Failure analysis of epoxy molded IC packages

Abstract

Purpose The aim of this paper is to present non-destructive and destructive methods of failure analysis of epoxy moulded IC packages on the example of power MOSFETs in SOT-227 package. Design/methodology/approach A power MOSFET in SOT-227 package was examined twice using X-ray inspection, at first as the whole component to check if it is damaged and then after removing the upper part of package by mechanical grinding. The purpose of the second X-ray inspection was to prepare images for estimation of the total number and approximate location of voids in soft solder layers. Finally, power MOSFETs were subjected to decapsulation process using a concentrated sulphuric acid to verify existence of damage areas noticed during X-ray analysis and to observe other possible failures such as cracks in aluminium metallization or wires deformation. Findings X-ray analysis was revealed to be adequate technique to detect damage (e.g. meltings) in power MOSFETs in SOT-227 package, but only when tested components were analysed in the side view. This type of analysis combined with a graphic software is also suitable for voids estimation in soft solder layers. Moreover, it was found that a single acid (concentrated sulphuric acid) at elevated temperature can be successfully used for decapsulation of power MOSFETs in SOT-227 package without damage of aluminium metallization and aluminium wires. Such decapsulation process enables analysis of defects in wire, die and package materials. Research limitations/implications Further investigations are required to examine if the presented methods of failures analysis can be used for other types of components (e.g. high power resistors) in similar packages. Practical/implications The described methods of failure analysis can find application in electronic industry to select components which are free of damage and in effect which allow to produce high reliable devices. Apart from it, the presented method is applicable to evaluate reasons of improper work of tested electronic devices and to identify faked components. Originality/value This paper contains valuable information for research and technical staff involved in the assessment of electronic devices who needs practical methods of failure analysis of epoxy moulded IC packages.

Research and Implementation of Three-Dimensional Spatial Information Characterization and Visualization of Fractures in Deteriorated Sandstone

“…Since Wilhelm Conrad Röntgen discovered X-ray in the Institute of Physics at the University of Würzburg in 1895, it has been widely used in medicine and industry. Many non-destructive detecting techniques based on X-ray have since been developed, including medical X-ray computed tomography (CT) equipment [1][2][3][4][5], angiography equipment [6][7][8][9][10], industrial X-ray CT equipment [11][12][13][14][15], industrial X-ray detectors [16][17][18][19][20] and so on.…”

Research and Implementation of Three-Dimensional Spatial Information Characterization and Visualization of Fractures in Deteriorated Sandstone

“…Since Wilhelm Conrad Röntgen discovered the X-ray in the Institute of Physics at the University of Würzburg in 1895, it has been widely used in medicine and industry. Many non-destructive detecting techniques based on X-rays have since been developed, including medical X-ray computed tomography (CT) equipment [1][2][3][4][5], angiography equipment [6][7][8][9][10], industrial X-ray CT equipment [11][12][13][14][15], industrial X-ray detectors [16][17][18][19][20], and so on. However, non-destructive testing technology is widely used in medical and industrial fields and is equally essential in construction.…”