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How Does The Circuit Board Works?

how does pcb work

PCB is a hardware device that translates electronic signals into mechanical actions, such as starting a motor or turning on a light bulb. In the early days of technology, circuits were quite simple. 

But everything changed as science and technology improved. For example, it is also used in many medical instruments.

In this article, we will go over how circuit boards work, and how they are used in medical industry. There is also a quick guide on how to disassemble the broken PCB and troubleshoot. 

What Is Circuit Board?

Printed Circuit Board (PCB) also called Circuit boards. They are thin boards that carriers electronic components to be connected to each other. 

The printed circuit board provides support and effective blocking for all components mounted on its surface, and the lines in the center of the board provide a platform for communication and cooperation between components. 

What Parts are Inside the Circuit Board?

Generally, a printed circuit board has three main parts: substrate, traces and components. The base is the board itself, which is usually made of a non-conductive material such as fiberglass or epoxy resin. The stand provides a platform for mounting and connecting components. 

Traces are conductors on the board made of conductive materials, usually copper. The traces connect the components on the board to form a complete circuit capable of performing complex tasks. 

The components on each circuit board are themselves critical to making those boards work and transferring power or energy. There are many different components that work in tandem to ensure their function, such as resistors, transistors, and capacitors.

How These Parts are Working in Circuit Board?

Typical use of green PCB 1

•  Resistors are one of the most critical components for circuit boards to work because they transmit current to generate voltage and dissipate power in the form of heat.

•  Transistors are used to switch or control electronic signals on a circuit board. During the life of a circuit board, other parts of the board sometimes require more energy or charge.

•  Capacitors retain charge within the circuit board and release it when this power is needed elsewhere.

•  Inductors store energy within the board in the form of a magnetic field when current flows through them. They are often used to block signals within the circuit board, such as interference from other electronic devices or equipment.

•  Diodes are devices that allow current to flow in one direction but not the other, and can be used to stop current from flowing through the board in the wrong direction, which can lead to damage.

Printed Circuit Board Does Not Work

How Does Circuit Board Work in Medical Devices?

There are several types of circuit boards used in medical devices, primarily dependent on the function and complexity of the device. According to the structure and function of circuit boards, circuit boards can be categorized into the following types in medical devices: 

– Single panel: only one side has wires and components, suitable for simple circuits such as blood pressure monitors, blood glucose meters, and so on. 

– Double-sided panel: there are two sides have wires and components, connected through the over-hole, suitable for medium complexity of the circuit, such as electrocardiographs, ultrasound meters, etc..

Multilayer PCB Board

– Multilayer board: there are multiple layers of wires and components, connected by insulating layers and adhesives, suitable for high complexity circuits, such as magnetic resonance imaging machines, CT scanners, etc.. Multilayer boards can greatly improve the performance and stability of circuits, reduce electromagnetic interference and noise, and save space and weight. But the manufacturing cost of multilayer boards is quite high, the design and testing is very difficult, and once a failure occurs, it is almost impossible to repair. 

Circuit Board and Medical Equipment

Medical devices often require smaller and denser Circuit boards, and the testing requirements for the products are also more stringent. These Printed Circuit boards may be used to connect electronic components that play a vital role in medical devices such as defibrillators, MRIs, medical imaging systems, CT scans, and more.

Circuit boards are used in a wide range of applications in medical equipment, covering a wide range of fields such as diagnosis, treatment and monitoring. The following are some examples of circuit boards used in medical equipment:

Defibrillator: A defibrillator is a medical device used to treat cardiac arrhythmia, which restores the normal beating of the heart by means of an electric shock. The circuit board work as core components in the defibrillator. The circuit board of the defibrillator needs to be characterized by high precision, high stability, high safety and high tolerance to ensure the safety of the patient’s life.

A typical PCB used in Medical devices

MRI: MRI’s control system is composed of multi-layer circuit boards, which are responsible for controlling the strength and direction of the magnetic field, generating and receiving RF signals, and processing and displaying images. The circuit board of MRI needs to be characterized by high speed, high sensitivity, high anti-interference and high compatibility to ensure the quality and efficiency of imaging.

CT Scanning: CT scanning is a medical imaging technology that utilizes X-ray and computer technology to obtain cross-sectional images of the human body. Boards used for CT scanning need to be characterized by high resolution, high dynamic range, high signal-to-noise ratio and high parallelism to ensure image clarity and speed.

How to Take Troubleshooting When Circuit Boards Do Not Work

If the PCB does not work, there are several steps you can take to troubleshoot.

1. Identify the symptoms: This is the first step, where the problem is observed and described, such as no power, no output, wrong output, or erratic behavior. The symptoms can help to narrow down the possible causes and locations of the failure.

2. Locate the fault: This is the second step, where the board is inspected and tested, using various tools and methods, such as visual inspection, multimeter, oscilloscope, or logic analyzer. The board is checked for any signs of physical or electrical damage, such as cracks, burns, or shorts, and the components and the traces are measured for their values, voltages, currents, or signals. The fault is located by following the circuit from the power supply to the input and output ports, and isolating the faulty component or trace.

3. Repair or replace the fault: This is the third step, where the board is fixed or replaced, depending on the severity and type of the fault. The board is repaired by using various tools and methods, such as soldering iron, desoldering pump, or solder wick, and the faulty component or trace is removed, cleaned, or reconnected. The board is replaced by ordering a new board from the manufacturer or a supplier, or by making a new board from scratch.

4. Verify the solution: This is the fourth step, where the board is tested again for functionality and performance, and the problem is verified to be solved. The board is checked for any errors or defects, and the components and the traces are measured again for their values, voltages, currents, or signals. The board is then installed in the device and operated normally, and the results are observed and compared with the expected results.

In conclusion, PCBs can fail for various reasons. Troubleshooting circuit board failures involves identifying, locating, repairing, or replacing the fault, and verifying the solution. 

If you would like to learn more about how PCBs work, what they are made of, or how ELE PCB can help you with your project, please contact us for more information. We have a good industry reputation and years of knowledge with PCB manufacture. Work with us to design PCBs that ensure reliability and precision, and take your product to the next level.


ELE PCB has got the IS09001:2015, IS013485:2016, ROHS and FCC certifications. We can offer all kinds of services, including PCB manufacturing and PCB assembly, sample orders and batch orders. For PCB assembly, utilizing 7 high-speed SMT PCBA lines from Yamaha and Sony, to meet our customers’ needs. Our extended services include PCB design &PCB Layout, hardware design engineering, firmware &software development, and personalization. ELE company is honored as an excellent supplier from any company all around the world. We deeply believe that our good service and experience will completely meet your needs. Integrality, value and innovation are the forces that drive our success.



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About Michael

Michael is the general manager of ELEPCB, a leading PCB design and manufacturing company based in China. He has over 10 years of experience in the PCB industry, and has been involved in various projects.

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