One of the most difficult and costly quality control criteria in manufacturing is the determination of bond integrity of joined materials especially when they are at the micro-scale. A good example is the semiconductor and microelectronics industries where interconnection and circuit traces are in the order of 0.001 inch in diameter or smaller. Though interconnects may have physical contact, the bonding integrity may not always exist. This phenomena is often found in ball bonds, wedge bonds, ribbon welds, circuit traces and thin coatings.

Traditionally, the degree of attachment is tested by contact means such as pull, shear and peel methods. With the increase in demand for products that are smaller, lighter in weight and more reliable, these quality control tasks are becoming more challenging every day. The mechanical test tools (such as hooks and shears) cannot be further reduced in size to accommodate the miniaturization trend. At times, latent defects are left in the product, causing product failures in the field.