Dye and Pry Testing
The dye and pry technique relies on the ability of a very low viscosity dye to penetrate a fracture while under a high vacuum. Generally, a vacuum is applied for several hours, followed by a high temperature bake to cure the dye. Next, the BGA component or QFN is mechanically removed and the interfaces inspected for any traces of the dye on the surface of the pads. If the bonds are intact, dye will not penetrate and stain the pads. However, if there is a complete or partial fracture, the dye will coat the fractured surface and subsequent inspection will identify the fractured solder joints.