| 摘要 |
PURPOSE:To prevent erroneous insertion of pins at the assembly time by providing legs for enhancing the heat dissipation effect on the back surface of an LSI package, thereby eliminating the necessity of disposing special pins at a particular location. CONSTITUTION:An LSI package 1 has a plurality of connection pins 2 on the perimeter portion of the back surface thereof, and a projective leg 4 at each of the four corners of the central square portion where there are no connection pins. With this, when packaged into a printed wiring board, the air flow around the back surface of the LSI package is improved, whereby the heat dissipation effect can be improved. Therefore, it is not necessary to use special pins which are different in shape from the conventional connection pins, and the conventional connection pin 2 of a simple shape is sufficient by itself, so that cost reduction and elimination of erroneous insertion of the pins at the assembly time can be accomplished. Further, as to the projection legs of the central portion, although a total of four projective legs are provided, or one for each of the four corners, any number of projective legs not less than three are available for stable fixing. In addition, this projective legs may be integrally formed with the ceramic material of the package. |
