Complete PCB Assembly Workflow For Beginners

When designing and ordering the Printed Circuit Board Assembly (PCBA), the process involves transforming your electronic designs from a digital schematic into a fully functional hardware prototype. The complete flow may sometimes feel a little overwhelming for the user at first. We must start from the schematic and design the PCB layout. Then, the manufacturing files are assembled, and the board with the right components is prepared.

Fortunately, manufacturers like JLCPCB make this process simple, affordable, and accessible to everyone. In this article, we will walk through the entire PCB assembly workflow step by step, using a DIY NiMH/NiCd battery charger project as an example. By the end, you will understand the complete flow from schematic to finished PCB and how to order PCBA directly from JLCPCB by uploading Gerber, BOM, and CPL files.

Step 1: Start with the Schematic Design.

Every PCB begins with a schematic diagram; the logical blueprint defines how electronic components connect. PCB schematic tells us the pins, quantities, and component values. There is a lot of software out there, but some industry-standard ones are KiCad, Altium Designer, and EasyEDA. It is always suggested that standard component libraries be used, and a net checking rule should always be performed after completing the schematic.

In my NiMH/NiCd charger project, the schematic included a charging IC, current-limiting resistors, and connectors for the battery. This schematic was the foundation of the final PCB design.

Step 2: PCB Layout Design

Once the schematic is complete, the next step is to convert it into a PCB layout. This step is where the design becomes physical. After importing all the components, placement and routing are done in this step. This step cannot be seen merely as the art of copper tracing, but there are a lot of considerations, from signal integrity to impedance matching. In the example design of the charger board, I arranged power components closer to the input, some decoupling capacitors near the IC, and connectors at the edges for easy access.

Always keep in mind the minimum capabilities of the manufacturer; the design is fabricated as per those. There is a minimum resolution of traces, spacing, and vias, all available on the manufacturer's website.

Step 3: Preparing Manufacturing Files (Gerbers)

As one of the previous articles says, Gerber files are the most reliable option for PCB manufacturers to fabricate boards nowadays. These files describe each layer of the PCB: copper traces, silkscreen, solder mask, and drill holes. Gerber files include top and bottom copper layers, solder mask, drill, and board outline DXF.

If you use EasyEDA, you can directly generate a JLCPCB-compatible Gerber ZIP file. In KiCad and Altium, ensure you use the correct plotting settings. EasyEDA also includes the part and footprint information directly from the online database.

Step 4: Generating BOM and CPL Files.

When you want PCBA (Printed Circuit Board Assembly),you must also provide the supporting files containing:

• BOM (Bill of Materials): A detailed list of all components, including part numbers, values, packages, and manufacturers.

• CPL (Component Placement List): Also called the Pick-and-Place file. Provides X-Y coordinates, rotation, and reference designators for SMT machines.

For example, the BOM of my charger project included resistors, capacitors, a microcontroller, and connectors. The CPL ensured that each component was placed correctly during automated assembly. Copies of both is attached below. In EasyEDA, all the files, Gerber, BOM, and CPL, are available under the fabrication section.

Step 5: Step-by-Step Ordering Process:

1. Go to the JLCPCB PCBA page.

2. Upload the Gerber file of your project.

3. Upload BOM and CPL files.

4. Preview your PCB assembly in the browser; JLCPCB automatically maps parts to their stock library.

5. Select components from JLCPCB’s vast parts database. It will automatically mark DNP for parts that are not required or that you have not chosen.

6. Choose assembly options (e.g., SMT assembly, selective assembly).

7. Confirm order and proceed to checkout.

JLCPCB has faster services because BOM matching is done internally with already stocked components. Large and fully capable assembly lines can cut the overall assembly cost and time, which makes it ideal for prototyping.

Why Choose JLCPCB for Beginners?

While there are many PCB service providers, JLCPCB is especially suited for students, makers, and beginner engineers because of:

• Integration with EasyEDA for one-click ordering.
• Massive component library with real-time stock updates.
• Affordable pricing with PCBs starting at $2 for five boards.
• Reliable quality and fast global shipping.
• End-to-end workflow from Gerber to PCBA in a single platform.

JLCPCB becomes a one-stop solution to all prototyping needs from PCB manufacturing to PCBA, CNC, and 3d printing.

Conclusion:

The complete PCB assembly workflow from schematic design to receiving a fully assembled PCB is discussed here and concluded as follows:

1. Create the schematic.
2. Design the PCB layout.
3. Generate Gerber files.
4. Prepare BOM and CPL files.
5. Upload everything to JLCPCB; remember that Gerber files alone are not enough for a PCBA order.
6. Receive, inspect, and test your assembled PCB.

Using my NiMH/NiCd battery charger project as an example, we’ve seen how each step works in practice. For beginners, the combination of EasyEDA + JLCPCB provides a cost-effective and professional way to go from an idea to a working circuit board.