COVER Table showing reliability of different electronic assemblies according to the IEC 1709 3) . Source: Koh Young Koh Young’s KY-P3 M3 overview and close-up images. Source: Koh Young Need for accurate inspection Pin connection assembly for electronic modules often occur near the end of the final assembly process. Yet, if manufacturers identify defects at this stage, the PCB must undergo arduous rework or, in some cases, scrapped altogether. Therefore, manufacturers must accurately inspect the boards beforehand. Various testing methods such as manual inspection, electrical test, x-ray inspection, and more are available. However, some techniques are becoming obsolete as board complexity continues to increase. For example, manual inspection of a board with over 100,000 connector pins is not efficient and will likely allow failures to escape. Even worse, these pins are becoming shorter and thinner, so traditional methods cannot detect crushed and bent pins. Enter Automated Optical Inspection (AOI), which is a machine-based visual inspection process for the entire PCB. The camera autonomously scans the board and detects production faults, including critical defects (e.g., missing pins) and quality concerns (e.g., deviated pins, bent pins). An AOI solution is the best choice to achieve the assembly quality requirements. Various pin applications with 3D AOI capability Realizing the growing importance of accurate inspection, Koh Young has developed the KY-P3 pin inspection solution. Using its proven True 3D inspection innovations, the company designed the KY-P3 to identify defects like missing pins or pin offset, as well as co-planarity and position by accurately measuring the pin-to-pin pitch. Like its sister AOI systems, the KY-P3 uses the Koh Young patented Source: Koh Young KY-P3 defect detection examples. Missing: Defective when the pin is absent from its expected location. Source: Koh Young Dimension (Height): Defective when height dimension varies from the reference. Source: Koh Young Pad Overhang (Offset-x/y, Center Distance): Defective when the center point exceeds the programmed reference center. Source: Koh Young Odd Shape – Shoulder Coplanarity: Defective when the height gap between two shoulders is out of tolerance. 56 EPP EUROPE November 2019
COVER shadow-free Moiré technology to measure the z-axis profilometry across the entire board. The company uses the height threshold to extract the pin body and pin tip information. This dataset allows the KY-P3 to provide a reliable pin height and offset measurement with CAD dimensions. It simply locates the pin body accurately during the very first stage of the inspection process. Superior flexibility combined with proven accuracy Among the many inspection items, the KY-P3 strength is in its height measurement capabilities, which guarantees 0.75 percent accuracy for pins up to 25 mm height. When measuring pin height on an angled or pointed tip, the challenge is complicated compared to pins with the more common flat tip. The KY-P3 exercises a height range algorithm, which sets the minimum and maximum heights, and then calculates the average height. Using this height range, manufacturers can obtain accurate height information for sharp pin tips with the KY-P3. Sources 1) Joakim Mattsson, Thorsten Callies, Bart Kerckhof ed. Press-Fit Technology. TE Connectivity, July 2014, Publication. Print. 2) HOME › Press Releases › Pin Insertion Machine Market worth 276.7 Million USD by 2022. (n.d.). Retrieved. 3) Sauveplane, J. B., & Mindreci, G. C. (2016). Connector Press-Fit Technology for space-flight applications. ESA/ESTEC, 1–8. Retrieved July 20, 2018. Accurately extracting the pin tip translates to an accurate pin offset measurement. Manufacturers often use a specific distance below the pin tip to locate a suitable measurement plane reflecting the full pin length. Then, the manufacturer calculates the center point of the measurement plane as a reference point to measure the absolute and relative pin-to-pin distances. The KY-P3 helps manufacturers ensure maximum alignment accuracy, which is essential in producing high-quality PCBs. Increased efficiency, reduced costs The drive to improve profitability is constant. The synergy between the KY-P3 pin inspection solution and the KSMART software of the company allows manufacturers to improve the overall process and drive costs down. For example, manufacturers can track the pin-insertion machine performance in real-time using RTM@KSMART. The software module allows manufacturers to monitor and manage Cpk data by part, job, or fixture in real-time. Going further, The KY-P3 can generate a significant set of reliable measurement data to help manufacturers optimize the pin-insertion machine and adjust tolerances to meet customer Cpk expectations. Source: Koh Young EPP EUROPE November 2019 57
