White Horse Laboratories physical inspection services
External Visual inspection is the physical inspection of the parts by using high and low powered microscopes. The inspection covers marking, body, terminal, permanency and mechanical characteristics testing.
Decapsulation is a process by which we remove the plastic or ceramic insulation from the part to examine the internal die and wafer, checking the die topography and die markings. This is a destructive test (parts cannot be used again after “decap”) but is the best way to determine whether components are counterfeit.
Radiography, or “X-ray analysis”, looks through the soft insulation of the part to photograph the hardware of the part (die, wafers, wires, leadframe) without damaging or destroying the component. Most internal physical damage to components is caused during their assembly process, when the wafer is attached to the die and terminals and then insulated, which result in electrical failures such as opens and shorts.
X-ray identifies broken die and wafers, crossed wires (shorts), broken wires or separate wire bonding (opens), and even missing wafers (dummy parts).
White Horse follows the international JEDEC standard for solderability using the “dip and look” process. Terminals are submerged in flux and then a solder bath (lead-free or regular leaded) in accordance with the standard. To pass solderability, the new solder must cover 95% of the solder pad and show proper wicking on the terminal leg. Parts that fail solderability are difficult to connect to the circuit board.
A complete report including photographs and analysis is submitted with each work order.
X-ray looks through the plastic or ceramic insulation on the part to the hardware inside (wafer, die, wires, substrate, solder joints, etc.). The first photograph shows a complex part with good wire bonding, no damage to wafer or die, and no crossed or broken wires.
The second photograph shows good wire bonding, wire integrity, and no cracks or breaks in the wafer; however, the grey patches between the three wires toward the bottom of the photograph are either water pockets have penetrated the component insulation. When the part is placed on the circuit board and goes through a reflow oven, the water will heat and turn to steam and try to escape. This rapid expansion causes the insulation of the part to explode, often referred to as “popcorning”.