Mid Loss Laminate Selection Criteria for High Speed Circuits
Mid-loss laminates optimize high-speed signal reach between 5 and 28 Gbps by controlling dielectric loss without imposing low-loss fluoropolymer costs.
TDR Coupon Testing
Impedance Verification
Quality assurance methods use step pulses to measure the characteristic impedance of traces on a sacrificial portion of the panel. Performing tdr coupon testing confirms that the fabrication process met the design requirements for signal integrity. This procedure identifies boards that would otherwise fail in high-speed operation due to manufacturing drift.
Test Architecture
A coupon is a small circuit board manufactured on the same panel as the main product to ensure it undergoes identical processing. It contains transmission lines of specific widths and lengths that represent the most sensitive signals on the board. The testing equipment applies a fast-rise time step and records the reflections caused by impedance discontinuities.
By analyzing the time and amplitude of these reflections, the system calculates the impedance at every point along the trace. This spatial resolution allows technicians to distinguish between problems in the trace itself and issues at the connector interface.
Process Feedback
Results from these tests provide immediate data to the production line regarding the accuracy of the etching and lamination steps. If the impedance falls outside the allowable tolerance, the panel is rejected. Statistical analysis of the test data helps in adjusting the chemical baths and press cycles for future batches.
This rigorous verification ensures that every shipped board maintains the signal quality necessary for modern electronics.