Patent ID: 8872035

Claim:
A hermetic feedthrough for an implantable medical device, comprising: a sheet having a hole, wherein the sheet comprises a first material that is a ceramic comprising alumina; and a second material substantially filling the hole, wherein the second material comprises a platinum powder mixture and an alumina additive, wherein the platinum powder mixture comprises a first platinum powder having a median particle size of between approximately 3 and 10 micrometers and a second platinum powder that is coarser than the first platinum powder and has a median particle size of between approximately 5 and 20 micrometers; wherein the platinum powder mixture comprises between approximately 50 and 80 percent by weight of the first platinum powder and between approximately 20 and 50 percent by weight of the second platinum powder; wherein the first and second materials have a co-fired bond therebetween that hermetically seals the hole.