PCB Online Testing Strategies
Online testing is a crucial step in detecting manufacturing defects in printed circuit board assemblies. By utilizing a bed of needle fixtures, each node on the circuit board can be tested individually for performance consistency and defect analysis. Here are some key strategies for effective online testing:
1. Test Point Placement
- Ensure that each signal to be tested has designated pads or test points throughout the PCB.
- Place test points on a grid pattern to allow for probe testing on both sides of the board.
- Consider using special detection points for critical signals if testing every signal is not feasible.
2. Fault Isolation
- Address common faults like short-circuits among component pins and outer conductors during the design phase.
- Implement additional test vectors or alternative techniques for isolating faults in specific components or groups.
3. Functional Design Considerations
- Separate tests for different functions at a physical level to enhance test efficiency.
- Group test connectors or ferrules within connectors to improve circuit testability.
- Use a mix of digital and high-performance simulation signals may require multiple test instruments.
By incorporating these strategies into your online testing plan, you can ensure the reliability and performance of your printed circuit board assemblies. Effective test point placement, fault isolation techniques, and functional design considerations are essential for a successful online testing process.
