CTI-4 Leakage Tracking Tester by Kaige

Overview

The CTI-4 Leakage Tracking Tester is a fully automated, precision-engineered instrument designed for evaluating the surface resistance of solid insulating materials under combined electrical stress and conductive contamination. Based on the established principles of comparative and proof tracking index determination, the system applies a controlled DC or AC voltage across standardized platinum electrodes (2 mm × 5 mm) mounted on the specimen surface, while delivering precisely metered droplets (0.1% ammonium chloride solution) from a fixed height of 35 mm at 30-second intervals. The test quantifies the material’s ability to resist the formation of conductive carbonized tracks—a failure mode initiated by localized dry-band arcing, electrolytic decomposition, and thermal degradation. This electrochemical–thermal degradation process is governed by IEC 60112:2003, which defines the methodology for determining both the Comparative Tracking Index (CTI) and Proof Tracking Index (PTI). As a certified test platform compliant with UL 746A, ASTM D3638-92, and DIN EN 60112/VDE 0303-1, the CTI-4 supports rigorous qualification of polymeric insulators, encapsulants, PCB substrates, and molded semiconductor packaging components used in high-reliability power electronics and automotive applications.

Key Features

• Fully automated test sequence—including voltage ramping, droplet dispensing, real-time current monitoring, arc detection, and pass/fail evaluation—minimizing operator intervention and inter-laboratory variability.
• High-stability voltage source with programmable output up to 600 V DC/AC (50/60 Hz), calibrated traceably to national standards and equipped with overcurrent and short-circuit protection.
• Gravity-fed, non-contact droplet delivery system ensuring consistent 0.05 mL ± 0.005 mL droplet volume per IEC 60112 requirements; no pump-induced pulsation or cross-contamination risk.
• Integrated digital current sensing (0.1 mA resolution) and time-synchronized event logging to capture onset of leakage current spikes, sustained arcing (>2 s), or complete breakdown.
• Electrode alignment fixture with micrometer-adjustable horizontal/vertical positioning and quick-release mechanism for repeatable 2 mm electrode spacing and 5 mm contact length.
• Corrosion-resistant stainless steel test chamber with transparent polycarbonate viewing window, ventilation port, and integrated fume extraction interface for safe handling of NH₄Cl aerosols.

Sample Compatibility & Compliance

The CTI-4 accommodates flat, rigid specimens measuring 100 mm × 100 mm × 3–10 mm (thickness), including thermoset epoxies, silicone gels, PBT, LCP, and molded PA66-GF30 used in semiconductor leadframes, IC sockets, and power module housings. Specimen mounting conforms to IEC 60112 Annex A requirements for surface flatness (<0.1 mm deviation) and edge clearance (≥10 mm from electrode ends). All test protocols are pre-configured to enforce strict adherence to standard-defined KA (number-of-droplets-to-failure at fixed voltage) and KB (voltage step-down testing until 50-droplet survival) methods. Full audit trail generation—including operator ID, environmental conditions (temperature/humidity logged via optional external sensor), calibration certificate references, and raw time-current-droplet data—supports GLP and ISO/IEC 17025 laboratory accreditation. Data integrity complies with FDA 21 CFR Part 11 requirements when paired with validated software modules.

Software & Data Management

The CTI-4 operates under Kaige’s TrackControl v3.2 software suite, deployed on a dedicated industrial PC with Windows 10 IoT Enterprise. The interface provides real-time visualization of voltage, leakage current waveform, droplet counter, and elapsed test time. Test templates are locked to specific standards (e.g., “IEC 60112_KA”, “UL 746A_PT1”) to prevent parameter drift. All measurement data—including CTI/PTI calculation logs, image snapshots of track morphology (via optional USB microscope integration), and electronic signatures—are stored in encrypted SQLite databases with SHA-256 hash verification. Export formats include PDF test reports (with embedded digital signature), CSV raw data, and XML for LIMS integration. Software validation documentation (IQ/OQ/PQ protocols) is provided for regulated environments.

Applications

• Qualification of molding compounds and underfill materials for advanced packaging (e.g., Fan-Out Wafer-Level Packaging, SiP).
• Comparative assessment of halogen-free flame-retardant systems in PCB laminates and connector housings.
• Lot-release testing of encapsulants for high-voltage SiC and GaN power modules operating above 600 V.
• Failure analysis support—correlating CTI degradation with moisture absorption, ion migration, or thermal aging exposure per JEDEC JESD22-A121.
• Supplier qualification audits requiring third-party traceable CTI data aligned with automotive OEM specifications (e.g., VW TL 50000, GMW15635).

FAQ

What standards does the CTI-4 fully support out-of-the-box?
IEC 60112:2003, UL 746A, ASTM D3638-92, DIN EN 60112, and VDE 0303-1—all implemented as pre-validated test methods within TrackControl software.

Can the CTI-4 be used for PTI determination per IEC 60112 Clause 9.2?
Yes—the instrument executes the stepwise voltage reduction protocol (KB method) automatically, recording the lowest voltage at which the specimen withstands 50 droplets without tracking.

Is calibration certification included with shipment?
Each unit ships with a factory calibration certificate (traceable to PTB, Germany) covering voltage output, droplet volume accuracy, and timing interval compliance—valid for 12 months.

Does the system meet electromagnetic compatibility (EMC) requirements for lab use?
Yes—CE-marked per EN 61326-1:2013 (industrial environment) and tested to EN 61000-4-2/3/4/6 immunity limits.

How is electrode maintenance performed between tests?
Platinum electrodes are cleaned ultrasonically in isopropanol after every five tests; wear inspection and replacement are guided by built-in electrode life counter and visual reference charts supplied in the operation manual.