PCB Test – The Ultimate FAQ Guide in 2022

Introduction:

If you plan to build your own boards, you must have a comprehensive PCB testing guide. You will learn how to perform PCB testing and what questions you should ask yourself before you start using its comprehensive and user-friendly approach. There is no better way to start than reading this guide. PCB testing is an important part of any electronic product design, and any failure can result in thousands of dollars in lost revenue.

Aging testing is a rigorous type of PCB testing that identifies early failures and determines the board’s load capacity. While aging testing can be harmful to electronic components, it can help you save time and money in the long run. Unlike functional testing, aging testing pushes power through the board continuously for 48 to 168 hours. If a board is found to be defective after this time, it will need to be reworked or returned to the manufacturer.

When creating a PCB, consider the thickness and design of the PCB. 1.6-mm FR-4 is used to create standard 12-layer PCBs. these and other questions will be answered in the final FAQ guide. The thickness of the PCB can affect the performance of the board. In addition, keep signal integrity in mind when designing your PCB. Before assembly, perform signal integrity testing to ensure your design meets your expectations.

PCBs were widely used for fluorescent lamp ballasts before they were banned in 1979. This is a concern if the ballast leaks, and if this happens, the ballast containing the PCB will be discarded as hazardous waste. But don’t worry, the ultimate FAQ guide will answer all your PCB testing and other PCB-related questions. The comprehensive coverage of PCB regulations in the guide is essential for anyone interested in using PCB testing.

What is PCB Test?

What exactly is PCB testing? You may be wondering what it is, and you may be confused about what to do. Here are some things you should be aware of. For example, aging testing involves applying maximum power to an electronic device for 48 to 168 hours. Because it does not determine whether the PCB is ready for deployment, this type of testing is called infant mortality testing. It is also not appropriate for every project, but it can help you avoid a potentially embarrassing or dangerous product release. Aging testing also helps eliminate premature failure, which can shorten the life of a product or board.

Why do I need PCB testing? Since PCBs are an important part of electronics, defective PCBs can reduce productivity and even cause fires. The best way to avoid these problems is to perform PCB testing prior to manufacturing. This helps avoid errors that could compromise product functionality and ensures a defect-free final product. As a result, it reduces production and maintenance costs while also ensuring customer satisfaction with product quality.

PCB Flying Probe Testing

AOI is the most basic PCB test and is usually the first step. It verifies that the board matches the schematic. Mechanical errors, on the other hand, cannot be detected visually and must be detected using a microscope. PCB testing is required for all PCBs, but is expensive, costing tens of thousands of dollars per board. Fortunately, Absolute Electronics offers reliable PCBs from reliable sources.

How Do You Perform a PCB Test?

Why is PCB Test Necessary?

There are many answers to this question. For example, PCBs are an important part of electronic equipment. However, they are expensive and time-consuming to produce, and you often don’t know why you need PCB testing. To answer this question, you must first understand the advantages of PCB testing. Here are some examples.

PCB testing is required if you want to ensure that your product is fully functional. There are two types of PCB testing: in-circuit testing and flying probe testing. In-circuit testing involves comparing the electrical characteristics of electronic components with the specifications of a standard circuit card. The former requires the use of special fixtures that look like circuit cards and allow you to view the actual board prior to startup.

When you use in-circuit testing, you inject voltage into the circuit, which will provide you with a diagnosis of problem areas on the board. Using this method, you can detect problems before they affect the entire assembly. The downside to in-circuit testing is that it is expensive, costing tens of thousands of dollars. In addition, it is not always possible to obtain a PCB that has passed all the required tests.

AOI Testing Machine

The aging test, commonly used in the military, is a much more intense PCB test. It determines the load capacity of a board and decides whether it can withstand the load. However, it is not a good choice for medical or military applications, and it can lead to the premature death of your board. It may also have an impact on the way the device works. It is critical to test the board before releasing it to the public.

7 Most Popular PCB Testing Methods During PCB Manufacturing and Assembly

In PCB manufacturing and assembly, the seven most common PCB testing methods are used. Each of these methods has distinct advantages and disadvantages. Depending on the type of board, these methods can be applied to it. The bare board PCB test verifies continuity after the board has been manufactured, whereas the netlist/functional test verifies shorts prior to board fabrication. A common manual testing method is a visual inspection. Automatic optical inspection (AOI) is another type of inspection that uses a vision system to capture a circuit board and compare it to a set of design rules. TDR impedance testing ensures proper signal function and can aid in the prevention of performance and reliability issues. Military PCB Inspection Group A (A) also addresses visual standards, chemical resistance, and physical changes.

