In a preferred implementation, a solder alloy consisting essentially of {HEAD ~ tin} 96.5% to silver 3.5% with a melting point of about 221° C. is used to attach disks 10 to {TAIL ~ AGA} 50 at solder joints 55 
In a preferred implementation , a solder alloy consisting essentially of { HEAD ~ tin } 96.5 % to silver 3.5 % with a melting point of about 221 ° C. is used to attach disks 10 to { TAIL ~ AGA } 50 at solder joints 55
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH