How Do X-Ray Machines Work in SMT and Welding?

It isn’t a secret that x-rays play a crucial role in industrial inspection. Undoubtedly, x-ray inspection has made long strides in the NDT industry. For example, advances in science have led to the integration of sensors, computers, and communication, making x-ray inspection a go-to technique. More specifically, x-ray inspection machines are now fast, safe, and easy to use. 

Again, with x-ray inspection technology, you can comfortably inspect a weld’s internal structure and determine the Surface-Mount Technology (SMT) quality. But, whether in SMT or welding, you can’t assume the role x-ray inspection plays in ensuring that products meet the set safety and quality standards.

But to understand how x-ray machines work in SMT and welding, let us discuss the two processes separately.

How SMT X ray Machine Works

Look around and inside any electronic device. You’ll see a multitude of minute devices mounted on the surface of boards, usually called printed circuit boards (PCB). Instead of fitting electronic devices onto the boards through holes, these devices are technically soldered on the boards. This way, more electronic components are packed onto a smaller space.

Typical PCBs with electronic devices mounted on the boards

Electronics manufacturing has over time advanced to levels that make inspection complicated. Unfortunately, SMT joints are typically hidden under packages making traditional inspection methods such as ultrasonic, optical, and thermal imaging insufficient.  Moreso, SMT makes packages and leads smaller, resulting in modern PCBs with higher density than other methods would.

But these PCBs must be inspected for quality, reliability, and safety standards.

So, the x-ray inspection method is applied here.

Owing to its ability to penetrate PCB layers to inspect packages, coatings, and solders, the X-ray inspection method has become popular and the most preferred.

To understand how SMT x-ray inspection works, you first need to know how x-ray inspection works in general.

First, all x-ray inspection gadgets consist of three elements:

  • Detector

It’s usually found on the other side of the sample. Its main purpose is to collect x-ray protons before converting them into an image.

  • X-ray Tube

It generates x-ray photons.

X-ray tube

  • Platform

Its purpose is to rotate the sample in different positions to be inspected from different angles and magnitudes.

Here is how x-ray machines work

For SMT X ray imaging to work, the x-ray photons are passed through the PCBA and collected on the other side where the detector is. The material’s atomic weight, thickness, and density determine how the x-ray photons travel through the material.

Typically, suppose the material under observation is heavy. In that case, it absorbs more x-ray photons that make them easier to image than the lighter ones that come out as transparent.

It’s interesting to note that PCB components have heavier elements, which are easily visible on an x-ray image.

X-ray Image indicating solder joints

And this is how SMT x-ray imaging is done:

X ray Welding Inspection Machine

Inspection of welds guarantees quality, safety, and aesthetics. Technically, the right x-ray welding machine offers results in real-time with clear images from and detecting flaws fast.

To reduce labor costs and enjoy more benefits of the unified operation of production and evaluation, you need a machine with fully automatic loading and unloading manipulator. With such a machine, you improve production efficiency while getting images with high resolution, automatic defect identification, and automatic judgment functionalities.

An x-ray welding machine

How X ray Welding Machine Works

The x-ray welding machine works using the same principle as any other x-ray machine. However, for this machine, the main material being tested is the welding object. 

  • Step #1: A radioactive isotope or the tube produces Xrays
  • Step #2: The x-rays (radiation) goes through the welding
  • Step #3: The radiation from the welding material reaches the photographic film. 
  • Step #4: The photographic film captures the image of the weld’s internal structure 
  • Step #5: On the image, the darker areas indicate the weld’s thinner areas

X-Ray Machine Maintenance

Just like any other machine, X-ray machines require regular preventive maintenance to reduce downtimes, enhance safety and improve image quality.

While we understand that you value the good working condition of your x-ray weld and SMT inspection machine, we’re going to share with you what an effective preventive maintenance looks like.

Verification of Functional Abilities

First things first. Only a qualified service engineer should undertake preventive maintenance tasks. To do this, you should first verify how well the machine is functioning. Here, you check the movement of the machine parts, production of x-rays, and image reception. Once these functions are observed and tested, the service engineer gets the baseline reference on the system performance level of the system.

Usually, to get a proper system performance level, you use the image quality check, also called the reference object (phantom).

Once you complete all the preventive maintenance steps, you need to do another quality check to confirm the image quality is either the same or better.

At this stage, you also align the tube and the detector as well as verifying and adjusting them.

Cleaning the Machine’s Interior

Conducting a bit of housekeeping helps in restoring or maintaining the X-ray machine’s optimal performance. Piled dust and debris in the x-ray machine system impedes its movement, appears in the images and also interferes with the cooling system.

To avoid these occurrences, ensure you clean the x-tube enclosing and replace the o-rings. Ensure you regularly inspect the high voltage cables, clean and grease them.

Blow out the dust and lint from the electronic components, wipe the table-top and lubricate the rails and gears.

Test the Mechanical and Electrical Systems

During preventive maintenance, routine checks on the mechanical and electrical systems are conducted. These systems include warning lamps, safety interlocks, and sensor tests. 

To ensure these systems are functioning optimally, the Service Engineer (SE) inspects, verifies and replaces the wire terminations as well as these secure mounting hardware. 

In case of moving systems, the service engineer checks their motion control operations where the SE sets each axis to its default position and verifies all the crash limits accordingly. In the same vein, adjust motors, sensors, and encoders as required. 

Finally, conduct full tests on the functions of the workstation. Pay attention to and address all the issues such as file up, installation of software patches and updates DR applications that testing has brought to light. 

Wrap Up

Clearly, x-ray machines have an important role in inspecting the quality of SMT and weld products. Choosing the right SMT X ray and X ray welding machines can make all the difference regarding the quality of results you expect. Additionally, understanding the basic working principles of x-ray machines can guarantee your safety and that of others.

Leave a Reply

Your email address will not be published. Required fields are marked *