In the electronic hardware industry, whether it is R&D, production or testing, you will always encounter all kinds of "boards". Among them, the three names of development board, test board, and aging board sound a bit similar, but the actual work is very different. Brothers who have just entered the industry may be confused, today we will break it open and crush it to chat, what are they all doing, why is one indispensable.
1. Development Board: Engineer's "Creative Sandbox" and "Trial and Error Paradise"
Imagine if you want to build a concept car, you can't just start the mold and mass-produce it after drawing it on paper, right? You have to have a prototype that can run and try first. The Development Board does this job, it is the starting point and core experimental platform for hardware development.
Core tasks: exploration, verification, learning, debugging.
What does it look like? It is usually designed around a processor or microcontroller with a single core (such as the common ARM Cortex-M series, RISC-V chips, etc.). The board is rich in resources: various peripheral interfaces (USB, network port, serial port, ADC, GPIO pin), debugging interface (convenient for computer programming and debugging programs), display interface, and may even come with some small modules (WiFi, Bluetooth). The design is open and flexible, making it easy for you to connect to various sensors, screens, or your own modules.
Who is using it? Hardware engineers use it to verify whether the chip function meets the standards and whether there are any pitfalls in the circuit design. Software engineers frantically write code, adjust drivers, and run systems on it; Students and makers use it to bring their whims to life; The project manager uses it to assess the feasibility of the scheme.
What pain points does it solve? It allows you to run through the core ideas, adjust the software, and dig out potential hardware pits (such as chip heating, interface mismatch) in advance before investing a lot of money in a formal product board (PCBA). Save time! Save money! Avoid design "rollovers"!
Life cycle: Mainly active in the early stage of the project. When the product design is finalized and mass production begins, its core mission is basically completed (of course, it may be invited to come out of the mountain in the later software upgrade and debugging).
To use an analogy: a development board is like a Lego baseboard. Provide you with a basic framework (CPU, memory, basic peripherals) and a bunch of standard interfaces (Lego bumps), you can freely build various sensors, actuators (Lego bricks), quickly build a prototype of your idea, and verify whether it can move, so it's fun.
2. Test board: "golden-eyed" quality inspector on the production line
The product is designed, and the drawings are sent to the factory to start production. Pieces of soldered circuit boards (PCBA) came down from the assembly line. The question is: how to ensure that every board is good? Welding is not false? The components are not wrong? Functioning normally? Rely on the human eye to see one by one? It's tiring to death, and it's unreliable. At this point, the Test Board / Test Fixture is time to come into play.
Core task: In the mass production process, quickly, accurately and automatically find out the hardware defects and functional abnormalities on each PCBA.
What does it look like? Highly customizable! It is tailored for specific models of PCBAs. Imagine a sturdy base filled with dense, high-precision spring probes (Pogo Pins). When your PCBA is placed, the probe will accurately hit the test point reserved on the board. It is connected to an automated test equipment (ATE) to automate a series of complex test procedures.
What is it measuring?
Basic physical examination: Is there a power short? Is there an open circuit (disconnection) on the signal line? Are the values of the basic components such as resistance and capacitance correct?
Functional validation:Can the CPU run? Is memory read and written right? Do you recognize the USB plugged into the computer? Is the network port working? Are the buttons working? Is the indicator light on? Is the sound that should ring?
Program programming: The software program (firmware) that should be injected into it is burned at one time.
Who is using it? Test engineer on the factory production line. This is an indispensable part of mass production.
What pain points does it solve? Efficiency! A board can be measured in a few minutes or even tens of seconds. Accurate! Automated testing eliminates human error. Traceable! The test results are automatically recorded, and which board is clearly dismissed, which is convenient for maintenance and analysis. The goal is to prevent a board with a hardware defect from flowing into the next process or reaching the customer
Life cycle: As long as this model of PCBA is still in production, the test board must accompany it. When the product is discontinued, it is "retired".
For example: the test board is like an automated X-ray machine + functional detector in a factory. It doesn't care how advanced the design concept is, it only focuses on the PCBA that has just rolled off the production line in front of it: "Are the muscles and bones (lines) intact?" Are the internal organs (components) complete and healthy? Are the organs (functional modules) functioning normally? Quick scanning, accurate judgment, qualified release, unqualified callback.
3. Aging board: "high-pressure sauna" that specializes in treating "premature death"
Some electronic devices break down inexplicably within a few days of buying them, which is mostly a phenomenon of "early death" (early failure). In order to screen out these "weak" products before leaving the factory and improve the long-term reliability of the products sold, it is necessary to hire a burn-in board / aging board.
Core task: Conduct "stress testing" on PCBA or key components, accelerate the exposure of potential defects, and eliminate those "weak chickens" that cannot survive.
What does it look like? Leather is hard to fuck! To withstand prolonged temperatures and pressures, the structure must be strong. It is usually designed to "torture" multiple identical PCBAs at the same time. The core is to provide a stable and powerful power supply, and can simulate the actual working load of the product (such as making the CPU perform at full load and letting the power chip output *** current). It is often used in conjunction with a burn-in chamber, where the board is placed in a "sauna" (such as roasting at 70°C+ for 24 hours or more), and sometimes "torture" such as cyclic switching and high voltage.
What is it doing? Let the PCBA continue to operate in harsh environments that far exceed normal working conditions. High temperatures accelerate the deterioration of materials inside components (e.g., electrolytes, solder joints), and voltage/load shocks can test the limits of power supplies and power devices. Those boards/devices with potential process defects, material defects, or insufficient design margins are prone to die early under this kind of "severe torture".
Who is using it? It is also mainly used in factory production, especially when products with high reliability requirements (such as industrial equipment, servers, medical instruments, automotive electronics) or new products are just introduced into mass production.
What pain points does it solve? Improve long-term reliability of products after leaving the factory and reduce the early failure rate of the client (commonly known as the "repair rate"). While it adds some cost and time, it's often worth the reputational and financial losses caused by large-scale recalls or repairs after a product goes to market. It believes in the cruel law of "it is a mule or a horse, pull it out for a walk".
Life cycle: Along with the product production cycle, especially for early batches or products with high reliability requirements. As the production process matures and stabilizes, the aging intensity or ratio may decrease.
For example: the aging board is like the devil instructor of the boot camp. Throw recruits (PCBAs who have just rolled off the production line) into extremely harsh environments (high temperature, high pressure, high load) for long-term high-intensity training. Those "soldiers" who are not determined (insufficient design margin) and have hidden injuries (defects in materials or processes) will fall behind (fail) in training and be eliminated. Only the "soldiers" who have passed the test can be considered more reliable, sent out on tasks (delivered to customers).
To sum up, the division of labor is clear:
Development board: belongs to the front end of R&D. It is an explorer and experimenter, and the goal is "Can the idea be realized?" Is it easy to use? ”。 It is characterized by flexibility, openness and abundant resources
Test board: belongs to the production link. It is a ruthless quality inspector, and the goal is "Is the hardware qualified for this board just made?" Is it functioning normally? ”。 It is characterized by a high degree of customization, automation, and fast and precision
Aging board: also part of the production process (usually after testing). It is a cruel stress tester, and the goal is to "screen out those 'short-lived ghosts' that may break down in a few days, and make the factory products more durable!" ”。 It is characterized by harsh environment, long time, and batch processing
Understanding the differences and uses of these three boards is crucial for controlling the R&D cycle, production quality, and ultimate reliability of hardware products. The design is cool for a while, and the mass production crematorium is good? By using the test board and the aging board well, this tragedy can be avoided to a large extent. The next time you see them in a lab or factory, you should be able to recognize who is who and what key role they are playing.