Linear vibrator

1. A linear vibrator comprising:

a fixed part having an inner space of a predetermined size formed therein;

at least one magnet disposed in the inner space and generating magnetic force;

a vibration part including a coil disposed to face the magnet to generate electromagnetic force through interaction therewith, and a mass body;

a substrate having one end connected to the vibration part to serve as a free end, and the other end connected to the fixed part to serve as a fixed end; and

a connection protrusion formed on the fixed part and inserted into a connection hole formed in the substrate so as to allow the substrate to be fixed to the fixed part,

wherein the connection protrusion includes an insertion portion placed in the connection hole,

wherein the connection protrusion includes a locking portion bent from an end of the insertion portion in an inner diameter direction or an outer diameter direction by a predetermined angle, and protruding outwardly of the connection hole, and

wherein the locking portion is wider than the connection hole, to prevent the substrate from being separated from the fixed part.

2. The linear vibrator of claim 1 , wherein the connection hole has a circular, polygonal, cross-shaped, or linear cross section in a radial direction.

3. The linear vibrator of claim 1 , wherein the substrate includes a movable piece vibrating in association with the vibration part and a fixed piece extending from the movable piece to be connected with the fixed part, and

the connection hole is formed in the fixed piece.

4. The linear vibrator of claim 1 , wherein the fixed part includes a case providing the inner space and having an exposed lower portion, and a bracket sealing the inner space, and

the magnet is connected with one surface of the bracket or one surface of the case.

5. The linear vibrator of claim 1 , wherein the fixed part includes a case providing the inner space and having an exposed lower portion, and a bracket sealing the inner space, and

the magnet is provided in plural, each of the plurality of magnets being connected with one surface of the case or one surface of the bracket.

6. The linear vibrator of claim 1 , further comprising a damper connected to one surface of the substrate to prevent contact between the vibration part and the fixed part due to a vibration of the vibration part.

7. The linear vibrator of claim 1 , further comprising a yoke plate formed on at least one surface of the magnet and allowing a magnetic flux to smoothly flow into the magnet through the coil.