In the electronics industry, breadboards and printed circuit boards (PCBs) are both essential components used to connect electric details. The first type of boards is considered a bit commercially outdated. And they serve rather as prototyping bases for constructing the second type.
Let’s review breadboards and PCBs separately and compare them to each other. This way, the understanding of these fundamental pieces of electronics will be complete. We will also provide a guide on how to turn a breadboard into a PCB at the end of the post, so stick with us here.
What is PCB?
Let’s start with learning more about the more advanced electronic component – PCB. It is simply a laminated “sandwich” that comprises multiple specialized layers. Without further ado, let’s review all of them listed in the order:
- Prepreg. It is a composite layer. Typically – glass fabric substrate coated with resin, or simply fiberglass. You may have heard of it as FR4, polyimide, Teflon, Rogers material, etc. All these are simply cores needed to deposit other layers onto them.
Prepreg is the basis of any PCB. It is a strong, rigid enough material, characteristics of which will define most properties of the finished component. Usually, more than one layer of prepreg is used to build the board. Insulation or other layers may be put between preppers, so the fabricated material has enhanced characteristics.
- Laminate. While laminating is rather a process, copper-clad laminates are simply prepregs composed of thin layers of copper foils. High pressure and temperature forces copper to fully coat the board, so the foil becomes an integral part of it.
- Copper foil. Electrodeposited (ED) and rolled-annealed (RA) types of copper foil can be used for PCB production. After laminating, copper is then etched, so only thin traces of it are left to conduct electric signals.
- Solder mask. In its turn, a solder mask is applied after a prepreg is coated with copper and the etching process is already finished. This layer is simply polymer resin of green (typically), red, blue, black, or any other color of your choice, if necessary.
Types of solder masks are top and bottom-side, epoxy liquid. liquid photoimageable (LPI) ink, and dry film photoimageable ones. They differ in the ways of their application. As such, the first two are applied using solder mask inkjet printing (a relatively new method) or silkscreen printing. The third is applied directly onto the surface, UV-light cured, and its leftovers are washed off. The last is also applied directly and UV-light cured.
Soldermask protects the copper layer from oxidation – rusting. It also may enhance a PCB with additional properties such as chemical or humidity resistance, better mechanical strength, and others.
- White legend. Also known as nomenclature, this outermost PCB layer is simply information applied onto a component’s surface. A white or any other contrast to the solder mask ink is silk screen printed. The ink used is non-conductive, epoxy or acrylic. It can be applied either manually or by using Liquid Photo Imaging (LPI) or Direct Legend Printing (DLP) methods.
This layer is non-functional, as it does not enhance the characteristics of PCBs. But, it provides absolutely vital pieces of information to technicians. Without such data, testing or assembling electronics is impossible.
- Final finish. It is the last layer, which is not obligatory, just like applying white legend. But in most cases, the application of an additional layer is performed to enhance a PCB’s characteristics.
Some types of finishes are immersion silver, immersion tin, and electroless nickel immersion gold. It is easy to see that final finishes are mostly exposing PCBs to a solution with dissolved elements. They may enhance a PCB’s appearance, prevent solder bridges, and make electronics long-lasting.
So, the simple answer to the question “what is PCB?” is the combination of all the above-detailed layers.
How Does PCB Work?
As you may understand, a PCB is basically a laminated structure that is fully prepared for having electronic components deposited on it. Types of such components are the following:
- Resistors that are needed to transmit electric current.
- Transistors that are needed to switch, activate, and deactivate electronic signals.
- Capacitors that are needed to hold an electric charge and release when required.
- Inductors that are needed to store electric charge in the form of a magnetic field may be used to block electric signals.
- Diodes that allow an electric signal to flow in a particular direction or may block it completely.
The above-mentioned copper traces that allow transmission of electric signals are bridges that connect the listed components.
Technically, there are multiple other details incorporated in a fully-fledged PCB. Here are a few examples:
- Pad. Exposed metal of a board’s surfaces needed to mount a component onto it.
