Assembly of printed circuit boards

Kulbir Singh
Kulbir Singh
Kulbir Singh has worked as an engineer in a variety of settings. He runs his own company InfoRange IT Inc in Calgary, Alberta. Kulbir shares his experience and insight about his work in a PCB manufacturing facility, where he worked as a production engineer looking after manufacturing of motherboards.

Assembly of printed circuit boards

Have you ever wondered how Printed Circuit Boards (PCBs) are made? How are all the different components on the PCB put up on the board? It’s all so fascinating as much as it may sound complicated! I have had the oppourtunity to work in a big organization, PUNCOM where assembly of PCBs was an important part of the factory’s production. I had the opportunity to work here as a production engineer in the assembly section. It not only allowed me to have an insight into the production processes but also needed me to plan a variety of processes, assembly procedures, personnel allocation to processes etc. Our organization was into manufacturing and sales of telecommunication equipment.We had a variety of product lines involving multiplexers in PCM (Pulse code modulation), DTL (Direct to line) and radio technologies. The wide product range of PUNCOM covered and still covers voice and data multiplexers, optical/transmission equipment, digital radios, PLCC, broadband equipment and related services. It caters to the growing telecommunication, networking and broadband needs of major organizations and service providers. EMS collage of word concepts While all the science behind these products involved electronics, electronic circuitry, design logistics, PCB design, circuit innovation and testing, the processes involved in the manufacture of the final products were unique and involved aspects of electronic, electrical, chemical and mechanical engineering. The assembly section overlooked the manufacturing and production of the designed product. I’ll discuss a few processes and procedures that I, as a production engineer, was involved with, in my role, there. The assembly section almost covered one-third area of our main floor. We were a team of about 60 people in the assembly section. The store carrying all the inventory was next to the assembly section of the factory. Requistion orders for parts would be made by our department and the inventory for parts would be released by the store. All these transactions were computerized and centrally monitored. The whole plant as air-conditioned. There were other buildings and departments in our organization and these were all part of a great, modern, electronic product manufacturing facility. The components were inserted on the PCB using highly sophisticated machines. These machines guided the operators with optical guidance system about exact placement of components on the blank PCB. The machines were called Blakell Semi-Automatic Insertion machines. The optical light beam would exactly fall into the place where the component would have to be placed. The machine was programmed to guide in a sequential way for all components to be placed on the PCB in their precise location, one after the other. All the components would be placed in containers around the working area in the machine. The components were parts like resistors, capacitors, transistors, Integrated circuits, microprocessors, diodes and the other electronic parts that we commonly spot on a computer mother board. The operator would pick up a component from one of the special containers and put it a the spot where the machine threw a light signal in the form of an exact light point. The process would continue till all the components would be put on the printed circuit board one after the other. Eventually the batch of PCBs with all the components inserted on these would be taken to a wave soldering machine. The wave soldering machine was housed in a separate room, which was given temprature control through exhaust fans and other related systems. The wave soldering is a technology involved thermally treated, molten liquefied solder material in a reservoir in the machine. A conveyor belt moves on the machine. The distance between the surface of the molten solder and the underside of the PCB is delicated adjusted. The PCB’s are placed on the belt and the belt moves in a controlled speed just above the molten solder. As the components on the PCB get in touch with the molten solder, the soldering takes place for the entire batch of PCBs on the moving belt. And then there would be testing of PCBs using a machine called KTS In-Circuit Tester. This would test the PCB for it’s different components after installation using access to various circuit nodes. A variety of other test processes would happen too, using spectrum analyzers, data analyzers, logic analyzers, power meters etc. It was an enriching experience to work in the production assembly section of an electronic and IT based manufacturing organization! Industrial, manufacturing and production engineering are fields that can be applied in the translation of ideas to realities in any area, product or process!