| 摘要 |
PURPOSE:To lengthen the service life of the lead frame of a plastic sealed IC in vapor and to enable to improve the reliability of the IC by a method wherein a stepping is provided at the intermediate parts of the inner leads of the leads frame and the wire-bonding area of the point part of each inner lead is made higher than the other part of the lead frame on the side of the semiconductor placing part. CONSTITUTION:The steppings 9 of the inner lead parts of the leads 7 of the plastic sealed IC are provided at the intermediate parts of the leads 7 and water content is prevented from intruding through the interfaces between the leads 7 and a sealing plastic 8. Moreover, the level of the height in the surface of the wire-bonding pads 3 of the point of each lead and that in the surface of a silicon chip 5 are made in such a way as to become equal to each other to shorten as short as possible the fine wire, and the wire-bonding area of the point part of each lead is made higher than the other part of the lead frame on the side of the semiconductor placing part. By this method, the service life of the lead frame is lengthened in vapor under the prescribed conditions and the reliability of the plastic IC is improved. |
