With a wealth of electronic packaging solutions available it would be all too easy to unwittingly select a product which features some of the required attributes but is not designed to be deployed in a specific environment. The latest solutions now come in a variety of sizes and materials and can be fully customised to ensure they are fit for purpose. Glenn Conlon of Cannon Electronic Packaging takes a look at the electronic packaging options being used in a diverse range of applications.

At some point or another most of us have owned a pair of shoes that don’t really fit properly. More often than not we will struggle on regardless, telling ourselves that they just need ‘wearing in’ when deep down we know that they are never going to be anything other than ill-fitting and uncomfortable. The same can often be said about electronic packaging – there is no ‘one size fits all’ option, no rack, subrack, case enclosure that will look and feel right in any situation.

Definition

Electronic packaging can be broadly categorised as subracks, chassis, system cases and plug in units – defined as follows:

–  Subracks house printed circuit boards (PCBs) or plug in units, are typically made of metal and come in modular form.

– 19in chassis come in modular form and are used for the protection of PCBs.

– Systems cases are designed for two common applications – the assembly of electronic boards that conform to IEC60297-3-10x or IEEE 1101.x standards and to house individual electronic or mechanical components.

– Plug-in units are mechanical components that serve to carry one or more PCB. The boards housed in a plug in unit are thus combined into a larger electronic function unit that is self-contained and testable. These function units are then integrated into the subrack or system case.

Electronic packaging is used in an array of everyday applications, so many that it is easy to assume that every solution is a standard, off-the-shelf product, designed to work in all scenarios. The truth is rather different.

In order to understand why every solution needs to complement its environment we need to take a look at some of the market sectors that are well known for using bespoke electronic packaging.

Electronics

The test and measurement, medical and general electronics industries use extremely sensitive electronics and often require 19in solutions; rugged parts to protect against vibration and shock and thermal management options to reduce the risk of overheating.

The printed circuit boards that reside inside electronic medical equipment must be afforded proper protection so hospital personnel can comfortably rely on the high-tech equipment at their disposal in an emergency scenario. Electronic packaging that isn’t specifically designed to handle the knocks and shakes that it will inevitably suffer in a busy hospital environment will not stand up to long term scrutiny and will need to be replaced in no time at all.

The medical industry naturally requires flexible solutions that can be transported from room to room with the minimum of fuss as well as surfaces that can be easily cleaned in line with infection control procedures. Well designed electronic and enclosure systems that fit neatly into this environment help to ensure that doctors and nurses are fully focused on helping to fix patients and not machinery.

Industrial

As you would expect, industrial solutions need to be of an industrial nature. Not only should they be rugged enough to withstand significant vibration and shocks, they also need to be designed with ingress protection in mind in order to keep out dust and water.

Standard off-the-shelf electronic packaging rarely offers the complete levels of protection required and it is important to look closely at the sort of conditions the packaging will have to cope with on a day to day basis. For example, electronic packaging that has proven successful on a car assembly line may not have the attributes to survive installation on a North Sea oil rig.

Transportation

Road and rail networks require a variety of roadside and trackside cabinets/enclosures to house signalling controls, sensors and security systems. These enclosures need to be rugged enough to hold up against the elements, provide easy access for maintenance personnel and secure enough to withstand attempts at vandalism. With all this in mind the products chosen for the role could well feature a variety of strengthened plastics, steel covers, castings and aluminium extrusions. These materials may also require protection from harsh environments and therefore standard plating, painting or even a special coating may be applied.

The transportation sector also requires electronic packaging for internal applications, for example the latest trains now feature driver machine interfaces,  European vital computers – providing juridical recordings, a CAB radio, a Euro antenna, radar/GPS capabilities, wheel sensors and more, all of which require different electronic packaging with different attributes. The majority of these systems play a vital role in ensuring reliability and passenger safety, allowing no room for compromise on packaging and enclosure design and performance.

Defence

Military applications demand the toughest enclosures, able to withstand very large shocks and rough treatment no matter the size. Electronic packaging solutions for military use are often designed with specific features for protection of sensitive electronics as well as displays and are constructed from lightweight materials such as aluminium, plastics or formed steel. Strengthened HMI devices and rugged PC/display housing can be integrated as required, alongside carefully considered thermal management solutions that encourage airflow without jeopardising the structural integrity or ingress protection of the unit in any way.

Design and test

Whatever the application, the key to success undoubtedly starts with the design. Simulation programmes can be used to test the design before deployment, helping to iron out any deficiencies before the product reaches the site. The process takes into account stress and displacement, frequency and buckling, thermodynamic optimisation, dissipation of heat especially from unidentified hotspots, as well as impedance calculations for backplane and PCB design.  All of this ensures there are no unwelcome surprises once the solution is in operation. Comprehensive testing of both standard and bespoke solutions can significantly reduce the need for maintenance or operational alternations further down the line.

By selecting products from a company with the requisite design experience, the end user can be sure that they are getting a solution that has been engineered to a high standard, has been produced with precision tools and, more importantly, has been developed by a team with an intimate knowledge of the market and an ability to spot potential problems as well potential opportunities to incorporate design innovations.

Standards

A range of global standards are now applied to electronic/electrical packaging cases, cabinets and subracks in order to maintain quality levels and guarantee performance. Some of the latest electronic packaging standards comprise dimensional specifications as well as the criteria for physical integrity, electromagnetic compatibility and thermal management.

Standard electronic packaging is designed to hold the 19 inch Eurocard and the standards provide a platform for manufacturers to work from, allowing them to create standardised modular designs and then customise the solution to fit the application. By using uniform parts with bespoke add-ons customers can be sure they are getting the highest quality solutions with the added features they require.

Diversity

With numerous options available to the end user, electronic packaging is more diverse than ever before. As well as the array of sizes and materials on offer, surfaces can be powder coated, finished with a chromate conversion coating, or even engraved with lasers to provide a superior finish.

As manufacturing techniques evolve and new standards help to raise the bar in design and production, there is no reason to settle for an electronic packaging solution that isn’t the perfect fit – just like the ill-fitting shoes it will just end up causing significant discomfort for the user.