Just use chmod()
after your upload functions..
<?php
/*
* All your upload code here; then pass the filename
* to the chmod below
*/
chmod($uploadedFile, 0644);
?>
Official documentation:
http://php.net/manual/en/function.umask.php
states:
"It is better to change the file permissions with chmod() after creating the file."
The documentation refers to the umask php function, however, the same principle applies in general.