As EVs, 5G and autonomous systems demand smaller connectors that carry more power and data, the plastic housing becomes a structural, safety-relevant component. This episode reviews the key material properties — flow, CTI, HDT, moisture (MSL) and UL94 flame retardancy — and which polyamides suit reflow versus wave soldering.
Miniaturization has turned the connector housing from a simple handle into a structural part with several demanding, sometimes conflicting requirements. Sub-0.1 mm walls need high melt flow; shrinking creepage in 800 V systems requires a high comparative tracking index (CTI) to prevent surface tracking; soldering at around 260 C requires high heat-deflection temperature (HDT) and low moisture uptake (MSL-1) to avoid the popcorn effect; and there is growing demand for halogen-free UL94 flame retardancy. The episode maps materials to process: high-temperature polyamides Stanyl (PA46) and ForTii (a semi-aromatic polyamide, PPA) for the small, precise parts run through reflow soldering, and bio-based EcoPaXX for higher-power, through-hole parts run through wave soldering. The recommended approach is to involve material expertise at the concept phase, which allows thinner walls, lower field-failure risk and shorter time-to-market — because the material, not the geometry, is usually the limiting factor.