The industrial connector space has in the past sometimes been defined more by what it isn’t – communications, computing, consumer, aero/space/defence, transportation etc – rather than what it is. However, this is changing, for a couple of reasons: firstly certain areas such as robotics and industrial automation with the advent of the Smart Factory (sometimes called Industry 4.0) are becoming ‘bigger news’; and second because in some segments, – oil and gas, industrial vehicles, even medical which is sometimes included under ‘industrial’ – the increasing use of electronics systems has been a driver in connector development.
Industrial applications are often also termed ‘hi-rel’ – that is, any activity where the connector cannot fail – and usually involves applications in environments that are subject to harsh operating conditions, usually resulting from shock, vibration and temperature variation. Industrial sectors which require very high performance connectors include:
Robotics
Industrial & Factory Automation (Smart Factory/Industry 4.0)
Industrial vehicles (off-road)
Oil & Gas
Marine & Undersea
Scientific Equipment
Test & Measurement
Metering
There is significant growth in all the above sub-sectors. This is due to a number of factors including the increased use of electronic systems that are being used for monitoring and control, and also the emergence of sophisticated robotics and metering systems. Quite simple, electronic systems are all-pervasive and almost every piece of equipment used today relies on them. This in turn means that the components used must be rugged and reliable.
Influencing factors
Connectors used in the industrial market share many similar drivers with other markets – size, weight, cost are always important – but industrial applications also tend to put more stress on all types electronic components that are used, and this is especially true of connectors. This is because as well as having an electrical function (carrying the power or signal) they also often make a physical connection. Often, too, they must be capable of being mated and unmated many times. This is why, for so long, some industrial users refused to specify surface mount connectors. Even today, hi-rel connector maker Harwin offers through hole and surface mount variations of its Datamate, Gecko and M300 Hi-Rel connector families, and also includes different locking mechanisms for extra security.
Size; Weight; Signal Density
Looking more closely at the evolving connector requirement we can identify three common factors: size, weight and signal density – all markets want ‘smaller, lighter’. The industrial market has responded and connector pitches have shrunk down to 2 and 1.25 mm. A good example of this is Harwin’s 1.25mm pitch Gecko family. Another way of maximising space utilisation is to combine the functionality of connectors, for example by combining signal and power, and sometimes coax and even opto in the same package. Mix-Tek Datamate from Harwin is an example of a connector family that can mix signal (to 3A), power (to 40A) and coax (to 6GHz) in a variety of configurations all within one common, lightweight, space-saving modular body shell.
Of course, as sizes reduce and densities increase, there is the issue of EMI and crosstalk. This is a system wide issue so connector design is a significant issue.
Cost
In the past, industrial applications, especially on the factory floor, often relied on connectors developed for military and defence applications, where cost was a (sometimes distant) secondary concern. For industrial users, as connector usage proliferates to service the exponential requirement for localised yet widespread sensing and monitoring required by factory automation programs such as Smart Factory or Industry 4.0, cost is very much an issue. (And even military programs are subject to stringent cost analysis due to budget cuts!) So alternatives had to be found. Harwin’s hi-rel product range – chiefly comprising the Datamate, Gecko and M300 families – offer high performance, surviving extremes of shock, vibration and temperature, yet are much lower cost than military products.
For lower cost industrial applications that still require high quality and small size, Harwin’s Archer 1.27mm pitch connector M50/M52 range is several percentage points more cost-effective than other manufacturers’ products.
High-performance
The interconnect system chosen must be suitable for the application. Therefore, while it may be tempting to go for an ultra-small, cheap device developed perhaps for use in consumer goods, such devices are not suitable for most industrial applications as they are not rugged enough to survive extremes of shock, vibration and temperature; neither are they designed for repeated mating and demating cycles. Operating conditions must be considered very carefully before a connector is specified.
If we combine all these factors, ideally industrial connectors need to be small, lightweight, cost-effective and high-performance. To achieve such a challenging order, special contact technology – the heart of any hi-rel connector – has been developed. In Harwin’s case, we use special beryllium copper clip contacts which ensure that signal integrity is maintained even in harsh environments. Body material is important too: plastics used must be highly robust but also may be required to be fire-resistant, exhibit no outgassing and of course be RoHS-compliant, made environmentally friendly materials, ideally eliminating harmful chemicals even before they are added to restricted substances lists for system future-proofing.
A recent example which illustrates this combination of factors is Harwin’s M300 high density power connectors that can handle currents up to 10A. Based on a 3mm pitch, the connectors are designed for rugged environments and withstand twice the number of operations as older generation products. M300 connectors feature a 4-fingered Beryllium Copper female contact which delivers excellent electrical and mechanical performance. Devices suit 18 to 22AWG applications and are designed for use in temperatures of between -65 and +175degC and are rated for 1000 operations. They pass shock (EIA-364-27: 100g 6ms No Discontinuity >1µs and vibration (EIA-364-28 10g No Discontinuity >1µs) testing. Jackscrews are available for extra security.
Design Flexibility
Design engineers are very creative people, possibly because they are continuously being pushed to deliver more functionality, whilst – as we have mentioned before – reducing size and cost. Therefore it is important that connector manufacturers respond with solutions that are flexible. One example from Harwin is the introduction of a horizontal mounting style for its 1.25mm pitch, hi-rel Gecko product family. G125 series connectors offer high performance in a miniature package. The 1.25mm pin spacing results in a 35% space saving over other high-performance connectors such as Micro-D. Connectors can handle 2A per contact and function within a wide temperature range (-65 to +150degC) and under extreme vibration (Z axis 100g 6m/s). Other features common to the Gecko connector family include polarization points that prevent mis-mating, easy identification of the No 1 position for fast visual inspection and optional latches that allow simple and fast de-latching. Optional special tooling is available for use in confined applications. The horizontal style connectors feature a new mechanical hold-down latching system for additional connection security.
The new horizontal versions reduce stacking height of PCBs to just 5.6mm. Available in the standard eight positions – 6, 10, 12, 16, 20, 26, 34 and 50 – the new style also facilitates mother & daughter board configurations.
Above all, when determining which interconnect system to employ, always consider the application and the demands that the environment and usage pattern will place on the connectors. Over-specing a connector may cause financial problems, underspecing it most certainly will!
