NMR-imaging of water content in the polymer matrix of silicon chips

The distribution of water in the polymer matrix of a silicon microchip was studied by NMR imaging. The chip was saturated with water in a water steam atmosphere and then dried in five steps. After every change of the water content a three-dimensional (3D) NMR image was acquired. A 3D back-projection spin-echo sequence was used to avoid fast gradient switching during the sequence. The experiments show that water invades the chip mainly through the gap between the metallic parts and the polymer body.