Select to List data from another table

I have a system from which I register the personal data enc_dados_pessoais and another table that stores complementary data enc_dados_complementares .

In the personal data table, the user registers only the basic information and clicking next , goes to the complementary data. I need to list only the users who did not finalize the supplementary data.

The primary key of the enc_dados_pessoais table is IdUsuarios and the foreign key of the enc_dados_complementares table is IdUsuarios . So I did it this way:

SELECT * FROM enc_dados_principais princ LEFT JOIN enc_dados_complementares
comp ON princ.IdUsuarios <> comp.IdUsuarios;

But it is not returning those who did not fill, only those who filled in the supplementary data.

I have already tried to use INNER JOIN , RIGHT JOIN and JOIN , but it also did not work.