At this point, it is almost a given that Apple will release a new iPhone model in the fall, the only question is when exactly and what improvements will the new model (or models) have - it has been widely rumored that Apple will produce larger iPhones this year, one with a 4.7-inch display and another with a 5.5-inch display.
According to a report from Digitimes, Foxconn will once again be the primary supplier of Apple's next iPhone and it is said that the company will begin production of the smaller 4.7-inch model in July. Production of the larger 5.5-inch model will begin later in August.
That said, Apple will also be looking to Pegatron and Wistron to help. Pegatron is believed to be the secondary supplier for the 4.7-inch model, whereas Wistron will step in to continue to supply Apple with the current 4-inch models.
The report also suggests that the larger 5.5-inch model will be marketed as a premium model and will be available in lower quantities and will have exclusive features such as a sapphire glass display.