Keywords: PCB Manufacturer, PCB Manufacturing

A complex procedure is required in the printed circuit board PCB Manufacturing process for ensuring the finished product performance. After the production of the first layer, the fabrication processes used only differ though circuit boards can be multilayered, double, or single.

PCB Parts

There are four main PCB parts:

Copper Layer: This layer can either be a full-on copper or copper foil coating based on the board type. The point of the copper is still the same Regardless of which approach is used to carry electrical signals from and to the PCB.

Substrate: the substrate is the most important and first part, which is usually made of fiberglass. As it helps resist breakage and provides core strength to the PCB, Fiberglass is used. The substrate can be considered as the PCB’s skeleton.

Silkscreen:  the silkscreen is the final part of the circuit board. Used to show test points, logos, part numbers, component references, and symbols switch settings, the silkscreen is usually on the component side of the board. The silkscreen can be known as nomenclature or legend also.

Solder Mask: the solder mask is the third piece of the PCB, which is a layer of polymer.  The copper is protected by it so that it doesn’t short-circuit while in contact with the environment. The solder mask, in this way, acts as the skin of the PCB.

PCB manufacturing

With verification and design, the steps of the PCB design process start and continue through the circuit boards fabrication. To prevent incomplete circuits or short circuits and ensure accuracy, many steps require machine-driven tools and computer guidance. Before they are delivered to customers and packaged, the completed boards must undergo strict testing.

Step One: PCB Designing

Of course, the design is the beginning step of any PCB manufacture. PCB design and manufacture always start with a plan. For the PCB that fulfills all the requirements as outlined, the designer lays out a blueprint.

Extended Gerber is an excellent piece of software when it comes to PCB design as it also works as an output format. All the information is encoded in Extended Gerber that the designer needs, such as the other pieces of component notation, the number of solder masks needed, and the number of copper layers. All the aspects of the design and different parts are checked once a design blueprint for the PCB is encoded by the software, to make sure that there are no errors.

The finished PCB design is sent off to a PCB fabrication house once the examination by the designer is complete so that the PCB can be built. On arrival, a second check is performed by the PCB design plan by the fabricator. This is known as a Design for PCB Manufacturer check.

Step Two: Engineering Questions and Design Review

Checking the design for potential flaws or errors is another key step of the printed circuit board fabrication process. To ensure there are no incorrect structures or missing components, an engineer goes over every part of the PCB design. The design moves to the printing phase after getting clearance from an engineer.

Step Three: PCB Design Printing

The PCB design can be printed after all the checks are complete. Rather a plotter printer is used, which is a special kind of printer. A film of the PCB is made of a plotter printer.

In two ink colors, the inside layers of the PCB are represented:

Clear Ink: Denotes the PCB’s non-conductive areas like the fiberglass base

Black Ink: Used for the PCB’s circuits and copper traces

This trend is reversed on the outer layers of the PCB design. Line of copper pathways is referred to as by the clear ink but areas where the copper will be removed, are denoted by black ink.

A simple two-layer PCB needs four sheets as the accompanying solder mask and each PCB layer gets its film. One for every layer and one for the accompanying solder mask.

They’re lined up and a hole after the film is printed. The hole is known as a registration hole. It is punched through them. To align the films in the process, later on, the registration hole is used as a guide.

Step Four: Printing the Interior Layers Copper

In the process, the first step is Step four where the making of the PCB starts by the manufacturer. Copper is then pre-bonded to that same piece of the laminate after the PCB design is printed onto a piece of laminate material, which serves as the PCB structure. To reveal the blueprint from earlier, the copper is then etched away.

Next, a type of photo-sensitive film covers the laminate panel. This is called the resist. a layer of photo-reactive chemicals makes up the resistance that hardens after being exposed to ultraviolet light. To get a perfect match between what’s printed to the photoresist and the photos of the blueprint, the resist allows technicians.

They receive a blast of ultraviolet light once the laminate and the resist are lined up using the holes from earlier. Through the translucent parts of the film, the ultraviolet light passes hardening the photoresist. This indicates copper areas that are kept as pathways. In contrast, any light is prevented from getting to the areas by the black ink that isn’t meant to harden. Thus, they can be removed later. 

It is washed with an alkaline solution once the board has been prepared to remove any of the leftover photoresist. To remove anything left on the surface, the board is then pressure-washed and left to dry.

On top of the copper, the only resist that should be left on the PCB after drying is found that remains as PCB part when it’s finally popped free. To make that there are no errors, a technician looks over the PCBs. It’s on to the next step if no errors are present.

Step Five: Remove Copper by Etching the Inner Core or Layers

Before the PCB fabrication process can continue, the inner or core layers of the printed circuit board need to have extra copper removed. Exposing the rest of the board to a chemical and covering the necessary copper on the board is involved in Etching. All unprotected copper is removed from the PCB by the chemical etching process, leaving only the necessary amount of the board.

In the amount of copper etching solvent or time used, this step may vary. More copper might be used in those with heavier structures or large PCBs. Thus, more copper undergoes etching for removal in PCB Manufacturing. Therefore, extra solvent or time is required for these boards.