Fox EMS's Multi-Stage PCBA Quality Control Process for Reliability Tesing and Validation

https://cdn.pcbdirectory.com/news/1774260235922_639098570359367581.webp712370

Fox EMS, an electronics manufacturing services provider specializing in PCB assembly, testing, and quality control for high-reliability applications, outlines its PCBA quality control process, covering inspection and testing stages applied throughout production and at final validation to ensure boards meet IPC Class 2, Class 3, or MIL-SPEC standards. During production, Fox EMS monitors and validates every stage through closed-loop systems to ensure boards follow required specifications. At the end of manufacturing, PCBAs are assessed using Automated Optical Inspection (AOI), ICT/FCT, and visual checks, along with additional customized quality controls based on application needs.

Fox EMS begins with First Article Inspection (FAI), where the first assembled board of each batch is inspected and tested. The board is checked after every production step, and measurements are conducted to confirm the value of passive components, as well as the placement and part numbers of all BOM items.

Automated Optical Inspection (AOI) is used by Fox EMS to detect assembly errors. The system uses arrays of colored LEDs and high-resolution cameras to analyze reflected light from solder joints. Image processing identifies missing or misplaced components, soldering short circuits, disconnected components, and misalignment. This process is applied to all boards delivered by the company.

Solder Paste Inspection (SPI) is conducted by Fox EMS after solder paste printing and before pick-and-place operations. It inspects solder paste deposits on SMD pads, addressing defects that originate from improper solder paste printing.

For assemblies using BGA, QFN, or other leadless components, Fox EMS applies Automated X-ray Inspection (AXI). X-rays penetrate IC packages and reflect on dense metal connections, enabling detection of missing solder joints and component misalignment.

Fox EMS performs Functional Testing (FCT) using customized test fixtures that power the board, measure data from test points, and simulate operating conditions. The company works with clients to implement, adapt, or optimize testing methods for production.

In-Circuit Testing (ICT) at Fox EMS evaluates individual components on the board. Measured values are compared with circuit schematics, and boards are checked for short and open circuits. Testing is carried out using flying probes for small volumes or customized fixtures for mass production.

Fox EMS also conducts anechoic chamber testing for boards used in applications such as radar systems, antennas, and sensors. The chamber provides a controlled, interference-free environment for accurate and repeatable testing, particularly for military, aerospace, and communication applications.

Additional quality checks at Fox EMS include Burn-In Testing (BIT), high-voltage testing, thermo-cycling, and vibration testing, depending on application requirements.

Click here to learn more about the PCBA quality control approach by Fox EMS.