阅读说明：本技术 用于电子元器件的激光清洗设备及方法 (Laser cleaning equipment and method for electronic components ) 是由 肖海兵 姜家吉 周泳全 陈树林 于 2019-10-18 设计创作，主要内容包括：本发明公开一种用于电子元器件的激光清洗设备,该用于电子元器件的激光清洗设备包括机座、可移动地设置在所述机座上的加工台、设置在所述加工台上方的激光清洗头和用于产生激光束的激光发生器,所述激光清洗设备还包括设置在所述激光束的传输光路上的第一光束整形单元和第二光束整形单元,所述第一光束整形单元用于将激光发生器产生的激光束耦合进光纤,所述第二光束整形单元用于调节从所述激光清洗头发射出的聚焦光斑的形状和能量分布。本发明用于电子元器件的激光清洗设备可增强对于微电子器件的清洗效果,保证微电子器件的产品性能,同时提高清洗效率。此外,本发明还公开一种用于电子元器件的用于电子元器件的激光清洗方法。(The invention discloses laser cleaning equipment for electronic components, which comprises a base, a processing table movably arranged on the base, a laser cleaning head arranged above the processing table, and a laser generator for generating laser beams, and further comprises a first beam shaping unit and a second beam shaping unit which are arranged on a transmission light path of the laser beams, wherein the first beam shaping unit is used for coupling the laser beams generated by the laser generator into optical fibers, and the second beam shaping unit is used for adjusting the shape and the energy distribution of focusing light spots emitted from the laser cleaning head. The laser cleaning equipment for the electronic components can enhance the cleaning effect on the microelectronic devices, ensure the product performance of the microelectronic devices and improve the cleaning efficiency. In addition, the invention also discloses a laser cleaning method for the electronic component.)

1. The laser cleaning equipment for the electronic components is characterized by comprising a base, a processing table movably arranged on the base, a laser cleaning head arranged above the processing table, and a laser generator for generating laser beams, and further comprising a first beam shaping unit and a second beam shaping unit which are arranged on a transmission light path of the laser beams, wherein the first beam shaping unit is used for coupling the laser beams generated by the laser generator into optical fibers, and the second beam shaping unit is used for adjusting the shape and the energy distribution of focusing light spots emitted from the laser cleaning head.

2. The laser cleaning device for the electronic components as claimed in claim 1, wherein the first beam shaping unit includes a beam expander and a first converging lens, which are sequentially arranged along a transmission direction of the laser beam, and the beam expander includes a diverging lens and a second converging lens.

3. The laser cleaning device for the electronic components as claimed in claim 1, wherein the second beam shaping unit includes a third condensing lens, a collimating lens and a focusing lens which are arranged in this order along the transmission direction of the laser beam.

4. The laser cleaning device for the electronic components as claimed in claim 1, further comprising a frequency doubling chip disposed between the first beam shaping unit and the second beam shaping unit, wherein the frequency doubling chip is configured to perform frequency doubling on the laser beam coupled into the optical fiber to control the laser beams with different wavelengths to be output.

5. The laser cleaning device for the electronic components as claimed in claim 1, further comprising a cooling device for cooling the laser generator and/or the laser cleaning head, wherein the cooling device comprises a water chiller and a cooling water path.

6. The laser cleaning apparatus for electronic components according to claim 1, further comprising an air supply auxiliary device for blowing off vapor generated on the surface of the workpiece toward the circumferential direction of the laser cleaning head, wherein the air supply auxiliary device is arranged above the processing table and includes an air supply and an air blowing path.

7. The laser cleaning apparatus for electronic components as claimed in claim 6, wherein the gas in the gas source is an inert gas.

8. The laser cleaning apparatus for electronic components according to claim 1, further comprising a particle collecting device for collecting evaporation residues generated on the surface of the workpiece after the laser cleaning, wherein the particle collecting device comprises an absorption channel and a collector.

9. The laser cleaning apparatus for electronic components according to any one of claims 1 to 8, further comprising a visual inspection device disposed above the processing table for positioning a workpiece carried on the processing table, the visual inspection device including a CCD camera.

