SHANGHAI (Reuters) -Chinese chip foundry Semiconductor Manufacturing International Corp (SMIC) said it had signed a framework agreement to invest $7.5 billion for a new 12-inch foundry production line in Tianjin. The plans mark an ongoing expansion for the Shanghai-based company, which is under U.S. sanctions related to ties to China’s military, which the company denies. It is a key part of China’s drive to build up its domestic chip sector. According to a late Friday filing, the new fab will have a production capacity of 100,000 12-inch wafers per month serving process nodes between 28 nanometres and 180 nanometres. The…