Connection method for yarn wire and circuit board

A connection method for a yarn wire and a circuit board, comprising processes of:

• providing at least one yarn wire, a back adhesive, and a circuit board;
• wherein at least one through hole penetrates through two opposite sides of the circuit board, wherein a diameter of the through hole is defined as D, a diameter of the at least one yarn wire is defined as d, a shrunken diameter of the yarn wire being stretched is defined as dmin, and a jig thickness of a jig is defined as t, the diameter of the through hole, the diameter of the at least one yarn wire, the shrunken diameter of the yarn wire being stretched, and the jig thickness having a relation of:
• 2d>D>2dmin+t;
• placing the at least one yarn wire on the back adhesive so that the back adhesive is disposed on one side of the yarn wire, aligning the yarn wire with the through hole of the circuit board, and using the jig to penetrate through the back adhesive along an assembly direction such that the yarn wire is extruded into and passes through the through hole;
• pulling the jig out along a pulling direction, wherein the yarn wire applies a frictional force and an abutting normal force on an inner wall of a periphery of the through hole, and a portion of the yarn wire that passes through the through hole forms a protruding wire segment in a shape of a round loop;
• and
• adhering a fixing back adhesive to one side of the circuit board, wherein the fixing back adhesive is adhered to the circuit board and the protruding wire segment so that the yarn wire and the circuit board are connected and fixed to each other.