10. A laser cleaning method for electronic components is characterized by comprising the following steps:

placing a workpiece to be cleaned on a processing table;

starting a laser generator, coupling laser beams emitted by the laser generator, and outputting the laser beams to a laser cleaning head;

focusing the received laser beam on the surface of a workpiece to be cleaned through a laser cleaning head, and adjusting the shape and energy of a focusing spot focused on the surface of the workpiece;

and controlling the laser cleaning head and the processing platform to move along a preset track so as to clean the surface of the workpiece.

Technical Field

The invention relates to the technical field of laser cleaning, in particular to laser cleaning equipment and a laser cleaning method for electronic components.

Background

It is known that in the fabrication process of microelectronic devices, non-conductive oxide layers and contaminant particles are easily generated on the surface of the microelectronic devices, and the oxide layers and the contaminant particles may cause damage to the microelectronic devices.

Disclosure of Invention

The invention mainly aims to provide laser cleaning equipment for electronic components, which is used for solving the technical problem of poor cleaning effect of the existing chemical cleaning method.

In order to solve the technical problems, the invention provides laser cleaning equipment for electronic components, which comprises a base, a processing table movably arranged on the base, a laser cleaning head arranged above the processing table, and a laser generator for generating laser beams, and further comprises a first beam shaping unit and a second beam shaping unit which are arranged on a transmission light path of the laser beams, wherein the first beam shaping unit is used for coupling the laser beams generated by the laser generator into optical fibers, and the second beam shaping unit is used for adjusting the shape and the energy distribution of focusing light spots emitted from the laser cleaning head.

Preferably, the first beam shaping unit includes a beam expander and a first converging lens that are sequentially arranged along a transmission direction of the laser beam, and the beam expander includes a diverging lens and a second converging lens.

Preferably, the second beam shaping unit includes a third condensing lens, a collimating lens, and a focusing lens, which are sequentially disposed along a transmission direction of the laser beam.

Preferably, the laser cleaning device for electronic components further includes a frequency doubling chip disposed between the first beam shaping unit and the second beam shaping unit, where the frequency doubling chip is configured to perform frequency doubling on the laser beam coupled into the optical fiber to control output of laser beams with different wavelengths.

Preferably, the laser cleaning equipment for the electronic component further comprises a cooling device for cooling the laser generator and/or the laser cleaning head, and the cooling device comprises a water cooler and a cooling water path.

Preferably, the laser cleaning equipment for electronic components further comprises an air source auxiliary device for blowing off the vapor generated on the surface of the workpiece towards the circumferential direction of the laser cleaning head, wherein the air source auxiliary device is arranged above the processing table and comprises an air source and an air blowing path.

Preferably, the gas in the gas source is an inert gas.

Preferably, the laser cleaning equipment for the electronic components further comprises a particle collecting device for collecting evaporation residues generated on the surface of the workpiece after laser cleaning, and the particle collecting device comprises an absorption channel and a collector.

Preferably, the laser cleaning equipment for the electronic component further comprises a visual detection device which is arranged above the processing table and used for positioning a workpiece carried on the processing table, and the visual detection device comprises a CCD camera.

The invention also provides a laser cleaning method for the electronic component, which comprises the following steps: placing a workpiece to be cleaned on a processing table; starting a laser generator, coupling laser beams emitted by the laser generator, and outputting the laser beams to a laser cleaning head; focusing the collected laser beam on the surface of a workpiece to be cleaned through a laser cleaning head, and adjusting the shape and energy of a focusing light spot focused on the surface of the workpiece; and controlling the laser cleaning head and the processing platform to move along a preset track so as to clean the surface of the workpiece.

