As with the insulation layer 30 (FIG. 1C), the electrical insulation layers 46, 47 and 48 (FIG. 1C) can comprise an electrically insulating material, such as a glass (e.g., borophosphosilicate glass), a polymer (e.g., polyimide, polydimethylsiloxane (PMS)), or an oxide (e.g., SiO2).