Microfocus X-Ray Systems

To capture high-resolution images of test subjects at increased inspection sizes, microfocus X-ray devices are essential. A good microfocus X-ray system is an investment you must make if your industry depends on quality assurance to meet market needs like high yield and manufacturing standards.

MQS provides dependable industrial X-ray inspection equipment for a wide range of uses, from manufacturing to research & development. In order to complement your current systems and achieve the flexibility that may not be available with off-the-shelf OEM solutions, we can customize the solution. Partner with us immediately to upgrade your vital inspection systems.

An Overview

Microfocus units are X-ray devices with focused spots that are less than 100 m in size. Advanced micro-focus systems may achieve a focal spot size of as little as 5 m by concentrating the electron beam on the target and providing enough cooling to prevent overheating.

When compared to conventional radiography, micro-focus radiography makes it easier to see the intricate details of an object by creating magnified X-ray images, which in turn improves the capacity to detect flaws. Due to the low penumbra effect, micro-focus X-ray systems with focal spots that are close to a point source are helpful in getting extremely high-resolution images.

A constant X-ray beam is produced by the X-ray source from the tiny focal point. The beam projects an X-ray image onto the detector sensor after passing through the sample that is mounted on the manipulator turntable. An image in visible greyscale is created from the transmitted X-ray projection by the sensor and presented on a monitor. The sample’s magnification is determined by where it is in relation to the X-ray source and detector. By increasing the number of pixels the X-ray image is projected over, moving the sample closer to the X-ray source magnifies the sample and enhances spatial resolution. The micro-focus X-ray spot makes sure the image is always sharp even when working at maximum magnification. The related software provides picture integration and contrast amplification.

MQS Resources

X-Tek HMX225 micro-focus advanced X-ray system

Features:

• 5-10 µm Focal Spot Reflection Target X-ray Source
• 25 to 225 kV, 0 – 2000 µA, 225 Watt
• 5 axis fully programmable manipulator
• Maximum scan area 480 x 450mm 
• Geometric Magnification up to 160x
• System Magnification up to 400x
• Feature recognition: down to 5µm

Benefits

• Image Enlargement
• Improved Radiographic contrast
• Reliable detection of micro features

Applications

• Inspection of integrated circuits and PCBs
• Inspection of high-quality castings and weld material
• Tube to tube sheet weld inspection
• Inspection of composites and ceramics for micro-voids and structural inhomogeneity
• Inspection of inaccessible areas
• Inspection of turbine blades of the aero engine to detect hairline cracks

Types of Micro Focus X-ray Tube Systems

Micro Focus

By offering the lowest focusing point size and allowing the magnification factor to rise, microfocus tubes have been utilized to improve image quality by raising the visual resolution. Systems using micro-focus and micro-CT can reliably achieve resolutions as small as 2 microns. As you are aware from earlier studies of the inverse square law and focal spot size, the smaller the focal point, the less surface area is available to boil off electrons. Your filament current is constrained as a result, which limits your tube current. If you’ve ever used or played with an adjustable power supply linked to an incandescent light bulb, you know that the light can be made brighter and brighter as the current increases until the filament of the light bulb burns out. The filament of an X-ray tube operates under the same principle. Therefore, creating a filament with a size in the micron range has physical restrictions. 

A crucial engineering challenge that has been studied for almost as long as the x-ray tube has been around is the creation of smaller, higher power focal points. In fact, a stable, compact focal spot is still necessary even for high energy requirements and the development of linear accelerator tubes. Both of these approaches require an electron beam that is stable as it travels to the target region. A grid bias can also be used to control the electrons that are boiled off by the X-ray tube filament. Magnetic fields are created to direct and shape the electron beam in order to accomplish exact size and sculpting.

Grid Bias X-ray Tube

Early in the 1960s, the grid tube was granted a patent. The technique was created to regulate the time between turns of the X-ray beam. High tension cables are used in various early and modern x-ray systems to transfer high voltage from the x-ray transformer to the x-ray tube. The wires have a capacitive value and can store a charge because they are made up of conductors and an insulator. The cable charge will drain depending on the tube conduction; the higher the conduction, the higher the tube current, and the faster the cable is discharged. If we were to think of the tube as a huge variable resistor, the circuit would be a straightforward R/C network. The HV capacitance or lag in early X-ray systems was particularly unfavorable since the x-ray would continue for a brief period of time after the exposure was instructed to stop. By basically shorting the cathode electron beam, a grid tube will enable the operator to operate at greater frame rates and turn off the X-rays. Early cardiology exams used a 35mm movie camera and an image intensifier (we will discuss imaging later) to record the flow of blood mixed with a radio-opaque substance through the heart muscle. The beam was shut off between frames to prevent radiation to the patient and to ensure that each exposure produced a quick, blur-free image. The heat was generated significantly during the discharge control that followed to stop the X-rays. The management of the beam size and form was made possible by grid advancements and improvements brought about by this technology.

Micro-Focus Transmission Tube

The focal spot size and beam quality in a contemporary micro-focus X-ray tube will depend on the form of the filament, the grid shape and bias, the electromagnetic control of the beam width, and the target thickness and materials. The operator will have a stable focal point of ideal size and energy thanks to it and its ability to keep the system cool. The sections of a micro-focus tube, which has a 2-micron focal spot size and an almost limitless exposure period, are visible in the transmission tube image. This kind of X-ray tube is utilized in the diondo microfocus systems to swiftly and precisely give the operator a high-resolution CT image. ​

The choice of the X-ray tube is crucial, as different applications require different target materials and thicknesses.” The thickness of this layer ranges from 1 to 10 microns, depending on how the X-ray tube is used. For this layer, several materials might be employed depending on the task. Which materials and the transmission target type are ideal for your application?” Because this 300,000 electron volt beam is analogous to an electron beam welder used in metal deposition additive manufacturing, maximum heat dissipation for the target is required. A tube target that is not properly cooled can result in disfigurement from melting. To learn more about choosing an X-ray tube for CT and digital radiography systems, get in touch with us.