Board Level Shields

What are board level shields and how do they protect electronic components from electromagnetic interference?

Board level shields are metal cages that are placed on printed circuit boards to protect sensitive components from electromagnetic interference (EMI). These faraday cages minimize crosstalk and prevent signal degradation. As devices become more densely packed and operate at higher frequencies, ensuring signal integrity is an increasingly complex challenge for design engineers. Engineers use board level shields to improve signal integrity and device reliability.

Left unprotected, EMI impairs circuit integrity by coupling unwanted signals into sensitive traces and components, often resulting in logic errors, timing violations, or degraded signal quality. These effects can compromise device reliability, especially in high-density or high-speed designs where margins are tight. Board level shields allow design engineers to mitigate EMI at its origin, contributing to compliance with EMC standards, reduce the risk of costly redesigns, and maintain robust system performance in electrically noisy environments.

What are the different types of PCB shields?

Laird™ board level shields are available in both one-piece and two-piece surface mount designs. One-piece designs, or drawn shields, are fully enclosed and soldered directly onto the PCB, offering six sides of EMI protection (with the sixth side being the board itself). While one-piece board level shields offer robust and economical EMI protection, these materials limit access to components underneath.

Two-piece board level shields feature a frame and a removable cover, allowing design engineers to easily access the shielded components. Two-piece solutions allow for easier repair to components, access to PCB test points and automatic optical inspection.

In addition to standard surface mount shields, Laird™ portfolio includes custom shield designs to meet unique PCB shielding needs.

When should board level shields be used versus other EMI shielding solutions?

Historically, design engineers managed EMI at the enclosure level, shielding the complete system with fingerstock gaskets or grounding contacts. Today, with the increase of higher frequency applications and more compact devices, engineers must manage EMI at the PCB level. Board level shields are the ideal solution as they not only prevent EMI from being transmitted from the board but also prevent neighboring EMI from interfering with the circuit.

Laird offers a variety of materials to help mitigate EMI challenges throughout high-performance electronics, including:

• Electrically conductive elastomers and form-in-place elastomers
• Fabric-over-foam gaskets
• Fingerstock metal gaskets
• Microwave absorbers
• Vent panels

The choice between board level shields and other solutions depends on frequency, space constraints, thermal requirements, and inspection needs.

What are the different characteristics of PCB shields that design engineers must consider?

Design engineers must evaluate several factors when selecting PCB shields. Importantly, engineers must consider the shielding effectiveness of material solutions. Many Laird™ board level shields offer shielding effectiveness of 40 dB at 1 GHz.

Additionally, engineers should consider material type, surface finish, and accessibility. Laird offers a range of base materials including cold rolled steel tin pre-plated, nickel silver, stainless steel, phosphor bronze and beryllium copper.

Laird™ one-piece, two-piece, one-piece with spring fingers and custom shield designs – as well as vented and unvented options – ensure accessibility, enhance design freedom and minimize tooling costs.

View our board level shields catalog for more information on our comprehensive line of board level shields.

What are common applications for board level shields?

Board level shields are used across a wide range of applications, including automotive infotainment and ADAS systems, 5G antennas, AI systems, and consumer electronics. In automotive ADAS, drawn shields are essential for managing high-frequency signals without leakage. AI chips, which face both EMI and thermal challenges, also benefit from specialized shielding solutions like spring-finger shields that allow direct thermal contact with heat sinks. As devices become more interconnected and compact, the need for effective board-level EMI protection continues to grow.

How does Laird help manufacturers design, prototype and implement custom shielding solutions?

Laird is a trusted partner to technology brands and high-performance electronics manufacturers because of its end-to-end support that spans design, prototyping and production. Our field application engineers collaborate closely with customers to understand unique EMI challenges and develop tailored shielding solutions.

Laird experts use the latest CAD systems to develop custom shield designs. Drawing upon extensive experience with application engineering, advanced design and materials science, Laird engineers will create a precise and tailored solution to address the most complex board level shield and contact issues.

Laird’s prototyping capabilities provide manufacturers rapid, cost-effective soft tooling for fit, form, and function testing. Advanced simulation capabilities, including EMI modeling and forming analysis, enable precise design optimization. This comprehensive approach provides manufacturers with high-performance, manufacturable shielding solutions that meet their specific technical demands. We also provide pre-production support, including consulting and technical assistance, to help implement the solution into your manufacturing processes and ensure fast, efficient production. With manufacturing plants throughout North America, China, Asia and Europe, Laird provides worldwide access to parts, serving customers globally.