The invention relates to the technical field of
charged particle beam control, and discloses an electrostatic deflector for a
focused ion beam and an
assembly process thereof, the electrostatic deflector comprises an
electrode assembly, a mounting
flange, an insulation structure and a positioning structure; an upper
electrode and a lower
electrode of the electrode
assembly are correspondingly arranged; part of the upper electrode is embedded into the mounting
flange; the insulating structure is arranged on one side, far away from the upper electrode, of the mounting
flange, and part of the lower electrode is embedded into the insulating structure; the positioning structure sleeves the lower electrode; the
thermal expansion coefficient of the electrode assembly is A, the
thermal expansion coefficient of the insulation structure is B, and 1 < = A / B < = 1.5. The proportional relation between the
thermal expansion coefficients of the electrode assembly and the insulation structure is limited, the thermal expansion coefficients of the electrode assembly and the insulation structure are matched, the deformation quantity difference of the electrode assembly and the insulation structure under the extreme working condition is reduced, thermal stress
cracking is avoided, and the assembly precision and
structural integrity of the electrode assembly and the insulation structure are maintained; the
electric field is distributed according to design, and
distortion is avoided.