A glass to {HEAD ~ metal seal} is formed between {TAIL ~ the insulative preform} 12 and the metal package 14 at the aperture 16 to provide a hermetically sealed package 
is formed between
A glass to { HEAD ~ metal seal } is formed between { TAIL ~ the insulative preform } 12 and the metal package 14 at the aperture 16 to provide a hermetically sealed package
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH