On-line detection device and method for donor film thickness for laser induced transfer

Abstract

The present invention discloses an online detection device and method for the thickness of a donor film for laser induced transfer. The online detection device integrates a thickness detection device of the donor film into the laser induced transfer device to realize in-situ detection of the thickness of the donor film, thereby omitting the step of measuring the thickness of the donor film by an independent external detection device before laser transfer. Thanks to the integration of the thickness detection device and the laser induced transfer device, the laser induced transfer process using this device can quickly adjust the processing parameters of the transfer laser according to the actual thickness of the donor film before or during the transfer to ensure the transfer quality of the laser induced transfer. In addition, the present scheme also proposes a method for using the above-mentioned online detection device, in which the monitoring laser is continuously turned on during the laser transfer process, and the thickness of the donor film is detected online during the laser transfer process, so as to adjust the processing parameters of the transfer laser in real time, which can effectively take into account both the processing efficiency and the transfer effect.

Description

Technical Field

[0001] The invention relates to the technical field of laser induced transfer, and in particular to an online detection device and method for the thickness of a donor film used for laser induced transfer. Background Art

[0002] Laser Induced Forward Transfer (LIFT) is a micro-processing technology that uses laser as a driving force to transfer materials from a donor substrate to a receptor substrate. This technology has the advantages of non-contact processing, high processing accuracy, and strong adaptability. It is suitable for integrated circuit processing and repair, micro-optoelectronic device preparation, microbial production and other fields.

[0003] The basic process of laser induced transfer technology includes: using high-energy pulsed laser to irradiate a transparent substrate coated with a material film (i.e., donor substrate), the laser is focused on the interface between the transparent substrate and the material film through the transparent substrate, and the laser energy of the pulsed laser is absorbed by the material film and converted into heat, thereby deforming the local material film area, and finally forming a jet droplet under the combined effect of vaporization pressure, surface tension, etc., and leaving the surface of the material film (hereinafter referred to as "donor film"), and depositing on the receptor substrate to form a two-dimensional or three-dimensional metal transfer structure. Laser induced transfer technology can not only process solid films, but also liquid films such as metal particle slurry films, so it can be used for printing a variety of materials, including metals, metal oxides, semiconductors, superconductors, etc.

[0004] During the transfer process, the thickness of the donor film will significantly affect the transfer effect. Due to the influence of the donor film preparation process and the characteristics of the material itself, the consistency of the material film thickness on the donor substrate is difficult to ensure. The above situation is particularly evident on the thicker donor film.

[0005] For example, a solid metal film with a micron thickness is prepared by physical deposition combined with chemical plating. However, the thickness of the film prepared by chemical plating is affected by the process, solution composition fluctuations, etc., and different batches may produce fluctuations in thickness from submicron to micron. Assume that there are two donor films with a standard production thickness of 50μm from different batches. Due to the influence of the coating process, the actual production thickness is only 48μm and 52μm. If the laser processing parameters during the transfer process are set according to the standard production thickness of 50μm, and the laser with the above processing parameters is used to irradiate the donor film with an actual production thickness of only 48μm, then the donor film with a production thickness of only 48μm will be sputtered and dispersed due to excessive laser power; if the laser with the above processing parameters is used to irradiate the donor film with an actual production thickness of 52μm, then the donor film with a production thickness of 52μm will be difficult to transfer or even impossible to transfer due to too small laser power.

[0006] For another example, a slurry composed of nano-metal particles can be used to prepare a slurry film of tens of microns or even thicker, but due to the coating accuracy and the fluidity of the slurry itself, the thickness of the slurry film also fluctuates on the micron scale. Suppose there is a donor film with a standard production thickness of 50μm. Due to the influence of coating accuracy, the donor film actually produced has both region A with an actual production thickness of only 48μm and region B with an actual production thickness of 52μm. If the laser processing parameters during the transfer process are set according to the standard production thickness of 50μm, and the laser with the above processing parameters is used to irradiate region A and region B respectively, the donor film in region A will also have a situation where the droplets generated are sputtered and dispersed due to excessive laser power, and the donor film in region B will have a situation where the droplets generated are too small due to too low laser power, making it difficult to transfer or even impossible to transfer.

