Two suppliers to the electronics industry are combining. Entegris has agreed to acquire electronic chemicals maker ATMI in a deal worth $1.2 billion. Entegris’s business is mainly in filtration and silicon wafer handling equipment. It earned $69 million on $716 million in sales in 2012. ATMI supplies materials for copper circuitry, deposition, ion implantation, and other semiconductor manufacturing techniques. The company, which recently agreed to sell its bioreactor business to Pall, earned $42 million on $407 million in sales in 2012. The transaction follows another recent deal in the electronic materials sector: Merck KGaA’s agreement to acquire AZ Electronic Materials for $2.6 billion.