Probe card for testing power devices under high temperature and high voltage

A probe card for testing power devices under high temperature and high voltage, wherein the probe card is sequentially provided with an air inlet system, a PCB board, an switching layer, a guide plate and a probe from top to bottom;

• the bottom of the air inlet system is provided with a plurality of lower air outlets and side air outlets, the PCB board is provided with a first through-hole with the same position, shape and quantity as the lower air outlet, the switching layer is provided with a second through-hole with the same position, shape and quantity as the lower air outlet, the guide plate is provided with a third through-hole with the same position, shape and quantity as the lower air outlet;
• The lower air outlet, the first through-hole, the second through-hole and the third through-hole are coaxially arranged;
• The high-temperature and high-pressure gas ejected from the lower air outlet is blown between the guide plate and the tested wafer after successively passing through the first through-hole, the second through-hole and the third through-hole;
• the air inlet system also comprises a pressure-relief hole, and the pressure-relief hole is tapped with threads on the inner wall, and it's screwed with an adjusting part, and the adjusting part includes a contact end with a T-shaped section and a through-hole in the middle, an annular magnet and an fixed end of the upper magnet, and the wide side wall of the contact end is sleeved with threads for screwing on the inner wall of the pressure-relief hole, the narrow part is provided with an annular magnet, and the narrow side wall is sleeved with threads, and the inner wall of the fixed end of the upper magnet is tapped with threads for screwing on the narrow side wall of the contact end, and the bottom of the wide part of the contact end and the upper part of the fixed end of the upper magnet fix the annular magnet;
• the pressure-relief hole is also screwed with a valve part on the inner wall, and the valve part comprises a connector with an inverted T-shaped section and a stepped through-hole, which is narrow at the top and wide at the bottom, and the narrow side wall of the connector is sleeved with threads for screwing on the inner wall of the pressure-relief hole, and a circular magnet is placed at the wide part of the stepped through-hole, and the circular magnet is stuck with a sealing gasket on the top and equipped with a notch on the side wall and a notch at the bottom, and the notch on the side wall is connected with the notch at the bottom, and the wide inner wall of the stepped through-hole is tapped with threads, and is screwed with a shielding ring with a through-hole in the middle, and the circular magnet can move up and down above the shielding ring under the attraction of the annular magnet and the push of the compressed air;
• the function of each structure is as follows:
• the thickness of the edge of the guide plate is greater than that of the central area;
• the air inlet system is used to provide high-temperature and high-pressure gas and normal temperature and high-pressure gas, the lower air outlet is used to inject high-temperature and high-pressure gas to the probe, and the side air outlet is used to provide normal temperature and high-pressure gas to the PCB board;
• the PCB board is used for connecting the testing machine and the signal wiring;
• the switching layer is the medium between the probe and the PCB board, which is used to realize the signal distance conversion;
• the guide plate is used for accommodating the probe;
• the probe is used for connecting the tested wafer.