Calculating Landed Cost Crossover between Flying Probe and Fixture Tooling
Landed cost crossover balances fixture NRE against probe runtime fees, shifting financial advantage to fixtures once batch volume savings offset tooling costs.
Layout Revision Frequency
Design Iteration
The rate of changes applied to printed circuit board design files over a given period measures the stability of the design process. A high layout revision frequency indicates ongoing modifications due to electrical failures, component obsolescence or mechanical interference. This metric applies during the prototyping phase and drops to zero once the design is frozen for volume production.
The boundary of this process is reached when the manufacturing release package receives final sign-off from the quality assurance team.
Manufacturing Cost
Frequent modifications to the copper routing or layer stackup disrupt the tooling setup at the board fabrication facility. Each new iteration of layout revision frequency requires the generation of new photolithographic masks, drill files and test programs, which increases the total cost of the project. These modifications can introduce new assembly defects if the placement of components is altered without updating the corresponding pick-and-place files or thermal profiles.
To mitigate this risk, changes are batch-processed and verified using automated design rule checks before the updated files are transmitted to the fabricator.
Stability Assessment
Tracking the revision history across multiple prototype builds reveals systemic weaknesses in the initial design requirements. The trend should show a steady decline in the number of changes as the product nears release.