Japanese conglomerate Toshiba Corp. and electric parts company Rohm Co. will collaborate in the power semiconductor business, sources familiar with the matter said Thursday. The two companies are spending a combined 380 billion yen ($2.6 billion) to expand their production of power semiconductors, and Japan’s Ministry of Economy, Trade and Industry is expected to shoulder up to about 130 billion yen of the cost, they said. Power semiconductors are capable of handling high voltages and large electric currents and are commonly used in electric vehicles. The collaboration by Toshiba and Rohm will…