Title :
Mechanism of electromigration in ceramic packages induced by chip-coating polyimide
Author :
Kohara, Masanobu ; Mashiko, Youji ; Nakasaki, Koichi ; Nunoshita, Masahiro
Author_Institution :
Mitsubishi Electr. Corp., Hyogo, Japan
fDate :
12/1/1990 12:00:00 AM
Abstract :
The mechanism of electromigration between the inner leads of large-scale integrated (LSI) chips in ceramic packages that are coated by thick polyimides to prevent alpha-particle-induced soft errors is discussed. Short-circuit failures between neighboring inner leads in the packages were monitored in the final test after burn-in of LSI devices. The shorting paths between the leads were observed by an optical microscope and scanning electron microscope (SEM). It was found that the path was produced by a deposit between the inner leads. The deposit was found to be composed of electromigration nickel from the inner lead. Also, n-methyl-pyrrolidone (NMP) and water were found in the package by gas analysis. A possible short-circuiting mechanism is discussed
Keywords :
electromigration; failure analysis; large scale integration; nickel; packaging; polymer films; protective coatings; reliability; LSI chips; LSI devices; NMP; Ni electromigration; SEM; ceramic packages; chip-coating polyimide; deposits between inner leads; electromigration between inner leads; final test after burn-in; inadequate baking; mechanism of electromigration; n-methyl-pyrrolidone; short-circuiting mechanism; thick polyimides; water; Ceramics; Condition monitoring; Electromigration; Electron optics; Large scale integration; Optical microscopy; Packaging; Polyimides; Scanning electron microscopy; Testing;
Journal_Title :
Components, Hybrids, and Manufacturing Technology, IEEE Transactions on