AOI Testing Room

Common methods include stress tests and functional tests. These tests are carried out to eliminate flaws and ensure the quality of a product. The first three testing methods are unusual, whereas the latter is the most common. Stress tests are typically performed on newly released products. These tests are used to ensure the safety of components before they are shipped to customers. This guide will give you a basic understanding of the process if you’re wondering which PCB testing method is best for your PC.

The most common PCB testing method is automated optical inspection (AOI). It employs two or three high-resolution cameras to capture images of various components on the PCB. It can detect potential defects early in the process and save a significant amount of money when compared to fixing a board that fails after final testing. To ensure that their PCBs are defect-free, some PCB manufacturers use this method several times during the manufacturing and assembly process.

1. PCB Visual Inspection

The PCB Visual Inspection (PVC) software tool helps detect defects on circuit boards. The inspection is performed by pointing a digital microscope at the PCB inspection point and then adjusting the height and angle of the camera. Afterward, the software generates a live image of the PCB area, which can be saved as a post-inspection report. The PCB vision inspection software can be used to check a variety of factors, such as whether parts are present and in the correct position, as well as their polarity and soldering.

The software uses nine cameras to capture 3D images of the PCB. The AOI software uses these images to evaluate the 3D properties of the board, and it even lets you compare a live PCB to a gold sample. You can determine if any component is faulty by comparing the two images. The images you see are often too dark or too bright, which is why MVI software is the best choice for many engineers.

PCB Visual Inspection

The PCB Visual Inspection tool will also help you detect errors that may have gone undetected before. When evaluating the electrical characteristics of a board, it is critical to determine if the solder joints are strong enough to withstand the load. Solder joint strength and stability can make or break a device. PCB vision inspection software is an essential tool for this task. Inspection software can help you locate defects quickly and accurately.

2. In-Circuit Testing(ICT)

In-circuit testing is a type of white-box testing in which electrical probes are used to check for opens and shorts on a populated printed circuit board. Basic quantities such as resistance and capacitance are also checked to determine if the circuit is built correctly. Because it has no visible components and can be performed remotely, in-circuit testing is also known as “white-box” testing.

Pin-bed testing is the first in-circuit testing method. This test involves inserting a set of spring-loaded pins into a fixture based on the PCB layout. Faults on PCBs can be easily identified and repaired or scrapped using this method. This method is useful for quickly checking the functionality of small PCBs.

In-circuit testing is not always as reliable as other types of testing. Despite rigorous testing, circuits can still be defective, but it is difficult to determine the exact location of a fault using in-circuit testing. Some manufacturers may not have access to all nodes on the board. In addition, access points for some ICs may be shielded by large components. In-circuit testing, despite its limitations, can be a valuable asset for manufacturers.

In-circuit testing is more reliable, easier to use, and more cost-effective than other testing methods. The method is also capable of detecting manufacturing defects. Its main advantage is that it is economical for medium and high-volume production runs. In-circuit testing also ensures adequate coverage of manufacturing defects. In addition, it can be done on a much smaller scale without affecting the reliability of the product.

3. Flying Probe Testing(FPT)

The process of determining if a component is functioning properly is called flying probe testing. As the name implies, this method involves inserting probes into the board. The probes measure the values of the components as they move from one position to the next to determine if they are properly installed. Unlike traditional ICT testing methods, Flying Probe does not require fixturing.

Typically, FPT is used for prototype boards and low-volume PCB assembly. It is more convenient, cost-effective, and often faster than traditional methods for small lots with high coverage. Depending on the complexity of the board, test results are usually available within a few hours. This method is typically performed on an offline computer using a test program generator application. The flying probe tester also requires Gerber, BOM, or ECAD files.

The Masterboard defines the test points, component format, and debug of the FTP tester. Once the master board is complete, the board components are placed inside the FTP tester. The probe compares the signal to the baseline data to test the operation and failure of each component. This helps the manufacturer determine if the PCB is working properly. If not, the device will need to be repaired. The FTP tester uses a patented process called probing flight.

The Flying Probe is an excellent option for small to medium volume production. Because of the low cost of testing, there is no need for expensive bed-of-nails fixtures. In addition, the Flying Probe can be used in the prototyping process. More accurate than ICT, the Flying Probe can detect 99% of defects. The cost of developing a test program is comparable to the cost of purchasing a fixture.

4. Automated Optical Inspection (AOI)

In manufacturing, an automated optical inspection system (AOI) can be a valuable asset. The use of camera scanning equipment is a non-contact testing method that can detect quality defects and catastrophic failures. This is an outline of the procedure. Let’s start with the basics: What is the definition of automated optical inspection? What applications does it have in manufacturing? What are the benefits and drawbacks?

The underlying technology of AOI systems is very similar. One or more cameras move in the X-Y direction on one component in each AOI system. The camera is then precisely positioned at a specific location and the resulting image is captured. The images are then processed by software that uses sophisticated image processing algorithms to detect defects based on predefined inspection features. While not as accurate as manual inspection, this process is useful for manufacturers who need to inspect products quickly and accurately.

