Flexural Endurance Test after Flexible Circuit Manufacturing
GE Research has developed a version of the flexural endurance test based on the IPC standard. Added features to the tester include:
Automated resistivity monitor with threshold
Multiple circuit load (4–up)
Pogo-pin quick connection
Variable-speed motor
Fine-pitch pattern (25mm traces)
Automated data logger
GE Research has also developed a number of TEG monitor cells that are assembled as blocks in a library for use on multiple platforms (RF, DC, analog, PWB, thin core, silicon, etc). The TEG blocks can be assembled in the field area of the panel to aid in process monitoring, second-level assembly, and reliability screening. GE Research has also developed specific tooling to aid in the characterization of thin-core flexible interconnect materials.
Examples of the tools include elongation test stands, flexural endurance systems, and automated electrical testing platforms. The TEG monitors are regularly used in healthcare, military, and commercial flex circuit Manufacturing. These monitors are often used as screening tools for vendor capability demonstrations. Electrical performance, and the corresponding electrical functional testing, is also a critical aspect in flexible printed circuits. Procedures for functional testing are application–specific, but generally, basic function including impedance characterization is tested. Often, users overlook characterization of surface isolation resistance because its adverse impact on electrical performance in low-signal amplitude (microvolts, microamps) applications is not considered or because of the difficulties in obtaining valid data at low-signal amplitudes, especially in the environments required for isolation resistance testing.