The PCB, or Printed Circuit Board, serves as the foundation for electronic circuits. In modern electronics, PCBs are virtually ubiquitous.
PCB design represents the final step in circuit design, essentially serving as a redesign of the primary circuit. Some new engineers may underestimate the importance of PCB design, often relegating this tedious and complex task to technicians. To illustrate its significance, I will share a story about PCB design. Due to company confidentiality, the specific location and name have been omitted.
The company in this story manufactures telephones. Standard push-button telephones may not be high-tech by today’s standards, but they offer notable improvements over the earlier rotary dial phones. For example, they incorporate a dual-tone/pulse dial control IC, and some models feature a hands-free function. With the hands-free button, users can make or receive calls without lifting the handset. Those familiar with the basic principles of telephone circuits understand that the hands-free feature relies on two key circuits: the “automatic receive/transmit control circuit” and the “audio power amplifier circuit.” These are typically implemented using off-the-shelf integrated circuits, with little need for innovative circuit design.
During the early stages of China’s reform and opening-up, some forward-thinking companies earned significant profits by producing telephones. The company I’m referencing sent its latest products to the head of Beijing for a trial. This new push-button telephone with a hands-free function was much more convenient than the rotary phones of the time. After a period of testing, the official was very satisfied and decided to recommend the product to relevant departments.
However, at a critical moment, something unexpected happened. One late night, the phone began buzzing! There was no apparent reason—no one would have dared to call the chief’s home at such an hour. Even stranger, when the receiver was picked up, no one was on the other end. After a while, the phone began beeping continuously. In a panic, the chief called the security personnel, who in turn contacted the telecommunications staff in the middle of the night. After some investigation, they discovered that the hands-free function had been mistakenly triggered, leading to the false alarm. The chief was furious!
This incident delayed the phone’s sales plan for several years. Eventually, it was determined that the root cause of the malfunction was poor PCB design, which led to the hands-free function being accidentally activated. Subsequently, the company switched to mechanical buttons for the hands-free feature on all its phone models, which then passed the telecom network access approval. The company suffered direct economic losses from this incident amounting to tens of millions of yuan.
Some designers mistakenly view PCB design as a simple task, relying on software tools like PROTEL for automatic layout and routing. If a single-sided PCB fails to connect, they simply use a double-sided board. If that doesn’t work, they switch to a multilayer board or add jumpers. If a short jumper doesn’t fix the issue, they opt for a longer one. And if that still doesn’t work, they continue to rely on jumpers until the problem is resolved.
1. I know an experienced engineer who, in the early years, did not use a computer for PCB design. Despite that, they were able to complete complex circuit designs involving hundreds or even thousands of components. Moreover, the PCBs they designed were exceptionally neat in terms of layout and routing, with minimal jumpers and crossovers. The placement of the critical components was both organized and logical, fully meeting the process specifications. The early domestic black-and-white TV PCBs we encountered were true masterpieces created by the engineers of that era.
2. Even though I have been using a computer for PCB design for quite a long time, I still believe there is much to learn from those old engineers. Today’s younger engineers can hardly imagine how these pioneers used only pencils and graph paper to complete such intricate PCB designs. Personally, I’ve gained a great deal of knowledge from these engineers, including how to arrange components for easy routing, how to optimize board space under dual in-line ICs, and the importance of thorough planning before starting the layout and wiring process.
3. PCB design is not just about technology; it is also an art form. Art, by nature, involves subjective judgment, so engineers should continually work on improving their own skills and aesthetic sense.
4. Tools can certainly help us complete a lot of complicated tasks, but what they automate is not always optimized for every product. The automated solutions provided by design software focus on general and standard aspects of product design, rather than ensuring the most optimized layout for each unique product. For instance, when using PROTEL or similar software tools, automatic layout and routing may offer a basic connection scheme. In a sense, it simply links the required components together. Therefore, truly designing a PCB for a product involves a deep understanding of its specific requirements, allowing the designer to craft a customized solution.
5. I have worked on designing PCB systems, but due to my initial inexperience, I used PROTEL to design a PCI board (currently being studied with PROTEL). Through this experience, I gained a profound appreciation for the complexity of PCB design. For example, in my project, I worked with a chip that required a dual-layer design with up to 160 connections. Without using automatic routing, my challenge was to ensure all the connections were made while minimizing high-frequency interference and adhering to the chip’s specific wiring length requirements. This was truly a headache. As a hobbyist interested in radio technology, I also had some understanding of the inner workings of black-and-white TV sets. As a result, I have deep respect for the hard work and wisdom of the older generation of PCB designers. I hope to have the opportunity to learn the essence of PCB design one day. I may have rambled a bit, but I wanted to share my thoughts.
6. Many PCB manufacturers share similar sentiments. PCB design is not just about making electrical connections; it also requires knowledge of circuits, the production process, and an eye for aesthetic design. It is indeed an art form. If cost-saving is a priority, it’s crucial for the boss to recognize the value of this work.
7. A fully developed initial plan can still fail if the routing is poorly designed. Inefficient routing can lead to many unforeseen issues, such as circuit oscillation, poor signal-to-noise ratio, inadequate signal separation, or even causing high-power amplifier circuits to burn out. The consequences of poor design are truly hard to imagine.
