As the world goes digital, the demand for bandwidth and higher frequency signals grows while devices physical size and circuit real estate shrinks, yet some inventions stand the test of time and continue to be critical to the future.

One such technology is the elastomeric connector technology, a unique component used predominantly in display systems but now finds new horizons in concurrent interconnection challenges.

Table of contents

In this artical you'll learn about:

Introduction

Elastomer definition - As the term suggests, an elastomer is associated with materials that have elastomeric properties. These materials can be polymers and monomers, mainly based on silicone rubber.

Elastomeric connector has elastomeric properties that aid in joining two components in an electronic circuit using compression force only, creating a solderless electrical connection. This is extremely advantageous in a variety of applications where additional re-flaw process is not allowed, such as in electro-optical systems, or when solder is not recommended such as in systems that are prone to shock and vibrations.

The relevance of elastomeric connectors has only risen over the past decade, as demand for smaller circuits with nonformal geometries and requirements grows, the need for out-of-box interconnection solutions grows as well. Now this makes the right time to understand elastomeric connectors, go over their operating principle and applications, and see why they are fashionable in the electronics world.

What is an Elastomeric Connector?

An elastomeric connector is a type of electrical component that has multiple conductive paths constructed in or around an insulating elastomeric core. These conductive paths allow the connector to showcase anisotropic conductive properties as electrical connection can be achieved in one direction only.

The conductors can be made of alternating silicone layers with and without a conductive additive, or metal wires from various metals and with a variety of cross section geometries, plating and finish such gold-plated copper and more.

The elastomeric core material is often silicone rubber monomer, but can be made of any flexible material, depending on the system requirements and environmental conditions.

The conductive-insulating arrangement allow the connector to connect to any contact pads pattern thus utilizing the design flexibility of board design to create almost any type of connection thru the same connector, let it be power, signals, control lines, hi speed or any combination of them all.

Elastomeric connectors’ simple design makes them a cost-effective and reliable component in modern PCBs, board-to-board connections, and Custom connectors designs.

When an elastomeric connector is being forced against a substrate with conductive pads, for example, a PCB, each conductive path on the connector can be touching a metal pad or the insulation gap between the pads. If it touches the insulation gap, then no electric contact is performed and no electrical current is flowing thru this path, but if the conduit on the connector touches a metal pad, then it makes contact which enable electrical current flow thru this conduit. If there is another substrate with similar pad layout touching the connector on its other side, then electrical connection is formed between these 2 pads. the connection that is formed actually “copies” any pads layout regardless of pitch, pads width and gap. The wider a pad is, it is likely to contact more conductive paths on the connector and allow higher current flow, making it suitable for hi-power applications as well.

Advantages of Elastomeric Connectors Over Mechanical Connectors

The question then remains about the efficacy of elastomeric connectors over their counterparts.

Why are they better than mechanical connectors? The answer is obvious.

One of the main goals of modern-day PCB design in the 21st century is to reduce cost, size, and weight while providing better features and adaptability. With today’s electronic devices like a smartwatch or smartphone, the need for components with an extremely small form factor and the ability to withstand shock and vibrations is higher.

In comparison, elastomeric connectors make for a cost-effective alternative while also providing high tolerance with limited design constraints. The biggest advantage, however, is the design flexibility which enables creative solutions for interconnection challenges.

The History of Elastomeric Connectors

Elastomeric connectors for LCD is perhaps their first application, owing to the requirement to adapt to the delicate construction of the display systems. Still today, LCDs and other display mechanisms use elastomeric connectors as they are perfect for the light, controlled current transfer between components. The conductive-insulating property of elastomeric connectors makes it the ideal choice for LCDs.

Since then, elastomeric connectors have been used in a variety of applications such as other electroluminescent displays, smartwatches, chip-to-board connections, monitor screens, CCTV, and memory cards. Their use has only widened in approach with digital systems requiring more compactness. This is where their use in customer connectors helps designers achieve better hybrid connectors.

Elastomeric Connectors Applications in the 21st Century

Elastomeric connectors can be used in a variety of applications across industries. Here are some of the most common ones in today’s age:

Requirements

While the advantages of elastomeric connectors outweigh that of their alternatives, there is a band of requirements which needs to be managed. Here are some of them:

  • Voltage / Current / Freq / Allowed resistance
  • Duty cycle
  • Allowed compression force
  • Boards alignment features
  • Pitch
  • Board separation

Benefits

As noted above, elastomeric connectors allow easy movement of light charge between components. In addition, they are cost-effective and extremely reliable due to a variety of intrinsic properties (which are listed below).

  • Flexible construction that can adapt to the environment.
  • Fail-proof construction.
  • Easy plug-and-play setup
  • High resistance to shocks, vibration, and temperature changes.
  • Gasket-like seal to resist external factors such as moister and gasses.
  • Stable resistance.
  • Zero insertion force (solder-free connections).
  • Cost-effective.

This list of advantages can be further expanded by manufacturers. For instance, the elastomeric connectors for LCD manufactured by Z-Axis Europe, allow for advanced solder-free connections, which makes them great for plug-and-play.

They are available in a single line or 2D matrix connectors. The difference between them is:

  • Matrix connectors are suitable for BGA and other 2D contact layout.
  • Single line contacts are suitable for 1 single row of contacts.

Test fixtures for testing environments

In addition to the above-mentioned applications, elastomeric connectors are also used in testing environments. Such environments – also known as test fixtures – are critical to a product testing process thru manufacturing and helps unearth operational issues.

Z-Axis Europe has identified the benefits of elastomeric connectors for testing applications and developed various solutions for testing challenges. In the European region, Z-Axis supplies customized test fixtures and flex test fixtures.

Elastomeric connectors have stood the test of time and continue to be used widely across digital applications. Their high efficacy and over-all cost-effective adaptability to various design modules make them a good choice of designers. As noted above, their advantages and range of applications far outweigh those provided by incumbents like mechanical connectors and other micro connectors.

Contact us for more information about elastomeric connectors, Z-Axis Technology and other similar state-of-the-art devices.