Chip packaging glass stitch welding monitoring system based on ultrafast laser

Abstract

The utility model discloses a chip packaging glass stitch welding monitoring system based on ultrafast laser, which comprises an upper computer, a data acquisition unit and a plurality of acoustic emission sensors used for acquiring that the ultrafast laser focuses on a welding interface combination part of chip packaging glass, the data output end of the acoustic emission sensor is connected with the data acquisition unit, and the data acquisition unit is in data communication connection with the upper computer; the data acquisition unit comprises a signal filter, a pre-amplifier and a Labview data acquisition card, and the data output end of the acoustic emission sensor is connected with the upper computer through the signal filter, the pre-amplifier and the Labview data acquisition card in sequence. The glass stitch welding quality monitoring system can monitor the final quality of glass stitch welding and realize on-line real-time monitoring of welding, so that the loss of destructive detection is reduced while the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the field of laser welding technology, and in particular to a chip packaging glass stack welding monitoring system based on ultrafast laser. Background Art

[0002] The most common defects in glass laser welding joints are pores, cracks, lack of fusion, and low connection strength. The most common problem in glass welding is that the gap between the welding glasses is too large, resulting in the inability of the molten body to form an effective connection. Regarding the effect of the thickness of the air layer between the glasses on the performance of picosecond laser welding, most of the gaps between the glasses are calculated by interference fringes, and the effects of different gaps on the weld are analyzed. When the gap between the glasses is too large, the weld becomes discontinuous and the strength decreases significantly. Therefore, monitoring the gap between the welding glasses is of great significance. The existing glass laser welding monitoring methods are as follows:

[0003] (1) The interference fringes between the glasses are directly observed under a microscope to determine the gap between the glasses. However, since white light is used as the illumination source, the color of the interference fringes and the wavelength of the light are difficult to confirm, and the calculated results have large errors.

[0004] (2) The soda-lime glass micromachining process was monitored using the laser-induced breakdown spectroscopy (LIBS) method. The laser focus position was accurately determined based on the position with the highest intensity of the plasma spectrum excited on the sample surface. This method has the ability to monitor and correct the focus position online, realize feedback and information transmission, and then achieve automation. However, since it relies on spectroscopy for analysis, the transparent material that the laser passes through should have different elements from the underlying substrate to distinguish it, or auxiliary elements should be added between the two materials for positioning;

[0005] (3) High-speed cameras and photodetectors are used to detect plasma emission during glass welding. The welding strength or cracking is predicted by whether the melt is regular during welding. The plasma formation during welding of non-optical contact and optical contact glass is analyzed to study the influence of different welding gaps on plasma emission. The feasibility of monitoring welding gaps and irregular welds by analyzing the changes in plasma emission is also analyzed. The monitoring of plasma focuses more on the intensity of its emission spectrum.

[0006] (4) Optical coherence tomography (OCT) technology was used to locate the weld of glass welding by using the gaps generated during the glass welding process and data evaluation methods. The positioning deviation was only in the sub-nanometer range. However, this method is limited by the working principle of OCT and can only monitor the welding process of specific types of glass. If used in practical applications, OCT needs to be coaxially arranged with other optical devices.

[0007] Therefore, in view of the fact that most of the current research on ultrafast laser glass welding focuses on the research of welding process, the final monitoring means are mostly offline monitoring of its tensile / shear strength and welding interface morphology. There is a lack of diversified and low-cost monitoring means, and it is impossible to monitor the intuitive characterization phenomenon of welding signals during the welding process, and thus it is difficult to reflect the quality of welding during the welding process. When cracks, insufficient fusion and other defects appear on the glass substrate, the laser welding parameters cannot be adjusted in time according to the welding situation, causing damage to the product or poor welding, and ultimately leading to high product defective rate. Research on the characterization of various signals and defect detection in the process of ultrafast laser glass lap welding is extremely important for achieving stable and efficient glass welding. Utility Model Content

[0008] The purpose of the utility model is to provide a chip packaging glass stack welding monitoring system based on ultrafast laser. The utility model can monitor the final quality of glass stack welding and realize online real-time monitoring of welding, thereby improving production efficiency and reducing the loss of destructive testing. In order to achieve the above purpose, the utility model adopts the following technical effects:

[0009] According to one aspect of the utility model, the utility model provides a chip packaging glass stack welding monitoring system based on ultrafast laser, the glass stack welding monitoring system includes a host computer, a data acquisition unit and a plurality of acoustic sensors for obtaining the ultrafast laser focusing on the welding interface junction of the chip packaging glass, the data output end of the acoustic sensor is connected to the data acquisition unit, and the data acquisition unit is connected to the host computer for data communication; the data acquisition unit includes a signal filter, a preamplifier and a Labview data acquisition card, and the data output end of the acoustic sensor is connected to the host computer through the signal filter, the preamplifier and the Labview data acquisition card in sequence.

