Lens driving module with casing having plastic material and assembly method thereof

1. An optical element driving module, comprising:

a movable portion for connecting an optical element;

a fixed portion movably connected to the movable portion, wherein the fixed portion comprises:

a base; and

a casing arranged with the base along a main axis, wherein the casing comprises a top wall and a side wall extended from edges of the top wall along the main axis, and the top wall comprises:

a first surface facing the movable portion;

a second surface facing away from the first surface; and

a third surface facing away from the second surface; and

a driving assembly for moving the movable portion relative to the fixed portion,

wherein a minimum distance between the first surface and the second surface is different from a minimum distance between the second surface and the third surface.

2. The optical element driving module as claimed in claim 1 , wherein a minimum distance between the first surface and the main axis is less than a minimum distance between the second surface and the main axis, and the minimum distance between the first surface and the second surface is less than the minimum distance between the second surface and the third surface.

3. The optical element driving module as claimed in claim 2 , wherein the first surface directly faces the movable portion, and none of the fixed portion is positioned between the first surface and the movable portion.

4. The optical element driving module as claimed in claim 2 , wherein the third surface faces the driving assembly, and the driving assembly is at least partially disposed on the third surface.

5. The optical element driving module as claimed in claim 4 , wherein the base comprises:

a fourth surface facing the sidewall; and

a fifth surface facing the driving assembly and adjacent to the fourth surface, wherein the fourth surface and the fifth surface are not parallel.

6. The optical element driving module as claimed in claim 5 , wherein the second surface faces the driving assembly, and the second surface does not overlap the fifth surface when viewed along a normal direction of the second surface.

7. The optical element driving module as claimed in claim 1 , wherein a gap is formed between the third surface and the sidewall.

8. The optical element driving module as claimed in claim 7 , further comprising a position sensor and a circuit component electrically connected to the position sensor, and the circuit component is disposed in the gap.

9. The optical element driving module as claimed in claim 8 , wherein the second surface faces the position sensor.

10. The optical element driving module as claimed in claim 8 , wherein the top wall further comprises a sixth surface facing the circuit component, and the minimum distance between the second surface and the third surface is different from a minimum distance between the second surface and the sixth surface.

11. The optical element driving module as claimed in claim 10 , the minimum distance between the second surface and the third surface is greater than the minimum distance between the second surface and the sixth surface.

12. The optical element driving module as claimed in claim 1 , wherein the casing further comprises an U-shaped accommodating portion, and the driving assembly is at least partially disposed in the accommodating portion.

13. The optical element driving module as claimed in claim 12 , wherein the accommodating portion has two recesses opposite with each other, and the driving assembly is at least partially disposed in the recesses.

14. The optical element driving module as claimed in claim 12 , wherein the accommodating portion comprises a seventh surface facing the driving assembly, and a minimum distance between the first surface and the seventh surface is different from a minimum distance between the first surface and the third surface.

15. The optical element driving module as claimed in claim 14 , wherein the accommodating portion further comprises an eighth surface facing the base, and the minimum distance between the first surface and the seventh surface is different from a minimum distance between the first surface and the eighth surface.

16. The optical element driving module as claimed in claim 15 , wherein the minimum distance between the first surface and the seventh surface is less than the minimum distance between the first surface and the eighth surface.

17. The optical element driving module as claimed in claim 15 , wherein the minimum distance between the first surface and the third surface is less than the minimum distance between the first surface and the eighth surface.

18. The optical element driving module as claimed in claim 15 , wherein the minimum distance between the first surface and the seventh surface is less than the minimum distance between the first surface and the second surface.

19. The optical element driving module as claimed in claim 1 , wherein the top wall further comprises a ninth surface at least partially overlaps the movable portion in a normal direction of the ninth surface, and the third surface and the ninth surface face different directions.

20. The optical element driving module as claimed in claim 19 , wherein the ninth surface does not overlap the driving assembly when viewed along the normal direction of the ninth surface.