{"id":172,"date":"2023-01-27T21:51:14","date_gmt":"2023-01-27T21:51:14","guid":{"rendered":"https:\/\/www.pcbassemblyexpress.com\/blog\/?p=172"},"modified":"2023-01-27T21:51:15","modified_gmt":"2023-01-27T21:51:15","slug":"pcb-assembly-explained","status":"publish","type":"post","link":"https:\/\/www.pcbassemblyexpress.com\/blog\/pcb-assembly-explained\/","title":{"rendered":"PCB Assembly Explained"},"content":{"rendered":"\n

PCB Assembly is the process of building a Printed Circuit Board (PCB). That means placing the components on their designated locations and soldering them to the board. This creates both mechanical and electrical connections between the PCB and the components.<\/p>\n\n\n\n

There are multiple methods to do PCB assembly. Hand soldering is the most basic one. It consists of hand-placing the components to then using solder wire and a soldering iron. This tedious manual process is only viable for very small batches. For larger quantities, automation is required.<\/p>\n\n\n\n

Surface Mount vs Through Hole Assembly<\/strong><\/h4>\n\n\n\n

There are two mounting technologies in PCB Assembly. The first developed technology was through-hole assembly. It works by inserting the component\u2019s pins or leads into copper-plated holes that pierce through the PCB. On the other side of the board, solder is applied and molten with heat to form a junction.<\/p>\n\n\n\n

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Through Hole Assembly <\/em><\/figcaption><\/figure><\/div>\n\n\n\n

Through hole was the dominant technology in the early days of the PCB industry. Over time, with the increasing need for miniaturization, surface mount technology was developed.<\/p>\n\n\n\n

Surface mount consists of placing components onto the surface of the PCB. The component package has flat legs, pads or solder balls. Previously, solder paste (a mixture of small solder particles and flux) is applied over the PCB pads, so the component\u2019s pins sit over a layer solder paste. This eliminates the need of holes on the PCB. Finally, the board and components are heated up, melting the solder to form a junction in a process called reflow<\/em>.<\/p>\n\n\n\n

Surface mount devices are typically smaller than through hole components, in part because of the absence of leads, allowing more compact designs with the same functionality and capability.<\/p>\n\n\n\n

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Surface Mount Assembly <\/em><\/figcaption><\/figure><\/div>\n\n\n\n

Materials and Equipment<\/strong><\/h4>\n\n\n\n

For automated PCB assembly, specialized equipment is required. To operate the machines, staff with special training is needed. This means a considerable initial investment, but the resulting streamlined process is capable of building a large number of boards in relatively short time. The most important equipment units that you will find in an automated assembly line are:

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For Surface Mount Assembly<\/p>\n\n\n\n