Apple has asked its suppliers to produce as many as 90 million units of iPhones toward the end of 2015. In order to meet the demand, the company has reportedly enlisted the help of a third assembler of the next generation of iPhones.

In 2014, Apple reportedly ordered a record of 70 million to 80 million iPhone units in the initial production of its current iPhone 6 and iPhone 6 Plus flagship devices. This year, the company told its suppliers to produce 85 million to 90 million units of handsets with 4.7-inch and 5.5-inch displays.

Analysts estimate that the sales of the iPhones reached more than 61 million during the first quarter, proving once again that the current iPhone devices are the best-selling models that Apple has ever created.

The next generation of iPhones will most likely hit the market in the fall. According to reports, the new iPhones will bear the same designs of the well-loved iPhone 6 and iPhone 6 Plus. Apart from having the same screen sizes, the new iPhones will also bear the same screen resolution. There's also the possibility of adding a fourth color option.

The upcoming iPhones are also expected to feature Force Touch, the same technology found in the Apple Watch and Macbook. Force Touch is the next most significant sensing feature following the Multi-Touch. Force Touch can easily distinguish between a light tap and a deep press.

It is believed that suppliers started production of iPhone models with Force Touch in June. The large-quantity production of manufacturing parts, on the other hand, began earlier this month.

China-based Hon Hai, also known as Foxconn, has been increasing its workforce in anticipation of the mass production of the iPhones set to begin next month. The company is Apple's primary assembler of the iPhone, with Pegatron also filling in the gaps. Taiwan-based Wistron is said to be the third supplier, which may be hired by Apple in order to speed up production.

A quarterly record of sales showed that over two-thirds of Apple's sales came from the iPhones. For the past two quarters, at least 135.7 million iPhones have been sold, which is 43 percent higher than what was recorded for the same period in 2014. While the iPhones have enjoyed immense popularity in a number of places, it is China which emerged as the company's biggest smartphone market to date.

Photo: Kārlis Dambrāns | Flickr