Head-in-pillow defect

The Head-in-Pillow (HiP) defect is a type of manufacturing flaw that can occur in the production of electronic components, particularly in surface mount technology (SMT) solder joints. It is characterized by the appearance of a solder joint where a portion of the component (the "head") appears to be properly soldered, while another portion (the "pillow") is either poorly soldered or completely detached from the substrate.