In-Circuit Test (ICT) Testing and System Manufacturers

In-Circuit Test (ICT) is a crucial method for testing printed circuit board (PCB) assemblies to identify manufacturing defects. It’s a comprehensive test that checks for faults in individual components like resistors, capacitors, and integrated circuits. ICT also detects opens, shorts, and other defects in the PCB’s conductive traces. Widely used in electronics manufacturing, ICT ensures the quality and reliability of PCB assemblies before they reach customers.

Let’s delve into the basics of In-Circuit Test (ICT) testing and explore ICT tester systems from leading vendors and manufacturers.

ICT Test System Components

Here are the common components you’ll typically find in an ICT tester system:

• Test Fixture: This is a specialized interface between the PCB assembly being tested and the ICT tester. It usually consists of a “bed of nails” or pogo pins that make contact with test points on the PCB. The fixture also includes circuitry for applying test signals and measuring the responses.

• ICT Tester Hardware: This is the main unit responsible for generating test signals, applying them to the PCB being tested, and measuring the responses. It includes analog and digital signal generators, voltage and current measurement circuits, and other necessary hardware.

• ICT Tester Software: The software controls the ICT tester hardware and interprets the test results. It generally includes a user interface for setting up tests, defining parameters, and analyzing results. The software may also provide features like fault diagnosis, reporting, and data logging.

• Test Probes and Accessories: Various probes and accessories are used with the ICT tester system for specific tests and measurements. These might include specialized probes for testing specific components, adapters for different PCB form factors, and other accessories to ensure proper contact and alignment during testing.

ICT Testing Process

• Test Program Development: Before starting ICT testing, a test program needs to be created. This involves developing a set of test procedures and instructions for the ICT tester. The test program specifies the tests to be performed, the conditions, and the expected responses.

• PCB Setup: The PCB assembly to be tested is placed in the test fixture, ensuring proper alignment and contact with the test probes. The fixture is designed to accommodate the specific form factor and layout of the PCB.

• Test Execution: The ICT tester applies test signals to the PCB assembly through the test probes and measures the responses. These tests typically check for opens, shorts, component values, and other electrical characteristics. The tester might also perform functional tests to verify the proper operation of specific circuits or features.

• Data Analysis: The ICT tester software analyzes the test results and compares them to the expected responses defined in the test program. Any discrepancies or failures are flagged as defects, and diagnostic information may be provided to help with troubleshooting and repair.

• Fault Diagnosis and Repair: If defects are detected, the PCB assembly may undergo further diagnosis to identify the root cause. Once identified, the faults can be repaired or rectified, either manually or through automated processes.

• Reporting and Documentation: After testing is complete, a report summarizing the test results, including any defects found and their locations, is generated. This report provides valuable feedback to the manufacturing process and can be used for quality assurance and customer documentation.

In-Circuit Test (ICT) System Manufacturers

Latest ICT test systems offer features such as:

• Boundary scan
• Automated probing
• Optical inspection
• Functional testing
• Programming

Beyond these factors, the selection of an ICT system depends on the type of product being tested.

Any product design should incorporate testability considerations. DFT (Design for Testability) adds specific testability features to the product’s design, making it easier to develop and apply manufacturing tests for the Device Under Test (DUT) hardware.

Here’s a list of ICT tester manufacturers:

Conclusion

Overall, ICT testing is an essential step in electronics manufacturing for ensuring the quality and reliability of PCB assemblies. By detecting defects early in the production process, ICT helps minimize scrap, rework, and field failures, ultimately improving product quality and customer satisfaction.