- Finger. A specialized pad intended to connect PCBs with each other.
- Annular ring. A copper ring around a hole in a PCB.
- Slot. Any hole that does not have a round form.
- Mouse bites. A drilled spot for separating boards from panels – larger PCBs comprising many smaller PCBs.
In simple words, PCB works in accordance with the programmed design by transmitting electrical signals in an intended manner. The ways the current can be controlled are various. They are designed with the help of all the details and components listed above. It ensures the operating of a PCB in accordance with the programmed actions that an electronic device is expected to perform.
What is a Breadboard?
Breadboard that is also known as protoboard is simply a construction base for modeling new electronics – prototyping. It is a solderless terminal array board that has points – holes with an electrical connection.
So, why do we need breadboards? They are perfect models that can be reused multiple times. In contrast to PCBs, breadboards are not soldered, and components onto them can be easily mounted and dismounted at any time. This benefit made breadboards popular amount technicians designing new electronics and engineering students.
How Does Breadboard Work?
A typical modern breadboard is a perforated plastic block that has tin-plated or phosphor bronze spring clips under each drilled hole – tie or contact point. Spacing between points is typically 2.54 mm. which equals 0.1 inches. Monolithic integrated circuits and dual in-line packages can be inserted into a breadboard as well. Also, leads of discrete components and interconnecting wires (fulfilling the same function as copper traces do) are used to complement the design.
Each such point is a ready-to-use equivalent of a PCB’s pads from a certain perspective. A user can connect a component to it, like a transistor, and use it to turn an electric signal on and off. Let’s review a few of the many potentials details to integrate into breadboard circuits to complement the insight into this electronics’ functioning:
- Terminal strips. Simply the areas to mount electronic components. It has an accommodated notch with clips on it.
- Bus strips. A power description detail that is needed to supply voltage. It is similar to a conventional wire.
- Jump wires. Wire sets serve the purpose of connecting newly mounted electronic components to ensure the electrical connection between them.
In simple words, breadboards work very similarly to PCBs. But instead of being specifically drilled and prepared to mount components holes, breadboards have perforated holes with contact points integrated. Removable wires play the role of copper traces. Other electronics also have their alternatives in both types of boards, but they still share the same main working principle.
Breadboard vs PCB
Breadboards can hardly be compared to PCBs. These boards are just intended for slightly different uses, and the latter literally emerged from breadboards. Still, let’s review the ways these electronic parts are different from each other.
How to Turn Breadboards into PCBs
As mentioned previously, PCBs emerged from breadboards. It means that less advanced components can be finalized. So, let’s take a look at the step-by-step process for turning a breadboard’s design into a PCB’s layout.
- Create a project in Virtual Breadboard (VBB) software. Download the application, and set up the Breadboard Template.
- Layout the breadboard circuit. Simply transfer a regular breadboard circuit to a raw PCB layout by using digital electronic components like resistors, diodes, wires, etc. You should have specialized knowledge of how to do so. But assuming you know the basic electronic principles, you can successfully place components so they create a viable design.
- Emulate the layout. It is an optional stage, but you can run an emulation of the newly created design. In most cases, the program will show you if your layout may function as expected once actually built.
- Convert breadboard layout to PCB layout. To do this, you should simply click PCB Direct preview. This way, you will receive a PCB-like layout that you can actually use to design a PCB. Drill holes, mount components and connect them with copper traces.
It is essential that you try your PCB design before actually getting down to fabricating circuit boards. Breadboards are what can save your time and give an opportunity to try a layout in a safe way. If your design is successful, you may fabricate a PCB with the same layout and place it inside your electronic device.
Summary
Breadboards are the ancestors of modern PCBs. These components serve the purpose of modeling circuits before actually fabricating such boards. The good thing about breadboards is that they can be reused multiple times.
In contrast to breadboards, PCBs are intended to serve as a part of electronics. They are more advanced, durable, and long-lasting editions of the obsolete breadboards. Still, both components are in use. The first serves students who practice their assembly and circuit design skills, and the second is for the actual manufacture.