This page contains a Flash digital edition of a book.
Switch Technology


Membrane or Touchscreen?


Changing market requirements, especially the rise of the touchscreen, are putting pressure on manufacturers of membrane keypads. But, as Paul Bennett explains, membrane technologies are evolving to meet the challenge


T


he US membrane keypad market is worth an estimated $500million, and with continued investment in new technologies by membrane keypad manufacturers, there continues to be a growing demand for this tried and tested product from global application and instrumentation manufacturers. However, despite growth, touchscreen technology has attracted a lot of recent attention and according to a report from NPD DisplaySearch Touch Panel Analysis, by the end of 2012, revenues in the touchscreen market will have topped $16billion, meaning it has almost doubled over the past six years. How can manufacturers of membrane keypad technology compete with touchscreen technology?


The choice between membrane and


touchscreens is being driven by changing market requirements. In particular, customers are demanding devices with integrated components - which allow the best user interface experience. Also, materials are changing with manufacturers moving away from costly metals; having found that advanced polymeric overlay materials, when combined with hard- coated textured polyester films, can give a brushed metal or steel finish.


Some industries, for instance, medical,


now require products to meet a certain standard of hygiene and be resistant to harmful bacteria. Products manufactured


with special antimicrobial films and hard- coats, such as Microban – which is proven to inhibit the growth of fungi and moulds including MRSA, Salmonella Enteritidis, Escherichia Coli and Listeria Monocytogenes – are increasingly preferred.


Membrane or touchscreen? Sometimes, when it isn’t practical to have a keypad, touchscreens can be a good option. Additional integration to include off-the-shelf LCD modules with circuit boards offer greater capabilities, and the sleek design and high-tech appearance is becoming ever more popular. But, touchscreens aren’t suitable for many applications; they can wear quickly, reducing optical clarity, be fragile and less accessible, especially when surface feel or tactile feedback is required, or when gloves are worn. And with technology getting smaller – designing easy interaction on a small touchscreen can be difficult.


Membrane keypads can be compact, in some cases assemblies can be designed as thin as 0.4mm, giving a more modern look. Advances in manufacturing means that silver circuits can be printed double sided to produce the equivalent of four layer PCBs that can fit smaller and more compact applications. Polymeric overlay materials and textured hard coats are also very thin and low in weight.


Hydrophobic and oleophobic coatings


are abrasion resistant, biocompatible and can be applied to both membrane keypads and touchscreens, but when maximum resistance is required, membranes are usually the best option. There are many other things to consider when deciding between a touchscreen and membrane keypad, so for electronics manufacturers, here are some of the key areas to consider: Cost effectiveness: Membrane keypads are cost effective to produce in a high volume, and cheaper to produce than PCBs with key mats. This is also the case in comparison to more expensive touchscreens – as prices of Indium Tin Oxide (ITO), often used as a conductor, have soared due to its limited availability. Rapid prototypes, which can play an important part in the development process of a new product, are also cost effective with zero artwork and tooling costs. Prototypes, which are ideal for shows and exhibitions, can be manufactured at a fast turnaround and can be used to test a design before it has been finalised or fully manufactured. Custom design: Touchscreens may seem more convenient and give the impression that everything is at your fingertips, but it is somewhat harder to customise the face of the product compared to a membrane. Each membrane keypad can be tailor-made in design, in any shape or colour and can be embossed, include fibre optics, surface mounted light emitting diodes (LEDs), electro-luminescent back illumination, and stiff metal back panels with printed circuit boards. A number of finishes can also be used, including; brush finished stainless steel, and chrome ink technology – which gives a bright metallic finish.


32 March 2013 Components in Electronics


Durability Largely, because membrane keypads are particularly robust and can handle extreme environmental conditions, they are an ideal option for many products across a wide range of industries, including; fire and security, medical, catering and instrumentation. Materials can be carefully selected to provide the required specification, which may include scratch or chemical resistance and flexibility. Touchscreens simply cannot match the durability of membrane keypads, which can be IP (Ingress Protection) rated, which defines the level of protection it has from the intrusion of solid objects, and the ingress of liquids. Fascia has the ability to rate keypads up to IP68, which ensures the keypad is sealed and cannot be damaged even when submerged in water.


Where to start?


When designing or manufacturing a new product, it might be difficult to know what type of screen or keypad to use and it is therefore advisable to seek some expert advice from a manufacturer in the industry. It is important to manufacture with a company that utilises the latest technology. It is also important that each product is value engineered. At companies like Fascia we identify cost savings by taking a value engineering approach to make suggestions about materials, adhesives and specification of parts, to ensure customers receive the most cost efficient and high- quality product possible.


Fascia Graphics | www.fasciagraphics.co.uk


Paul Bennett is the Managing Director of Fascia Graphics


www.cieonline.co.uk


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44