CN-121994797-A - Nondestructive testing method and system for application defects of thermal interface material

CN121994797ACN 121994797 ACN121994797 ACN 121994797ACN-121994797-A

Abstract

The application relates to the technical field of thermal interface material defect detection, in particular to a nondestructive detection method and a nondestructive detection system for thermal interface material application, wherein the nondestructive detection system comprises an electric displacement table, heating laser, detection laser, a photoelectric detector, an acousto-optic modulator, a lock-in amplifier, an optical element and a data processing unit; the electric displacement table is used for fixing a sample and accurately controlling the position of the sample, the sample is of a silicon-thermal interface material-substrate sandwich structure, a metal film is plated on an upper silicon wafer of the sample to serve as a transduction layer, heating laser is used for heating the sample, the acousto-optic modulator is used for modulating the heating laser to enable the heating laser to heat the sample in a sine waveform mode, detecting laser is used for detecting temperature fluctuation of the sample, the photoelectric detector is used for collecting a detecting laser reflection signal, and the lock-in amplifier is used for extracting a detecting laser phase and amplitude signal. The application can realize nondestructive rapid detection of the defects of the thermal interface material in the application scene.

Inventors

LI XUANCHENG
HAN MENG
SHI HANG
Me Yimin
SUN RONG

Assignees

中国科学院深圳先进技术研究院
深圳先进电子材料国际创新研究院

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (10)

1. A system for non-destructive inspection of a thermal interface material application defect, comprising: the device comprises an electric displacement table, heating laser, detection laser, a photoelectric detector, an acousto-optic modulator, a lock-in amplifier, an optical element for laser guiding and a data processing unit; The electric displacement table is used for fixing a sample and accurately controlling the position of the sample, wherein the sample is of a silicon-thermal interface material-substrate sandwich structure, and a metal film is plated on an upper silicon wafer of the sample to serve as a transduction layer; the heating laser is used for heating the sample, and the acousto-optic modulator is used for modulating the heating laser to heat the sample in a sine waveform manner; The photoelectric detector is used for collecting detection laser reflection signals; the electric displacement table and the phase-locked amplifier are both connected with the control unit, and the phase-locked amplifier is used for extracting and detecting laser phase and amplitude signals.
2. The system for non-destructive inspection of defects in a thermal interface material according to claim 1, further comprising a control Wen Tai, said temperature control station for effecting different temperature tests of a sample.
3. The system for non-destructive inspection of defects in a thermal interface material of claim 1, further comprising a pressure application fixture for applying pressure to a sample to effect different pressure testing of the sample.
4. The system for non-destructive inspection of defects in a thermal interface material of claim 1, wherein said optical component comprises a dichroic mirror, a mirror, an objective lens, an optical isolator, and a filter.
5. The system of claim 1, wherein the heating laser wavelength is matched to the metal of the metal film to provide a greater absorptivity to the layer, and wherein the detection laser wavelength is matched to the metal of the metal film to provide a greater photothermal reflectance to the layer.
6. The system for non-destructive inspection of defects in thermal interface material of claim 1, wherein the metal film has a thickness of 100nm to 200nm.
7. The system for non-destructive inspection of defects in a thermal interface material of claim 1, wherein said photodetector is wavelength matched to a detected light.
8. A method for non-destructive inspection of defects in a thermal interface material based on the system for non-destructive inspection of defects in a thermal interface material according to any one of claims 1 to 7, comprising the steps of: fixing a sample on an electric displacement table, and enabling the upper surface of a metal film to coincide with the focal plane of an objective lens of an optical element; step two, heating laser and detecting laser are turned on, and the laser is irradiated to the surface of the metal film; the control unit controls the electric displacement table to move the sample, adopts the photoelectric detector to collect amplitude and phase data of the laser reflection signal detected at each position by using the lock-in amplifier, and adopts the data processing unit to record the amplitude and phase data of the laser reflection signal detected at each position; Outputting a phase distribution map or an amplitude distribution map of a scanning area by using the amplitude or phase data of the detection light reflection signals reflected by each position of the sample recorded in the step three; and fifthly, judging whether the interface is uniform or not through the phase distribution diagram.
9. The method for non-destructive testing of defects in thermal interface materials according to claim 8, wherein in step five, the phase is known to correspond to the sample structure one-to-one according to equation (1), wherein equation (1) is as follows: Wherein ω is the modulation angular frequency, The phase delay introduced for the system is, Is in the form of inverse hanker transformation of thermal response in the frequency domain.
10. The method for non-destructive inspection of defects applied to a thermal interface material according to claim 8, wherein the sample is moved with the motorized displacement stage during the scanning process, and the position of the two lasers is unchanged.

