Custom Fields Orders adding Array

Dears,

Is it possible to include as Custom Order Fields value an Array?
I tried the following code and the variable was never added to Orders Backend, while it was added correctly to DB (even get_post_meta was ok).

$envios = array (
                 [0] => '990083935372'
                 [1] => 'correos'
                 [2] => 'something...correoschile_etiquetas/990083935372.pdf'
               );
update_post_meta( $order_id, 'tiene_envio',  $envios );

Then I tried to include other value like:
update_post_meta( $order_id, 'cualquier_cosa', 'jajajaj' );

And it worked just right on Order backend. So my only guess is it not possible to add arrays as Customs Order value, is that right?

Best regards,

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