[0010] The above scheme is further preferred, wherein the data acquisition unit also includes a signal display and an RS232 to BNC interface, the Labview data acquisition card is connected to the signal display via a high-frequency coaxial transmission line of an RS232 to BNC connector, and the Labview data acquisition card is communicatively connected to the host computer via a PCX bus, a PCI bus or a USB data cable.

[0011] The above scheme is further preferred that a wireless communication module is provided on the Labview data acquisition card and is communicatively connected to the signal control end of the ultrafast laser. The wireless communication module is a 2.4G wireless communication module, a wifi communication module or a 485 / 422 wireless communication module.

[0012] The above scheme is further preferred in that an alarm indicator light and an automatic / manual control button are provided on the Labview data acquisition card.

[0013] The above scheme is further preferred, in which a Labview software platform and a MATLAB software platform are loaded in the host computer, a signal output end of the Labview data acquisition card is connected to a signal input end of the host computer equipped with the LabVIEW software platform, and the Labview software platform and the MATLAB software platform interact with each other.

[0014] The above scheme is further preferred, wherein the Labview data acquisition card adopts a NIPXI-5100 data acquisition card.

[0015] The above solution is further preferred, the spacing between the welding interfaces of the chip encapsulation glass is 0.5-20um, and the welding interface area is 0.01-100mm 2 .

[0016] In the above scheme, the ultrafast laser emits a pulse laser with a pulse width ranging from 50 fs to 20 ps and a wavelength of 500 nm to 700 nm.

[0017] The utility model adopts the above technical solution, and the utility model has the following technical effects:

[0018] (1) The utility model adopts an acoustic emission sensor to monitor the ultrafast laser glass welding process, explores the signal characterization during the ultrafast laser glass welding process, realizes more reliable, feasible and regular ultrafast laser welding process monitoring, and establishes a reliable glass welding monitoring system based on acoustic emission signals.

[0019] (2) The utility model performs online monitoring of the chip packaging glass stack welding process, with fast detection speed and low detection cost. The welding quality can be directly judged through the data monitored during the welding process, thereby improving production efficiency and reducing the loss of destructive detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a system principle diagram of a chip packaging glass stack welding monitoring system based on ultrafast laser. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are only for the purpose of enabling readers to have a thorough understanding of one or more aspects of the utility model, and these aspects of the utility model can be realized even without these specific details.

[0022] like Figure 1 As shown, the utility model provides a chip packaging glass stack welding monitoring system based on ultrafast laser, the glass stack welding monitoring system includes a host computer 10, a data acquisition unit 20 and a plurality of acoustic sensors 2 for obtaining the welding interface junction of the ultrafast laser 1 focused on the chip packaging glass, the data output end of the acoustic sensor 2 is connected to the data acquisition unit 20, and the data acquisition unit 20 is connected to the host computer 10 for data communication; the data acquisition unit 20 includes a signal filter 3, a preamplifier 4 and a Labview data acquisition card 5, the signal filter is a low-pass filter, the preamplifier 4 is an I / V conversion amplifier, the collected sound current signal is converted into a voltage signal and amplified, the data output end of the acoustic sensor 2 is connected to the host computer through the signal filter, the preamplifier, and the Labview data acquisition card 5 in sequence; the spacing between the welding interfaces of the glass sheet packaging glass is 0.5-20um, and the welding interface area is 0.01-100mm 2 The ultrafast laser emits a pulse laser with a pulse width ranging from 50fs to 20ps, and a wavelength of 500nm to 700nm. The acoustic sensor monitors the sound signal of a continuous spectrum near 500nm to 700nm, and the welding is determined to be successful. The acoustic sensor transmits the monitored acoustic signal to the Labview data acquisition card for quantification and sends it to the host computer for processing to obtain the sound time-frequency signal, and the collected data is displayed in the form of a waveform signal to monitor the final quality of the glass overlap welding, and to realize online real-time monitoring of the welding, and the feedback control signal is uploaded to the welding system through the Labview data acquisition card by the host computer to control the welding system.

[0023] In the present utility model, if Figure 1As shown, the data acquisition unit also includes a signal display and an RS232 to BNC interface. The Labview data acquisition card is connected to the signal display through a high-frequency coaxial transmission line of an RS232 to BNC connector. The signal display is a digital oscilloscope or a digital spectrum analyzer. The acoustic signal collected by the Labview data acquisition card is directly displayed as a waveform signal by the digital oscilloscope or the digital spectrum analyzer after processing; the Labview data acquisition card is communicatively connected to the host computer through a PCX bus, a PCI bus or a USB data line, and the acoustic signal collected by the Labview data acquisition card is uploaded to the host computer through the PCX bus, the PCI bus or the USB data line. A wireless communication module is provided on the Labview data acquisition card that is communicatively connected to the signal control end of the ultrafast laser. The wireless communication module is a 2.4G wireless communication module, a wifi communication module or a 485 / 422 wireless communication module. The collected acoustic signal is sent to a remote monitoring through the wireless communication module. The host computer uploads the feedback control signal to the welding system through the Labview data acquisition card and the wireless communication module to control the collection of the acoustic sensor and the welding of the welding system.

