A light source module (200; 201), comprising: a printed circuit board; and a plurality of light emitting diode packages mounted on the printed circuit board to form a first chain structure (101_a1, 101_a2) and a second chain structure (101_b1, 101_b2), each light emitting diode package comprising: a light emitting diode chip configured to generate light; a case configured to accommodate therein the light emitting diode chip; first and second leads (131, 133) spaced from each other in the case and including an anode lead and a cathode lead electrically connected to the light emitting diode chip; and four dummy leads (141, 143, 151, 153) spaced from the first and second leads (131, 133) and electrically insulated from the first and second leads (131, 133), the four dummy leads (141, 143, 151, 153) comprising: a first dummy lead and a third dummy lead spaced from the anode lead; a second dummy lead spaced from the cathode lead and connected to the first dummy lead in the case through a first wire; and a fourth dummy lead spaced from the cathode lead and the second dummy lead and connected to the third dummy lead in the case through a second wire; wherein one end of the anode lead is exposed from a first side of the case and one end of the cathode lead is exposed from a second side of the case, wherein one end of the first dummy lead and one end of the third dummy lead are exposed from the first side of the case to thus face each other in a state where the anode lead is interposed therebetween, wherein one end of the second dummy lead and one end of the fourth dummy lead are exposed from the second side of the case to thus face each other in a state where the cathode lead is interposed therebetween; and wherein the cathode lead of one light emitting diode package (101_a1) of the first chain structure is connected (221, 223) to the anode lead of another light emitting diode package (101_a2) of the first chain structure through two (151, 153) of the interconnected dummy leads of an adjacent light emitting diode package (101_b1) of the second chain structure. a printed circuit board; and a plurality of light emitting diode packages mounted on the printed circuit board to form a first chain structure (101_a1, 101_a2) and a second chain structure (101_b1, 101_b2), each light emitting diode package comprising: a light emitting diode chip configured to generate light; a case configured to accommodate therein the light emitting diode chip; first and second leads (131, 133) spaced from each other in the case and including an anode lead and a cathode lead electrically connected to the light emitting diode chip; and four dummy leads (141, 143, 151, 153) spaced from the first and second leads (131, 133) and electrically insulated from the first and second leads (131, 133), the four dummy leads (141, 143, 151, 153) comprising: a first dummy lead and a third dummy lead spaced from the anode lead; a second dummy lead spaced from the cathode lead and connected to the first dummy lead in the case through a first wire; and a fourth dummy lead spaced from the cathode lead and the second dummy lead and connected to the third dummy lead in the case through a second wire; a light emitting diode chip configured to generate light; a case configured to accommodate therein the light emitting diode chip; first and second leads (131, 133) spaced from each other in the case and including an anode lead and a cathode lead electrically connected to the light emitting diode chip; and four dummy leads (141, 143, 151, 153) spaced from the first and second leads (131, 133) and electrically insulated from the first and second leads (131, 133), the four dummy leads (141, 143, 151, 153) comprising: a first dummy lead and a third dummy lead spaced from the anode lead; a second dummy lead spaced from the cathode lead and connected to the first dummy lead in the case through a first wire; and a fourth dummy lead spaced from the cathode lead and the second dummy lead and connected to the third dummy lead in the case through a second wire; a first dummy lead and a third dummy lead spaced from the anode lead; a second dummy lead spaced from the cathode lead and connected to the first dummy lead in the case through a first wire; and a fourth dummy lead spaced from the cathode lead and the second dummy lead and connected to the third dummy lead in the case through a second wire; wherein one end of the anode lead is exposed from a first side of the case and one end of the cathode lead is exposed from a second side of the case, wherein one end of the first dummy lead and one end of the third dummy lead are exposed from the first side of the case to thus face each other in a state where the anode lead is interposed therebetween, wherein one end of the second dummy lead and one end of the fourth dummy lead are exposed from the second side of the case to thus face each other in a state where the cathode lead is interposed therebetween; and wherein the cathode lead of one light emitting diode package (101_a1) of the first chain structure is connected (221, 223) to the anode lead of another light emitting diode package (101_a2) of the first chain structure through two (151, 153) of the interconnected dummy leads of an adjacent light emitting diode package (101_b1) of the second chain structure.