Ultra Clean (UCTT) - 2018 Q4 - Annual Report

or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 28, 2018 Commission file number 000-50646 | Ultra Clean Holdings, Inc. | | --- | | (Exact name of Registrant as specified in its charter) | | Delaware 61-1430858 | | (St ...