3M Glass Bubblesfor Communications Infrastructure

• 3M™ Glass Bubbles have long been used to reduce component weight and manage material costs across a range of industries: automotive, aerospace and more. With special grades for use in electronics, these benefits can be extended to 5G applications.

• With a true density as low as 0.32 g/cm³, 3M™ Glass Bubbles can help you achieve tight density control and significant lightweighting. In radome covers as well as plastic and composite device components, you can reduce final part weight by 15–40%, all while optimizing signal integrity. In CCL materials, you can partially replace expensive resins and save significant costs.

Due to their hollow structure, 3M™ Glass Bubbles possess a very low coefficient of thermal expansion (CTE). They can help you control thermal expansion in CCLs by tailoring the resin system CTE to better match the CTE of copper. This allows the dielectric and conductive layers to expand and contract in tandem, improving dimensional stability and reducing delamination between layers.

See the effects of 3M™ Glass Bubbles on the CTE of a PPO resin at various content levels. In-plane (XY-axis) and through-plane (Z-axis) data are shown. At 55% volume, a CTE of 69 μm/(m⋅°C) in-plane and 158 μm/(m⋅°C) through-plane can be achieved. Multiple material requirements, not just thermal expansion, will determine the best content level for your application.

• In addition to low loss properties and lightweighting capabilities, 3M™ Glass Bubbles are compatible with a range of high shear, high pressure manufacturing processes. Featuring high crush strengths of up to 16,000 psi (110 MPa), they can be compounded and injection molded with glass fibers for reinforced composite parts. This makes them an excellent choice for plastic and composite device components with complex geometries.

• Unlike irregularly shaped fillers, 3M™ Glass Bubbles are spherical and roll easily over one another. This can help you increase volume loading capacity and lower resin demand while reducing shrinkage and warpage in molded plastic parts.