Manufacturing steps of PCBA board

PCBA is the abbreviation of PCB Assembly, PCBA board refers to the complete circuit board when all components and connectors are soldered.Traditionally manual processes (hand soldered) were used to develop PCB Assemblies. In modern days this process is automated due to low pitched ICs, small components footprints and dense circuits. PCB assembly process steps can be divided into the following links for easy understanding.

Bare boards that have not yet undergone pcba process steps

Manufacturing process of PCBA board

Step-1 (PCB Design): Circuit designers develop circuits using various PCB design tools including Altium, Protel, Orcad and Kicad etc. These tools can transform the designed circuits into manufacturing files. PCB manufacturing foundries use these files to draw conductive pathways (copper usually) over non-conductive substrate (like FR-4) with specific dimensions.

The result is bare PCB board with all required pathways and drilled vias, which is the first requirement of PCBA

Step-2 (Components Procurement and Storage) : The first step of the process yields bare PCB and BoM (Bill of Material). Bill of material (BoM) enlist the all the components required for the PCB assembly including ICs, passive components (R, L, C), connectors and through hole components. In this step these components are arranged, inspected and properly stored prior to installation on the bare PCB board.  

Step-3 (SMD components stuffing): The ICs, passive components and connectors can be SMD (surface mount Devices) or through hole. Both have different approaches for stuffing and soldering on the board. In this step we will discuss SDM components stuffing only.

If SMD need to be stuffed on one side only, a screening printer is used to print solder paste on the pads using stencils. After this placements of components are carried out and hot air is passed though the assembly which is called “Reflow”. This type of soldering is called Reflow Soldering which is different as compared to THT technology. 

If PCBA board has SMD components on both sides, and additional step is involved before screening of solder paste. In this new PCBA manufacturing process SMT adhesives are applied to bond surface mount devices (SMD) to the PCB board. These adhesives bond the components to the board and avoid their displacement during next processes. After applying adhesives solder paste is applied though screening printers and components are placed. Reflow soldering is the last step in this process. 

SMD plugin

Step-4 (X-Ray Inspection): After SMD components placement an X-Ray inspection is carried out to check for any shorts or unsoldered pins. Multiple strategies are followed to debug the PCB along with manual soldering.

Step-5 (Wave soldering):  For THT (through-Hole technology) components a different process of soldering is used which is termed as “Wave soldering”. THT components have long leads, so drilled holes are made available on PCB board. Leads are inserted in these holes and that are soldered into the board and waves of molten solder is applied to attach the leads to the PCB board.  

Step-6 (Manual Soldering): Due to some uneven and non-standard components and objects, manual soldering is carried out in this pcb assembly manufacturing process. This step is skipped if all components are as per standard and got proper geometry. 

Step-7 (Final Inspection and Packaging): In this last but most crucial step of PCBA development, a thorough inspection is carried out of the assembly. Although inspections are carried out during each step, but this final inspection is most important. Final inspection is carried out by most experienced and well trained quality inspector who can point out any issue and debug before packaging. 

FS Technology PCBA Services

FS Technology is serving the PCBA industry since 18 years by providing cost effective solutions for low to high volume demands. Being equipped with state of the art production and inspection equipment and trained professionals for the above steps, FS tech is emerging as global partner for technology innovators. FS Tech project management exposure with international partners ensures smooth flow of the projects. Meeting high quality standards and on time completion of projects distinguishes FS Tech among other competitors. 


The above is the whole content of “Printed Circuit Board Assembly Manufacturing Process”. If you are still new to the PCB industry, the content below is for you!

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