Undressing Wearables: Electronic Materials are Essential to
Function and Reliability
Art Ackerman
Henkel Electronic Materials LLC
The second quarter of 2015 saw triple digit growth in the wearables market, according to
market analyst IDC, and the category continues to expand. With shipment volumes of 18.1
million units, Q2 2015 represented a 223% increase in shipments over the same period in the
prior year. Wearable market leaders like Fitbit, Apple, Xiaomi and Garmin continue to drive
new developments and broaden wearables applications, while consumers continue to embrace
their style, function and convenience.
Sustained growth in the sector, however, is dependent upon reliable function of the individual’s
preferred wearable device(s). In other words, while fashion and style are key factors,
dependability and high functionality play equal – if not more important - roles. Extremely
capable electronics materials that allow for high-volume processability, adaptability to
manufacturing dynamics and miniaturized designs, as well as delivery of robust device
protection against multiple environmental factors, are non-negotiable for products in the new
wearables ecosystem.
Processability and Function
Materials that effectively provide signal carrying through robust electrical interconnects are
what allow wearables to work as designed. With increasing use of flex circuitry and highly
miniaturized dimensions, using material formulations such as Henkel’s electrically conductive
adhesives and inks deliver fast, low temperature processing for high-volume, sensitive
componentry. The ability to accommodate flexible substrates while also ensuring the required
performance is a delicate
balance, but one that
advanced materials can
provide.
As consumer cost
expectations are also a
big consideration for
manufacturers of
wearables, the materials
selected must align with
cost/performance ratios.
This is where a
breakthrough material
such as Henkel’s game-
changing LOCTITE® GC 10 temperature stable solder paste can add tremendous value. While
providing superior performance on the line and in use, LOCTITE GC 10 also adds an entirely new
dimension to the performance of the bottom line. Temperature stability delivers
unprecedented storage flexibility, shipping cost reduction and stability in process – all
combining to offer an exceptionally low cost of ownership. This material, in addition to market-
leading solders such as LOCTITE HF 212, also ensure compliance through their low halogen
content and lead-free composition, which are important factors for the wider consumer
market.
Reliability
The high reliability of handheld smartphones and tablets has established a precedent for
wearables that is a bit more challenging to accommodate. Whereas the protection of handheld
devices certainly isn’t easy, the primary concerns are around drop and shock, as well as the
occasional coffee or soda spill. With wearables, the constant proximity of the devices to the
human body introduces the need not only for shock and drop protection, but safeguarding from
moisture and salts in sweat, fluids such as sunscreen oil or soda, extreme temperatures, water
submersion and more. It’s a completely different scenario with wearables.
While this may seem like uncharted territory, device protection – even from the
aforementioned conditions and materials --- is something Henkel has been managing for quite
some time. Novel encapsulants that deliver both UV and shadow cure capability can be applied
specifically to areas that require reinforcement as well as moisture or physical protection.
Underfill material development is an area where Henkel has excelled and these products are
essential for area array devices that are more sensitive to bend, shock and drop. Plus, with
Henkel’s robust reworkable underfill solutions, substrate recovery is an option if a component
becomes non-functional, helping to eliminate scrap and reduce cost. Low pressure molding
materials like Henkel’s award-winning TECHNOMELT® formulas are also emerging as possible
contenders for the external housing of wearable devices. In fact, electronics-enabled
wristbands for consumers in different industries are already incorporating the materials in high-
volume production. For these products, TECHNOMELT has successfully been employed for the
encapsulation of RFID devices, flex circuitry and embedded sensors that are integrated into a
wristband, raising the reliability level of these devices through protection from water, skin
exposure and normal wear and tear from environmental impacts. Each application has specific
reliability and longevity requirements as well; while the wristbands used for the entertainment
industry are generally for short-term, consumable use, those in the medical industry tend to be
more sophisticated and high-reliability products.
Resources beyond Compare
Henkel’s reputation in the industry as the premier semiconductor and electronics assembly
materials supplier is well-deserved. And, when it comes to wearables, Henkel’s decades of
expertise within the handheld, communications and medical sectors have informed some of the
latest advances in wearables manufacturing. The ability to partner with a single source for