IEC 60191-6-13:2016 specifies a design guideline of open-top-type semiconductor sockets for Fine-pitch Ball Grid Array (FBGA) and Fine-pitch Land Grid Array (FLGA). In particular, this part of IEC 60191 establishes the outline drawings and dimensions of the open-top-type test and burn-in sockets applied to FBGA and FLGA. This edition includes the following significant technical changes with respect to the previous edition:a) BGA package nominal length and width have been newly expanded to 43 mm and 43 mm, respectively. Accordingly, six socket sizes have been added to the socket group numbers 1, 2 and 3, and twenty-two socket sizes have been added to the socket group number 4.