die 32 has two terminal fixing blocks 321 322 respectively corresponding to the first terminal supporting base 301 and the second terminal supporting base 302 the shapes of the terminal fixing blocks 321 322 may correspond to those of the first terminal supporting base 301 and the second terminal supporting base 302 the cavity of the supplemental die 32 is similar in shape to the cavity 300 of the first die 30 referring to fig3 e 3f and 3 g when the supplemental die 30 is disposed on the first die 30 the terminals 10 are respectively clamped between the terminal fixing blocks 321 322 and the terminal supporting bases 301 302 thus the coil 1 is positioned and fixed in a predetermined position in another embodiment as shown in fig3 m and fig3 n a recess is disposed on terminal fixing block 321 to contain the terminal 10 and the shapes of terminal fixing blocks 321 322 also may correspond to those of the first terminal supporting base 301 and the second terminal supporting base 302 therefore the coil 1 is clamped by the supplementary die 32 and the first die 30 and positioned and fixed in the predetermined position in some embodiments the supplemental die 32 may be omitted in this case only the first die is provided and two terminal supporting holes not shown in the cavity of the first die fix the terminals a first dust filling process is performed as shown in fig3 h to fill dust 4 in the cavity 300 the material of the dust is selected.