http://dow-chipseal.se-com.com/ excerpt Dow Corning Corporation has developed a tamper resistant composite using silicon-based thin film materials for the U.S. Government. These materials inhibit and deter access of sensitive information contained within the hard and soft logic regions of a semiconductor device. The main thrust has been on improving the security of integrated circuits that are used for encryption, stored information (memory), microcontrollers, and advanced circuit designs. Since then, commercial grades of this composite, referred to as ChipSeal� Tamper Resistant Composites, have been developed in conjunction with semiconductor manufacturers and are being used in advanced commercial applications. ChipSeal Tamper Resistant Composites are a significant advancement over existing forms of die-level security protection deployed today. The ChipSeal Composite can be applied to nearly any completed semiconductor device wafer and does not interfere with wafer fabrication or device assembly processes. ChipSeal Composites were designed to permit forward integration in electronic packaging and are compatible with single chip and multi-chip packaging techniques, including hermetic, plastic, and smartcard packages. The ChipSeal Composite raises the level of technical sophistication and investment required to attempt tampering. ChipSeal Composites can meet or exceed the security requirements that will boost consumer confidence in new electronic products. ..... A. Physical Protection: 1.Opaque to normal inspection of circuit layout (also see section C below). 2.Mechanical techniques to abrade or remove the coating from the chip surface induce damage into the semiconductor chip resulting in non-functionality and loss of volatile memory. 3.Thermal shock resistant. 4.Tenacity of adhesion and thickness renders the coating virtually impossible to lift or flake off. 5.Hardness of the coating prevents probe penetration into active regions. 6.Temperature resistant. 7.Techniques to remove the coating are not compatible with maintaining power to the device. B. Chemical Protection: 1.Virtually impervious to all household chemicals and harsh industrial chemicals. 2.Industrial decapsulation techniques to remove the chip from its plastic package will not penetrate the coating (red fuming HNO3 or hot H2SO4). 3.Resistant to strong mineral acids and bases. 4.Resistant to severe environmental and saturated moisture conditions. 5.Techniques to chemically remove the coating induce damage into the semiconductor chip resulting in non-functionality and loss of volatile memory. C. Opacity: 1.Opaque to normal view under any magnification. 2.Virtually impervious to a variety of known frequencies within the UV - Visible electro-magnetic spectrum. 3.Virtually impervious to a variety of known frequencies within the infrared spectrum. 4.Virtually impervious to a variety of known frequencies within the x-ray spectrum.
