Leak rate ：：≤1×10 -9 Pam 3 /s
Flatness of copper surface：≤0.008mm
Parallelism between copper surfaces：    ≤0.03mm
Concentricity between flange and copper：≤0.5mm
Pull test：≥5KN/cm 2
Temperature cycling：-65℃～200℃ ５circles
Plating thickness：2-7μ

Ceramic：93.5%min AL 2 O 3
Glaze：Color white ,T ≥14 0℃
Flange：TU1(OFHC·Cu)or Ni42Fe58 Alloy
Copper contact：TU1(OFHC·Cu)
Solder：Ag72Cu28 Alloy
Gate tube：TU1(OFHC·Cu)or Ni42Fe58 Alloy