Composite interface substrate for a probe card and methods for forming and operating the same

A test apparatus comprising a probe assembly, the probe assembly comprising:

• a composite interface substrate comprising a bonded stack of a proximal interface substrate and a distal interface substrate, wherein the proximal interface substrate comprises first metal interconnect structures embedded in first dielectric material layers having a first Vickers hardness and further comprises probe contact pads, and wherein the distal interface substrate comprises second metal interconnect structures embedded in a high-hardness dielectric layer having a second Vickers hardness that is greater than the first Vickers hardness;
• a printed circuit board that is attached to the distal interface substrate;
• and
• an array of probe needles attached to the probe contact pads and vertically extending downward from the probe contact pads.

A method manufacturing a test apparatus, comprising:

• providing a proximal interface substrate comprising first metal interconnect structures embedded in first dielectric material layers and further comprising probe contact pads;
• providing a distal interface substrate comprising second metal interconnect structures embedded in a high-hardness dielectric layer having a Vickers hardness greater than 500 HV;
• and
• bonding the distal interface substrate to the proximal interface substrate such that the second metal interconnect structures are electrically connected to the first metal interconnect structures.