The contacting part 262 is an edge portion on an inner periphery portion 262a side of the main part 61. The contacting part 262 is an annular portion that surrounds the opening of the shielding portion 206. By having the contacting part 262, a gap between the heat conductive portion 5 and the shielding portion 206 is closed. By having such shielding portion 206, the small pieces of the graphite sheet 4 can be received by the shielding portion 206 without letting them to adhering to the circuit board. Further, according to the shielding portion 206, since the heat conductive portion 5 comes into contact with the outer periphery portion 51, the heat conductive portion 5 can be reduced in size.

The fourth embodiment is described with reference to FIG. 10. The fourth embodiment is different from the above-described embodiments in the configuration related to a shielding portion 306 and the configuration including a coated portion 42. The configurations, operations, and effects not particularly described in the fourth embodiment are the same as those in the above-described embodiments, and the differences from the above-described embodiments are described in the following.