7410.21.30.20 - Having copper on one side only

This HTS classification, 7410.21.30.20, specifically designates copper-clad laminates where the base material is entirely composed of plastics impregnated glass, and which feature copper on *only one* side of this composite structure. These materials are foundational components in the manufacturing of printed circuit boards (PCBs) and other electronic applications where electrical conductivity is required on a single surface of a non-conductive, reinforced plastic substrate. The key defining characteristic is the singular presence of copper.

The distinction between this category and its sibling, 7410.21.30.40, lies solely in the configuration of the copper cladding. While this subheading covers laminates with copper on one side only, the sibling category addresses those with copper present on both the upper and lower surfaces of the plastic-impregnated glass base. Therefore, the number of copper-clad surfaces is the decisive factor for differentiating between these two closely related classifications.

As this is a leaf node within the HTS database, there are no further subcategories that divide this specific classification. The criteria for inclusion are precisely met by a laminate featuring a plastics-impregnated glass base with copper applied to a single face, adhering to the thickness specifications outlined in the parent categories.