Ideas & Solutions
PCB specification for press-fit technology
The principle for a press-fit connection is that a contact terminal of the connector is pressed into a printed circuit board instead of soldering. Production of printed circuit boards that meet the requirements of press-fit technology is extremely important for a good press-fit connection. The material and structure of a printed circuit board plated through hole has at least as high an influence on the quality of a press-fit connection as the press-fit zone itself. The standard «EN IEC 60352-5:2020 Solderless Connections Press-In Connections. General Requirements, Test Methods and Practical Guidance» covers the specifications for the structure of a printed circuit board and contain the design guide for Press Fit Rigid Printed Board Backplanes. The decisive characteristic of a high-quality press in connection is not only a final diameter of the plated through hole withing the permissible tolerances (usually +/-0.05 mm comparing to +/-0.1 mm for regular holes), but also a correct hole structure: When placing the PCB order, don't forget to mention in your PCB documentation the table with all press-fit hole sizes with a special, more strict tolerance requirements. In some high-speed projects it could be interesting to use the backdrilling technology in combination with press-fit connectors, to improve the signal integrity by removing the "stub" - the unneeded part of the plated hole under the connector pins which acts as "antenna": More about the PCB hole requirements for the press-fit technology (PCB hole HAL tin, PCB hole copper) you can find here (de/eng) and here (eng)