality of signal input wirings that are arranged in parallel to each other at a first pitch, and

the second wiring is one of a plurality of signal output wirings that are arranged in parallel to each other at a second pitch equal to the first pitch.

6. An ink jet head, comprising:

a first substrate including a first wiring;

a second substrate coupled to the first substrate, the second substrate including a second wiring overlaid on the first wiring at a connection region;

a plurality of ink jet elements on the first substrate configured to cause ink to be ejected from a plurality of nozzles; and

a thickness of the first wiring at the connection region being less than a thickness of the second wiring at the connection region, and a width of the first wiring at the connection region being greater than a width of the second wiring at the connection region, wherein

the first wiring is a common wiring extending from an edge of the first substrate and electrically connected in common to the plurality of ink jet elements, and

the second wiring is a common connection wiring extending between a first edge of the second substrate and a second edge of the second substrate opposite the first edge.

7. The ink jet head according to claim 6 , further comprising:

a drive circuit provided on the second substrate and configured to drive the plurality of ink jet elements.

8. The ink jet head according to claim 6 , wherein the second substrate is a printed substrate.

9. The ink jet head according to claim 6 , wherein the first wiring and the second wiring are electrically connected by an anisotropic conductive film at the connection region.

10. The ink jet head according to claim 6 , wherein the first substrate is an inflexible substrate.

11. The ink jet head according to claim 6 , wherein the thickness of the second wiring at the connection region is at least 20 times greater than the thickness of the first wiring at the connection region.

12. An ink jet head, comprising:

a first substrate including a first wiring;

a second substrate coupled to the first substrate, the second substrate including a second wiring overlaid on the first wiring at a connection region and a third wiring;

a third substrate coupled to the second substrate, the third substrate having a fourth wiring overlaid on the third wiring at a second connection region;

a plurality of ink jet elements configured to cause ink to be ejected from a plurality of nozzles; and

a drive circuit provided on the first or second substrate and configured to drive the plurality of ink jet elements,

a thickness of the first wiring at the connection region being less than a thickness of the second wiring at the connection region, and a width of the first wiring at the connection region being greater than a width of the second wiring at the connection region, and

a thickness of the third wiring at the second connection region being less than a thickness of the fourth wiring at the second connection region, and a width of the third wiring at the second connection region being greater than a width of the fourth wiring at the second connection region.

13. The ink jet head according to claim 12 , wherein

the first wiring is one of a plurality of signal input wirings that are arranged in parallel to each other at a first pitch, and

the second wiring is one of a plurality of signal output wirings that are arranged in parallel to each other at a second pitch equal to the first pitch.

14. The ink jet head according to claim 12 , wherein the first wiring and the second wiring are electrically connected by an anisotropic conductive film at the connection region.

15. The ink jet head according to claim 12 , wherein the first substrate is an inflexible substrate.

16. The ink jet head according to claim 12 , wherein the second substrate is a printed substrate.

17. The ink jet head according to claim 12 , wherein the drive circuit is provided on the second substrate.

18. The ink jet head according to claim 17 , wherein the plurality of ink jet elements are provided on the first substrate.

19. The ink jet head according to claim 18 , wherein

the first wiring is a common wiring extending from an edge of the first substrate and electrically connected in common to the plurality of ink jet elements, and

the second wiring is a common connection wiring extending between a first edge of the second substrate and a second edge of the second substrate opposite the first edge.

20. The ink jet head according to claim 18 , wherein

the first wiring is connected to a signal input terminal of one of the ink jet elements, and

the second wiring is connected to a signal output terminal of the drive circuit.