Head in pillow defect of BGA package case study

A common defect that is experienced in BGA soldering as well as other leaded types of components is called Head in Pillow. This defect is created when an intermetallic bond is not established between the component lead and the substrate. This is sometimes referred to as a cold solder joint or intermittent solder joint connection. This type of defect may be hard to detect through visual inspection and ICT in circuit test and can lead to field failures.