Group by where all subrows fullfill the requeriments

Hello,

I have this select

                      select c.obra, sum(d.importe)
      from d_albven d inner join c_albven c
                     on d.numero=c.numero and d.empresa=c.empresa
      where d.familia<>'HO' and c.factura is not null
      group by c.obra
      having min(fecha_fac)>=@dateini and min(fecha_fac)>=@datafi

But I want better select to extract only the c.obra where all the factura is not null, if there is a row where the factura is null then the c.obra doesn't must apper.

Best regards,