Boosting flexibility in industrial electronics through innovative PCB termination technology.

With har-flexicon, the new product family of PCB terminals and PCB connectors, Harting Technology Group is advancing progress towards modularity and miniaturisation in industrial electronics.

The central application area for these new solutions for the single-wire connection of circuit boards is industrial automation together with measuring, control and regulation technology. The areas of mechanical engineering, power engineering and transport technology, however, also stand to benefit. Harting is targeting all industries where electrical and electronic devices such as PLCs, drives, sensors, actuators and interface sub-assemblies, etc., are deployed.

Modularity and miniaturisation are important prerequisites for the high-tech strategy dubbed "Industry 4.0", by which the German government intends to advance the computerisation of traditional industries - above all, production technology. Currently, the largest project of the Federal Ministry of Education and Research (BMBF) is the leading-edge cluster "Intelligent Technical Systems OWL" (it's OWL), in which 174 companies, universities, scientific centres of excellence and industry-related organisations in the region of East Westphalia-Lippe ("OWL") are collaborating. Harting is also among the participating companies in the region.

Under the "Industry 4.0" concept, the "smart factory" offers more adaptability, resource efficiency and ergonomics while attaining new levels of integration. Here, components are smaller, more powerful, and combine more and more functions in the tightest of spaces.

The trend towards miniaturisation and performance compression not only extends to individual devices and the periphery, but also to printed circuit board technology and its connections. Though it may well be a passive component, PCB termination technology nonetheless contributes significantly to overall system performance. High data transfer rates and operating reliability are key factors in the system. Powerful and inexpensive connection concepts are required for future developments.

For economic reasons, previous solutions such as the use of made-to-specification machinery, sophisticated production technologies or complicated assembly processes - which in turn are prone to error - are virtually precluded from use.

Here, it should be noted that connectors must withstand exceptionally high stresses from their surroundings, more so than the devices and components that they connect. Extreme vibration as well as tensile and shock loads resulting from mating cycles must be endured, all without adversely affecting the technical properties of a connector.

Innovative devices that offer an increasing diversity of features and benefits, also in connection with contracting device volumes, necessitate efficient device design and powerful components with higher efficiency and higher power density. Conventional PCB termination technology must not take a back seat in this miniaturisation trend. The components must also become continuously smaller and more powerful - and Harting continues to make decisive contributions in this area.

Pinnacle of Miniaturisation

The new pinnacle in miniaturisation is the smallest PCB connector from the new har-flexicon product family. Its 1.27 mm pitch and a height of 5 mm from the top edge of the circuit board make it unique in the market. Here, four wires with cross-sections of 0.05 to 0.14 mm? (AWG28 -26) can be connected. Currents up to 4 amps can be transmitted, depending on the connection cross-section. Other products in the family are available with a pitch of 2.54 mm, 3.50/3.81 mm and 5.00/5.08 mm in straight and angled versions with up to 25 pins.

By reducing pitch sizes, manufacturers of machinery - as well as manufacturers of components such as sensors and actuators - have gained an entirely new freedom in product development. This also opens up new planning options for plant construction engineers and enables them to venture into new service areas.

Despite these new framework conditions, users are unwilling to make any compromises in terms of manageability. They expect the new termination technology to be able to be assembled as quickly and easily as the conventional technique using larger pitches. There are economic reasons for this, since the assembly of a system should be planned as cost-effectively as possible.

Cost-effective in Assembly, Service and Maintenance

The har-flexicon product family meets these expectations. Its manageability in the field, during assembly as well as during service and maintenance work, positively impacts the cost-effectiveness of an overall system - faster and easier replacement of components in the event of failure translates into lower costs since this also increases system availability.

With har-flexicon, even the connection elements with the smallest pitch can be easily assembled in the field without special tools. Fast, screwless termination technologies with push-in spring-cage connection and IDC termination make this advantage possible.

Flexible single conductors can be contacted via rapid IDC (Insulation Displacement Connector) termination technology, without the need for separate stripping. This gives users the option to employ a simple solution or fixation for the connector.

This error-avoiding contact securing increases mating reliability and presents no problems whatsoever in the face of repeated insertion and removal. And, the plug connection can be performed quickly even under difficult ambient conditions.

Cost Advantages for Manufacturers

The new technology also offers advantages in PCB loading for manufacturers of devices and components such as sensors and actuators. While the SMT method (Surface Mount Technology) is currently the standard for the assembly of components such as capacitors or integrated circuits (IC), the elements comprising the termination technology are often still the last through-hole parts on the board to be wired. There were good reasons for this, too, as the parts constituting the termination technology need to withstand other forces than those borne by the electronic components. The mechanics of plugging and disconnection produce shear forces that can affect the strength and secureness of the connection. Conventional mounting techniques such as THT (Through-Hole-Technology) and the normal wave soldering were intended to ensure proper function.

However, this meant that manufacturers had to specially set up their own mounting and soldering process for the termination technology.

Thanks to har-flexicon, this important cost factor is a thing of the past - as is already the case with the earlier introduced har-flex product family. Both product series are fully aligned to the workflows of the SMT process and can be processed by today's standard machining methods and procedures. The relevant parts are already delivered in tape and reel packaging and can be placed onto the PCB using the automatic pick-and-place method. The lower mechanical strength of typical SMT components in comparison to through-hole mounting is offset by the fact that the connector has larger contact zones that securely connect it to the circuit board. Thanks to this special design, the har-flexicon and har-flex product families bring a significant cost advantage over traditional printed circuit board connection concepts.

Lennart Koch, Global Product Manager Device Connectivity at Harting Technology Group in Espelkamp.