Description

Nondestructive testing method and system for application defects of thermal interface material Technical Field The application relates to the technical field of thermal interface material defect detection, in particular to a nondestructive testing method and a nondestructive testing system for application defects of a thermal interface material. Background Thermal Interface Materials (TIMs) are commonly used to fill the gaps between heat sources and heat sinks of electronic devices, such as chips and covers, and covers and heat sinks, to provide a thermal path to prevent thermal failure of electronic components due to excessive temperatures. Interface defects (gaps, cracks, oxide layers and the like) possibly existing in the thermal interface material in practical application can cause the influence of heat dissipation efficiency reduction, mechanical performance reduction, long-term reliability reduction, electric performance reduction and the like in the practical application. Thus defect detection of thermal interface materials is critical to their development and use. The currently commonly used material defect detection methods mainly comprise optical microscope observation, scanning electron microscope observation (SEM), X-ray tomography (X-ray CT), ultrasonic scanning (Ultrasound Testing), focused Ion Beam (FIB) and thermal imaging detection. The optical microscope is mainly used for observing surface defects with larger size, and has simple operation and low cost, but defects inside the multilayer structure cannot be detected. Scanning electron microscopy has higher resolution and microscopic defects are observed, but often sample preparation times are long, requiring destructive means to observe internal defects. X-ray tomography has the disadvantage of high equipment costs and limited resolution by the nature of the material. Ultrasonic scanning is the most common non-destructive defect scanning means, however, the interface resolution is lower for some micrometers, and the sample needs to be immersed in water, which may affect some electronic devices. Focused Ion Beam (FIB) requires cutting of the sample to observe internal microscopic defects, is complex to operate, expensive to equipment, and can only be used for small area sample observation. Conventional thermographic inspection can only detect defects at the surface or shallow interfaces. Disclosure of Invention The embodiment of the application provides a nondestructive testing method and a nondestructive testing system for application defects of a thermal interface material, which can realize nondestructive rapid detection of the working state and defects of the thermal interface material in application, and have important significance for performance cognition of the thermal interface material and application of the thermal interface material in various thermal management scenes and the like. In order to solve the technical problems, in a first aspect, the embodiment of the application provides a nondestructive testing system for defects of a thermal interface material, which comprises an electric displacement table, heating laser, detection laser, a photoelectric detector, an acousto-optic modulator, a lock-in amplifier, an optical element for guiding laser and a data processing unit, wherein the electric displacement table is used for fixing a sample and accurately controlling the position of the sample, the sample is of a silicon-thermal interface material-substrate sandwich structure, a metal film is plated on an upper silicon wafer of the sample to serve as a transduction layer, the heating laser is used for heating the sample, the acousto-optic modulator is used for modulating the heating laser to enable the heating laser to heat the sample in a sine waveform, the detection laser is used for detecting temperature fluctuation of the sample, the photoelectric detector is used for collecting detection laser reflection signals, and the electric displacement table and the lock-in amplifier are connected with a control unit, and the lock-in amplifier is used for extracting detection laser phase and amplitude signals. In some exemplary embodiments, the nondestructive testing system further comprises a temperature control table for realizing different temperature tests of the sample. In some exemplary embodiments, the nondestructive testing system further comprises a pressure applying clamp for applying pressure to the sample to realize different pressure tests of the sample. In some exemplary embodiments, the optical element includes a dichroic mirror, a mirror, an objective, an optical isolator, and a filter. In some exemplary embodiments, the heating laser wavelength matches the metal of the metal film such that the transduction layer has a greater absorptivity thereto, and the detecting laser wavelength matches the metal of the metal film such that the transduction layer has a greater photothermal reflectance thereto. In some exemplary