[0007] In order to avoid the above situation, the existing method generally uses high-precision detection instruments (such as step meters, atomic force microscopes, etc.) to accurately measure the thickness and surface morphology of the donor film before laser transfer. This will inevitably reduce the processing efficiency of laser transfer, making it difficult to take into account both processing efficiency and transfer effect. Summary of the invention

[0008] The purpose of the present invention is to provide an online detection device for the thickness of a donor film for laser induced transfer, integrate the thickness detection device of the donor film into the laser induced transfer device, realize the in-situ detection of the thickness of the donor film, and omit the step of measuring the thickness of the donor film by an independent external detection device before laser transfer.

[0009] The purpose of the present invention is to propose an online detection method for the thickness of a donor film for laser induced transfer, which is applied to the above-mentioned online detection equipment. By performing online detection of the thickness of the donor film during the laser transfer process, the processing parameters of the transfer laser can be adjusted in real time to take into account both the processing efficiency and the transfer effect.

[0010] To achieve this object, the present invention adopts the following technical solutions:

[0011] An online detection device for the thickness of a donor film for laser-induced transfer, comprising a monitoring laser, a monitoring shaping device, a polarization beam splitting and focusing device, a transfer laser, a transfer shaping device, a dichroic mirror, a photodetector and a filter;

[0012] The polarization beam splitting and focusing device comprises a polarization beam splitting prism, a quarter wave plate and a focusing lens which are arranged in sequence;

[0013] The transfer laser, the transfer shaping device, the dichroic mirror, the polarization beam splitter prism, the quarter wave plate and the focusing mirror are located on the same optical path, and the transfer laser is used to emit the transfer laser, the transfer shaping device is used to shape the transfer laser, the dichroic mirror is used to transport the transfer laser from the transfer shaping device to the polarization beam splitter prism, the polarization beam splitter prism is used to transmit the transfer laser, the quarter wave plate is used to adjust the polarization state of the transfer laser, and the focusing mirror is used to focus the transfer laser;

[0014] The monitoring laser, the monitoring shaping device, the polarization beam splitter prism, the quarter-wave plate and the focusing mirror are located on the same optical path, and the monitoring laser is used to emit the monitoring laser, the monitoring shaping device is used to shape the monitoring laser, the polarization beam splitter prism is also used to reflect the monitoring laser, the quarter-wave plate is also used to adjust the polarization state of the monitoring laser, and the focusing mirror is also used to focus the monitoring laser;

[0015] The photodetector, the filter, the dichroic mirror, the polarization beam splitter prism, the quarter wave plate and the focusing mirror are located on the same optical path, and the focusing mirror, the polarization beam splitter prism and the filter are all used to transmit the reflected laser light formed after the monitoring laser light is reflected by the donor film, and the dichroic mirror is used to transmit the reflected laser light from the polarization beam splitter prism to the filter, the quarter wave plate is also used to adjust the polarization state of the reflected laser light, and the photodetector is used to receive the reflected laser light and convert the light intensity of the reflected laser light into an electrical signal;

[0016] The transfer shaping device and the monitoring shaping device both include a polarization light processor, which is used to adjust the incident light to a specific single polarization direction, and the polarization direction of the transfer laser entering the polarization beam splitter prism is perpendicular to the polarization direction of the monitoring laser entering the polarization beam splitter prism.

[0017] Preferably, the photodetector comprises any one of a photodiode and a photomultiplier tube, and the polarized light processor comprises any one of a half-wave plate, a polarization beam splitter, a Glan-Taylor prism, a Wollaston polarizing prism and a Rochon polarizing prism.

[0018] Preferably, the monitoring and shaping device further includes any one or more combinations of a collimator, a beam expander, a beam reducer and an optical gate.

[0019] Preferably, the transfer shaping device also includes any one or more combinations of a collimator, a beam expander, a beam reducer, an optical gate, an acousto-optic modulator, a scanning galvanometer and a fast-reflection mirror.

[0020] Preferably, the filter is a broadband filter, the polarization beam splitter prism is a broadband polarization beam splitter prism, and the quarter wave plate is a broadband quarter wave plate.

