Optionally, the shielding cover accessory 52 may further include a through hole 532. The through hole 532 may be arranged on the flat bottom 5211, and most of the through hole 532 is formed on the part of the flat bottom 5211 located between the two recesses 5212. For example, an orthographic projection of the through hole 532 on the flat bottom 5211 has a shape of rectangular.

For example, the shielding cover body 51 and the shielding cover accessory 52 included in the shielding cover 5 may be made of the same material. The material of the shielding cover 5 may include a metal material, such as stainless steel, cupronickel and the like.

FIG. 7 is a partial enlarged view of part I of the rear cover in FIG. 2. Referring to FIGS. 2 and 7, the rear cover 1 includes a positioning bottom 16 in the second concave portion 152. The positioning bottom 16 has a flat surface. The positioning bottom 16 is substantially parallel to the second concave bottom 1525. Specifically, the rear cover 1 further includes a connecting sidewall 17 in the second concave portion 152, and the connecting sidewall 17 is substantially perpendicular to each of the second concave bottom 1525 and the positioning bottom 16. A side of the positioning bottom 16 is connected to the second concave bottom 1525 through the connecting sidewall 17. The other side of the positioning bottom 16 is connected to the first concave sidewall 1521.