Signal integrity / EXPLORE THE LIBRARY

Signal Integrity in HDI PCBs

HDI can create compact transitions, but electrical performance still depends on the complete signal and return-current path. Explore impedance, loss, coupling, stubs, timing and power delivery as connected design decisions.

Keep the return path in the design.

Choose a guide around the symptom or constraint you need to resolve. Use the calculators to understand sensitivity to geometry, then move to an appropriate solver or measurement plan before committing production tolerances.

Explore signal integrity

12 resources
01 / Signal integrity

Controlled Impedance: Turn a Target into a Manufacturable Geometry

Define impedance by layer, reference plane, trace geometry, material inputs, tolerance, and an agreed coupon plan.

02 / Signal integrity

Microstrip vs Stripline: Choose the Route and Its Reference Together

Compare outer and embedded transmission lines using access, dielectric environment, references, and channel transitions.

03 / Signal integrity

Differential Pairs: Control Symmetry Through the Entire Channel

Design differential pairs with consistent geometry, matched environments, reference continuity, and intentional transitions.

04 / Signal integrity

Signal Return Paths: Review the Copper Beneath the Route

Identify return-current continuity across HDI escapes, plane voids, connectors, and layer changes before routing release.

05 / Signal integrity

Via Stubs: Find Unused Barrel Before It Consumes Channel Margin

Identify via stubs from actual layer usage and compare routing, backdrilling, and blind-via options for the channel.

06 / Signal integrity

Backdrilling vs Microvias: Choose by Escape Geometry and Channel Needs

Compare controlled-depth drilling and HDI via structures using residual stubs, routing clearance, lamination, and verification.

07 / Signal integrity

Crosstalk in HDI: Inspect the Escape and Vertical Transitions

Manage coupled noise through spacing, reference proximity, parallel length, via geometry, and realistic aggressor scenarios.

08 / Signal integrity

Insertion Loss: Measure the Channel You Intended to Model

Build an insertion-loss budget that separates line attenuation, transitions, launches, and material assumptions.

09 / Signal integrity

Length Matching: Close the Timing Path, Not Just the CAD Number

Use path definitions, package delay, layer-dependent propagation, and restrained tuning to meet interface timing requirements.

10 / Signal integrity

Power Integrity for HDI: Design the Supply Path from Regulator to Package

Review DC drop, transient response, plane geometry, decoupling, and the package boundary as a connected power network.

11 / Signal integrity

Decoupling Layout: Shorten the Complete Power-and-Return Loop

Place capacitors using connection inductance, via access, power-plane geometry, and device-specific requirements.

12 / Signal integrity

Reference-Plane Transitions: Give Return Current a Defined Route

Review old and new reference conductors at every layer change and avoid treating all stitching connections as equivalent.