Taking the heat: Laser direct structuring for e-scooter components

Two-wheeled transportation dominates the personal vehicle market throughout Southeast Asia, where more than 80% of households own one. Yet, as air pollution levels continue to increase – taking the lives of nearly 7 million people every year through heart disease, stroke, lung cancer, and other respiratory diseases – government regulations will increasingly drive the market towards non-combustion-based electronic scooters.

Congested Asian cities generate an incredible demand for the growth of the e-scooter market. The high cost of internal combustion and electric cars is one significant reason, but cars are also impractical on traffic-clogged streets where the availability of parking spaces and charging stations is extremely limited.

A number of e-scooter components require specialized materials. The Envalior portfolio of materials is designed to meet the specific needs of these applications, including the use of Laser Direct Structuring (LDS) for electronics integration.

Integrated electronics

E-scooter manufacturers use Molded Interconnected Devices (MID) components, where electronic circuits are integrated with thermoplastic parts. LDS offers a number of advantages over the 2K injection molding and hot stamping processes traditionally used to manufacture MIDs.

Both 2K injection molding and hot stamping require product-specific tooling to embed circuitry on components. As parts become increasingly miniaturized and more complex, there’s a rise in tooling costs, and any design changes needed after prototype testing require changing the molds.

LDS can be used to locally plate the surface of any 3D structure, right after the injection molding of the components. The design options are virtually limitless if the structure can be completed in one or two layers.

LDS technology offers a broad range of other advantages to designers and manufacturers, including:

Significant reduction in component count, space, height and cost.
Rapid prototyping and volume production of new designs without changing the molds.
Integration of new functionalities, such as combing semiconductors, magnets, and more in one package.
Increased product reliability through simplified design and avoidance of connectors and wires.
Simplified manufacturing to three process steps (molding, laser structuring, metallization).
A short and environmentally friendly process.
Avoiding chemical surface activation (no acids used).
Omitting the use of photoresists, and wet or dry etching.

Since it was invented in Germany in the late 1990s, LDS technology has improved significantly. Today, the following are the main characteristics of LDS:

Resolution of ~80µm line width and ~50µm pitch.
Laser drilled Vias enabling 2nd layer contacts.
No clean room requirement, no extreme chemicals or temperatures.
Proven mechanical strength of electrical traces.
Proven performance against Ag and Cu migration.

While some materials used in LDS manufacturing – such as polycarbonate/acrylonitrile butadiene styrene (PC/ABS), polyphthalamides (PPAs) and liquid crystal polymers (LCPs) – can experience warpage and delamination, Envalior’s ForTii grades for LDS have been developed to offer a well-balanced material for electronic components requiring lead-free reflow soldering. ForTii is characterized by high mechanical strength and temperature resistance, and solid MSL2 performance according IPC/JEDEC J-STD 020D. In miniaturized applications with wall thicknesses less than 0.5mm, we have also tested MSL1 levels.

LDS is a proven technology that avoids issues with delamination, warpage, and mechanical strength seen in alternative processes. Envalior’s ForTii LDS grades offer solutions for e-scooter manufacturers as they look to expand their markets.

To learn more about ForTii grades, or to request test samples, contact us or visit plasticsfinder.envalior.com for additional information, including technical data sheets.