TY - GEN SP - 224 N1 - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions. KW - life test KW - encapsulation KW - printed circuit board KW - impedance KW - FR4 KW - solder PB - IMAPS - International Microelectronics Assembly and Packaging Society A1 - Ali, I A1 - Xue, F A1 - Henriquez, CP A1 - Niederhoffer, T A1 - Idil, AS A1 - Iang, DJ A1 - Lancashire, HT AV - public TI - Initial L ife Test of Silicone E ncapsulated FR 4 Printed Circuit Boards for Pre-Clinical A ctive Implants SN - 2222-8748 Y1 - 2024/03/06/ ID - discovery10190389 UR - http://dx.doi.org/10.4071/001c.94758 EP - 227 N2 - Silicone encapsulated FR 4 printed circuit boards may provide a rapid solution for protecting pre-clinical prototype implant electronics. Interdigitated electrodes (IDE s) with and without solder coating were manufactured on Cu-FR 4 laminates and silicone encapsulated (N = 14). IDE s were aged in saline and change in impedance was measured. Solder coated IDE s had stable 1 kHz impedances throughout the aging period with promising lifetimes for pre-clinical prototypes. A single uncoated IDE failed with a fall in impedance and verdigris. Other uncoated IDEs showed increasing impedance and dark copper(II) oxide. Failures attributable to contaminants and moisture ingress are under investigation. ER -