Automotive Materials Solutions: From Engines to Entertainment Systems
With the electronics content of modern automobiles increasing substantially over the last decade, the materials used to facilitate device interconnection, protection and thermal control have also transformed to address next‐generation requirements. Obviously, the location of the electronic device within the vehicle drives the materials requirements.
But, there is not a “one size fits all” class of products for many applications, and there may be numerous materials approaches to achieve certain performance and/or cost objectives. Materials specialists that offer know‐how in multiple formulation techniques – for example, being able to marry adhesive performance with thermal control in a hybrid material – are providing superior value to automotive manufacturers as they consider next‐generation designs.
To get a sense for the evolving materials requirements in the auto market, it is helpful to understand what’s necessary based on a device’s location within the vehicle.
Under the Hood
Currently, any device that will be placed close to the engine must be able to withstand temperatures as high as 150°C. Moving forward, however, it’s likely that temperature stability requirements will be closer to 175°C. For under‐the‐hood applications, ceramic substrates in combination with electrically conductive adhesives (ECAs) for component mounting are typically the norm. Though novel solder materials such as Henkel’s Innolot products have proven viable for very high temperature environments up to 150°C, conventional solder materials generally can’t cope with these conditions.
Once the substrate is populated, it then has to be protected. While temperature resistance is critical, there are also certain chemicals from which the assembly must be shielded. Potting materials that deliver a high level of temperature resistance – up to 175°C – in combination with the ability to cope with various substances such as brake fluids and transmission oils, offer the most complete and reliable solution for under‐the‐ hood applications. Some advanced potting solutions not only provide temperature and chemical resistance capability, but thermal dissipation abilities as well. As automotive electronic devices continue to add greater function in a smaller form factor, a multi‐ purpose potting material will be required.
Now on to the place where so many of us spend so much of our time – inside our cars! Here, we have a personal connection to our electronic devices and rely on our entertainment systems to keep us occupied, our GPS’s to get us where we’re going and our seatbelts and airbags to keep us safe. Though the 85°C temperature capability of the materials used here is lower than that required under the hood, reliability and long‐ term performance are still very important.
For these applications, using traditional soldering processes on FR4‐type printed circuit boards is the predominant approach. As many of these electronics incorporate CSP and BGA devices, robust underfill materials are also an integral part of the completed assembly. In most cases, the PCBs are then protected with a conformal coating. While conformal coatings do offer a very cost‐effective solution for board protection, there are situations where alternative materials may provide a more streamlined alternative. Take Henkel’s MACROMELT low‐pressure molding materials, for example. MACROMELT offers the option to encapsulate, protect and provide the outer shell of the device all in one simple step. While not ideal for all applications, MACROMELT has been used effectively for a variety of in‐cabin sensors and, in the case of modern hybrid vehicles, the main power connector.
From Bumper to Bumper
There are a myriad of other electronic devices on an automobile for which Henkel formulates high performance material solutions. These include driver/passenger safety/security and assistance devices, tire sensors and high brightness LEDs, to name a few. Materials used for these electronics include solders, underfills, conformal coatings, conductive adhesives and thermal interface materials, among others.
The materials selections that must be addressed is mind boggling to say the least. And, automotive electronics manufacturers rely heavily on suppliers to provide process and materials expertise. That’s why partnering with a company like Henkel that has proven success in all of these formulation disciplines can deliver outstanding value. Understanding not only the compatibility between materials on a single device, but being able to offer the best, most cost‐effective approach is key to delivering an end product that is reliable, affordable and enjoyable!
The latest automotive electronics systems require materials that address multiple requirements. For instance, a potting material not only needs to offer mechanical protection, but thermal compatibility, heat dissipation capability and chemical resistance as well. A thermal interface adhesive must not only deliver excellent thermal management performance, but do so in a highly reliable adhesive format. The ability to unite these complex formulation criteria into a single product can only be delivered bymaterials specialists with a broad and deep knowledge base for numerous material types. This is where Henkel leads the field. With unmatched global resources and a team of talented, multi‐faceted materials experts, Henkel offers multiple material options that put you in the driver’s seat.
For more information, log onto www.henkel.com/electronics or call 714‐368‐8000.