[0021] An online detection method for the thickness of a donor film for laser induced transfer, using the above-mentioned online detection device for the thickness of a donor film for laser induced transfer, comprises the following steps:

[0022] A. preparing a donor film; wherein the donor film comprises a donor substrate and a donor film, and the donor film is attached to the lower surface of the donor substrate;

[0023] B. Turning on the monitoring laser and irradiating the upper surface of the donor substrate with the monitoring laser emitted by the monitoring laser;

[0024] C. Keeping the monitoring laser turned on, the transfer laser is turned on at the same time, and the transfer laser emitted by the transfer laser irradiates the upper surface of the donor substrate;

[0025] D. The photoelectric detector receives the reflection information of the reflected laser formed after the monitoring laser is reflected by the donor film, and determines the thickness of the donor film according to the reflection information.

[0026] Preferably, the reflection information is the time consumed for the maximum reflectivity of the monitoring laser to drop from 80% to 20%.

[0027] Preferably, the difference between the central wavelength of the monitoring laser and the central wavelength of the transfer laser is ≥50 nm.

[0028] Preferably, the thickness of the donor film is ≥ 2 μm.

[0029] Preferably, the transmittance of the donor substrate to the monitoring laser and the transfer laser is ≥90%.

[0030] The technical solution provided by the present invention may include the following beneficial effects:

[0031] 1. The online detection device of this scheme integrates the thickness detection device of the donor film into the laser induced transfer device to realize the in-situ detection of the thickness of the donor film, thereby omitting the step of measuring the thickness of the donor film in an independent external detection device before laser transfer.

[0032] 2. Thanks to the integration of the thickness detection device and the laser induced transfer device, the laser induced transfer process using this equipment can quickly adjust the processing parameters of the transfer laser according to the actual thickness of the donor film before or during the transfer to ensure the transfer quality of the laser induced transfer.

[0033] 3. The online detection method of this scheme continuously turns on the monitoring laser during the laser transfer process, and performs online detection of the thickness of the donor film during the laser transfer process, thereby adjusting the processing parameters of the transfer laser in real time, so as to take into account both the processing efficiency and the transfer effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the reflectivity of the monitoring laser changing with time according to the present invention.

[0035] Figure 2 It is a schematic structural diagram of Example 1 of an online detection device for the thickness of a donor film for laser induced transfer according to the present invention.

[0036] Figure 3 It is a schematic structural diagram of Example 2 of an online detection device for the thickness of a donor film for laser induced transfer according to the present invention.

[0037] Among them: monitoring laser 1, monitoring shaping device 2, polarization beam splitting and focusing device 3, polarization beam splitting prism 31, quarter wave plate 32, focusing mirror 33, transfer laser 4, transfer shaping device 5, dichroic mirror 6, photodetector 7, filter 8, donor substrate 9. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] The technical solution provides an online detection device for the thickness of a donor film for laser-induced transfer, comprising a monitoring laser 1, a monitoring shaping device 2, a polarization beam splitting and focusing device 3, a transfer laser 4, a transfer shaping device 5, a dichroic mirror 6, a photodetector 7 and a filter 8;

[0040] The polarization beam splitting and focusing device 3 comprises a polarization beam splitting prism 31, a quarter wave plate 32 and a focusing lens 33 which are arranged in sequence;

[0041] The transfer laser 4, the transfer shaping device 5, the dichroic mirror 6, the polarization beam splitter prism 31, the quarter wave plate 32 and the focusing mirror 33 are located on the same optical path, and the transfer laser 4 is used to emit the transfer laser, the transfer shaping device 5 is used to shape the transfer laser, the dichroic mirror 6 is used to transport the transfer laser from the transfer shaping device 5 to the polarization beam splitter prism 31, the polarization beam splitter prism 31 is used to transmit the transfer laser, the quarter wave plate 32 is used to adjust the polarization state of the transfer laser, and the focusing mirror 33 is used to focus the transfer laser;

