Method for mass-manufacturing of miniature resistor

A method for mass-manufacturing of a miniature resistor, comprising the steps of:

• (A) providing a foil sheet made of an electrically conductive material having a predetermined resistance value;
• (B) forming a plurality of slits penetrating through the foil sheet and arranged in multiple longitudinal and transverse rows so as to define a patterned foil sheet, the patterned foil sheet including a plurality of resistor blanks arranged in a matrix array, a plurality of connecting regions situated at intersections of the longitudinal and transverse rows, and a framing strip that loops around the resistor blanks, the slits and the connecting regions, the slits aligned in each of the longitudinal and transverse rows being spaced apart from each other at intersections of the longitudinal and transverse rows, the resistor blanks being connected to each other by the connecting regions and the framing strip;
• (C) bonding a first photoresist film and a second photoresist film respectively to a top surface and a bottom surface of the patterned foil sheet so as to cover the resistor blanks;
• (D) forming a plurality of holes in the first photoresist film such that the holes expose top surfaces of the resistor blanks;
• (E) forming a plurality of protruding blocks made of an electrically conductive material that has a predetermined resistance value in the holes such that the protruding blocks filling the holes are connected to the top surfaces of the resistor blanks;
• (F) removing the first photoresist film and the second photoresist film from the patterned foil sheet so as to expose the resistor blanks;
• (G) encapsulating the patterned foil sheet and the protruding blocks using an encapsulating material such that the encapsulating material covers the top and bottom surfaces of the resistor blanks without covering outer surfaces of the protruding blocks;
• (H) performing a cutting process to remove parts of the encapsulating material extending along intersecting cutting lines passing through the slits, the connecting regions and the framing strip so as to obtain a plurality of individual resistor blanks that are separated from one another;
• and
• (I) forming two external electrodes respectively on the protruding blocks and on two opposite side surfaces of each of the individual resistor blanks so as to obtain the miniature resistor.