PCB Testing Technology and Methods, Explained

The value of the printed circuit board (PCB) market is expected to keep growing by 5% up until 2030. In other words, this critical technology is only becoming more important to all industries.

If you’re working with a design related to PCB testing, you need to know all the ins and outs of PCB testing. This is critical if you want your equipment to work right long-term.

That’s where this article may be valuable to you. Detailed below, we’ll go over everything you need to know about PCB testing technology and methods. Keep reading to ensure you’re staying ahead of industry trends.

Non-Intrusive PCB Testing

Some PCB strategies are unique from other testing methods. In particular, non-intrusive PCB testing methods don’t require physical contact with the circuit board.

Instead, they rely on technologies such as optics and X-rays to inspect the board and its components. Non-intrusive testing methods are typically faster and less expensive than other testing methods.

SPI 3D (Solder Paste Inspection)

This part of testing checks that the solder paste has been applied correctly to a printed circuit board before it’s assembled. SPI 3D involves scanning the board and creating a 3D image of the solder paste. This image is then compared to the board’s design to check that the paste is in the correct places.

SPI 3D is a non-destructive testing method that is fast and accurate. It can detect issues with the solder paste, such as incorrect amount or shape, which can cause problems in assembly. This helps to ensure that the board is correctly assembled the first time.

Automated Optical Inspection (AOI)

Automated Optical Inspection, or AOI, is a great way to test PCBs using machines. These machines take pictures of the board and use software to find any problems. They can look at things like solder joints, components, and markings.

At Geospace, we use AOI to test PCBs at different stages. We use it after the solder paste application to check for any problems with the paste.

We also use it after component placement to ensure they are in the right spot. Finally, we use it after the board assembly to check for any final problems.

When PCB technologies don’t work right, it can be very frustrating. Learn more about emerging trends in PCB failure analysis here.

JTAG (Joint Test Action Group)

This method uses a standardized set of signals to test the connections between components on the board. JTAG can test individual components, such as integrated circuits or memory chips.

JTAG can also be used to program and debug the board. It’s commonly used in the electronics industry for debugging and testing microcontrollers.

X-Ray Inspection

Equipment for this process typically includes an X-ray generator, a detector or imaging device, and a computer or software system. This last component will process and analyze the images.

The generator produces X-rays that pass through the PCB. It can then create an image of the internal components, solder joints, and other features. The detector or imaging device captures the X-ray image and converts it into a digital format.

In-Process Testing

This type of PCB testing occurs during the manufacturing process itself. It’s useful in this way to detect potential issues before the PCB assembly is complete. This allows for immediate corrections and prevents the need for costly rework or scrap.

During in-process testing, the PCB assembly may be tested multiple times at different stages of production. Let’s look at some examples.

Thermal Scanning

Thermal scanning measures the heat generated by the board to detect any hot spots or anomalies. It can detect problems such as short circuits, open circuits, and bad connections.

Thermal scanning can also be used to monitor a board’s performance over time. This can be ideal to ensure it works correctly even after extended use.

Functional Testing

This method applies signals to the board and verifies that the board behaves as expected. Functional testing is typically performed after the board is assembled and powered on.

This is an intrusive testing method, as it requires physical contact with the board. However, functional testing can be time-consuming and expensive, especially for complex boards. That’s why it’s best to entrust this process to experts who can get it right the first time.

Reflow Profiles

Reflow profiles are a critical component of the surface mount assembly process. They define the temperature and time required to melt the solder paste and form the solder joints.

The reflow process is important because it ensures that components are securely attached to the printed circuit board. These profiles are carefully designed to ensure proper melting and bonding of the solder paste.

Environmental Testing Methods

These testing methods test how printed circuit boards perform in various conditions. With these, manufacturers can identify and fix any issues before the board goes to the market.

RF Chambers test how the board performs in electromagnetic fields. This process checks how the board responds to different frequencies and signal strengths. One example would be radio frequency interference.

Temp/Humidity Chambers are self-explanatory. They test how the board performs in different temperature and humidity conditions. This type of testing is essential for ensuring the board can withstand extreme environments.

Hass-Halt Chambers tests how the board performs under stressful conditions. They specifically test temperature, humidity, and vibration.

These environmental testing methods are essential for many reasons. Their main purpose, though, is ensuring that printed circuit boards can operate reliably. Additionally, there are often other testing tools available, depending on your testing service provider. For further guidance, check out this article about the latest PCB industry trends.

Invest in the Right PCB Strategies

Now that you know more about PCB testing, be sure to continue your research on the subject, as strategies are constantly evolving. It’s up to you to continue investing in the best PCB strategies of the day.

Fortunately, we can ensure you’re on the right track when it comes to PCB technology. We encourage you to contact Geospace Technologies now to ensure your project is where it needs to be.