Global tablet shipments are expected to grow 47.5% on year to 21.58 million units in the second quarter of 2012; however, compared to the first quarter, shipments will drop 8.2%, according to Digitimes Research ( senior analyst James Wong, who added that Taiwan’s shipments will account for 88% of global shipments and reach 18.9 million units, down 2.74 million units from the first quarter.

As for rankings, according to the DigiTimes Research, Apple will remain as the leading tablet vendor in the second quarter, while Lenovo will drop out of the top five. Asustek Computer will have a chance to become a top three vendor, benefiting from its cooperation with Google for 7-inch products.

As in terms of processors, Apple’s processors will account for 70% of the total tablet shipments, while Nvidia will need to rely on Amazon’s new 8.9-inch tablet PC to compete against Texas Instruments for market share in the second quarter. Nvidia may also lose its major client Samsung Electronics in the second half of the year.