[0042] The monitoring laser 1, the monitoring shaping device 2, the polarization beam splitter prism 31, the quarter wave plate 32 and the focusing mirror 33 are located on the same optical path, and the monitoring laser 1 is used to emit the monitoring laser, the monitoring shaping device 2 is used to shape the monitoring laser, the polarization beam splitter prism 31 is also used to reflect the monitoring laser, the quarter wave plate 32 is also used to adjust the polarization state of the monitoring laser, and the focusing mirror 33 is also used to focus the monitoring laser;

[0043] The photodetector 7, the filter 8, the dichroic mirror 6, the polarization beam splitter prism 31, the quarter wave plate 32 and the focusing mirror 33 are located on the same optical path, and the focusing mirror 33, the polarization beam splitter prism 31 and the filter 8 are all used to transmit the reflected laser formed after the monitoring laser is reflected by the donor film, and the dichroic mirror 6 is used to transmit the reflected laser from the polarization beam splitter prism 31 to the filter 8, the quarter wave plate 32 is also used to adjust the polarization state of the reflected laser, and the photodetector 7 is used to receive the reflected laser and convert the light intensity of the reflected laser into an electrical signal;

[0044] The transfer shaping device 5 and the monitoring shaping device 2 both include a polarization light processor, which is used to adjust the incident light to a specific single polarization direction, so that the polarization direction of the transfer laser entering the polarization beam splitter prism is perpendicular to the polarization direction of the monitoring laser entering the polarization beam splitter prism.

[0045] In order to avoid the influence of the thickness of the donor film on the laser-induced transfer effect, the existing method generally uses high-precision detection instruments to accurately measure the thickness and surface morphology of the donor film before laser transfer. This will inevitably reduce the processing efficiency of laser transfer, making it difficult to take into account both processing efficiency and transfer effect at the same time.

[0046] Therefore, in order to take into account both processing efficiency and transfer effect, this scheme proposes an online detection device for the thickness of the donor film for laser induced transfer, and integrates the thickness detection device of the donor film into the laser induced transfer device to realize in-situ detection of the thickness of the donor film, thereby omitting the step of measuring the thickness of the donor film by an independent external detection device before laser transfer; in addition, thanks to the integration of the thickness detection device and the laser induced transfer device, the laser induced transfer process using this device can quickly adjust the processing parameters of the transfer laser according to the actual thickness of the donor film before or during the transfer, so as to ensure the transfer quality of the laser induced transfer.

[0047] In the online detection equipment of the present scheme, the device for realizing laser transfer includes a transfer laser 4, a transfer shaping device 5, a dichroic mirror 6, a polarization beam splitter prism 31, a quarter wave plate 32 and a focusing lens 33 located on the same optical path, and the specific steps of laser transfer are as follows: the transfer laser emitted by the transfer laser 4 first passes through the transfer shaping device 5 for adjustment in a specific single polarization direction and other forms of shaping, including but not limited to laser collimation, spot size adjustment, polarization state adjustment, power adjustment, switching control and optical scanning, etc.; then the shaped transfer laser is allowed to enter the polarization beam splitter focusing device 3 through the dichroic mirror, and first passes through the polarization beam splitter prism 31 in the polarization beam splitter focusing device 3, and then passes through the quarter wave plate 32 to adjust the linear polarization to circularly polarized light or elliptically polarized light, and finally is focused by the focusing lens 33 and acts on the donor film. Since the donor film used for laser induced transfer includes a donor substrate 9 and a donor film attached to the lower surface of the donor substrate 9, when the transfer laser acts on the upper surface of the donor substrate 9, it passes through the donor substrate 9 and irradiates the interface where the donor film contacts the donor substrate 9, causing partial melting and falling off of the donor film, thereby realizing the material transfer of the donor film.

