Eliminate using Main/LaunchScreen storyboard

I am installing my app and have set my Launch Screen file as Main/LaunchScreen.Storyboard, it tries to open LaunchScreen/Main storyboard, but I don't want to use Main/LaunchScreen.Storyboard at all just want to start viewcontroller directly, but even if I set Launch Screen file as blank, it doesn't go to the first view controller, app opens with the black screen and starts the first viewcontroller after 7-8 seconds. I am not too sure what I did wrong, if I have changed any project settings accidently or should set Launch Screen file as something else, Please help me out to fix this. Appreciate your help.