Characterizing the Electric Field Coupling from IC Heatsink Structures to External Cables Using TEM Cell Measurements

• Published in: IEEE transactions on electromagnetic compatibility Vol. 49; no. 4; pp. 785 - 791
• Main Authors: Deng Shaowei, Hubing, T., Beetner, D.G.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Circuit boards; Closed-form equation; Design. Technologies. Operation analysis. Testing; Electric cables; Electric fields; Electric potential; Electromagnetic cells; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Emissions; Exact sciences and technology; Heat sinkg; Integrated circuits; Joining; mutual capacitance; Performance evaluation; Printed circuit boards; Printed circuits; radiated emissions; self-capacitance; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transmission electron microscopy; transverse electromagnetic (TEM) cell; Thermal management (packaging); Cable structure; self-capacitance; Printed circuit board; TEM mode; transverse electromagnetic (TEM) cell; Closed form equation; mutual capacitance; Electric field; Transmission electron microscopy; radiated emissions; Cavity; Magnetic coupling; Electronic packaging; Integrated circuit; Cooling system; Capacitance; Printed circuit; Measurement method; Radiated power; Closed-form equation; Magnetic field; Heat sink
• ISSN: 0018-9375; 1558-187X
• DOI: 10.1109/TEMC.2007.908825

One method for evaluating the unintentional radiated emissions from integrated circuits (ICs) involves mounting the IC on a printed circuit board (PCB) embedded in the wall of a transverse electromagnetic (TEM) cell. The signal voltages on the IC and its package produce electric fields that can couple to cables and other structures attached to the PCB, inducing common-mode currents that can be a primary source of unintentional radiated emissions. The signal currents in the IC and its package produce magnetic fields that can also result in common-mode currents on larger radiating structures. This paper describes a TEM cell measurement method employing a hybrid to separate the electric field coupling and the magnetic field coupling. The results of this measurement can be used to determine the product of the IC's self-capacitance and the effective voltage that drives this capacitance. This voltage-capacitance product characterizes the IC's ability to drive common-mode currents onto cables or enclosures due to electric field coupling. This information can then be used to estimate the resulting radiated emissions.