| 摘要 |
PURPOSE:To sharply reduce a microcrack or a package crack at a plastic package by a method wherein an outside face of a die bonding plate at a lead frame is formed at a protruding curved surface. CONSTITUTION:An outside face 2a of a die bonding plate 2 at a lead frame 1 is formed at a protruding curved face (a radius face) and prevents a local stress from being caused (because the local stress is dispersed). Accordingly, microcracks or package cracks are not caused in a plastic package composed of sealing resin. In this case, a good result is obtained if a curved surface state (a radius) at the protruding curved face 2a is set in such a way that an angle thetaformed by an extension A and a tangent B extended through an intersecting point C from a position on the opposite side ot the intersecting point C is made larger than 180 deg. at the intersecting point C at the extension A of a plate face 8 of the die bonding plate 2 and at an end part of the protruding curved face 2a. Generally, if this angle is 120 deg. or larger, the same effect can be expected. However, if the angle is less than 120 deg., the effect becomes insufficient. |