The embodiment of the invention has the beneficial effects that: the laser cleaning head emits laser beams, and the difference of the absorption capacities of the microelectronic device and pollutants (oxide layers) to the laser beams is utilized to enable the pollutants on the surface of the microelectronic device to change such as vibration, melting or gasification, so that the pollutants are separated from the surface of the microelectronic device, and the laser cleaning of the microelectronic device is realized. Compared with the existing chemical reagent cleaning method, the laser cleaning method for the electronic component provided by the invention not only can enhance the cleaning effect on the microelectronic device, ensure the product performance of the microelectronic device, but also can effectively improve the cleaning efficiency on the microelectronic device.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of a laser cleaning apparatus for electronic components according to the present invention;

fig. 2 is a front view of the laser cleaning apparatus for electronic components shown in fig. 1;

FIG. 3 is a functional block diagram of a laser cleaning apparatus for electronic components according to the present invention;

FIG. 4 is a schematic view of a laser cleaning principle of the laser cleaning device for the electronic components of the present invention;

FIG. 5 is a schematic diagram of the dust removal principle of the laser cleaning device for electronic components according to the present invention;

FIG. 6 is a functional block diagram of another embodiment of a laser cleaning apparatus for electronic components according to the present invention;

FIG. 7 is a schematic diagram of a laser coupling principle of the laser cleaning device for electronic components according to the present invention;

FIG. 8 is a schematic view of the focusing spot adjustment principle of the laser cleaning apparatus for electronic components according to the present invention;

fig. 9 is a schematic flow chart of an embodiment of a laser cleaning method for an electronic component according to the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be illustrative of the present invention and should not be construed as limiting the present invention, and all other embodiments that can be obtained by one skilled in the art based on the embodiments of the present invention without inventive efforts shall fall within the scope of protection of the present invention.

In order to solve the above technical problems, the present invention provides a laser cleaning apparatus for electronic components, which, with reference to fig. 1, 2 and 3, includes a base 1, a processing table 2 movably disposed on the base 1, a laser cleaning head 3 disposed above the processing table 2, and a laser generator 4 for generating a laser beam, and further includes a first beam shaping unit 5 and a second beam shaping unit 6 disposed on an optical path of the laser beam, wherein the first beam shaping unit 5 is configured to couple the laser beam generated by the laser generator 4 into an optical fiber, and the second beam shaping unit 6 is configured to adjust a shape and an energy distribution of a focused spot emitted from the laser cleaning head 3.

It should be noted that the laser cleaning apparatus for electronic components according to the present invention mainly utilizes the characteristics of high energy, high frequency and high power of laser, and makes the attachment or coating on the surface of the workpiece to be cleaned evaporate or peel off by applying a high energy density beam to the surface of the workpiece to be cleaned, such as a battery tab, and according to the difference between the absorption capacities of the substrate material and the attachment to the laser. Because the absorption coefficients of metal (to-be-cleaned workpiece) and nonmetal (oxide layer) to the same wavelength are different, the micro-electronic device cannot be damaged when the laser is used for cleaning, and the product performance of the micro-electronic device is prevented from being influenced when the laser is used for cleaning.

The laser cleaning equipment for the electronic components is controlled by a preset computer program, and the independent movement of the processing table 2 and the laser cleaning head 3 and the mutual linkage between the processing table 2 and the laser cleaning head 3 can be controlled by the computer program, so that the laser cleaning head 3 can complete the cleaning process of a workpiece to be cleaned, which is placed on the processing table 2. In a preferred embodiment, the processing table 2 has a three-axis motion module, specifically including X-axis, Y-axis and Z-axis motion. After the laser generator 4 has produced the laser beam, the computer program will execute the control beam shaping unit to be activated to shape the laser beam. Specifically, after passing through the first beam shaping unit 5, the laser beam is coupled into an optical fiber for conveying the laser beam, the coupled laser beam is conveyed into the laser cleaning head 3 through the optical fiber, and then the shape and energy distribution of a focused spot of the coupled laser beam focused on the surface of the workpiece to be cleaned are adjusted by the second beam shaping unit 6, so that a better cleaning effect and higher cleaning precision are obtained.

In order to improve the cleaning efficiency of the laser cleaning equipment for electronic components, referring to fig. 1, a feeding device 9 is arranged on one side of a processing table 2, and the automatic transfer of the workpiece to be cleaned can be realized through the feeding device 9, including conveying the workpiece to be cleaned onto the processing table 2 for cleaning by a laser cleaning head 3, and conveying the cleaned workpiece to a blanking area. The feeding device 9 can be realized by adopting structures such as a synchronous pulley, a gear rack, a roller and the like, but not limited to the structures, and the feeding device can be set by a person skilled in the art according to the actual situation only by realizing the transmission of workpieces. In addition, in order to reduce the labor cost, a manipulator can be arranged at the feeding and discharging positions, so that the workpiece to be cleaned is grabbed and transferred onto the feeding device through the manipulator, and is conveyed to the position of the processing table 2 through the feeding device, after the cleaning is finished, the workpiece is conveyed to the discharging position through the feeding device, and finally, the cleaned workpiece is transferred to a designated area through the manipulator.

