An electronic device comprising a base, comprising a bottom wall, three side walls and a mounting side, wherein each of the side walls is vertically connected to the bottom wall, and a height (H 1) of the side wall exists between a top end of each of the side walls and the bottom wall, and the three side walls and the mounting side are connected to each other and connected around the bottom wall; and a mark piece, disposed on the bottom wall and extending from the bottom wall in a direction away from the bottom wall, wherein the mark piece has a low scale and a high scale, a distance (D 1) from the low scale to the bottom wall is less than the height (H 1) of the side wall, and a distance (D 2) from the high scale to the bottom wall is the same as the height (H 1) of the side wall; a first colloid, filled in the base and located between the bottom wall and the low scale; a circuit board placed on top of the first colloid after the filled first colloid has reached the low scale, wherein the circuit board comprises: a board body, provided with a first surface and a second surface disposed opposite to each other, wherein the first surface faces the first colloid; a through hole, penetrating the first surface and the second surface of the board body; and a plurality of electronic components, disposed on the first surface and partially embedded in the first colloid as the distance (D 1) from the low scale to the bottom wall is greater than a longest distance (D 4) from tops of the electronic components to the bottom wall; a second colloid supplemented through the through hole to fill in the space between the first colloid and the first surface after the circuit board has been placed, the second colloid further filling the space between the second surface and the high scale; and the electronic device further comprising a cover on top of the second colloid. a base, comprising a bottom wall, three side walls and a mounting side, wherein each of the side walls is vertically connected to the bottom wall, and a height (H 1) of the side wall exists between a top end of each of the side walls and the bottom wall, and the three side walls and the mounting side are connected to each other and connected around the bottom wall; and a mark piece, disposed on the bottom wall and extending from the bottom wall in a direction away from the bottom wall, wherein the mark piece has a low scale and a high scale, a distance (D 1) from the low scale to the bottom wall is less than the height (H 1) of the side wall, and a distance (D 2) from the high scale to the bottom wall is the same as the height (H 1) of the side wall; a first colloid, filled in the base and located between the bottom wall and the low scale; a circuit board placed on top of the first colloid after the filled first colloid has reached the low scale, wherein the circuit board comprises: a board body, provided with a first surface and a second surface disposed opposite to each other, wherein the first surface faces the first colloid; a through hole, penetrating the first surface and the second surface of the board body; and a plurality of electronic components, disposed on the first surface and partially embedded in the first colloid as the distance (D 1) from the low scale to the bottom wall is greater than a longest distance (D 4) from tops of the electronic components to the bottom wall; a second colloid supplemented through the through hole to fill in the space between the first colloid and the first surface after the circuit board has been placed, the second colloid further filling the space between the second surface and the high scale; and the electronic device further comprising a cover on top of the second colloid. a board body, provided with a first surface and a second surface disposed opposite to each other, wherein the first surface faces the first colloid; a through hole, penetrating the first surface and the second surface of the board body; and a plurality of electronic components, disposed on the first surface and partially embedded in the first colloid as the distance (D 1) from the low scale to the bottom wall is greater than a longest distance (D 4) from tops of the electronic components to the bottom wall; a second colloid supplemented through the through hole to fill in the space between the first colloid and the first surface after the circuit board has been placed, the second colloid further filling the space between the second surface and the high scale; and the electronic device further comprising a cover on top of the second colloid.