Discrete device inspection equipment is mainly divided into three categories: wafer-level inspection, pre-packaging semi-finished product inspection, and post-packaging finished product inspection. Together they cover the full quality control flow from wafer processing to final shipment.
I. Wafer-Level Inspection Equipment
A. Wafer Electrical Probing Systems
The core setup combines a probe station with a semiconductor parameter analyzer to perform electrical spot checks on individual discrete device dies on the wafer. Key parameters such as forward voltage drop, reverse leakage current, and breakdown voltage are measured to screen out defective dies and control wafer yield.
For power discrete devices such as IGBTs and MOSFETs, thermal probe stations can be added to test the thermal resistance characteristics of the die.
B. Wafer Appearance and Defect Inspection Equipment
Automatic optical inspection (AOI) equipment uses high-resolution imaging to identify scratches, contamination, pattern shift, lithography defects, and other surface anomalies on the wafer.
Laser scanning inspection equipment is used to measure wafer thickness, warpage, and microscopic surface defects.
II. Pre-Packaging Semi-Finished Product Inspection Equipment
A. Bare Die Inspection Equipment
Die appearance AOI equipment detects edge chipping, contamination, cracks, and other visual defects on singulated bare dies.
Die bond strength testers measure the pull and shear force of wire bonds or pad connections, verifying the reliability of the bonding process.
B. Leadframe and Substrate Inspection Equipment
Lead coplanarity inspection systems use image measurement to confirm leadframe lead flatness, preventing bent or misaligned leads after packaging.
Leadframe appearance inspection equipment identifies oxidation, deformation, burrs, and similar defects.
III. Post-Packaging Finished Product Inspection Equipment
A. Electrical Performance Test Equipment
Automatic test equipment (ATE) for discrete devices covers diodes, transistors, MOSFETs, IGBTs, and other types. It automatically performs full-parameter testing including forward voltage drop, reverse leakage current, breakdown voltage, and switching characteristics. For IGBTs, short-circuit withstand test modules can also be added.
Withstand voltage testers (HiPot) and insulation resistance testers check insulation performance and voltage endurance, preventing leakage risks.
B. Appearance and Dimensional Inspection Equipment
Package appearance AOI equipment identifies package cracks, molding flash, lead deformation, and unclear markings.
Coordinate measuring machines (CMMs) or vision-based dimensional systems inspect package outline dimensions, lead pitch, and lead height to ensure compliance with packaging standards.
C. Reliability Inspection Equipment
High-temperature operating life (HTOL) chambers and highly accelerated stress test (HAST) chambers simulate long-term reliability performance under high-temperature and high-humidity conditions.
Lead pull testers and shear testers verify the bonding strength between package leads and internal structures.
Helium mass spectrometer leak detectors check the sealing integrity of plastic-encapsulated discrete devices, preventing moisture ingress that could cause device failure.
D. Marking and Packaging Inspection Equipment
Barcode/QR code scanning and verification equipment confirms marking correctness and readability.
Package appearance inspection equipment detects packaging damage, label misalignment, and other issues.
For precision probe holders, test fixtures, alignment jigs, and vacuum chucks used in the above inspection stages, Hansheng Automation provides custom machining based on customer drawings, supporting single-piece or small-batch delivery.
