Method for forming solder performs on welding spots of a circuit substrate and flip-chip method

The invention relates to a method for forming solder performs on welding spots of a circuit substrate, which comprises the following steps: providing the circuit substrate, wherein a plurality of conductive circuits and welding spots are formed on at least one surface of the circuit substrate; jetting photo resist onto the surface of the circuit substrate to form a photo resist layer with a plurality of accommodating holes, and exposing corresponding welding spots out of each accommodating hole; filling a metal material in each accommodating hole; heating the metal material to form the solder performs; and removing the photo resist layer. The invention also relates to a flip-chip method. The method for forming the solder performs on the welding spots of the circuit substrate and the flip-chip method can improve precision and yield of products.