A pressure sensor assembly includes a sensor die and a ceramic substrate. The sensor die has a first side and a second side that is opposite to the first side. The sensor die includes a silicon chip that has a diaphragm configured to be exposed to a working fluid. The sensor die includes one or more electrical sensing elements mounted on the diaphragm and configured to measure a pressure of the working fluid. The sensor die is mounted to the ceramic substrate via a solder layer that engages the ceramic substrate and the second side of the sensor die.