In the embodiment of the present invention, the laser generator 4 may be a carbon dioxide laser, a picosecond laser, a femtosecond laser, etc., the laser generator 4 is disposed outside the processing table 2, and is connected to the laser cleaning head 3 through an optical fiber, and the laser cleaning head 3 performs area cleaning on the workpiece by way of galvanometer scanning. Specifically, after the laser generator 4 generates the laser beam, the laser beam generated by the laser generator 4 is transmitted into the laser cleaning head 3 through the optical fiber, so that the laser cleaning head 3 can clean the workpiece. Because laser generator 4 and laser cleaning head 3 are separately set up, if laser generator 4 or laser cleaning head 3 break down, can maintain laser generator 4 or laser cleaning head 3 alone, it is compared in laser generator 4 and the laser cleaning head 3 that the fit set up, has the convenient characteristics of maintaining.

In order to obtain a good cleaning effect, parameters such as the wavelength, power density, pulse width, scanning speed and defocusing amount of the laser beam need to be controlled, wherein the cleanliness of the laser cleaning is represented by the ratio of the number of particles on the surface of the workpiece after the laser cleaning to the number of particles on the surface of the workpiece before the laser cleaning. Specifically, the shorter the wavelength is, the stronger the laser cleaning capability is, and the lower the cleaning threshold is, and when performing laser cleaning, the laser power density has an upper damage threshold and a lower damage threshold, and within this range, the higher the laser power density is, the stronger the cleaning capability is, and the more obvious the cleaning effect is. In the laser cleaning process, the faster the laser scanning speed is, the fewer the scanning times are, and the higher the power of the laser cleaning is, but the cleaning effect of the laser cleaning may be reduced. In addition, before laser cleaning, laser is mostly converged through a focusing lens combination once, and in an actual cleaning process, the laser is generally defocused, the higher the defocusing amount is, the higher the density of a focusing spot irradiated on a material is, the stronger the cleaning capability is, and the higher the efficiency is, but at a constant total power, the smaller the defocusing amount is, the higher the power density of the laser is, and the stronger the cleaning capability is. To reduce the effect of the laser beam on the substrate material, a cylindrical lens may be used to integrate the beam into a linear shape while increasing the efficiency of the laser cleaning. The parameters of the laser are also controlled according to a preset computer program, so as to realize the automatic control of the laser cleaning equipment for the electronic components, ensure the cleaning effect of the laser cleaning equipment for the electronic components and optimize the cleanliness of the workpiece.

In order to couple the laser beam generated by the laser generator 4 into the optical fiber, referring to fig. 7, the first beam shaping unit 5 mentioned in the above embodiment includes a beam expander and a first converging lens, which are sequentially arranged along the transmission direction of the laser beam, and the beam expander includes a diverging lens 51 and a second converging lens. The laser beam generated by the laser generator 4 is diverged by the diverging lens 51 with the focal length of F1, and then is converged for the first time by the second converging lens 52 with the focal length of F2, and the first converged laser beam is converged again by the first converging lens 53 with the focal length of F and coupled into the delivery optical fiber, and finally, the coupled laser beam is delivered into the laser cleaning head 3 by the delivery optical fiber.

