Microstrip antenna design on substrate of 10 mil (0.258mm) and 5 mil (0.168mm)

For designing wideband vivaldi antenna a thin substrate is more preferable,
A 5 mil sound like very thin material... is there anyone who work on 5 mil substrate, please share your experiance.

Can we make a microstrip antenna over a 5mil or 10 mil substrate,
will it be strong enought to stand alone ?

Thank you

Very thin microwave substrates often glued to main FR4 board which solves problem. Thick substrate may be perforated at Vivaldi end with multiple holes or maybe cutout. There are many papers on antenna recently. How wide is your bandwidth requirement? Microstrip magneto-electric dipoles give pretty wide bandwidth with a smaller pcb area and easier for building 2d arrays.