In-circuit test fixtures test and verify the integrity of the power delivery paths to individual printed circuit board (PCB) components. This hardware-based solution takes sensitive measurements such as continuity, resistance, capacitance, inductance, and shorts/opens to pinpoint power delivery problems easily.
Power integrity measurements enable manufacturers to ensure each PCB is connected end-to-end and meets the required specifications. Sometimes called bed-of-nails test fixtures, In-Circuit test ( help prevent power interference.
Catching PCB Defects with In-Circuit Testing
The PCB Power Delivery Network (PDN) consists of Voltage Regulator Modules (VRMs), power planes, and decoupling capacitors. Proper bypassing and decoupling ensure the accuracy, consistency, and reliability of PCB design and assembly.
This type of testing is crucial for ensuring the PDN is not corrupted or incorrectly modified during assembly. The ICT test allows PCB manufacturers to confirm that their PCB production processes are complete, accurate, and high-quality.
In-circuit testing fixtures are used to do the following:
Validate Capacitor Placement
Testing enables PCB manufacturers to design an efficient power network with sufficient wiring and copper skin to meet power requirements better. Capacitor placement is tested, and design improvements are made as necessary.
Test Power Networks
ICT fixtures probe the PCB voltage levels, stability, and efficiency to ensure electrical integrity meets quality standards. These dedicated rigs simulate various load conditions to identify and expose electrical issues.
Solder Joint Inspection
Checking the quality of the solder joints can reveal problems with continuity, shorts, and resistance. While visual inspection can identify abnormal shape, cracks, and insufficiencies, only ICT fixture testing can assess solder penetration and bond quality.
Component Value
PCB assembly combines multiple components from various suppliers. The only way to test the compatibility of each component with the PCB is to run an ICT fixtures test, which flags misalignments, orientation problems, and missing parts.
Benefits of In-Circuit Testing
While functional testing probes the PCB under real-world operational conditions, ICT focuses on transmission and processing to expose assembly errors. It is recommended to use both fixtures side by side to ensure the PCB is assembled correctly.
High Fault Coverage
In-circuit test fixtures contribute to the overall efficiency of PCB assembly by detecting 80 to 90% of assembly defects. This quality check reliably detects problems during production for immediate feedback and fast rectification of errors.
Reducing Production Time
ICT testing can be incorporated into the assembly line, with testing conducted as the board moves. That way, defects and their root causes are caught, allowing the manufacturer to rework faster.
Mass Production
Catching defects faster and reliably makes assembly more efficient. ICT fixtures enable manufacturers to test thousands of boards automatically using a standardized quality check for high-volume PCB manufacturing.
Cost Effectiveness
The cost of a new fixture can be considerably high, depending on its complexities, features, and connectors. However, it’s a one-time investment that reduces faults and warranty claims and solidifies the brand’s association with quality.
Supporting Quality Standards
Reducing field failure by catching defects early can improve the bottom line. Most PCB applications have stringent quality demands. In-circuit testing helps manufacturers meet these strict standards by validating PCB assemblies.
ICT vs Functional Testing: How Do They Compare?
Functional testing probes everything from the power-up sequence, execution, processing, and performance. ICT testing probes the PCB at the component level for shorts, component placements, orientations, and values.
While functional testing is conducted at the end of the assembly, ICT testing can be done before the final assembly. Manufacturers often use both fixtures to assess the PCB at the component and system levels.
Conclusion
In-circuit test fixtures improve defect detection and production efficiency. ICT protects PCB design standards and enhances customer satisfaction, leading to success in a competitive marketplace.
We, at Microhub, design and manufacture high-precision testing fixtures geared to ensuring PCB performance and reliability. We provide alternative solutions to reduce assembly time, defect detection in production, and time-to-market. Explore custom solutions today!
