It seems like you're asking about "PCB Matrix," but the term is not standard in the PCB (Printed Circuit Board) industry. It's possible that you might be referring to different concepts or terms. Here are a few possibilities:

1. PCB Layout Matrix: This could refer to the arrangement or layout of components on a PCB, where the components are organized in a grid-like pattern.

2. Matrix of PCB Designs: This might refer to a collection or series of PCB designs that share common features or attributes and are arranged systematically for comparison or selection purposes.

3. Matrix of Components: This could mean a list or table showing the types and quantities of components used in various PCB designs.

4. Matrix Trace Analysis: In some contexts, it might refer to a method of analyzing trace connections on a PCB using matrix-based techniques.

If none of these interpretations match what you were looking for, please provide more context or clarify your question. This will help me give you a more accurate and useful answer.