It’s often hard to distinguish between real life technology and devices you hear about in science fiction novels. Most of you probably use your computer to play solitaire and watch funny videos on the internet. This incredible technology has enveloped our society and even the most basic cell phone has more capabilities than a computer had 20 years ago.


To understand what circuit boards are made of, you must know how they are constructed and why each component is necessary to ensure a seamless product. The assembly process can be quickly done by heavy machinery, but dedicated computer enthusiasts still prefer to assemble their circuit boards by hand to accommodate unique modifications.


The construction of circuit boards is completed in a seven-step process consisting of creating a base circuit board, solder pasting as a primer, installation of surface mounted components, reflow bonds the paste, inspection of the circuit board, component insertion, and one last functionality test. If you have any questions during this process, visit this link for more information.


Printed Circuit Board Base

The distinct green surface of a circuit board has four layers: a substrate, copper, soldermask, and silkscreen. The substrate is a sturdy material that will ensure the component doesn’t bend under pressure. The copper works as a conductor to transmit electrical currents at a rapid pace. The soldermask is an insulator that protects against malfunctions that accidentally solder the wrong area. The silkscreen is placed over the entire unit and has letters and numbers to make the board easier to work on.


Solder Pasting

This is a quick step where you will place a thin stencil over the board and apply solder paste to the exposed sections. Solder paste will facilitate the proper bonding of the solder to the surface of the board.

Mounted Components

At this stage, the board is moved along the assembly line by a large vacuum arm. A machine will then insert all the surface mounted components that will perform most of the functions of the circuit board.


During the reflow stage, the board is placed into an oven that is heated to 250 degrees. This intense heat melts the solder in the paste and will ensure a strong bond between the surface mounted components and the base.


After the reflow process, the board is manually inspected as well as inspected by an Automatic Optical Inspection (AOI). The AOI has several cameras that closely inspect the quality of the solder and ensure all components are correctly assembled.


Component Insertion

Many circuit boards have components that need to be inserted in the board as opposed to mounted on the surface. These boards will have holes drilled during the first stage of assembly where the component will be inserted.  After the component is inserted it will undergo a process called wave soldering, where solder paste is applied to the entire bottom side of the board will undergo a second reflow process.


Functionality Test

The last stage is a basic functionality test to ensure your circuit board is ready for your computer.