testing circuits

Wafer Probe Stations are proven tools for testing circuits and devices on silicon wafers, bare wafers and open microchips.

Probe stations allow the user to place electronic, optical or RF probes on a device and then test the device's response to an external stimulus (electronic, optical or RF). These tests can be as simple as continuity or isolation checks or more complex, including full-featured testing of complex microcircuits.

Probe stations can run tests on wafers or after being sawn into individual chips.wafer testing Wafer-level testing allows manufacturers to test devices multiple times at different stages of the manufacturing process and to closely monitor the manufacturing process for any defects. Testing individual chips before final packaging eliminates defective devices from the cycle and ensures that only functional devices are packaged. Probes are used throughout R&D, product development and failure analysis, and engineers need flexible and accurate tools to perform a range of tests in different areas of the device.

What makes a good probe bench different and adds value to your testing is the ability to precisely control the position of these probes on the device,wafer probe the mode of application of external stimuli, and the ambient conditions around the device while the test is in progress.

The Probe Station consists of six basic functional components:

A device to hold the chip in place without damaging it.

-Load table-Used to position the chuck in x, y, z, and Theta (θ).

Manipulator - Used to place the probe on the test equipment (Dut).

-Pressure Plate - Used to secure the manipulator and bring the probe into contact with the equipment.

- Probe Tip and Arm - Mounted on the manipulator, they can pass directly through the contact network equipment.

- Optics - Used for viewing and magnifying the device under test and the probe and tip.

How does it work?

The probe stage holds the wafer or chip on a chuck mounted on a platform that allows the DUT to be centered in the microscope field of view.

The manipulator is placed on the flat surface of the stage and the probe arm and tip are inserted into the manipulator. The probe tip must fit the test program to be performed. The user then positions the probe tip in precisely the correct position within the device by adjusting the appropriate manipulator. The probe is then brought into contact with the wafer by lowering the pressure plate; the device can now be tested.probe holder For wafers with multiple devices, after testing the first device, the plate can be raised and the platform supporting the wafer moved to the next device. The process of positioning the probe tip is repeated until all necessary devices have been tested. Both can be done manually by the operator, but if the stage and manipulator are motorized and the microscope is connected to a computer vision system, the process can become semi- or fully automated. This increases the productivity and throughput of the probe station and reduces the labor required to run multiple tests.


Related Hot Topic

What steps are included in chip testing?

An overview of the testing of chips. There are two phases to the Chip test. One is the Wafer test, often known as the CP (Chip Probing) test. The chip is tested in the other process, called the Final Test (FT), prior to packaging.