[0048] The device for realizing the donor film thickness detection in this scheme includes two parts, wherein the first part is the emission mechanism of the monitoring laser, and the second part is the feedback mechanism of the monitoring laser (i.e., the receiving mechanism of the reflected laser). Specifically, the emission mechanism of the monitoring laser includes a monitoring laser 1, a monitoring shaping device 2, a polarization beam splitter prism 31, a quarter wave plate 32 and a focusing lens 33 located on the same optical path, and the emission path of the monitoring laser is specifically as follows: the monitoring laser emitted by the monitoring laser 1 first passes through the monitoring shaping device 2 for adjustment of a specific single polarization direction and other forms of shaping, including but not limited to laser collimation, spot size adjustment, polarization state adjustment, power adjustment and disconnection control, etc.; then enters the polarization beam splitter focusing device 3, and is first reflected to the quarter wave plate 32 through the polarization beam splitter prism 31 in the polarization beam splitter focusing device 3, and is adjusted from linear polarization to circular polarized light or elliptically polarized light through the quarter wave plate 32, and finally is focused by the focusing lens 33 and acts on the donor film. When the monitoring laser acts on the upper surface of the donor substrate 9, it passes through the donor substrate 9 and irradiates the interface where the donor film contacts the donor substrate 9, thereby being reflected to form reflected laser.

[0049] Furthermore, the receiving mechanism of the reflected laser is located on the same optical path, including the focusing mirror 33, the quarter wave plate 32, the polarization beam splitter prism 31, the dichroic mirror 6, the filter 8 and the photodetector 7, and the reflected laser first passes through the donor substrate 9 and the focusing mirror 33 in sequence, and then passes through the quarter wave plate 32 to be adjusted to a linear polarized light perpendicular to the polarization direction of the monitoring laser when it enters the quarter wave plate 32, and then passes through the polarization beam splitter prism 31, and then passes through the dichroic mirror 6 to allow the reflected laser to enter the filter 8, and finally enter the photodetector 7. Since the reflectivity of the monitoring laser will change after the donor film falls off, the photodetector 7 can detect the intensity change law of the reflected laser, that is, the reflectivity change law, and the current actual thickness of the donor film can be known, such as Figure 1 Shown is the reflectivity (R H ) Schematic diagram of its change over time.

[0050] The dichroic mirror 6 in this solution plays the role of separating the transferred laser light and the reflected laser light. In one embodiment, the dichroic mirror 6 can reflect the transferred laser light and transmit the reflected laser light at the same time, thereby achieving the separation of the transferred laser light and the reflected laser light. Figure 2 In another embodiment, the dichroic mirror 6 can transmit the transferred laser light and reflect the reflected laser light to separate the transferred laser light from the reflected laser light. Figure 3 shown.

[0051] It should be noted that, in a specific embodiment, the inspector can obtain the relationship between the time consumed for the maximum reflectivity to drop from 80% to 20% of the maximum reflectivity and the thickness of the donor film by looking up the table, thereby adjusting the processing parameters of the transfer laser; in another specific embodiment, the inspector can calculate the current actual thickness of the donor film according to the time consumed for the maximum reflectivity to drop from 80% to 20% of the maximum reflectivity through a preset mapping relationship, thereby adjusting the processing parameters of the transfer laser.

[0052] It should be further explained that the filter 8 in this solution can be any one of a broadband filter and a narrowband filter.

[0053] Further, the photodetector 7 includes any one of a photodiode and a photomultiplier tube; it should be noted that the receiving wavelength of the photodetector 7 includes the wavelength of the reflected laser.

[0054] To further illustrate, the polarized light processor includes any one of a half-wave plate, a polarization beam splitter prism, a Glan-Taylor prism, a Wollaston polarizing prism and a Rochon polarizing prism.

[0055] To further illustrate, the monitoring and shaping device 2 also includes any one or more combinations of a collimator, a beam expander, a beam reducer and an optical shutter.

[0056] To further illustrate, the transfer shaping device 5 also includes any one or more combinations of a collimator, a beam expander, a beam reducer, an optical shutter, an acousto-optic modulator, a scanning galvanometer and a fast-reflection mirror.

[0057] To further illustrate, the filter 8 is a broadband filter, the polarization beam splitter prism 31 is a broadband polarization beam splitter prism, and the quarter wave plate 32 is a broadband quarter wave plate.

