MEASURING THE HYGROSCOPIC CAPACITY OF INTEGRATED CIRCUIT PACKAGES AND PRINTED CIRCUIT BOARDS

摘要

The electronics manufacturing and assembly industry has well-defined standards regarding moisture sensitivity of electronic device components during manufacturing and assembly of electronic devices. [1] [2] These known industry standards have yet to be applied or inform how digital forensic scientists are addressing electronic devices exposed to or damaged by water or other liquids. Significant risk exists to data stored within integrated circuit packages if specific steps are not followed when addressing electronic devices that have been exposed to water or other liquids. Liquid absorbed within the integrated circuit packages may turn into a vapor when exposed to heat, creating damaging expansion within the chip if the device is exposed to standard repair, rework or chip-off processes. [3] In this study, integrated circuit packages (computer chips) and printed circuit boards are exposed to a control liquid to understand the amount of liquid the discrete devices will absorb over a defined duration. The hygroscopic coefficient is the equilibrium when the maximum amount of liquid can be absorbed. The study seeks to identify the time duration at which hygroscopic coefficient is achieved on integrated circuit packages and printed circuit boards. By understanding the amount of liquid absorbed in a given duration, the results may inform digital forensic science practitioners on the duration of drying that will be required to safely remove the absorbed liquid from the devices. Additionally, different liquid types (e.g. freshwater, salt water, brackish water) may absorb at different rates, requiring different techniques based on the type of liquid exposure. Testing for this study includes the use of laboratory grade water testing equipment and analytical balances to measure the impact of liquid and duration against the materials composition of the electronic devices. After attending this presentation, attendees will gain an understanding that integrated circuit packages (computer chips) and printed circuit boards have the capacity to absorb water they come in contact with; the variables affecting the amount of water absorbed; and the implications of hygroscopic capacity when addressing electronic devices that have been exposed to or damaged by liquids. This research will impact the forensic science community by providing results from direct method experiments guided by extensive research in another scientific discipline but little previous research applied to digital forensic science. This presentation will seek to broaden the understanding of the impact of liquid exposure to electronic devices by examining the effect on the two primary discrete parts of electronic devices. The results of this study may impact the direction provided to forensic service providers (FSP) and the practices used by FSPs when addressing evidence that has been exposed to or damaged by liquid.