Semiconductor device and inspection method

1. A semiconductor device, comprising:

a semiconductor element having an element main surface and an element back surface facing opposite each other in a thickness direction, and first and second electrodes arranged on the element main surface;

a first lead on which the semiconductor element is mounted;

a second lead arranged to be spaced apart from the first lead and electrically connected to the first electrode;

a third lead arranged to be spaced apart from the first lead and the second lead and electrically connected to the second electrode;

a plurality of first connecting portions bonded to the first electrode and the second lead; and

a sealing resin configured to cover the semiconductor element,

wherein the sealing resin includes a resin main surface facing the same side as the element main surface, a resin back surface facing the same side as the element back surface, and a resin side surface connected to the resin main surface and the resin back surface,

wherein the second lead includes a second lead exposed portion exposed from the sealing resin,

wherein the third lead includes a third lead exposed portion exposed from the sealing resin,

wherein the second lead exposed portion includes a portion located on the resin main surface with respect to the third lead exposed portion, and

wherein the third lead exposed portion includes a back surface and a terminal end surface while a main surface of the third lead is covered with the sealing resin in the thickness direction.

2. The semiconductor device of claim 1 , further comprising:

a fourth lead arranged to be spaced apart from the first to third leads and electrically connected to the first electrode,

wherein the fourth lead includes a fourth lead exposed portion exposed from the sealing resin, and

wherein the fourth lead exposed portion includes a portion located on the resin main surface with respect to the third lead exposed portion.

3. The semiconductor device of claim 2 ,

wherein the second lead exposed portion includes a second lead top surface exposed from the resin main surface, and

wherein the fourth lead exposed portion includes a fourth lead top surface exposed from the resin main surface.

4. The semiconductor device of claim 2 ,

wherein the second lead exposed portion includes a second lead end surface exposed from the resin side surface,

wherein the third lead exposed portion includes a third lead end surface exposed from the resin side surface,

wherein the fourth lead exposed portion includes a fourth lead end surface exposed from the resin side surface, and

wherein distances between the second lead end surface and the resin main surface and between the fourth lead end surface and the resin main surface in the thickness direction are smaller than a distance between the third lead end surface and the resin main surface in the thickness direction.

5. The semiconductor device of claim 4 , wherein dimensions of the second lead end surface and the fourth lead end surface in the thickness direction are twice or more of a dimension of the third lead end surface in the thickness direction.

6. The semiconductor device of claim 4 , wherein dimensions of the second lead end surface and the fourth lead end surface in the thickness direction are more than half of a dimension of the resin side surface in the thickness direction.

7. The semiconductor device of claim 2 ,

wherein the second lead exposed portion includes a second lead back surface exposed from the resin back surface,

wherein the third lead exposed portion includes a third lead back surface exposed from the resin back surface, and

wherein the fourth lead exposed portion includes a fourth lead back surface exposed from the resin back surface.

8. The semiconductor device of claim 2 , further comprising a plurality of second connecting portions bonded to the first electrode and the fourth lead.

9. The semiconductor device of claim 8 , wherein the plurality of first connecting portions and the plurality of second connecting portions are wires.

10. The semiconductor device of claim 2 ,

wherein the semiconductor element is a transistor, and

wherein the second electrode is a gate electrode.

11. The semiconductor device of claim 10 , wherein the semiconductor element further includes an electron traveling layer made of a nitride semiconductor.

12. The semiconductor device of claim 10 , wherein the first electrode is a source electrode.

13. The semiconductor device of claim 10 , wherein the first electrode is a drain electrode.

14. An inspection method of inspecting a bonding state of the plurality of first connecting portions of the semiconductor device of claim 2 in a state in which the semiconductor device is mounted on a circuit board, the inspection method comprising:

a signal input process of inputting a pulse signal to the third lead;

a voltage detection process of detecting a sense voltage which is a voltage of the fourth lead with respect to the second lead; and

a comparison process of comparing the sense voltage at a turn-off time of the pulse signal with a threshold voltage.

15. The inspection method of claim 14 , wherein the voltage detection process includes bringing two probes for detecting the sense voltage into contact with the second lead exposed portion and the fourth lead exposed portion, respectively.

16. The inspection method of claim 14 , wherein the comparison process includes determining that the bonding state has deteriorated when the sense voltage becomes equal to or less than the threshold voltage.