
What’s a Printed Circuit Board? 8 Key Points to Be an Expert
Jan 17, 2022 A PCB or Printed Circuit Board is a bare board that serves 2 purposes which are mechanically support components and electrically connect electronic components.
Just so you know, some people use the term PWC ( printed wiring boards) or etched wiring board to refer to a PCB; if the board has no components mounted on it and only has copper tracks and features, then both terms are acceptable. Here’s a photo of what a printed circuit board looks like Every electronic device on earth has a PCB; it simply wouldn’t be able to exist without one. And like everything else in the technology world, things change fast. Here are 10 things you need to know to sound like an expert when talking about a PCB This is so basic that many forget to research it, but here’s what a printed circuit board’s materials usually consist of. Now you know what a printed circuit is made of This section will talk about how printed circuit boards are classified. So when someone talks about rigid PCBs, rigid-flex PCBs, flexible PCBs, multi-layer PCBs, or any other kind of printed circuit board, you know what they’re talking about. Let’s talk a bit about each one. This is the most common type of printed circuit board; its name already explains much of this PCB. Only one of its sides has a conductive copper layer, which means that electronic components, whether through-hole components or surface mount components ( more on this later), can only be assembled on one side of the PCB. Here’s an illustration of what a single-sided printed circuit board is composed of Single-sided PCBs are the go-to choice for low-cost and low complexity electronics; think of radios and basic calculators. They’re very basic, and people still use them because they’re You guessed it right, both sides of this type of PCB have a conductive layer; they’re also known as two-layer PCB. Circuits on one side of the board can be connected on the other side of the board with the help of holes drilled on the board; this makes it extremely useful for those electronics that require many components packed in a reduced space. Cellphones and other complex electronics use double-sided PCBs; this puts them in the middle / high complexity electronics applications. If it has more than two conductive inner layers of copper, then it is a multi-layer printed circuit board. Here’s something I want to explain because it’s a question many beginners ask; it goes something like this. A printed circuit board only has two sides; there can be more than 2 copper layers? If you think that is most likely because you believe that a double-sided PCB means that you can mount components on both sides of the printed circuit board. That’s not the case. The following illustration will clear things up It’s like a sandwich No matter the type of PCB, all of the components will be mounted on one side of the PCB; the one with the silk print overlay. How will the electronic components reach the second or third layer of copper? One must drill holes on the printed circuit board so the components can reach those copper layers. Great, now you know what a printed circuit board is made of and that it can be a one-sided, double-sided, or multi-layer. Another essential thing to understand about a printed circuit board; does your PCB design require a rigid or flexible printed circuit board? Their names are pretty self-explanatory; one you can bend, and the other one, well, is rigid. Here’s a photo of what a flexible printed circuit board looks like Here’s what the typical rigid printed circuit board looks like I mentioned that flexible printed circuit boards are great for connecting components and other PCBs, too; well, that’s what’s referred to as a rigid-flex printed circuit board. Here’s a photo What is this exactly? Well, we need to protect the copper traces from any external environment threat; they need to make it to the printed circuit board assembly process intact. This is exactly what the finish does. The most common types of printed circuit board finish are I wrote another article going into the details of each of these finish types; to find out which is the right one for your printed circuit board PCB, please click the following link. ENIG RoHs vs. OSP vs HASL vs. ISN vs IAG Comparison Table Go there, and you’ll find all the details on this topic, but I’ll leave here the most important questions you have to ask yourself to decide which type of finish you need for your printed circuit board Perfect, now you know what a PCB is made of, the types of PCB there are, and the types of finish you can apply on them. Now we’re going to talk about the most exciting part, at least for me. What’s all this? Let’s find out When it comes to electronic components for printed circuit board assembly; you have two big categories to choose from. Please note that the components you’ll use for your PCB design will depend on what your product needs to do; it’s not about what the cheapest components are; that’s not how you approach PCB design. These components are tiny, so small that picking them up with your hands and applying solder paste it’s either difficult or impossible, so how do you mount them on your PCBs? There’s an automated process called the SMT assembly process; this is a service all PCB manufacturers offer. Here’s a video of this PCBA manufacturing process. These are bigger than SMD components; you can choose to do it by hand or using an automated process for the PCB assembly. Nowadays, people go for SMD components because they’re smaller, and as electronic devices continue to shrink, they become the perfect option. Having components mounted on a PCB is also faster this way. If you used THT components, you’ll have to drill holes on the circuit board for the component leads to go through. This is an additional cost, and keep in mind that THT components are bigger. Flexible PCBs can only handle SMD components. As with many other things in the electronics industry, there’s a comparison table here. SMD vs. SMT vs. THT Technology – What works best for the mass manufacturing process? Your PCB design will include both types of components because there’s one thing THT components provide that SMD components don’t; thanks to the component leads, they provide stronger bonds to the printed circuit board. If you’ve made it this far now, you know a lot about a printed circuit board. The materials, the layers, the type, the components, and the finish; that’s a lot; you’re ready to have a basic conversation about PCBs. However, how do you actually design one? This is a bit technical. You have to understand all of that and more, way more. I won’t go into the details of designing a PCB, as that’s not the purpose of this article; I will give you the basic steps and leave you with some resources to learn more about how to design a PCB. Designing your Printed circuit board PCB right is extremely important; without a proper design, no device in the entirety of the electronics industry could exist. If you’re working on a big project, make sure you hire a professional. Design for Manufacturing Rules for PCB Layout. If you want to sound like an expert when discussing printed circuit board assembly, you have to know the costs. Here’s where many ask, is it cheaper in China? The short answer is, yes, the manufacturing process is cheaper in China. Allow me to give you some numbers for more clarity. 30 two-layer boards, 80x90mm in size, will cost you US$ 339 from a PCBA manufacturer in Germany. The same units with the exact specifications will cost you US$20 in China. Also, PCBA manufacturers in China have one week or less turnaround times. PCB assembly in the USA will have a turnaround time of a month and a unit price of US$3.48/unit for a 1k units’ order. The exact order made to a Chinese PCBA manufacturer would cost you US$0.37/unit and have a turnaround time of 5 days. Even after import tariffs are calculated, PCB assembly in China is cheaper and faster. Perfect; now onto the last thing you should know about to be an expert on Printed circuit board PCB. That’s the process right there; please click on the following link if you want to dig deeper into this. PCB Assembly Process in 14 Photos Well, that’s it for this article. If you’re looking for someone to help you with an electronics development project, please get in touch with us.1.What are printed circuit boards made of?
2.Printed Circuit Boards – The Layers
Quick printed circuit board categorization
Single-Sided Printed Circuit Board
Advantages of single-sided PCBs
Double-Sided Printed Circuit Board
Advantages of Double-sided PCBs
Multi-Layer Printed Circuit Board
Advantages of Multi-Layer PCBs
3. Printed Circuit Boards – Rigid or Flex PCBs
Reasons to use a flexible printed circuit board.
Reasons to use a rigid printed circuit board.
When to go for a rigid-flex circuit card assembly?
4. Printed Circuit Boards – The Finish
How to decide which PCB finish I need?
5.Printed Circuit Boards – Electronic Components
Let’s begin with surface mount components or surface mount device.
The other big category of electronic components is through-hole components.
SMT or THT Components for your PCB Design?
6. Printed Circuit Boards – How to Design It?
10 Steps for PCB Design
7. Printed Circuit Boards – The Cost
8. Printed Circuit Board Assembly Process
The assembly process goes like this