TSMC has announced plans to manufacture 28nm mobile chips in China. 

The company intends to shift less than 10% of its 28nm capacity across the Strait, but the announcement could be a sign of things to come.

TSMC chairman Morris Chang told reporters that the company is "always" expanding capacity and that it has plans to move into China, although he did not provide a specific timeframe.

"If we don't go there, Samsung will," Chang concluded.

But the move is not just about Samsung. The Chinese market simply needs a competitive node, since mainland-based Semiconductor Manufacturing International Corporation (SMIC) is having a hard time with 40nm manufacturing.

It remains unclear when TSMC's 28nm fab in China will be open for business, but it should be noted that the mature 28nm node still has plenty of life in it. Due to its maturity, the process is becoming relatively cheap and the price of a 300mm wafer in 28nm is less than half of a comparable wafer in 16nm FinFET.

What's more, the 20nm node is still in limbo. While it is used by Apple and Qualcomm for their flagship SoCs, the node has few design wins. According to Focus Taiwan, 20nm products accounted for 9% of TSMC's total sales in Q3, down from a previous projection made by the company. The 28nm process accounted for 34% of sales, down from 37% in Q2.

Shifting less than one tenth of 28nm capacity to China may not sound like a big deal, but it will give Chinese companies, namely smartphone and tablet makers, a chance to streamline their supply chain.