This study investigates the influence of parasitic parameters in high-frequency PCB transformers (HFT(PCB)) on the performance of single-ended resonant aerospace DC/DC converters. An interleaved winding high-frequency PCB transformer, IW-HFT(PCB), was designed and compared with conventional HFT(PCB) in terms of power MOSFET voltage stress, output efficiency, and transformer operating temperature. A 100W aerospace DC/DC converter prototype was developed for validation, demonstrating significant improvements in current density distribution, magnetic field uniformity, reduction of leakage inductance, and thermal management with IW-HFT(PCB). The IW-HFT(PCB) design increased the maximum DC/DC output efficiency by 1.35% and full-load output efficiency by 1.33%. Moreover, peak voltage stress on power MOSFETs was reduced by up to 51.35%, while transformer temperature decreased by 3.9 degrees Celsius.