Do test equipment sorters in the semiconductor industry require compressed air?

The core role of the sorter in chip testing

In the back-end testing stage of semiconductor manufacturing, the sort‑and‑test machine is a critical automated piece of equipment that interfaces between the die and the test handler. Its primary function is to precisely convey the dies under test into the test sockets; after electrical performance testing is completed, it sorts and collects the dies based on the test results. To ensure efficient and accurate loading and unloading, the sort‑and‑test machine incorporates sophisticated mechanical and pneumatic systems.

Key Applications of Compressed Air in Classifiers

As for whether a sorting machine requires compressed air, the answer is yes. Compressed air plays an indispensable role in the operation of the sorting machine, with specific applications including the following aspects:

• Pneumatic Actuation and DriveMany cylinders, pneumatic grippers, and valves inside the equipment rely on compressed air to power operations such as pushing and pulling material tubes, positioning pallets, and rapidly translating mechanical components.
• Vacuum Suction System: The pick-and-place robotic arms of sorting machines typically generate a vacuum using compressed air via the Venturi effect, enabling them to safely and reliably pick up tiny chips.
• Cleaning and PurgingBefore the chip is pressed into the test socket, the equipment injects high-pressure clean air to blow away even the tiniest dust particles from both the socket contacts and the chip’s surface, ensuring reliable test contact and preventing misjudgments caused by poor connectivity.
• Temperature Control AssistIn temperature‑controlled sorters that require high‑ and low‑temperature testing, compressed air is often used to facilitate airflow circulation or to actuate pneumatic proportional valves in the cooling and heating systems, thereby maintaining temperature stability within the test environment.

Stringent requirements for compressed air quality and stability

Although sorting machines require substantial compressed air, ordinary factory air supplies cannot be used directly. The chip‑testing environment imposes extremely stringent requirements on air‑quality standards:

• Extremely high cleanlinessIf the air contains fine particulates, they may clog precision micro‑pneumatic valves or contaminate test sockets; therefore, multi‑stage precision filtration is essential.
• Strict dryness: Moisture ingress into the pneumatic system can cause component corrosion, seal degradation, and even ice formation that blocks piping during low-temperature testing. Therefore, the dew point of compressed air must be maintained at an extremely low level.
• An absolutely oil-free environment: Oil‑gas mixtures can severely contaminate the chip surface and test contacts; therefore, an oil‑free air compressor must be used, or a high‑efficiency oil‑removal filter should be installed at the air‑source inlet.
• Pressure stability: Pressure fluctuations can cause deformation of the robotic arm’s movements or result in suction failure; therefore, the air supply system must be equipped with precision pressure regulators and an air storage tank to maintain constant air pressure.

Daily Maintenance and Management of the Gas Supply System

To ensure the stable operation of the sorting machine and maintain high test yields, the plant’s facilities department must perform regular maintenance on the compressed air system. This includes periodically replacing filter elements at each stage, draining condensate from the air receiver tanks and the bottoms of the filters, and using a dew‑point meter and a particle counter to routinely monitor air‑source quality. Only by supplying high‑quality, clean, dry air can the sorting machine’s performance be optimized and chip testing proceed smoothly.