Story // 07.09.2022

Hidden Heroes: SEKISUI Micropearls
Leading technology for the electronics, automotive and architectural industry

SEKISUI offers a comprehensive product range in Europe, which is a vast array of innovative high-performance materials for applications in four different business sectors: mobility, electronics, medical & diagnostics, and construction & infrastructure. With the series “Hidden Heroes,” we are taking a closer look at SEKISUI’s portfolio and offer deep but simple insights into the products of the European companies. Today, we will have a look at SEKISUI Micropearls.

The Micropearls product line offers one of the world's most comprehensive selection of uniform, monodisperse microparticles used in a wide variety of electronics, automotive and architectural applications.

Briefly described, SEKISUI Micropearls are microscopic spherical spacers made of co-polymer resins that enable high-tech solutions. They are resistant to heat, various chemicals, and provide a perfect base for further functionality through supplementary coatings, such as gold plating for electrical conductivity. As a result, these little heroes can be used in a wide range of products surrounding us every day and are often indispensable to make, for example, smartphones, wearables, and cameras work.

Monodispersity and Cv value – what is special about the product
Micropearls are almost invisible to the naked eye – but while being small in size, they are giant in function and quality. A close look under the electron microscope reveals spheres that are of the exact identical size. Monodispersity is the technical term to describe a low variance in size which is one of the most sought-after and key features of SEKISUI Micropearls: a highly uniform particle size distribution allowing a very accurate gap control and precise alignment of sensitive components in all sorts of electronic devices. This low coefficient of variation (Cv value) is a key benefit for modern world technology.

Micropearls: A wide range of applications
The Micropearls product series is available in a wide range of particle size over an exclusive variety of hardnesses, Cv categories (extra low, low, and standard) and coatings/platings. In comparison to other small particles, the advantage of Micropearls clearly lies in the deep portfolio of high quality, monodispersed microspheres that can be chosen to fit a pre-determined gap size or play a functional role in a stack of materials. Starting from the soft Micropearl SP grade made of co-polymer resin, the spacers are well equipped for fragile substrates and sensitive sensor technology. The softness of the core material can release internal stress, especially when thermal extension of the neighbouring components occurs. This alone already significantly increases the application possibilities above standard rigid spacers. The Micropearl EZ series, on the other hand, consists of an acrylic co-polymer, is very soft and even can absorb vibration and noise. Another example for a specialty grade particle series is the Micropearl AU series. Based on the Micropearl SP series as their core these spheres are plated with gold for added functionality geared towards electric conduction and excellent gap control. This enables, for example, their use in electronic components, securing electrical conduction between printed circuit boards, heat transfer and gap formation, and is used in various microelectronic applications. Other metal compositions are available as well.

One of the advantages of Micropearls: Compared to other materials, the softer types of co-polymeric plastic spacer particles can also be used with fragile and sensitive substrates as well.

In action: Micropearls in smartphones and automotive electronics
A specific example of the application of Micropearls is an object that billions of people worldwide use every day: the smartphone. Here, Micropearls are used on a variety of essential components. In a commercially available smartphone, various grades of Micropearls can be found in the camera module, in the display, on the touch panel attachment, or even in the smartphone's MEMS sensors, which are micro-electro-mechanical sensors used for e. g. the brightness sensor or the sensor for acceleration and rotations of the smartphone. Thanks to the high quality of the Micropearls, SEKISUI thus enables the manufacturers of commercially available smartphones to produce high-quality products and offer an indispensable, high-quality items for everyone.

Multiple application areas in a smartphone

In the automotive industry, Micropearls are an invisible yet indispensable ingredient to components such as the control units, intake manifolds, pressure sensors, in smart (dimming) glasses, head-up-displays or electrical systems and sensors like distance meters. In particular, the use in head-up displays in modern cars helps car manufacturers not only to maximise comfort but also increase safety in the vehicle because the driver can always keep his eyes on the road thanks to the display.

General Properties of Micropearls

  • Wide range of particle sizes from 3 μm to 600 μm with different hardnesses
  • Excellent resistance to heat, chemical substances, organic solvents, and tension
  • Wide usable temperature ranges from -40 to approximately 200 degrees Celsius
  • Available special features: Metal-coated types, particles with surface adhesives, and light-shielding black spacers

Micropearls product range
To meet the different requirements and technical parameters of the application areas, SEKISUI offers its Micropearls in different series and grades, each of which provides an individual solution for technically challenging applications.

Click here for more information about the Micropearls series and the Micropearls product range.