What should be ensured before starting a bumping operation on aluminum?

Before initiating a bumping operation on aluminum, it is crucial to ensure that the metal is clean and free of contaminants. Contaminants such as dirt, oils, and oxidation can negatively impact the quality of the bumping process and lead to defects in the final product. Clean surfaces allow for better adhesion and deformation of the aluminum during bumping, ensuring that the material responds uniformly to the applied forces and maintains its structural integrity.

In addition to cleanliness, other factors can influence the bumping process as well. For instance, although heating aluminum can make it more malleable and easier to work with, it is not a prerequisite that must be fulfilled before every bumping operation. Similarly, while lubricants can reduce friction and improve the bumping action, they are not universally required for all operations and depend on specific procedure requirements. Quick cooling is generally not part of the bumping operation as this may lead to undesirable properties in the metal. Therefore, ensuring that the aluminum is free from contaminants is the most critical step that must always be performed prior to starting a bumping operation.