Untangle your PCB Wiring: Route with the X-Y Rule PCB Design Process

Posted: May 25, 2026
Last Updated: May 16, 2026

If you are having a difficult time routing your PCBs, the X-Y rule PCB design technique may make it easier for you.

Introduction

Routing a PCB can sometimes be simple and easy or at times time-consuming and very hard. The situation really depends on the scale and complexity of the project. However, following certain guidelines or rules can have a drastic effect on the complexity of routing your PCB.

Laying out with a Rule

One of the initial steps in making a PCB is making a good component placement. As they say, your work is already half done after doing the placement well. With this, make sure to align your components and follow the flow of your circuit layout. Afterwards, you can go ahead and route your boards. Similarly, PCB routing has a set of rules to follow, and one of those rules is the X-Y rule PCB design process.

What is the X-Y Rule PCB Design Process

Each layer of a PCB has its own independent tracks. These tracks all have one common goal: to interconnect all the components on your PCB. Frequently, routing complexity decreases as the number of layers increases, so it’s important to take advantage of this situation. However, if you don’t follow the X-Y rule, you may find it hard to simplify your routes or have coupling and EMI issues between them.

The X-Y rule PCB design process takes advantage of orthogonal routing. Orthogonal routing refers to arranging PCB traces or interconnects at right angles (90°) between adjacent (or non-adjacent) layers, so that signals on one layer run horizontally while signals on the next layer run vertically.

Orthogonal routing has these advantages:

Organizes layout: Provides a systematic way to structure multilayer PCBs.
Minimizes crosstalk: Signals running parallel across adjacent layers can couple and interfere; orthogonal routing reduces this risk.
Improves signal integrity: Especially important for high-speed signals like clocks or data buses.

You’ll see here that there’s more to organized wiring when using the orthogonal approach.

You’ll be delighted to find out that when you’re doing mostly horizontal routes on one layer, there’s less chances of tracks criss-crossing or entangling one other. The same goes true when routing mostly vertical routes. Later, you’ll find it easier connecting all the tracks of your multilayer PCB design.

Practical Examples: Layer Assignments on Multilayer PCBs

There are different methods for assigning routing and power layers to your PCB stack-up. Below are examples for 2, 4, and 6-layer boards. Interestingly, the X-Y rule applies in these stackups.

Example 2 Layer PCB Stackup

Employing the X-Y rule is critical on 2-layer boards. Here, you’ll see that Layer 1 and Layer 2 are adjacent signal layers. Layer 1 is a mixed signal/power layer, while Layer 2 is a mixed signal ground and power layer. Adjacent vertical signal layers are very close, and the tracks can emit electromagnetic interference (EMI) to one another. With this, it’s vital to use orthogonal routing so that vertically adjacent tracks (especially high-speed and impedance-controlled lines) are at 90°, preventing long wires from running in parallel with each other.

Example 4 Layer Stackup

In a 4-layer stackup, electromagnetic interference between tracks of adjacent layers becomes less of an issue due to the sandwiched power or ground plane between the signal layers. However, do note that most designers still employ the X-Y rule PCB design process. Conforming to the rule simplifies routing and can produce lesser number of vias. Their design becomes more predictable and easier to debug.

Example 6 Layer PCB Stackup

A 6-Layer stackup helps in a complicated PCB design. Same as in the 4 Layer styackup, EMI issues between adjacent layers become less of an issue. Employing the X-Y rule is still common due to the same reasons when doing a 4 Layer PCB design.

Conclusion

Applying the X‑Y Rule to PCB routing brings order to what can otherwise be a messy process. It reduces crossovers, improves signal integrity, and makes layouts easier to debug. Cleaner designs also mean smoother collaboration with manufacturers and engineers. Whether you’re tackling a simple two‑layer board or a complex multi‑layer stack, this method scales with your needs and quickly becomes second nature.