AOI has many advantages. It is fast and non-contact and can detect small defects on PCB components. In addition to being non-contact, AOI can be used before and after soldering as well as on solder paste. Manual inspection used to be the only way to inspect PCBs, but that has changed. With AOI, production and testing can be done in less time and at a lower cost.

5. Automated X-Ray Inspection(AXI)

Automated X-ray inspection is a product inspection technique that uses X-rays. Unlike optical inspection, X-rays are completely invisible, but they are used as the source for these automated inspection systems. These systems can quickly and accurately check products for defects. Companies can easily improve business performance by using these devices, and consumers can benefit from more accurate results. Here are some of the benefits of automated X-ray inspection.

X-ray tubes produce X-rays. There are two types of X-ray tubes. The type you choose depends on the desired resolution. Higher resolution means that it is easier to detect the complex details in the X-rays. For example, CSP and BGA require a resolution of 2 mm. The sample manipulation stage is an important part of the inspection process. This allows the operator to examine the sample from a variety of angles, including tilt angles. The X-rays are then converted to a visual representation by a detector.

Another advantage of AOI is the ability to scan products without interrupting the manufacturing process. Due to its high flexibility and ease of use, the AXI method is ideal for high-volume production. The service’s user interface is friendly and intuitive, and there are several ways to customize it. Image resolution and magnification are two key parameters in volume inspection. AXI can inspect even the smallest products and parts.

6. Burn-In Testing

Aging tests can be performed in two ways. The first involves running the entire system, while the second involves individual components. The purpose of aging is to collect data on performance and failure conditions to improve future test procedures. Aging also helps to eliminate defective components by detecting the temperature at which they fail. For these reasons, aging testing is an important part of product development and evaluation.

The primary goal of aging testing is to identify devices that are prone to premature failure before they are placed on the market. In short, this testing involves subjecting components to extreme temperature and voltage conditions. The purpose of aging testing is to identify failures due to manufacturing defects and then identify them early enough to correct them and demonstrate trouble-free operation. The time spent under these conditions is added to the total time required for aging.

While aging may be beneficial, it may also be ineffective. The process can take hundreds of hours of continuous testing and requires extensive planning. It is critical to consider all potential constraints, such as time, equipment, and labor. In addition, the aging process should be carefully planned and a buffer built in for any potential rework. It typically takes more than 50 hours, but it depends on the product.

7. Functional Testing

Functional testing is an important part of software development. While unit and non-functional testing can demonstrate that an application is operational, the primary goal of functional testing is to ensure that the program meets user expectations. Broken functionality can cause the entire application to fail. Testing must be carefully planned and must cover all phases of the user journey. This requires collaboration between the product and testing teams. The following are some functional testing pointers.

First, functional testing simulates actual user behavior. This means that testing is not based on assumptions about the structure of the system, but on simulations of actual customer behavior. A functionally tested product will be free of bugs and errors. The size of the project is the most difficult aspect of functional testing. Therefore, it is critical to start small and simple, and then progress to more complex levels of sophistication. Then, combine various test conditions to ensure that the software is working properly.

AUT (Automated Functional Testing) is an effective tool for automating functional testing. Automated testing tools reduce manual work, save time, and prevent errors from slipping through the cracks. This type of testing is also very useful when testing complex systems. Automation tools such as Selenium are very useful, but it is important to note that they are not without flaws. Use appropriate non-functional testing tools to ensure the reliability of automated tests.

How to Protect Your PCB With Better Designs?

One approach is to protect the design data. Previously, engineers had to filter design data themselves before they could publish, which was time-consuming and error-prone. Better design now uses sequential part information to protect part data that can only be accessed by the engineering staff at the source. Only the owner knows where the data came from and can copy it.

EMI shielding is another way to protect the PCB. EMI shields are an important part of the PCB. They protect components from the electromagnetic interference caused by stray radiation from other PCB components. These shields should surround the board and individual components. Depending on the application, they can be made of metal, ceramic, or other materials.

A better design will include parallel lines to hide the visibility of the probe. Parallel lines reduce noise in the electronic power supply while increasing dynamic expansion. The PCB board with the sensor is protected by a rigid housing. The enclosure protects the device by acting as a shield. A signal suppression adhesive should be used to secure the PCB. this adhesive prevents all signals from reaching the PCB. these shields will also help the reverse engineer understand the PCB assembly.

Burn-In Testing

Moisture is another major cause of PCB corrosion and damage. Even traces of moisture can cause problems ranging from waveform distortion to complete failure. Moisture can also affect the board during manufacturing and installation. One way to protect PCBs with a better design is to use PCB coatings. However, remember that moisture protection requires a proper moisture barrier.