Semiconductor Testing

I. Definition of Semiconductor Testing

Traditional semiconductor testing is conducted via ATE systems, mainly including CP wafer probing test and FT final test after packaging. With the prevalence of wafer-level packaging, some chips can be diced and delivered after CP testing only.

Chip testing relies heavily on DFT design for higher fault detection efficiency. As chips grow more sophisticated in hardware and software, conventional testing falls short. SLT system-level testing is widely adopted to supplement FT coverage and lower chip defect rates.

II. Necessity of Semiconductor Testing

1、Manufacturing process deviations

Chip design can be verified error-free via simulation, UVM and FPGA verification, yet numerous wafer fabrication steps easily cause circuit and parameter abnormalities.

2、Defect rate control in mass production

Both mature and advanced processes have limited yield rates. End-product yield is affected by individual chip quality. Strict testing ensures compliance with DPM standards and stable mass production.

3、Optimization of design and manufacturing

Test data accurately locates wafer defects, facilitating iterative improvement of wafer fabrication and chip design to reduce root-cause flaws.

4、Simplified burn-in screening

Short-duration high-stress ATE testing quickly screens early failed chips, replacing time-consuming high-temperature burn-in and boosting delivery efficiency.

5、Industry reliability certification

Chips must pass JEDEC-standard reliability tests including ESD, temperature cycling, humidity and lifespan tests. Standardized ATE testing verifies performance for compliance.

III. Core Testing Procedures

Customized processes are formulated based on application scenarios, operating temperature and safety grades.

1、Automotive-grade chips: Ultra-high safety requirements with multi-round and multi-temperature zone full-range testing to pursue zero defects.

2、Consumer electronic chips: Cost-oriented streamlined testing to keep defect rates within acceptable limits.

Testing procedures directly affect production costs. The industry aims to simplify testing items and adjust criteria to balance cost and quality control.

IV. Focus of Tests at Different Stages

1.Wafer CP Test: Performed via probe cards, suitable for mid-to-low frequency tests. It eliminates defective wafers in advance to cut packaging costs.

2.Packaged FT Test: Covers full functional verification, analog parameter calibration and fuse programming.

3.SLT System-Level Test: Runs under real application scenarios to detect hidden faults missed by DFT-based tests. Due to high costs and poor fault positioning capability, the industry is optimizing ATE solutions to reduce or phase out SLT.