of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

CEO — Robert C. Daigle: Mr. Robert C. Daigle is retiring as CEO and will continue to serve on the Board as Executive Chairman, while Guy Shechter has been appointed as the new CEO.

Entry into a Material Definitive Agreement. On June 1, 2026, Amtech Systems, Inc. (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Titan Partners Group LLC, a division of American Capital Partners, LLC (the “Underwriter”), pursuant to which the Company agreed to issue and sell in an underwritten public offering (the “Offering”) an aggregate of 2,926,829 shares of its common stock, par value $0.01 per share (“Common Stock”), at a price to the public of…

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

President and Chief Operating Officer — Guy Shechter: Mr. Guy Shechter was appointed as President and Chief Operating Officer, bringing significant leadership experience from previous roles.

Chief Financial Officer — Thomas Sabol: Mr. Thomas Sabol was appointed as the Chief Financial Officer, replacing Mr. Mark Weaver who served as Interim CFO.

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

Interim Chief Financial Officer — Mark Weaver: Mr. Mark Weaver was appointed as the Interim Chief Financial Officer to replace Mr. Wade M. Jenke, who resigned.

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

Other Events. On December 9, 2025, the Board of Directors (the “Board”) of Amtech Systems, Inc. (the “Company”) authorized and approved a share repurchase program for up to $5 million of the currently outstanding shares of the Company’s common stock over a period of 12 months. Under the stock repurchase program, the Company intends to repurchase shares through open market purchases, privately-negotiated transactions, block purchases, 10b5-1 plans, or otherwise in accordance with applicable fe…

Chief Financial Officer — Wade M. Jenke: Mr. Jenke resigned to assume an executive role at another company.

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

Director — Asif Y. Jakwani: Appointment of Asif Y. Jakwani to the Board of Directors.

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

Termination of a Material Definitive Agreement. Effective September 11, 2024, Amtech Systems, Inc. (the “Company”) has paid off the $3.8 million outstanding under its Loan and Security Agreement with UMB Bank, N.A. and voluntarily terminated this facility. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. AMTECH SYSTEMS, INC. Date: September 17, 2024…

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

CFO — Lisa Gibbs: Lisa Gibbs resigned as CFO to take an executive role at another company, and Wade M. Jenke was appointed as the new CFO.

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

Changes in Registrant’s Certifying Accountant. On March 1, 2024, Amtech Systems, Inc. (the “Company”), upon the approval of the Audit Committee (the “Committee”) of the Board of Directors of the Company, notified Grant Thornton LLP (“Grant Thornton”), the Company’s current independent registered public accounting firm, that it would be dismissed from that position effective March 1, 2024. The audit reports of Grant Thornton on the Company’s consolidated financial statements as of and for the…

Robert C. Daigle: Compensatory arrangement amendment for Mr. Daigle.

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…

of Form 8-K and shall not be incorporated by reference into any filing of the Registrant, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference in such filing. The information in this Current Report, including the accompanying Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabil…