A substrate structure includes an insulation base material and a through hole. The through hole passes through the insulation base material. Besides, the through hole has a first opening, a second opening, and a third opening communicated with one another. The third opening is located between the first opening and the second opening. A first included angle is formed between an inner wall of the first opening and an inner wall of the third opening. A second included angle is formed between an inner wall of the second opening and the inner wall of the third opening. The minimum diameter of the third opening is at the center of the through hole and defines a neck end portion. Diameters of the first opening and the second opening gradually decrease in a direction toward the neck end portion.