[0024] In the utility model, an alarm indicator light and an automatic / manual control button are provided on the Labview data acquisition card, and the automatic / manual control button is used to start or stop the Labview data acquisition card from collecting welding sound signals and stop outputting collected data to the upper computer.

[0025] In the present utility model, if Figure 1As shown, the host computer is loaded with Labview software platform and MATLAB software platform, the signal output end of the Labview data acquisition card is connected to the signal input end of the host computer equipped with the Labview software platform, the Labview software platform extracts, saves and processes the collected data, the Labview software platform and the MATLAB software platform interact with each other, and the Labview data acquisition card adopts the NIPXI-5100 data acquisition card; the Labview data acquisition card performs data acquisition conversion and digital measurement on the analog signals measured by multiple channels, so as to obtain a large amount of data for analysis and processing; the NI data acquisition card is used to collect the acoustic emission signal generated in the glass stack welding process, and the acoustic emission signal monitored by the acoustic emission sensor during the welding process is sent to the NI data acquisition card for quantization and output of digital signal, and then sent to The Labview software platform presents it in the form of time domain, and then sends it to the MATLAB platform for denoising and frequency domain transformation; because the glass overlap welding process is formed by laser scanning one by one, the acoustic emission signal in the time domain form is sent to the MATLAB platform through the Labview software platform to denoise and intercept the acoustic and RF signals during each scan, and then the time-frequency diagram is obtained by Fourier transform through the MATLAB software platform; the image obtained after the frequency domain transformation is sent back to the Labview software platform for display, which is convenient and intuitive for observers to observe the values ​​and control the entire glass welding process. The sound signals collected by various acoustic sensors can be displayed in real time, and the collected data can be displayed in the form of waveform signals, so as to monitor the final quality of glass overlap welding and realize online real-time monitoring of welding, thereby improving production efficiency and reducing the loss of destructive detection.

[0026] The above is only a preferred embodiment of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications should also be regarded as the scope of protection of the utility model.

Claims

1. A chip packaging glass stack welding monitoring system based on ultrafast laser, characterized by: The glass stack welding monitoring system includes a host computer, a data acquisition unit, and a plurality of acoustic sensors for obtaining the welding interface junction where the ultrafast laser is focused on the chip packaging glass. The data output end of the acoustic sensor is connected to the data acquisition unit, and the data acquisition unit is connected to the host computer for data communication; the data acquisition unit includes a signal filter, a preamplifier, and a Labview data acquisition card, and the data output end of the acoustic sensor is connected to the host computer through the signal filter, the preamplifier, and the Labview data acquisition card in sequence.

2. The chip packaging glass stack welding monitoring system based on ultrafast laser according to claim 1 is characterized by: The data acquisition unit also includes a signal display and an RS232 to BNC interface. The Labview data acquisition card is connected to the signal display via a high-frequency coaxial transmission line of an RS232 to BNC connector. The Labview data acquisition card is communicated with the host computer via a PCX bus, a PCI bus or a USB data cable.

3. The chip packaging glass stack welding monitoring system based on ultrafast laser according to claim 2 is characterized in that: A wireless communication module connected to the signal control end of the ultrafast laser is arranged on the Labview data acquisition card. The wireless communication module is a 2.4G wireless communication module, a wifi communication module or a 485 / 422 wireless communication module.

4. The chip packaging glass stack welding monitoring system based on ultrafast laser according to claim 2 is characterized in that: The Labview data acquisition card is provided with an alarm indicator light and an automatic / manual control button.

5. A chip packaging glass stack welding monitoring system based on ultrafast laser according to any one of claims 1 to 4, characterized in that: The host computer is loaded with Labview software platform and MATLAB software platform, the signal output end of the Labview data acquisition card is connected to the signal input end of the host computer equipped with the LabVIEW software platform, and the Labview software platform and the MATLAB software platform interact with each other.

6. The chip packaging glass stack welding monitoring system based on ultrafast laser according to claim 5 is characterized by: The Labview data acquisition card adopts NIPXI-5100 data acquisition card.

7. The chip packaging glass stack welding monitoring system based on ultrafast laser according to claim 1 is characterized by: The spacing between the welding interfaces of the chip encapsulation glass is 0.5-20um, and the welding interface area is 0.01-100mm 2 .

8. The chip packaging glass stack welding monitoring system based on ultrafast laser according to claim 1 or 3, characterized in that: The ultrafast laser emits pulse laser with a pulse width ranging from 50 fs to 20 ps, ​​and a wavelength of 500 nm to 700 nm.

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