In the manufacturing processes of electronic boards (PCBA), it is essential to ensure that the products are electrically correct and functionally operational. For this, two main types of tests are used: In-Circuit Test (ICT) and Functional Test (FT). Each has a distinct and complementary technical purpose, acting at different moments in the quality chain.
ICT ensures that the board is assembled correctly. FT ensures that it works as it should.
🧪 What is In-Circuit Test (ICT)?
The In-Circuit Test (ICT) is a hardware test, performed directly on the assembled electronic board, to check for assembly defects, component values, and positioning.
✅ ICT detects:
- Short circuits and broken traces
- Missing, swapped, or out-of-value components
- Incorrect polarity (diodes, capacitors, LEDs, ICs)
- Resistors, capacitors, and transistors out of specification
- Presence of cold solder or poor contact
- Integrated circuits (via Boundary Scan or stimulation techniques)
🛠️ How it is done:
- Uses a fixture with test needles (pogo pins) that touch the PCB pads
- Specialized equipment (e.g., Keysight, Teradyne, or custom-made)
- Fast, automated, and traceable test
🔌 What is Functional Test (FT)?
The Functional Test is performed after the ICT, with the board already powered and often connected to peripherals. Its goal is to verify if the board works as expected, simulating its final use.
✅ FT validates:
- Serial communication (UART, I2C, CAN, USB, RS-485…)
- Operation of relays, LEDs, motors, and user interfaces
- Sensor readings (voltage, current, temperature, pressure…)
- Digital responses, PWM signals, boot time, firmware, logic
- Firmware updates or parameterizations
🛠️ How it is done:
- Uses an automated test bench, with measurement instruments (multimeters, power supplies, oscilloscopes, generators, cameras, etc.)
- Custom-developed with TestStand, LabVIEW, C#, Arduino
- Allows for deep diagnostics and customized tests
📊 Technical Comparison: ICT vs FT
| Criterion | ICT | Functional Test (FT) |
|---|---|---|
| Type of test | Passive electrical | Functional with powered board |
| When applied | After assembly (pre-power) | After system power-up and initialization |
| Execution time | Fast (10 to 60 seconds) | Variable (30 s to several minutes) |
| Required tooling | Fixture with needles | Custom interface (jig + instruments) |
| Detects assembly faults | Yes | No |
| Verifies real behavior | No | Yes |
| Cause diagnosis | Precise (assembly) | Complete (assembly, firmware, logic) |
🤝 How AJOLLY Testing applies ICT and FT
AJOLLY Testing offers complete and integrated solutions for both types of tests:
- Design of ICT jigs compatible with Ingun, Feinmetall, etc.
- Development of FT benches with modular hardware and custom software
- Integration with MES, ERPs, and traceability systems by serial number
- Support for repeatability tests, silver units, and Pareto analysis
👉We develop solutions that integrate In-Circuit Test (ICT) and Functional Test (FT) into a single tester, optimizing cycle time and reducing the need for operators on the production line.
The secret to quality lies in the balance between ICT and FT — and AJOLLY Testing helps you master both with precision and reliability.