・ Iridium is rare metal and does not make any compound with other materials.
No oxide on surface. Affinity with pad material is very low.
→This is advantageous as non-abrasive cleaning gel is available in tip cleaning, which prolong probe life.
・ As Iridium has low resistivity and high melting point, high CCC is expected.
(It was observed that just after CCC limit, pin begun to melt according to current increase.)
・ In automated pins inserting, pin material is required to have high Elasticity and Yield Strength as pins are inserted to holes by vibration.
As Iridium has high Elasticity and High Yield Strength, it is most suitable to this purpose.
Comparison of Physical Properties in probe metal group
| Material | Resistivity μΩ ・㎝ |
Melting point ( ℃ ) |
Hardness (Vickers) |
Elasticity GPa |
Yield Strength (MPa) |
|
|---|---|---|---|---|---|---|
| Iridium | 5.1 | 2,466 | 600～700 | 388 | 2,080 | |
| Rhodium | 5.1 | 1,964 | 532 | 229 | 1,603 | |
| Rhenium Tungsten | 9.6 | 3,000 | 700～800 | 308 | 2,800 | |