Guide on PCB Manufacturing Process

The printed circuit board (PCB) forms the backbone of all major electronic devices. These miraculous inventions appear in almost all computing electronics, including simpler devices such as digital clocks, calculators, and so on. In short, the PCB tells where power goes and makes your electronics come to life. As a professional PCB manufacturer, we are going to share the something about PCB with you.

PCB Manufacturing Process

Step 1: Design and output

The board should be strictly compatible with the PCB layout created by the designer using PCB design software. Commonly used PCB design software includes Altium Designer, OrCAD, Pads, Eagle, etc.

Step 2: From file to movie

After the designer outputs the PCB schematic file and DFM inspection by the manufacturer, PCB printing is started. Manufacturers use a special printer called a plotter to make photo films of a PCB to print circuit boards. Manufacturers will use these films to image PCBs.

Step 3: Print the inner layer

This step in PCB manufacturing prepares to make the actual PCB. The P laminate is the ideal body to receive the copper that makes up the PCB. The substrate material provides a robust and dust-proof starting point for the PCB. Copper is pre-bonded on both sides. The process involves scrubbing copper to reveal the design of the film.

Step 4: Remove unwanted copper

After removing the photoresist and covering the copper we wish to retain with a hardened photoresist, the board will move on to the next stage: removing unwanted copper.

Step 5: Layer alignment and optical inspection

After all layers are cleaned and ready, the layers need to be punched to ensure they are all aligned. The positioning holes align the inner layer with the outer layer. The technician puts each layer into a machine called an optical puncher, which can make precise correspondences, so it can precisely punch positioning holes.

Step 6: Layering and Binding

At this stage, the circuit board is formed. All the individual layers are waiting for their combination. After preparing and confirming the layers, they just need to merge together. The outer layer must be connected to the substrate.

Step 7: Walkthrough

To find the location of the drilling target, the X-ray locator can identify the appropriate drilling target point. Holes are then punched in the appropriate positioning holes to secure the stack for a series of more specific holes.

Step 8: Plating and copper deposition

After drilling, the panel is moved to the plating layer. This process uses chemical deposition to fuse different layers together. After thorough cleaning, the panel will undergo a series of chemical baths.

Step 9: Outer layer imaging

We first placed the layers in a sterile room to prevent any contamination from adhering to the surface of the layer, and then applied a layer of photoresist to the panel. The prepared panel enters the yellow room. Ultraviolet rays can affect photoresist. The UV level at the yellow wavelength is not sufficient to affect the photoresist.

Step 10: Plating

We returned to the plating room. As we did in step 8, we plated a thin layer of copper on the panel. The exposed portion of the faceplate of the outer photoresist stage receives electroplated copper.

Step 11: Final etching

At this stage, tin protects the required copper. Remove unwanted bare copper and copper under the remaining resist layer. Also, apply chemical solution to remove excess copper. At the same time, tin can protect valuable copper at this stage.

Step 12: Application of solder mask

Before applying solder resist to both sides of the board, clean the panel and cover with epoxy solder resist ink. The board receives a beam of ultraviolet light that passes through the solder mask photo film. The covered part is still not hardened and will be removed.

Step 13: Surface treatment

To increase the solderability of PCBs, we electroless plate them with gold or silver. At this stage, some PCBs also accept hot air pads. Hot air leveling produces a uniform pad.

Step 14: Silkscreen

The soon-to-be-completed circuit board receives inkjet writing on its surface to indicate all important information related to the PCB. The PCB finally enters the final coating and curing stage.

Step 15: Electrical test

As a final precaution, technicians perform electrical tests on the PCB. Automated procedures confirm the functionality of the PCB and its consistency with the original design.

Step 16: Profiling and V-scoring

Cut different boards from the original panel. The methods used are either focused on routers or using v-slots. The router planer has small protrusions along the edge of the circuit board, and the v-shaped groove cuts diagonal channels along both sides of the circuit board.