It can be understood that the laser light emitted from the optical fiber has non-uniform energy distribution, and the energy density near the optical axis of the beam is higher than that of the edge, and the cleaning effect is affected by directly applying the laser light for cleaning. The traditional improvement method is to filter out the light at the edge through a diaphragm, but the method causes more laser waste. For this purpose, the laser cleaning apparatus for electronic components according to the present invention proposes a second beam shaping unit 6, and referring to fig. 8, the second beam shaping unit 6 includes a third converging lens 61, a collimating lens 62, and a focusing lens 63, which are sequentially arranged along the transmission direction of the laser beam. The coupled laser beams are converged by a third converging lens 61 with the focal length of F3, then are collimated by a collimating lens 62 with the focal length of F4, and finally are irradiated to the surface of a workpiece to be cleaned by a focusing lens 63 with the focal length of F5, and a focusing spot with certain energy is formed on the surface of the workpiece. The scanning and cleaning of the laser cleaning head 3 on the surface of the workpiece are realized through the cooperative motion of the processing table 2 and the laser cleaning head 3.

In a preferred embodiment, referring to fig. 6, the laser cleaning apparatus for electronic components according to the present invention further includes a frequency doubling chip 7 disposed between the first beam shaping unit 5 and the second beam shaping unit 6, wherein the frequency doubling chip 7 is configured to perform a frequency doubling process on the laser beam coupled into the optical fiber to control the output of the laser beams with different wavelengths. As described above, the laser cleaning apparatus for electronic components according to the present invention mainly utilizes the difference between the absorption wavelengths of the microelectronic device and the contaminants to the laser, and after the laser is irradiated, the contaminants on the surface of the workpiece undergo physical or chemical changes such as vibration, melting, or vaporization, so as to be separated from the surface of the workpiece. Therefore, the laser wavelength has a large influence on the laser cleaning, and in order to achieve the optimal cleaning effect, the laser with different wavelengths needs to be selected and output according to the absorption difference of the workpiece and the pollutant on the wavelength. For this purpose, the technical solution of the present invention is to arrange a frequency doubling chip 7 between the first beam shaping unit 5 and the second beam shaping unit 6, so as to control the output of laser beams with different wavelengths through the frequency doubling chip 7. For example, an infrared laser beam with a wavelength of 1064nm outputs green light with a wavelength of 532nm after first frequency doubling, and outputs violet light with a wavelength of 266nm after second frequency doubling. Furthermore, when the corresponding wavelength is not very large, the pulse laser with higher repetition frequency can be utilized to enable the irradiated pollutants to form a larger temperature gradient instantly, so that stress is generated between the pollutants and the cleaned workpiece, the acting force of the pollutants attached to the surface of the workpiece is damaged through the stress, and when the acting force is offset, the pollutants are removed.

In another preferred embodiment, the laser cleaning apparatus for electronic components according to the present invention further includes a cooling device 8 for cooling the laser generator 4 and/or the laser cleaning head 3, and the cooling device 8 includes a water chiller and a cooling water path. Laser generator 4 can constantly produce high temperature at long-time operation in-process, and the normal operating that laser generator 4 will be influenced to the high temperature, consequently, need carry out water circulative cooling to laser generator 4 through cooling device 8 to control laser generator 4's service temperature makes laser generator 4 keep normal operating. Specifically, cooling water flows to 4 surfaces of laser generator through cooling water route to through the mode of heat transfer, take away the heat that laser generator 4 produced, and with the cooling water circulation after the heat transfer to the cold water machine, with carry out refrigeration treatment to it by the cold water machine, so circulation is reciprocal, realizes the cooling to laser cleaning head 3 and/or laser generator 4.

In a further preferred embodiment, the laser cleaning apparatus for electronic components according to the present invention further includes an air supply auxiliary device for blowing off vapor generated on the surface of the workpiece toward the circumferential direction of the laser cleaning head 3, the air supply auxiliary device being disposed above the processing table 2 and including an air supply and an air blowing path. In this embodiment, referring to fig. 4, in order to prevent the vapor generated during the laser cleaning process from splashing on the surface of the optical lens and causing secondary pollution to the workpiece, while the laser is irradiated onto the surface of the workpiece to be cleaned, a certain amount of shielding gas is blown to the cleaning region by the gas source auxiliary device, so as to blow off the vapor on the surface of the workpiece along the circumferential direction of the laser cleaning head 3.

