Semiconductor Inc. and Samsung Electronics Co., an industry report said Friday. A tearing down of the iPhone 4S revealed that Apple used NAND flash memory made by Hynix in its iconic smartphone for the first time, market research firm IHS iSuppli said. Dissecting a mint-condition iPhone is a commonly used practice in the industry to identify Apple\'s component suppliers whose names are closely guarded from the public. \"In another surprise development, the (iPhone) 4S employs a Hynix NAND flash memory device,\" said Andrew Rassweiler, a senior director at IHS. \"While IHS has already confirmed multiple suppliers for this part, it does mark the first time that IHS has identified a Hynix NAND flash in an iPhone, as opposed to devices from Samsung Electronics Co. Ltd. or Toshiba Corp. seen in all previous iPhone and iPad teardowns.\" There had been market speculation that Hynix was an important supplier to Apple for previous versions of the iPhone, but neither the U.S. company nor the chipmaker confirmed the rumor. NAND flash manufactured by Hynix was the second-most expensive single component after the display in the 16GB version of the iPhone 4S, it added, likely yielding significant profits for the chipmaker. The cost of the NAND flash by Hynix is estimated at US$19.20, while the display costs $23, the research firm said. The bill of materials, which shows the cost of hardware components, is $188 for the cheapest iPhone 4S model, not including software, licensing royalties and other expenses, IHS said. The 16GB iPhone 4S is available for $199 in retail markets with contacts from mobile operators. However, the cost of the NAND rises to $38.40 in the 32GB version and to $76.80 in the highest-end 64GB model, making it the most expensive set of components, according to IHS. IHS said the dual core A5 processor in the iPhone 4S \"appears\" to be manufactured by Samsung, the world\'s largest memory chipmaker, which supplied the A4 processor for the previous version of the iPhone. Samsung and Apple, despite their bitter lawsuits in 10 countries over mobile patents, plan to continue their strong partnerships in mobile chips, Lee Jae-yong, chief operating officer and heir apparent of Samsung Electronics, said earlier this week.