Our daily lives are completely dependent on electronics. Electronic components are present in everything, from our cars to our smartphones. The printed circuit board (PCB), also called the brain of these electronics, is at its core.
The majority of individuals can identify printed circuit boards when they see one. You’ll find these tiny chips covering copper and lines components at the centre of disassembled electronic gadgets. These boards are made of copper, fiberglass, and other metal components. They are joined together by epoxy and solder-masked for insulation, and this solder mask is the source of their distinctive green hue.
Let’s explore the process of printed circuit boards with the PCB Assembly Process.
Step 1: Solder Paste Stenciling
You have to apply solder paste on the board as the initial step in making PCBA. Except for using a mask, this procedure is similar to one used for shirt screen-printing. Consequently, only certain sections of the potential PCB can receive solder paste application from assemblers. The assemblers apply the solder paste where they have to place the components.
Step 2: Pick and Place
With the help of pick and place device, the PCBA process continues. Pick and place device installs mounting components or SMDs on the PCB. If you see a PCB, you will find that most non-connectors are SMDs.
Step 3: Reflow Soldering
After assembling, the assemblers ensure that the components and solder paste stays in place. Therefore, they let the solder paste dry before placing the components. Reflow is a technique used in PCB assembly to achieve this.
Once the pick and place procedure is finished, the PCB board is moved to a conveyor belt. A huge reflow oven—which resembles a commercial pizza oven—passes down this conveyor belt. The board is gradually heated to about 480 degrees Fahrenheit or 250 degrees Celsius in this oven, which is made of several heaters. This temperature will cause the solder in the solder paste to melt.
Step 4: Inspection and Quality Control
It is necessary to test the constructed board for operation once the surface mount components have been soldered during the reflow process. This does not signify that the PCBA has been completed. The movement during reflow frequently causes a connection to be of poor quality or lost entirely. This movement can occasionally result in misplaced components connecting parts of the circuit that shouldn’t be connected, leading to shorts, another frequent adverse effect.
Step 5: Through-Hole Component Insertion
Besides SMDs, there are other components on the board. But, the number of other component depends on the board’s type.The most popular type of PCB process is plated through-hole.
A PCB hole fully plated throughout is known as a plated through-hole.The holes help PCB components to transfer signals to the entire board. It is not possible to use soldering paste on this section of the board because it flows inside the hole without creating a bond between components.
Step 6: Final Inspection and Functional Test
After soldering, you have to conduct a test to check the capabilities of the board. A “functional test” is what is being performed here. This step evaluate the performance of the board while imitating the typical operating conditions. The PCB is exposed to the simulated signals and powerin this test while testers observe electrical properties.
The most effective method for cleaning residue off PCBs is to use a stainless-steel, high-pressure washing machine with deionized water. The gadget is not at risk while washing PCBs in deionized water, so the actual water itself—rather than the ions it contains—causes harm to a circuit. As a result, PCBs can be washed in deionized water without harm.