Further, the gas in the gas source mentioned in the above another preferred embodiment is an inert gas to protect the surface of the workpiece from oxidation. When laser cleaning is carried out by utilizing laser, a molten pool can be formed on the surface of a workpiece, and in order to prevent high-temperature metal from being damaged (oxidized) by external gas, inert gases, namely helium and argon, can be applied, the density of the inert gases is higher than that of air, the flow rate of the inert gases is lower than that of the air, and the inert gases cannot react with the high-temperature metal.

In a further preferred embodiment, referring to fig. 5, the laser cleaning apparatus for electronic components according to the present invention further includes a particle collecting device for collecting evaporation residues generated on the surface of the workpiece after the laser cleaning, wherein the particle collecting device includes an absorption channel and a collector. In the embodiment, evaporation residues are generated in the process of laser cleaning of the workpiece, so that the evaporation residues are prevented from polluting the surrounding environment, the evaporation residues can be sucked and collected in the collector through the particle collecting device, and the evaporation residues collected in the collector are treated after the cleaning is finished.

Furthermore, in the above embodiments, the laser cleaning apparatus for electronic components according to the present invention further includes a visual inspection device disposed above the processing table 2 for positioning the workpiece carried on the processing table 2, wherein the visual inspection device includes a CCD camera. In the embodiment, a CCD camera is used for image acquisition, and the acquired image is processed and analyzed so as to position the area to be cleaned on the surface of the workpiece; after the positioning is finished, planning a cleaning path by the control system; then, starting the laser generator 4, and focusing the laser beam generated by the laser generator 4 on the area to be cleaned of the workpiece through the laser cleaning head 3; then, a laser focus tracking system arranged on the laser cleaning head 3 measures and displays the distance between the focus of the laser output by the laser cleaning head 3 and the workpiece in real time; and finally, under the control of the control system, scanning the laser beam on the surface of the workpiece to be cleaned to finish laser cleaning.

Based on the laser cleaning equipment for the electronic components, the invention also provides a laser cleaning method for the electronic components, and referring to fig. 9, the laser cleaning method for the electronic components comprises the following steps:

step S10, placing the workpiece to be cleaned on the processing table;

step S20, starting the laser generator, coupling the laser beam emitted by the laser generator and outputting the laser beam to the laser cleaning head;

step S30, focusing the received laser beam on the surface of the workpiece to be cleaned through the laser cleaning head, and adjusting the shape and energy of the focusing light spot focused on the surface of the workpiece;

and step S40, controlling the laser cleaning head and the processing platform to move along a preset track so as to clean the surface of the workpiece.

Before laser cleaning, a workpiece to be cleaned can be placed on a processing table manually or by a manipulator; then, starting the laser generator, coupling the laser beam emitted by the laser generator through the first beam shaping unit consisting of the diverging lens, the second converging lens and the first converging lens, and outputting the laser beam into the laser cleaning head; the coupled laser beam is conveyed into the laser cleaning head through the optical fiber for laser cleaning, and before the laser beam is emitted from the laser cleaning head, the shape and the energy of a focusing light spot focused on the surface of a workpiece are regulated through the second beam shaping unit consisting of the third converging lens, the collimating lens and the focusing lens, so that the cleaning effect and the cleaning precision of laser cleaning are improved; and finally, controlling the laser cleaning head and the processing table to move along a preset track through a control system, and finishing the cleaning work on the surface of the workpiece in a galvanometer scanning mode.

It should be noted that the laser cleaning method for electronic components proposed by the present invention is based on a laser cleaning apparatus for electronic components, and therefore, what is mentioned in the laser cleaning apparatus is applicable to a laser cleaning method for electronic components, for example, during the laser cleaning process, an inert gas can be applied to blow off the vaporized materials, and at the same time, the purpose of protecting the surface of the workpiece from oxidation can be achieved. Since the technical solutions related to frequency doubling, cooling, gas source assistance, particle collection and CCD positioning are all described above, they are also applicable to the laser cleaning method for electronic components proposed by the present invention, and therefore, the applicant is not repeated herein.

The above description is only a part of or preferred embodiments of the present invention, and neither the text nor the drawings should be construed as limiting the scope of the present invention, and all equivalent structural changes, which are made by using the contents of the present specification and the drawings, or any other related technical fields, are included in the scope of the present invention.