1. A semiconductor device comprising:
a semiconductor substrate including a front surface and a back surface;
a semiconductor element and an electrode of the semiconductor element located on the front surface of the semiconductor substrate;
an openings on the back surface of the semiconductor substrate and reaching a lower surface of the electrode, wherein the opening is defined by a side surface and a bottom surface;
a first metal layer covering the side surface and the bottom surface;
a barrier metal layer covering the first metal layer in the opening;
solder filling the opening; and
a second metal layer in contact with the solder and located closer to the electrode than parts of the barrier metal layer, wherein the second metal layer is laminated on the barrier metal layer and covers at least a part of the barrier metal layer in the opening
2. The semiconductor device according to claim 1, wherein the second metal layer covers only a part of the barrier metal layer in the opening
3. The semiconductor device according to claim 1, wherein
the second metal layer covers a portion of the barrier metal layer overlapping the bottom surface, and
the second metal layer does not cover at least a portion of the barrier metal layer overlapping the side surface.
4. The semiconductor device according to claim 1, wherein the second metal layer covers all of the barrier metal layer in the opening.
5. The semiconductor device according to claim 1, wherein the barrier metal layer is selected from the group consisting of nickel, platinum, lead, titanium, and cobalt.
6. The semiconductor device according to claim 1, wherein the barrier metal layer is an oxide layer of one material selected from the group consisting of nickel, platinum, lead, titanium, and cobalt.
7. The semiconductor device according to claim 1, wherein
the barrier metal layer includes:
a first barrier metal layer, and
a second barrier metal layer,
the first barrier metal layer and the second barrier metal layer are laminated to each other at least once,
the second barrier metal layer has a lower stress than the first barrier metal layer.
8. The semiconductor device according to claim 7, wherein
the first barrier metal layer is nickel, and
the second barrier metal layer is one material selected from the group consisting of platinum, lead, titanium, gold, aluminum, niobium, and copper.
9. The semiconductor device according to claim 7, wherein the first barrier metal layer is thicker than the second barrier metal layer.
10. The semiconductor device according to claim 1, wherein
the barrier metal layer extends to an edge portion of the opening in the back surface, from inside the opening, and
the barrier metal layer is not located outside of the edge portion of the opening
11. The semiconductor device according to claim 1, wherein
the semiconductor element is a transistor including a gate, a source, and a drain located on the front surface, and
the electrode is a source electrode located on the source.
12. The semiconductor device according to claim 1, wherein
the first metal layer and the second metal layer include gold, and
the barrier metal layer includes nickel.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A flat type vibration motor, comprising:
a bracket with a shaft of which one end is inserted into and fixed to the center thereof;
a printed circuit board having a terminal portion receiving external electricity and disposed on the side of the bracket;
a stator disposed on the top of the printed circuit board;
a rotor rotatably installed in the shaft to generate vibration while rotating by interaction with the stator; and
a stopper installed on the other end of the shaft,
wherein the bracket and the shaft are electrically connected with the terminal portion.
2. The flat type vibration motor as set forth in claim 1, wherein the bracket or the shaft is used as an external power connection terminal.
3. The flat type vibration motor as set forth in claim 1, further comprising a contact portion provided in the printed circuit board so as to connect with the terminal portion and electrically connected with the bracket by contacting with the bracket.
4. The flat type vibration motor as set forth in claim 3, wherein the contact portion is connected to a negative terminal of the terminal portion.
5. The flat type vibration motor as set forth in claim 3, wherein the printed circuit board has an opening formed at the center thereof, the contact portion surrounds the opening, the bracket includes a flat portion and a projection portion projected downward from the center of the flat portion to correspond to the opening, and the projection portion is inserted into the opening and the flat portion contacts with the contact portion.
6. The flat type vibration motor as set forth in claim 1, wherein the rotor includes:
a bearing rotatably inserted into an outer peripheral surface of the shaft;
an upper substrate having a commutator formed on the bottom thereof and having the bearing inserted into the center thereof; and
a winding coil and a weight body supported on a rotor support fixed to the bearing and disposed on the top of the upper substrate, and
the flat type vibration motor further includes a brush of which one end is fixed to the terminal portion and the other end contacts with the commutator.
7. A flat type vibration motor, comprising:
a bracket with a shaft of which one end is inserted into the center thereof;
a printed circuit board having a terminal portion receiving external electricity and disposed on the side of the bracket;
a stator disposed on the top of the printed circuit board;
a rotor rotatably installed in the shaft to generate vibration while rotating by interaction with the stator; and
a case having an inner space covering the rotor,
wherein the bracket and the shaft are electrically connected with the terminal portion.
8. The flat type vibration motor as set forth in claim 7, wherein the bracket or the shaft is used as an external power connection terminal.
9. The flat type vibration motor as set forth in claim 7, further comprising a contact portion provided in the printed circuit board so as to connect with the terminal portion and electrically connected with the bracket by contacting with the bracket.
10. The flat type vibration motor as set forth in claim 9, wherein the contact portion is connected to a negative terminal of the terminal portion.
11. The flat type vibration motor as set forth in claim 9, wherein the printed circuit board has an opening formed at the center thereof, the contact portion surrounds the opening, the bracket includes a flat portion and a projection portion projected downward from the center of the flat portion to correspond to the opening, and the projection portion is inserted into the opening and the flat portion contacts with the contact portion.
12. The flat type vibration motor as set forth in claim 7, wherein the rotor includes:
a bearing rotatably inserted into an outer peripheral surface of the shaft;
an upper substrate having a commutator formed on the bottom thereof;
a winding coil and a weight body provided on the top of the upper substrate; and
a molding member integrally connecting the upper substrate, the winding coil, and the weight body, and
the flat type vibration motor further includes a brush of which one end is fixed to the terminal portion and the other end contacts with the commutator.