How many steps do you know for the PCB assembly process?

As a PCB & PCB assembly manufacturer, it’s necessary to let you know what our PCB assembly services are. PCB assembly is a complex and lengthy process involving many different phases, and also the key process for realizing the functions of the final product. Every steps must be executed exactly by paying utmost attention. Any minor error in the assembly process will lead to the failure of the final assembly. To help you know more the whole PCBA process, we've explained each steps in detail below.

Before the Assembly Process

1. Design for Manufacturability (DFM) Check

Then what’s the DFM CHECK? before the actual assembly process, manufacturers thoroughly check the PCB design file to check the functionality, and manufacturability. This stage, we called DFM, checks design specifications of a PCB, analyze any missing, redundant or potentially problematic features. The stage helps detect design errors, and allows the designers to instantly clear all the flaws, which in turn leads to successful production.

2.Electronic Components Checking

Ucreate PCB will do another step before assembly, that’s components checking, our engineer team will check the components package, value, qty,Footprint, part number, etc. if matched the BOM and the PCB board. there exist any mistakes we will solve with customer before start assembly.

Actual PCB Assembly Process steps

1.Solder Paste Printing

The solder paste printer which is designed to apply solder paste (a paste of small grains of solder mixed with flux) using a stencil and squeegees to the appropriate pads on the boards.

2.  Placing of Components

This stage of PCB assembly process is now completely automated. The pick and place of components such as surface mount components, which were once done manually, are now executed by robotic pick and place machines. These machines accurately place the components to the pre-planned areas of the board.

3.Reflow Soldering

Once the solder paste and surface mount components are all in place, they need to remain there. This means the solder paste needs to solidify, adhering components to the board. To accomplish this, the assembly with the solder paste, and the components on it is passed through a conveyor belt, which moves through an industrial grade reflow oven. The heaters in the oven melt the solder in the solder paste. Once this melting is done, the assembly is again moved in the conveyor belt, and exposed to a series of cooler heaters. The purpose of these coolers is to cool down the melted solder, and to attain a solidified state.

4.Inspection

After the reflow process, the PCB is subjected to inspection to check for its functionality. This stage helps identify poor quality connections, misplaced components, and shorts due to the consecutive movement of the board during the reflow process. The PCB manufacturers employ several inspection steps such asVisual Inspection,automatic optical inspection, andX-ray inspectionto examine the functionality of the board, recognize lower-quality solder, and identify any potentially hidden problems.

5: Through-Hole Component Insertion

Some types of PCBs require the insertion of through-hole components in conjunction with the usual SMD components. This stage is devoted for such component insertion. For this, plated-through hole is created with the help of which PCB components pass signals from one side of the board to the other. The PCB through-hole insertion usuallyManual SolderingorWave Solderingto achieve the results.

Wave SolderingManual Soldering

6: Final Inspection and Functional Test/IC Programming

After the soldering step of the PCBA process is finished, a final inspection will test the PCB for its functionality. This inspection is known as a "functional test". The test puts the PCB through its paces, simulating the normal circumstances in which the PCB will operate. Power and simulated signals run through the PCB in this test while testers monitor the PCB's electrical characteristics.

Functional TestIC Programming

7.Cleaning and Packing

As the soldering process leaves some amount of flux residues in PCBs, it is crucial to clean the assembly thoroughly before shipping the final board to a customer. For this, the PCBs are washed in deionized water. After the cleaning process, the board is dried thoroughly utilizing compressed air. The PCB assembly is now ready for the customers’ check and inspection.