Probe card (Probe card) is a test interface for wafer testing, consisting of a probe (probe pin), electronic components (component), wire (wire) and printed circuit board (PCB). Its main role is to test the bare core, i.e. wafer level test.

In the wafer test process, the object under test is placed on the probe table, and then the probes on the probe card are used to make direct contact with the solder pads or bumps on the chip. The chip signal generated by the lead-in tester (Atomic Test Equipment, ATE) is applied to the device under test, and the feedback signal from the device under test is transmitted back to the ATE, thus completing the entire test process. Through wafer testing, bad wafers can be screened out to avoid the flow of bad die into the packaging process, thus reducing the cost of chip manufacturing.

According to different application scenarios, probe cards can be divided into various types:

1. U-Probe: Probe card for storage device measurement The probe area of U-Probe is equal to the wafer size, so the probe can be placed anywhere on the wafer. It uses a crescent-shaped DUT layout to make the most efficient use of space and to fully utilize the tester's resources.The U-Probe is suitable for DRAM testing, and features a feature that reduces the number of touches required to test a wafer, and achieves uniform touches across the entire wafer to improve test yields. It also allows wafer-level probing using MEMS probe "microcantilevers" and thin-film multilayer technology. 2.

2. Vertical Probe Card: A probe card for multi-core testing of conventional logic products, including SoC and microcomputer products. Due to their short needle-like structure and vertical contact with the device, vertical types are best suited for measuring small pads and high frequency devices.

3. MEMS Probe Card: A probe card for logic devices, suitable for flip chip and fine pitch bump wafer testing of microprocessors and SoC devices. It is manufactured using vertical spring-type probes and MEMS technology, allowing for high precision and reliable testing. In addition, its structure allows replacement of single pins, reducing maintenance time.

4. SP Probe Card: Refers to a vertical spring-type probe card. SP-Probe for NAND flash is suitable for one-touch testing of 12-inch wafers. Its high pin pressure specification helps to achieve stable contact by making contact with the spacer under the oxide film, and also allows replacement of single pins for easy maintenance.

5. WLCSP Wafer Level Package Chip Test Probe Cards: Probe cards for test area array equipment. Probe tips are available in crown and flat sizes, and one can be selected according to the test environment. As the chip process is getting smaller and smaller, the foundry process is getting more and more advanced, and the test technology is also improving. The requirements for precision, yield, life, and consistency of probes are also getting higher and higher.