C&K: switched on to modern automobile requirements
Cars are increasingly becoming a platform for integrated electronics and software, with this element often comprising more than 30 percent of the vehicle’s cost. In this competitive environment, meeting new test and reliability standards while delivering the experience that drivers demand requires a holistic approach, and that is just as true for switches as for any other component.
Delivering reliable electronics
The growth of electronics in modern automobiles has meant a vast increase in the computing power required, and that trend will only hasten with the advent of the autonomous vehicle. The engine, power train, chassis, body systems, comfort systems, active safety and driver’s assistance systems all rely on electronics.
However, this complexity is causing problems when it comes to designing and testing these electronic systems – which is why most automakers are building their vehicles around the ISO 26262 standard. This standard is the industry’s attempt at establishing best practices for designing reliable and safe automotive electronics systems. The standard requires that carmakers perform an evaluation of the vehicle design to create an “automotive safety integrity level” (ASIL) rating that describes the failure impact based on exposure, controllability and severity. Car makers use this evaluation to design a vehicle’s electronic system architecture. The architecture’s requirements will be shared along the supply chain – and may have an impact on component definition.
Although switches are not the most expensive component within automotive electronics, they are critical to the success of any project because of their role within electronic units. The functional requirements depending on ASIL level for each function or system have a direct impact on the switch design and its properties.
Based on these new requirements, C&K can support electronic unit design by offering flexible, high-quality solutions. We have a wide range of switch contacting technology that enables designers and engineers to create the vehicle they intended without compromises based on three major properties: redundancy, self-failure detection and extended life.
Our high-quality switches extend the life expectancy of applications, including the double-throw and double-pole switches that are so important in creating an ISO 26262-compliant automobile. We develop and manufacture our own products and solutions, so we are able to provide our customers with a product assessment within real actuating conditions. This way, our customers can be confident that the switch works within their design before it is shipped. C&K also offers application engineering services to support customers within the design phase.
Haptics is the watchword for next-generation automotive switches
While ensuring that automotive switches perform their function reliably is of paramount importance, just as crucial is their look and feel. In modern vehicles manufacturers are enhancing the driver’s experience as an important way to differentiate their brands, and the look and feel of the interior plays a significant role here.
This is where haptics comes to the fore. It is defined as the science and physiology of the human sense of touch, and acoustics is now also at the center of automotive designers’ thought processes. The look, feel and sound form an important part of the brand identity of the vehicle, and switches are key to this. Haptics and acoustics not only differentiate one manufacturer from another, but can also be used to define the position of a model within a range of automobiles from the same manufacturer.
In the past, dashboards were predicated on robust pushbutton or toggle switches with relatively long travel. But in this age of smartphones, and with the proliferation of electronic gadgets, consumer tastes have evolved. They now demand smaller, more responsive tactile switches that still supply the same haptic experience they have been accustomed to.
Nowadays, automotive manufacturers, and the companies producing subsystems such as switch panels for them, often produce detailed specifications for the haptic and acoustic performance of the switches they select to ensure that they conform to the brand identity as well as delivering consistency over time.
There are several factors that define the sound made by a tactile switch, such as dome material and composition, structure and design of the switch body, and how the switch fits into the larger system. Characterizing the acoustics of any switch usually involves measuring the audible spectral components of the sound made, using an accurate sound meter in a carefully controlled environment. To achieve this C&K has invested in a state-of-the-art anechoic chamber with accurate sound evaluation that enables evaluation of individual switches and customer sub-assemblies.
Some integrators are attempting to build tactile switches themselves, fitting domes and membranes to a PCB to optimize the cost compared to a discrete switch. But this approach is fraught with problems. It needs many switches in an array to be cost-effective, specific PCB plating is required, and dust management is another challenge. An off-the-shelf tactile switch is guaranteed to perform to specification (including haptics and acoustics) by the manufacturer, and reliability is assured, as is the sealing of the assembly.
Delivering performance through a holistic approach
Having ensured that the switch selected for the automobile is reliable, meets the ISO 26262 standard and delivers the desired haptic experience for the customer, it is vital to ensure that it meets these requirements time after time.
While it is essential that any solution reflects the features and requirements that have been defined or highlighted, it must also meet the cost constraints in order to be commercially viable, as well as meeting the needs of the customer. In this context, “cost” refers to more than just the cost of the component; it also has to include everything needed to integrate the solution, for example connection costs and assembly costs – the so-called “total cost of ownership.”
However, this approach to design is only valid if the final design is well controlled in manufacturing so that every single product meets the customer’s needs. In many ways, the manufacturing process is at least as important as the product itself. As designers and manufacturers, we can adapt our processes and optimize our tools and machines to meet the needs of all customers and designs.
In summary, delivering custom solutions is much more than just meeting a specification. To be truly successful you must combine expertise with design excellence, innovative manufacturing engineering, attention to customer expectations and cost control.
In short, a holistic approach to custom switch design is the key to success.