no conversions

if a company ads pay per impersion and your account has no conversions at all
is that aproblem ?

Of course, it's is a problem. Why would they pay you if there's no conversion?
However, if the advertiser is just trying to promote their brand and not an actual product then it's fine. But if it's CPA or sales related ads, your account will be reviewed for quality and actions will be taken. It really depends on what they need.