MVI (Manual Visual Inspection)
Manual Visual Inspection (MVI) is a traditional method used in SMT production to identify defects in digital circuits. It involves visually inspecting the circuit using tools like magnifiers or microscopes, along with manual testing tools like metal needles or bamboo toothpicks for QFP pins. Common issues detected include soldering defects and bridge connections in IC pins.
Despite its flexibility and basic nature, MVI is becoming less suitable for moderately complex PCBs due to its decreasing reliability and cost-effectiveness compared to newer inspection methods.
ICT (In-Circuit Test)
In-Circuit Test (ICT) is a contact-based testing approach widely utilized for diagnosing faults in production. It employs a specialized pin bed fixture that connects to the PCB, allowing spring probes to test components such as resistors, capacitors, and ICs individually. This method enables quick fault detection by verifying analog and digital components separately.
ICT is effective in detecting various manufacturing defects, including soldering issues (bridging, excess solder, pseudo soldering) and component problems (incorrect resistance, missing components, wrong polarity). The ICT system is fast, reliable, and continuously evolving with advancements in IC technology, offering enhanced integration and I/O capabilities. As chip integration levels rise, methods like boundary scan and non-vector detection are gaining wider adoption.
AXI (Automated X-Ray Inspection)
Automated X-Ray Inspection (AXI) is crucial for examining components like BGAs and CSPs, where solder joints are concealed beneath the package. During AXI, the PCB assembly is inspected by an X-ray machine, which generates an image by passing X-rays through the board, highlighting the solder joints for sensor detection.
AXI technology has progressed from 2D to 3D, enabling better inspection of double-sided PCBs and multilayer boards by isolating and imaging each layer. 3D AXI can identify defects in BGAs, multilayer PCBs, and through-hole solder joints, providing detailed inspection by analyzing each layer of the solder joint. This thorough evaluation enhances the overall quality and reliability of the PCB.
Expert PCB Services
For all your PCB and PCBA needs, look no further! Our team of professionals at Well Circuits is here to provide you with top-notch services and solutions.
If you have any inquiries or require assistance with your PCB or PCBA projects, do not hesitate to reach out to us at info@wellcircuits.com.
Stay ahead in the world of electronics with Well Circuits!