PCB design represents the final step in circuit design, essentially serving as a redesign of the primary circuit. Some new engineers may underestimate the importance of PCB design, often relegating this tedious and complex task to technicians. To illustrate its significance, I will share a story about PCB design. Due to company confidentiality, the specific location and name have been omitted.
The company in this story manufactures telephones. Standard push-button telephones may not be high-tech by today’s standards, but they offer notable improvements over the earlier rotary dial phones. For example, they incorporate a dual-tone/pulse dial control IC, and some models feature a hands-free function. With the hands-free button, users can make or receive calls without lifting the handset. Those familiar with the basic principles of telephone circuits understand that the hands-free feature relies on two key circuits: the “automatic receive/transmit control circuit” and the “audio power amplifier circuit.” These are typically implemented using off-the-shelf integrated circuits, with little need for innovative circuit design.
During the early stages of China’s reform and opening-up, some forward-thinking companies earned significant profits by producing telephones. The company I’m referencing sent its latest products to the head of Beijing for a trial. This new push-button telephone with a hands-free function was much more convenient than the rotary phones of the time. After a period of testing, the official was very satisfied and decided to recommend the product to relevant departments.
However, at a critical moment, something unexpected happened. One late night, the phone began buzzing! There was no apparent reason—no one would have dared to call the chief’s home at such an hour. Even stranger, when the receiver was picked up, no one was on the other end. After a while, the phone began beeping continuously. In a panic, the chief called the security personnel, who in turn contacted the telecommunications staff in the middle of the night. After some investigation, they discovered that the hands-free function had been mistakenly triggered, leading to the false alarm. The chief was furious!
This incident delayed the phone’s sales plan for several years. Eventually, it was determined that the root cause of the malfunction was poor PCB design, which led to the hands-free function being accidentally activated. Subsequently, the company switched to mechanical buttons for the hands-free feature on all its phone models, which then passed the telecom network access approval. The company suffered direct economic losses from this incident amounting to tens of millions of yuan.
Some designers mistakenly view PCB design as a simple task, relying on software tools like PROTEL for automatic layout and routing. If a single-sided PCB fails to connect, they simply use a double-sided board. If that doesn’t work, they switch to a multilayer board or add jumpers. If a short jumper doesn’t fix the issue, they opt for a longer one. And if that still doesn’t work, they continue to rely on jumpers until the problem is resolved.
1. I know an experienced engineer who, in the early years, did not use a computer for PCB design. Despite that, they were able to complete complex circuit designs involving hundreds or even thousands of components. Moreover, the PCBs they designed were exceptionally neat in terms of layout and routing, with minimal jumpers and crossovers. The placement of the critical components was both organized and logical, fully meeting the process specifications. The early domestic black-and-white TV PCBs we encountered were true masterpieces created by the engineers of that era.
2. Even though I have been using a computer for PCB design for quite a long time, I still believe there is much to learn from those old engineers. Today’s younger engineers can hardly imagine how these pioneers used only pencils and graph paper to complete such intricate PCB designs. Personally, I’ve gained a great deal of knowledge from these engineers, including how to arrange components for easy routing, how to optimize board space under dual in-line ICs, and the importance of thorough planning before starting the layout and wiring process.
3. PCB design is not just about technology; it is also an art form. Art, by nature, involves subjective judgment, so engineers should continually work on improving their own skills and aesthetic sense.
4. Tools can certainly help us complete a lot of complicated tasks, but what they automate is not always optimized for every product. The automated solutions provided by design software focus on general and standard aspects of product design, rather than ensuring the most optimized layout for each unique product. For instance, when using PROTEL or similar software tools, automatic layout and routing may offer a basic connection scheme. In a sense, it simply links the required components together. Therefore, truly designing a PCB for a product involves a deep understanding of its specific requirements, allowing the designer to craft a customized solution.
5. I have worked on designing PCB systems, but due to my initial inexperience, I used PROTEL to design a PCI board (currently being studied with PROTEL). Through this experience, I gained a profound appreciation for the complexity of PCB design. For example, in my project, I worked with a chip that required a dual-layer design with up to 160 connections. Without using automatic routing, my challenge was to ensure all the connections were made while minimizing high-frequency interference and adhering to the chip’s specific wiring length requirements. This was truly a headache. As a hobbyist interested in radio technology, I also had some understanding of the inner workings of black-and-white TV sets. As a result, I have deep respect for the hard work and wisdom of the older generation of PCB designers. I hope to have the opportunity to learn the essence of PCB design one day. I may have rambled a bit, but I wanted to share my thoughts.
6. Many PCB manufacturers share similar sentiments. PCB design is not just about making electrical connections; it also requires knowledge of circuits, the production process, and an eye for aesthetic design. It is indeed an art form. If cost-saving is a priority, it’s crucial for the boss to recognize the value of this work.
7. A fully developed initial plan can still fail if the routing is poorly designed. Inefficient routing can lead to many unforeseen issues, such as circuit oscillation, poor signal-to-noise ratio, inadequate signal separation, or even causing high-power amplifier circuits to burn out. The consequences of poor design are truly hard to imagine.