[0058] An online detection method for the thickness of a donor film for laser induced transfer, using the above-mentioned online detection device for the thickness of a donor film for laser induced transfer, comprises the following steps:

[0059] A. Prepare a donor film; wherein the donor film comprises a donor substrate 9 and a donor film, and the donor film is attached to the lower surface of the donor substrate 9;

[0060] B. Turning on the monitoring laser 1 and irradiating the upper surface of the donor substrate 9 with the monitoring laser emitted by the monitoring laser 1;

[0061] C. Keep the monitoring laser 1 turned on, and turn on the transfer laser 4 at the same time, and the transfer laser emitted by the transfer laser 4 irradiates the upper surface of the donor substrate 9;

[0062] D. The photoelectric detector 7 receives the reflection information of the reflected laser formed after the monitoring laser is reflected by the donor film, and determines the thickness of the donor film according to the reflection information.

[0063] The present technical solution also proposes an online detection method for the thickness of the donor film using the above-mentioned online detection equipment. The monitoring laser is continuously turned on during the laser transfer process. By performing online detection of the thickness of the donor film during the laser transfer process, the processing parameters of the transfer laser are adjusted in real time to take into account both the processing efficiency and the transfer effect.

[0064] It should be noted that the donor film of the present embodiment can be a continuous solid film or a slurry film formed by coating a metal particle slurry, which is not limited here.

[0065] To further explain, the reflection information is the time consumed for the maximum reflectivity of the monitoring laser to drop from 80% to 20%.

[0066] Since the storage of the reflectivity of the monitoring laser may be subject to fluctuations and noise interference, this scheme preferably uses the time consumed by the maximum reflectivity of the monitoring laser dropping from 80% to 20% as the reflection information for the donor film thickness detection, which can effectively prevent the signal fluctuation from causing premature start or end of timing.

[0067] It is further specified that the difference between the central wavelength of the monitoring laser and the central wavelength of the transfer laser is ≥50 nm.

[0068] In order to enable the filter 8 to transmit the reflected laser formed by the monitoring laser reflected by the donor film while blocking the transferred laser, the present solution also optimizes the central wavelengths of the lasers emitted by the two laser generators to improve the detection accuracy of the donor film thickness.

[0069] It is further specified that the thickness of the donor film is ≥ 2 μm.

[0070] In a preferred embodiment of the present technical solution, the above-mentioned online detection method is used to detect the donor film with a thickness of ≥2 μm, which is more conducive to ensuring the transfer quality in laser induced transfer.

[0071] Further, the transmittance of the donor substrate 9 to the monitoring laser and the transfer laser is ≥ 90%, so as to prevent the donor substrate 9 from weakening the laser light intensity.

[0072] Example 1

[0073] An on-line detection device for the thickness of a donor film for laser induced transfer, such as Figure 2As shown, it includes a monitoring laser 1, a monitoring shaping device 2, a polarization beam splitting and focusing device 3, a transfer laser 4, a transfer shaping device 5, a dichroic mirror 6, a photodiode and a broadband filter; and the polarization beam splitting and focusing device 3 includes a broadband polarization beam splitting prism, a broadband quarter-wave plate and a focusing mirror 33 arranged in sequence.

[0074] Among them, the transfer laser 4, the transfer shaping device 5, the dichroic mirror 6, the broadband polarization beam splitter prism, the broadband quarter-wave plate and the focusing mirror 33 are located on the same optical path, and the transfer shaping device 5 includes a collimator, a beam expander, a half-wave plate and a scanning galvanometer arranged in sequence, and respectively performs collimation, spot expansion, polarization direction adjustment and two-dimensional scanning on the transfer laser. The monitoring laser 1, the monitoring shaping device 2, the broadband polarization beam splitter prism, the broadband quarter-wave plate and the focusing mirror 33 are located on the same optical path, and the monitoring shaping device 2 includes a collimator, a beam expander and a half-wave plate arranged in sequence, and respectively performs collimation, spot expansion and polarization direction adjustment on the monitoring laser.

[0075] The monitoring laser 1 and the transfer laser 4 in this embodiment both emit linear polarized light in a single polarization direction. Therefore, a half-wave plate is used as a polarization light processor in both the monitoring shaping device 2 and the transfer shaping device 5. By rotating the half-wave plate, polarized light in a specific polarization direction is obtained.

[0076] The photodiode, the broadband filter, the dichroic mirror 6, the broadband polarization beam splitter prism, the broadband quarter-wave plate and the focusing mirror 33 are located on the same optical path.

