Meaning
Resistance of a localized region of a material to plastic deformation is determined by applying a low indentation force through a diamond tip. Measuring micro-hardness allows engineers to characterize the surface properties of thin coatings and small-scale electronic components. The test is commonly applied to plated contacts, solder joints, and structural housing metals.
Contact Endurance
Surface wear on connectors is directly linked to the hardness of the plated finish. Optimizing micro-hardness prevents gold plated contacts from scraping off during repeated mating and unmating cycles. This mechanical stability guarantees a low-noise connection over the lifetime of the interface.
Solder Joint Integrity
Intermetallic compounds at the solder interface often exhibit different mechanical properties than the bulk solder. Variations in micro-hardness across these boundary layers indicate potential embrittlement that can lead to solder joint failure under vibration. Testing these regions helps qualify new alloy compositions for harsh environments, where thermal expansion mismatches generate cyclic shear stresses on the joints.
This characterization is essential for securing heavy RF components on multi-layer printed circuit boards.
Test Execution
Flat and polished surfaces are required to obtain accurate indent measurements. Handheld or automated hardness testers apply loads from one to one thousand grams force. These requirements define the boundaries of the test protocol.
