How is a PCB board( printed circuit board )made?[step by step]
A major concept in electronics is the printed circuit board = PCB. It’s so fundamental that people often forget to explain what a PCB is. Electronics have come a long way. The journey that started with vacuum tubes and relays went into silicon and ICs. It’s becoming more common in consumer products. Therefore, there is always pressure to reduce the size and manufacturing cost of electronic products. This drives manufacturers to seek better solutions.
PCB printed circuit board Beginning
Imagine a life full of wires like loads and wire loads.
Imagine connecting a motherboard to a bunch of wires or even a phone. Now, can you think about the size of this phone? Thus, PCBs were born to fit our delicate everyday objects into their super exotic enclosures.
Connect a lot of wires and a simple PCB
Here, we’re assuming that you’ve probably flown an airplane at least once in your life. My favorite journey is when the plane is slowly approaching. what is yours?
When you get closer you will get a new perspective of your own city. What do you see?
A well-connected system of roads, buildings, cars, houses and people. In the same way, a circuit board is a complete system. They lay the foundation for all the electronic components that bring our objects to life.
What’s inside the PCB(printed circuit board)
Puzzled? Let us first understand the process of making a PCB.
PCBs are usually like layer cakes or lasagna. If not delicious, but carefully placed alternating layers of different ingredients. They are laminated together with heat and adhesive, and the result is one object.
Let’s start in the middle and work this out.
In this paragraph, we will find out the inside of PCB. The base material or substrate is usually fiberglass. Historically, the most common designation for this fiberglass is “FR4”. The fiberglass is stacked on top of each other and held in place with resin, making a unit strong enough to hold the board. The high temperature plastics is for flexible PCBs.
Moreover, other materials make the cheaper PCBs. Epoxy or phenolic resins lack the durability of FR4 but are much less expensive.
In conclusion PCBs has:
- single-sided (one copper layer),
- double-sided (one substrate layer with two copper layers on either side),
- multi-layer (outer and inner copper layers, alternating with substrate layers).
Multilayer Lasagna or PCB(printed circuit board)
The next layer is thin copper foil. It is laminated to the circuit board with heat and adhesive. Typically, on double-sided PCBs, copper is applied to both sides of the substrate. In less expensive electronics, the PCB may only have copper on one side. When we say double-sided or double-layered boards, we are referring to the number of layers of copper in the lasagna.
This lasagna can have as few as 1 layer or as many as 16 or more layers.
The layer on top of the copper foil is the solder mask. This layer provides the typical green color to the PCB. Apply it to the copper layer to insulate the copper traces. It eliminates the possibility of accidental contact with other metals, solder or conductive bits. This layer helps users solder to precise locations and prevents solder jumpers.
Apply a white silkscreen layer on top of the solder mask. This silkscreen adds letters, numbers and symbols to the PCB. This makes it easier to assemble and instruct humans to better understand the board. We often use silkscreen labels to indicate the function of each pin or LED.
A printed circuit board
Now back to our analogy:
On the top of the PCB, you can notice a series of lines running all over the place, connecting the various components. Are our roads different, with cities connecting all places? But here, instead of cars moving around, electrons are flying over copper roads, rushing to power one component after another! These copper paths are called traces in our PCB city.
A city is where all major engineering takes place. Therefore, we have offices, local businesses and more on every corner. This center of human activity is like those square black shapes found on PCBs called integrated circuits (ICs). These ICs are where all the hard work in the PCB takes place, allowing for quick calculations.
Suburbs are typical places for homes, parks and schools. Similarly, from an airplane, you’ll notice that suburban rows of houses often look like little resistors found on a PCB. These resistors significantly control charge flow through resistance.
Moreover, no city is exempt from construction! Whether you’re building a new skyscraper or a new apartment complex, you’ll find new foundations everywhere. These foundations are like empty pads without components you find on a PCB. While they may be empty right now, the worker will solder the componts on it.
Even our PCB city has its own street name and address
In other words, this type of addressing, called screen printing, helps the person assembling or fixing the PCB to know exactly where and where the parts are.
All the company water we use comes from local storage tanks and the water finds itself going through pipes to different places. This system is like the holes you find on a PCB called vias. These help provide power from one side of the PCB to the other, just like our water goes from the local storage tank to our bathroom, it’s a highway.
Power plants in cities keep the lights running. Can you imagine a city without them? Hope it’s not a zombie infestation! Like power plants in cities, we put so-called capacitors on PCBs that store electricity. When it needs to generate electricity, they keep charging and release it.
In addition, street lights and signs help maintain order in a world full of crazy drivers. They control the flow of traffic in our labyrinthine streets and highways. On the PCB, diodes and their cousins LEDs are those signs and street lights. The diode controls the current flow on the PCB. It allows it to go in only one direction.
PCB Aircraft View
PCBs are the foundation of our future.
It allows us to create, discover and improve the human experience in unprecedented ways. Really possible. But today, we are just getting started with PCBs. However, until recently, we have evolved in an unimaginable way. Perhaps in the future, we might find ourselves using biodegradable circuit boards. Even calling them “green boards”. Alternatively, you can 3D print your own PCB at home!
There are so many uses for PCBs, and it all starts with you. Your bright engineering mind might have some great ideas, and it needs to get them out. PCBs are a broad subject that requires a lot of study time and dedication. If you want, go ahead and make changes to make life better.