Seal Integrity Testing Utilizing Non-Destructive Capacitive Sensing for Product Packaging Assurance

In this paper, a high-speed, high-accuracy, and non-destructive electro-capacitive sensing method to locate micro defects and anomalies present in product packaging is presented. Using two types of capacitive sensor, a single full plate capacitive electrode and a 14 electrode pair capacitive sensor array in a combined footprint of 306 mm(2), we show that micro-particles with an average size of 120 mu m incorporated in package seal can be detected and located with a latency 1 mu s for full plate sensor and 14 mu s for the sensor array. Our electrode design modeled using COMSOL Multiphysics shows excellent agreement with experimental results, providing a baseline for further electrode optimization. The proposed electro-capacitive technique is non-destructive and has no dependency on the package materials. In addition, its high accuracy and fast testing make it suitable for use in high throughput production line for packaging quality assurance.