Process for making a low-profile choke

A process for making a low-profile choke, comprising steps of:

• a) providing an etchable substrate having a top surface and a bottom surface;
• b) applying on one of the top and bottom surfaces of the etchable substrate a first masking layer including an array of first perforated patterns which are displaced from each other by a predetermined spacing and each of which includes a first perforation and a first coil-patterned slit having a first inner slit end and a first outer slit end and disposed to surround the first perforation;
• c) etching the etchable substrate through the first perforated patterns of the first masking layer to permit the etchable substrate to be formed with an array of first recessed patterns which are recessed from said one of the top and bottom surfaces of the etchable substrate, each of the first recessed patterns including a first core recess portion which corresponds to the first perforation and a first coil-patterned recess portion which corresponds to the first coil-patterned slit and which has a depth smaller than that of the first core recess portion;
• d) filling a magnetic material and a conductive material respectively into the first core recess portion and the first coil-patterned recess portion of each of the first recessed patterns so as to form in the etchable substrate a plurality of first magnetic cores and a plurality of first conductive coils, each with a first inner end and a first outer end respectively corresponding to the first inner slit end and the first outer slit end of the first coil-patterned slit;
• and
• e) slicing the etchable substrate along the predetermined spacing to obtain a plurality of choke bodies.