DigiMine.com, the Kirkland-based data mining company, is expected to announce a second round of private financing later this week. Founded last February by three former Microsoft executives, digiMine.com has collected at least $20 million in financing and will use the money to hire more workers and develop its software, sources say. The company is the brainchild of Usama Fayyad, who created and led Microsoft Research’s Data Mining and Exploration Group before he leaving to form digiMine. DigiMine.com is developing software that will help companies sift through huge volumes of information. The company plans to operate as a service that can cull data from company Web sites and provide detailed information for a fee. The company raised $5 million in venture capital in April.