Electrical Requirement
Industry guidelines establish the specific procedures and acceptance criteria for verifying the electrical integrity of unpopulated printed circuit boards. The use of ipc-9252 continuity standards ensures that every trace on a finished board is free from shorts or opens before assembly begins. These rules define the test levels based on the complexity and end use of the product.
Manufacturers select a test class that matches the reliability needs of the consumer.
Testing Class
Rigor varies between general electronic products and high reliability life support systems. Under the ipc-9252 continuity standards, class three products require one hundred percent netlist testing to guarantee every connection is verified. Flying probe or bed of nails testers execute the physical measurements.
The standard also specifies the maximum allowable resistance for a valid connection.
Verification Step
Verification of the netlist against the original design files catches errors introduced during the engineering stage. Compliance with ipc-9252 continuity standards protects the assembly house from mounting expensive components on defective substrates. The documentation provides a record of the test voltage and the isolation resistance limits used during the check.
This process is a fundamental part of the quality management system for any fabricator. Failure to meet these requirements results in the immediate rejection of the batch.
