Is SQL Server installation case sensitive or not?

>I have an update command like this:
>
>

>UPDATE EmailTemplate SET Subject_E=CAST(REPLACE(CAST(UPPER(Subject_E) AS NVarchar(MAX)),'[OldMemberTableName]','[Member]') AS NText)
>

>
>This works but it is case sensitive.
>
>If "OldMemberTableName" is like "OLDMEMBERTABLENAME", it will not be replaced.
>
>I tried inserting UPPER( syntax in there but it never replaces it properly.
>
>How can I make such command case insensitive?