To become en relación con un adjectivo describe un cambio. La traducción al español debe hacerse con uno de estos verbos que describen cambios (volverse, ponerse, convertirse, hacerse, llegar a ser etc.) o con un verbo específico, que describe un determinado tipo de cambio.

to become ...
apparent resultar obvio It became apparent that we could not help him.
anxious ponerse nervioso He became anxious, because she did not call him.
aware (of) enterarse We became aware of this problem only yesterday.
bankrupt declararse en quiebra They became bankrupt due to the bad management.
fond (of) tener cariño a alguien They became very fond of each other.
indispensable hacerse indispensable He worked so hard, he became indispensable.
liable ser responsable At the age of 18, people become liable for their action.
popular hacerse popular With his music, he became very popular.
redundant sobrar I wanted to avoid becoming redundant in the company.
sober desembriagar Very slowly, he became sober after a week of drinking.
successful tener éxito Thanks to hard work, he finally became successful.
upset ponerse acalorado I became upset when I heard the news.
valid ser válido The contract became valid last year.
visible ser obvio The tree became visible in the fog.
void ser inválido With this declaration, the old agreement becomes void.
worthless perder el valor The stone became worthless to her.