Definitions
There are a number of terms used in the RoHS Directive that require some explanation:
- Put on the market
- Maximum concentration value
- Homogeneous material
Put on the market
The definition of ‘Put on the Market’ should mean the initial action of making a product available for the first time on the community market, with a view to distribution or use in the community. For imported products this is when it clears customs for the first time in the EU. For product manufactured in the EU this is when the product has moved from the “phase of manufacture” to the stage of distribution. Making available can be either for payment or free of charge. This definition has been successfully applied to other Directives.
Maximum Concentration Values
For the purposes of the RoHS regulations, a maximum concentration value of up to 0.1% by weight in homogeneous materials for lead, mercury, hexavalent chromium, PBB and PBDE and of up to 0.01% by weight in homogenous materials for cadmium will be permitted in the manufacture of new EEE.
Homogenous Material
'Homogeneous material' is a material that cannot be mechanically disjointed into different materials.
The term 'homogeneous' is understood as being 'of uniform composition throughout', so examples of 'homogeneous materials' would be individual types of plastics, ceramics, glass, metals, alloys, paper, board, resins and coatings.
The term 'mechanically disjointed' means that the materials can be, in principle, separated by mechanical actions such as unscrewing, cutting, crushing, grinding and abrasive processes.
Using these interpretations, a plastic cover (for example) is considered a 'homogeneous material' if it consists exclusively of one type of plastic that is not coated with or has attached to it (or inside it) any other kind of material. In this case, the maximum concentration values of the RoHS Regulations would apply to the plastic. However, an electric cable that consists of metal wires surrounded by non-metallic insulation materials is an example of something that is not 'homogeneous material' because mechanical processes could separate the different materials. In this case the maximum concentration values of the RoHS Regulations would apply to each of the separated materials individually.
A semi conductor package would contain many homogeneous materials, which include the plastic moulding material, the tin electroplating coatings on the lead frame, the lead frame alloy and the gold bonding wires. |