Authors: Atharv Nikam, Saurabh Jagtap, Priti Choudhari, Gaurav Uphade, Abhijit Lohakane
Abstract: Shunt soldering in MID (Measuring Instrument Directive) meter printed circuit boards (PCBs) is a critical manufacturing operation that directly affects electrical accuracy, reliability, and produc-tion throughput. Conventional manual soldering of multiple shunts is time-consuming and prone to inconsistency due to operator dependency. This paper presents the design and implementation of an automated dual-heater shunt soldering system for MID meter PCBs, capable of soldering four shunts per PCB with high precision and repeatability. The proposed system integrates a fixture-based automation mechanism controlled by a PLC, employing three pneumatic cylinders and a stepper motor–driven linear positioning system. One pneumatic cylinder securely clamps the PCB, while two heating cylinders equipped with soldering gun tips simultaneously heat both ends of the shunt to ensure uniform solder joints. The stepper motor indexes the fixture in four discrete steps of 17 mm, covering a total travel of 51 mm, followed by automatic homing. At each position, solder wire is applied and heated automatically. Experimental evaluation demonstrates significant improvements in cycle time, soldering precision, and process repeatability, making the system suitable for industrial MID meter production and scalable automation environments.
