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This paper discusses commonly used reverse engineering methods to illegally recreate printed circuit board (PCB) designs. A solution using transformative electronics is presented to prevent the discussed reverse engineering methods by obfuscating the design. The transformative electronics solution is employed in a specific application that results in a reverse engineered board to be incorrectly recreated, where the signals would be distorted due to added electromagnetic interference (EMI). The non-conductive vias that are part of the obfuscation would allow the inclusion of EMI generators that would not affect the circuit in an original design but would prevent copied designs from working correctly. A machine learning algorithm is being designed to optimize the placement of the EMI sources in an original PCB.

To prevent any negative electromagnetic influence of high-density integrated circuits, an insulation package needs to be specially designed to shield it. Aiming at the low efficiency and material waste in traditional packaging methods, a printed circuit board (PCB) selective packaging system based on a multi-pattern solder joint simultaneous segmentation algorithm and three-dimensional printing technology is introduced in this paper. Firstly, the structure of PCB selective packaging system is designed. Secondly, to solve the existing problems, such as multi-pattern solder joints which are located densely in small welding areas and are hard to be extracted in the small-area integrated circuit board, a multi-pattern solder joint simultaneous segmentation algorithm is developed based on (geometrical) neighborhood features to extract and locate the optimal PCB solder joint areas. Finally, tests using three actual PCB are carried out to compare the proposed method with traditional multi-threshold solder joint extraction methods. Test results indicate that the proposed algorithm is simple and effective. Diverse solder joints can be optimally located and simultaneously extracted from the collected PCB image, which greatly improves the filling rate of the solder joint areas and filters out false pixels. Thus, this method provides a reliable location-finding tool to help place solder points in PCB selective packaging systems.

Advances in magnetoresistive type sensors provide a new technique for nondestructive evaluation of metal structures. Giant magnetoresistive and giant magnetoimpedance sensors provide high sensitivity and reduced size with GMI sensors also adding capabilities of high frequency range of measurements. Being produced with thin film processing techniques, the manufacturing cost of these sensors is low. An example is considered of detecting defects in printed circuit boards. System details and experimental results are provided. Computational modeling validation is introduced based on finite element as well as method of moments analysis.

The demand for better tools for machining printed circuit boards (PCBs) is increasing due to the extensive usage of these boards in digital electronic products. This paper is aimed at optimizing coating type on micro drills in order to extend their lifetime in PCB machining. First, the tribotests involving micro crystalline diamond (MCD), nano crystalline diamond (NCD) and bare tungsten carbide (WC-Co) against PCBs show that NCD–PCB tribopair exhibits the lowest friction coefficient (0.35) due to the unique nano structure and low surface roughness of NCD films. Thereafter, the dry machining performance of the MCD- and NCD-coated micro drills on PCBs is systematically studied, using diamond-like coating (DLC) and TiAlN-coated micro drills as comparison. The experiments show that the working lives of these micro drills can be ranked as: NCD$>$TiAlN$>$DLC$>$MCD$>$bare WC-Co. The superior cutting performance of NCD-coated micro drills in terms of the lowest flank wear growth rate, no tool degradation (e.g. chipping, tool tipping) appearance, the best hole quality as well as the lowest feed force may come from the excellent wear resistance, lower friction coefficient against PCB as well as the high adhesive strength on the underneath substrate of NCD films.

This paper discusses commonly used reverse engineering methods to illegally recreate printed circuit board (PCB) designs. A solution using transformative electronics is presented to prevent the discussed reverse engineering methods by obfuscating the design. The transformative electronics solution is employed in a specific application that results in a reverse engineered board to be incorrectly recreated, where the signals would be distorted due to added electromagnetic interference (EMI). The nonconductive vias that are part of the obfuscation would allow the inclusion of EMI generators that would not affect the circuit in an original design but would prevent copied designs from working correctly. A machine learning algorithm is being designed to optimize the placement of the EMI sources in an original PCB.

The dynamical model for a drawer structure with multi-layer printed circuit boards (PCBs) was established by the finite element method and the random vibration responses were analyzed in this paper. Firstly, the natural frequencies and their corresponding modes were obtained in terms of the finite element model of the drawer structure with PCBs. Secondly, the random vibration responses were obtained numerically for the drawer structure under random excitations. Finally, sensitive points on each layer of the drawer structure were selected to calculate the vibration responses and the acceleration power spectral density (PSD). The stress power spectral density of typical points on the PCB with high stress was also analyzed. The simulation results reveal that the largest vibration energy of the PCBs usually occurs in the middle layer of the structure and thus components in the middle of the PCBs are most likely to be destroyed.