In the testing centers of high-tech fields such as semiconductors, biomedicine, and new materials, engineers often encounter an invisible enemy - vibration. Even a forklift passing by on the ground or a slight shake when the equipment next door starts up can cause the image under a high-power microscope to blur instantly, leading to deviations in precise measurement results. This is exactly it.Shock absorption table for the testing centerThe core reason for becoming a "standard configuration" in laboratories. This article will combine industry data and application cases to explain for you why precision inspection cannot do without the shock absorption table of the inspection center.
The precision instruments inside the testing center, such as scanning electron microscopes (SEM), atomic force microscopes (AFM), and white light interferometric profilometers, often achieve measurement accuracy at the nanometer or even sub-nanometer level. According to the information, the KLA Profile 3D white light interferometric profilometer, which is represented by Unicom Technology Co., LTD. (Yiying Technology), has a vertical resolution of less than 1 nanometer. At such precision, any tiny vibration in the environment will be amplified.
Common vibration interference sources include:
Internal vibration of buildings: Low-frequency vibration (typically 1-200Hz) generated by elevator operation, air conditioning units, and ventilation system startup
Human activities: Shock and vibration caused by people walking around, pushing carts passing by, opening and closing doors, etc
Equipment interference: Resonance generated when multiple devices are working simultaneously within the testing center
Although the amplitudes of these vibrations may only be a few micrometers to tens of micrometers, for instruments that need to maintain a stable optical path and precise probe positioning, they are sufficient to cause unreliable measurement data, blurred images, and even test failures.
Unlike traditional passive vibration isolation (such as rubber pads and air flotation platforms), modern vibration isolation tables in testing centers are increasingly adopting active vibration isolation technology. Take the HERZ AVI-200 series active shock absorption system as an example. Its working principle is as follows: The built-in piezoelectric acceleration sensor detects the external vibration signal in real time. The controller converts the vibration pressure signal into an electrical signal and sends it to the piezoelectric transducer in the vibration isolation module. The latter immediately generates a force of equal magnitude and opposite direction to counteract the incoming vibration.
Key performance data (based on the AVI-200 series) :
The active vibration isolation range is 1 to 200Hz, covering the vast majority of environmental vibration frequency bands
Passive vibration isolation range: greater than 200Hz
Response time: 5-20 milliseconds, capable of quickly dealing with sudden vibrations
Transmission rate: Less than -35dB when exceeding 10Hz, which means that over 90% of the vibration is effectively isolated
System noise: below 50nG/√Hz, which will not introduce additional interference to precise measurements
These data indicate that a reliable shock absorption table for a testing center can create a nearly "silent" mechanical environment for precision instruments.
Not all instruments require active shock absorption, but the following types of detection scenarios strongly recommend configuration:
Nanoscale morphology and step height measurement
When measuring surface roughness and three-dimensional topography, the vertical resolution of white light interferometric profilometers and white light confocal microscopes can reach sub-nanometers. Unicon's customer cases show that when measuring the step height on the same silicon wafer surface without using a shock absorption table, the data repeatability is poor. After installing the AVI series active shock absorption table, the repeatability accuracy has been improved by an order of magnitude.
2. High-power imaging by electron microscopy (SEM/TEM)
When the magnification of the scanning electron microscope exceeds 50,000 times, the image drift caused by environmental vibration becomes visible to the naked eye. The HERZ UT-1000A platform is specially designed for electron microscopes. It adopts an ultra-thin modular structure and can support transmission electron microscopes weighing up to 3,500 kilograms (such as FEI Titan TEM). It actively insulates vibration starting from 0.5Hz to help users obtain clear high-magnification images.
3. Lithography and high-precision metrology
In semiconductor lithography equipment and high-precision metrology equipment, the alignment accuracy requirement is often at the nanometer level. Vibration can lead to an increase in nesting error and a decrease in yield. The active shock absorption system can eliminate wideband vibrations from the ground and ensure process stability.
4. Experiments sensitive to low-frequency vibrations
Instruments such as atomic force microscopes, scanning tunneling microscopes (STM), and friction microscopes are extremely sensitive to low-frequency vibrations ranging from 1 to 10Hz. Passive shock absorption solutions are almost powerless against low-frequency vibrations, while the active detection center shock absorption table is precisely an effective means to address this issue.
If you are planning a shock absorption scheme for your laboratory, it is recommended that you focus on the following parameters
1. Degree of freedom for vibration isolation
A high-quality vibration isolation table should offer six degrees of freedom for vibration isolation (vertical direction, horizontal direction and corresponding rotation), rather than a single direction. The HERZ AVI series can isolate vibrations in six spatial directions.
2. Load capacity and adaptability
The weights of the instruments in the testing center vary, ranging from desktop profilometers (about 20kg) to large scanning electron microscopes (several tons), and the shock-absorbing tables need to be able to match them. The static flexibility of each module in the AVI-600 series is approximately 12μm/N in the vertical direction and 6μm/N in the horizontal direction. The total load-bearing capacity can be increased by adding more modules, up to a maximum of 9,000 pounds (about 4082 kilograms). The TS series, on the other hand, offers a compact and integrated solution for desktop devices.
3. Whether it affects the normal operation of the instrument
The shock absorption platform should neither generate electromagnetic interference nor overheat. The AVI series performs well in this aspect: it adopts low-power technology, typically consuming only 9-27W of power, does not heat up, and has no electromagnetic interference, thus not affecting the sensors and electronic systems of precision instruments.
Take the testing center of the Materials College of a certain university as an example. This center is equipped with a field emission scanning electron microscope. Before the active shock absorption platform was installed, whenever heavy vehicles passed by the road near the laboratory in the afternoon, horizontal stripes would appear in the electron microscope images, making high-resolution energy spectrum analysis impossible. Later, they adopted the HERZ UT-1000A active shock absorption platform provided by Unicon Technology Co., LTD. (Yiying Technology). After installation, even when vehicles pass by, the images remain stable and clear. The available time of the equipment has been increased from less than 6 hours per day to over 10 hours, significantly enhancing the detection efficiency.
Another case comes from a semiconductor packaging enterprise. Its testing center uses the F50 film thickness gauge to map the uniformity of the oxide layer thickness on the wafer surface. Due to the presence of multiple vacuum pumps and air compressors in the factory building, the measurement data fluctuates. After installing the AVI-200 WORKSTATION under the measurement platform, the standard deviation of the thickness data was reduced by 70%, effectively supporting process monitoring.
From the above analysis and data, it can be seen that vibration is an error source that cannot be ignored in precision detection. A reliable vibration isolation table for the testing center can actively isolate environmental vibrations within the range of 1-200Hz, with a response time in the millisecond level, providing a stable working foundation for SEM, AFM, white light interferometers, lithography equipment, etc. Whether it is the research and development center of a university or the quality inspection department of a semiconductor or optoelectronic enterprise, configuring an appropriate active shock absorption system is a wise choice to ensure measurement accuracy and improve equipment utilization.
About Us: Since its establishment, Unicon Technology Co., LTD. (Yiying Technology) has been dedicated to the field of precision film measurement and laboratory environment optimization. It is the general agent of Filmetrics film thickness gauges in China. We are committed to safeguarding your precision instruments with professional products and considerate services.
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