How to Use Conductive Adhesives for Low-Profile Electrical Connections

Introduction

Conductive adhesives are a great way to make reliable electrical connections in low-profile and space-constrained designs. They can be an alternative to soldering or mechanical fasteners in applications where a thin, flexible bond is needed. In this article, I will provide an in-depth look at conductive adhesives, their properties, selection criteria, and best practices for use. My goal is to give electronics designers and engineers a comprehensive guide on leveraging conductive adhesives for their low-profile connection needs.

What are Conductive Adhesives?

Conductive adhesives are glues that are filled with conductive particles, allowing them to be both an adhesive and conductor of electricity. The adhesive portion is usually an epoxy, silicone, acrylic, or polyurethane base while the conductive portion contains metallic fillers like silver, copper, or nickel.

When cured, these adhesives form an anisotropic conductive bond. This means electricity can flow through the adhesive thickness-wise but not laterally across the surface. The conductive particles provide a bridge of conductivity through the adhesive while remaining isolated from adjacent particles.

Benefits of Conductive Adhesives

Here are some of the key benefits of using conductive adhesives:

Types of Conductive Adhesives

There are several base polymer options for conductive adhesives, each with their own characteristics:

Epoxy

Silicone

Polyurethane

Acrylic

Choosing the Right Conductive Adhesive

Several factors should be considered when selecting a conductive adhesive for an application:

Testing candidate adhesives under application-specific conditions is recommended to qualify performance. Consult manufacturers for free samples to evaluate.

Design and Application Best Practices

Follow these guidelines when designing and applying conductive adhesives for the best results:

Conclusion

Conductive adhesives present an excellent bonding solution for low clearance and flexible electrical connections. Choosing the adhesive type suited for your substrates and environment along with following good design and dispensing practices will result in reliable, low-profile bonds. Test candidate adhesives thoroughly to qualify performance before committing to production use. With careful selection and application, conductive adhesives can replace soldering and mechanical fasteners for many demanding electrical bonding situations.