The present invention relates to a press-fit pin press-fitted into a through hole of a printed circuit board and electrically connected thereto.
One of techniques for connecting an electronic component, such as IC, to a through hole of a printed circuit board having a circuit pattern is a press-fit connection technique. According to this technique, the circuit board and the electronic component can be interconnected to each other only by press-fitting an elastically bend-deformable press-fit portion of a press-fit pin into the through hole. Therefore, this technique can avoid drawbacks, such as poor connection, and thermal problems, as compared with related art soldering connection.
Thus, there has been a desire to connect a lead pin, which is used for taking a signal out of a printed circuit board, to the circuit board by performing press-fit connection. However, the lead pin is embedded in an insulator accommodating the circuit board by insert-molding in a state that opposite ends of the lead pin serving as connecting end parts to be connected to the circuit board and to an external part project from the insulator. That is, the lead pin is insert-molded in a state in which both end parts thereof are inserted and held in hole-portions provided in a molding die.
The press-fit portion is formed by snicking a plate-like pin material which constitutes the press-fit pin, and then performing a press process in such a way as to broaden the pin material in the widthwise direction thereof, so that the press-fit portion elastically deforms in the widthwise direction thereof. Therefore, the width dimension of the press-fit portion is nearly equal to that of the pin material at both end parts thereof, while that of the press-fit portion is larger than that of the pin material at the central part thereof.
Thus, in the case that the lead pin is constituted by a press-fit pin, the press-fit portion serving as a connecting end part connected to the circuit board cannot be inserted and held in the molding die. Consequently, the lead pin cannot be insert-molded.