The PCB Manufacturing Process for Engineers and Hobbyists by PCBgogo

PCBgogo, one of the largest and most popular PCB manufacturers in Shenzhen, China. Built over 2400 sqm of land, this company specializes in manufacturing high-quality PCB’s (Printed Circuit Boards) in low price. These boards are custom designed according to your needs. Just looking at the “product categories” PCBgogo specializes in, we realize how much they have expanded over the years. These categories include data communication, optical networking, medical treatment, industrial control, aerospace/military etc. just to name a few.

What is Printed Circuit Board (PCB)?

Printed Circuit Boards (abbreviated as PCB) are the backbone of all electronics. They are found in nearly all electronic devices from computers to small devices like calculators and digital clocks. PCB actually have a connecting function. They connect all the electrical components and at the same time, they route electronic signals according to the device’s need through a network of copper pathways.

Types of PCB and composition | PCB Manufacturing:

There are three major types of PCB

  • Single-sided (only one layer of conductive material, best used for low-density designs)
  • Double-sided (two conductive layers of material)
  • Multi-layered (has three or more conductive layers)

The basic composition of a circuit board consists of a thin copper foil which acts as a conductor. The copper sheet is laminated in between sheet layers of a non-conductive substrate. The most commonly used PCB is FR-4. Each conductive layer is connected by drilling holes and then copper plating them. There are four main parts to a PCB i.e. the substrate, the copper layer, solder mask and the silkscreen which are layered from the inside out.  

The PCB Fabrication Process By Pcbgogo:

Step 1: Designing your PCB

The first step is to design your PCB using a PCB designing software on your PC. Commonly used PCB design software include Eagle, OrCAD, and Altium Designer. Next, you will print out your layered design using a laser printer. Photo basic glossy transparent paper is used here. Manufacturers use a special plotter as a printer which makes photo films of the PCBs. Now you have to make sure that your components will actually fit into your design.
For this simply take print of your design and set your components to test if your design is correct. Now keep in mind that for the final layout you will need to use black ink, it should be dark enough to block UV light. Wait for the ink to dry then cut out the layout of your design. Keep a generous amount of blank space, it’ll make your process easier. Next, place your paper layout onto the PCB and apply pressure onto it by pressing an iron box onto the PCB. The layout is now attached to the PCB. Now to remove the excess paper soak it in water for two minutes, then peel off. If some bits still remain, then soak it for extra time then rub them off using your finger.

Step 2: Etching your PCB:

PBC has a number of copper layers with the substrate sandwiched in-between. By etching, you will remove the excess copper and leave only the desired copper traces which will act as pathways. Although there are many processes you can choose from for etching but here we will discuss the most commonly used one. The principle is to place the board in a chemical preparation which will eat away the excess copper. The chemical preparation is made up of ferric chloride or hydrochloric acid in this case. Dip the PCB in the solution. The copper layer will be removed over time. After etching, remove the black color by rubbing with acetone to give it a shiny finish.  Now, the PCB layout is complete | PCB Manufacturing.

Step 3: Drilling

To attach the respective components onto the PCB you will use the process of drilling. To find the location of the drill spots an x-ray location is used. Basically, a hole is drilled in the shape of rings. Drill bits, made of tungsten carbide, are used for making holes in PCBs. A Dremel drill press is commonly used in this process. For production on a large scale, automated drilling machines are used. For very small holes, laser directed processes are used.

Step 4: Conductor Plating:

Next plating of the surface material is done by using gold, tin, copper or nickel. This is done through electroplating. The outer layer has copper connections and in order to make it solderable, it must be plated prior to the process.

 

Step 5: Adding Solder Resist:

The areas which are not to be soldered are covered with a solder resist or solder mask. It is a thin layer of polymer that is applied to copper traces for protection from oxidation and to prevent solder bridges to form from adjacent or closely placed copper traces | PCB Manufacturing.

Step 6: Testing your PCB:

There are many ways to test your PCB. Industrial applications use methods such as Bed of Nails Test, Rigid Needle Adaptor, and CT Scanning Test etc. The technician performs electrical tests on the PCB. A small voltage is applied to the PCB to ensure that the voltage appears at the appropriate contact points where it is to be directed. Large industrial such as PCBgogo also use the Flying Probe test to test PCBs.

Step 7: Assembling:

The final step is assembling the PCB in PCB Manufacturing Process. All the respective components are assembled onto the respective holes. This can be done by either through-hole construction, which involves inserting the components into the holes drilled in the PCB and soldering to the copper traces, or surface-mount construction, which involves mounting the components directly onto the surface of PCBs. The result is the same, the components are fixed onto the printed circuit board, either mechanically or electrically.

Advantages of PCB over Bread-Board:

1: PCBs are more flexible in size and can be custom designed according to your need.

2: You can get a much higher density board with PCBs.

3 The circuit designs for PCBs are neater and well designed.

4: The custom shape of PCBs can even cover odd-shaped components.

5: For the production of a large number of PCBs you can use fully automated machines and the cost is lesser.

 

Read Next Article: Best PCB Manufacturer in China – PCBGOGO Review

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