[0077] The method of using the above-mentioned online detection device for the thickness of the donor film for laser induced transfer comprises the following steps:

[0078] A. Prepare a donor film; wherein the donor film includes a donor substrate 9 and a donor film, and the donor film is attached to the lower surface of the donor substrate 9.

[0079] B. Turn on monitoring laser 1;

[0080] The monitoring laser emitted by the monitoring laser 1 first passes through the monitoring shaping device 2 for collimation, spot expansion and polarization direction adjustment in sequence; then enters the polarization splitting and focusing device 3, and is first reflected to the broadband quarter-wave plate by the broadband polarization splitting prism in the polarization splitting and focusing device 3, and is adjusted from linear polarization to circular polarization light or elliptically polarized light by the broadband quarter-wave plate, and finally is focused by the focusing mirror 33 and acts on the upper surface of the donor substrate 9. After the monitoring laser acts on the upper surface of the donor substrate 9, it passes through the donor substrate 9 and irradiates the interface where the donor film contacts the donor substrate 9, thereby being reflected to form a reflected laser.

[0081] The reflected laser then passes through the donor substrate 9 and the focusing lens 33 in sequence, and then passes through a broadband quarter-wave plate to be adjusted into linear polarized light that is perpendicular to the polarization direction of the monitoring laser when it enters the broadband quarter-wave plate, and finally passes through a broadband polarization splitter prism, a dichroic mirror 6 and a broadband filter to enter the photodetector 7.

[0082] C. Keep monitoring laser 1 turned on and turn on transfer laser 4 at the same time;

[0083] The transfer laser emitted by the transfer laser 4 first passes through the transfer shaping device 5 for collimation, spot expansion, polarization direction adjustment and two-dimensional scanning in sequence; then, it enters the polarization beam splitting and focusing device 3 after being reflected by the dichroic mirror, and first passes through the broadband polarization beam splitting prism in the polarization beam splitting and focusing device 3, and then passes through the broadband quarter-wave plate to adjust the linear polarization to circular polarization or elliptically polarized light, and finally is focused by the focusing mirror 33 and acts on the upper surface of the donor substrate 9. After the transfer laser acts on the upper surface of the donor substrate 9, it passes through the donor substrate 9 and irradiates the interface where the donor film contacts the donor substrate 9, causing the partial melting and shedding of the donor film, thereby realizing the material transfer of the donor film.

[0084] D. The photodiode receives the reflected laser formed after the monitoring laser is reflected by the donor film, and calculates the time consumed by the monitoring laser to drop from 80% of the highest reflectivity to 20% of the highest reflectivity through the reflected laser, and obtains the current actual thickness of the donor film.

[0085] Example 2

[0086] An on-line detection device for the thickness of a donor film for laser induced transfer, such as Figure 3 As shown, it includes a monitoring laser 1, a monitoring shaping device 2, a polarization beam splitting and focusing device 3, a transfer laser 4, a transfer shaping device 5, a dichroic mirror 6, a photodiode and a broadband filter; and the polarization beam splitting and focusing device 3 includes a broadband polarization beam splitting prism, a broadband quarter-wave plate and a focusing mirror 33 arranged in sequence.

[0087] Among them, the transfer laser 4, the transfer shaping device 5, the dichroic mirror 6, the broadband polarization splitter prism, the broadband quarter-wave plate and the focusing mirror 33 are located on the same optical path, and the transfer shaping device 5 includes a collimator, a beam expander, a half-wave plate and a scanning galvanometer which are arranged in sequence, and respectively collimate the transfer laser, expand the light spot, adjust the polarization direction and perform two-dimensional scanning.

[0088] The monitoring laser 1, the monitoring shaping device 2, the broadband polarization beam splitter prism, the broadband quarter-wave plate and the focusing lens 33 are located on the same optical path, and the monitoring shaping device 2 includes a collimator, a beam expander and a half-wave plate which are arranged in sequence, and respectively collimate the monitoring laser, expand the light spot and adjust the polarization direction.

[0089] The monitoring laser 1 and the transfer laser 4 in this embodiment both emit linear polarized light in a single polarization direction. Therefore, a half-wave plate is used as a polarization light processor in both the monitoring shaping device 2 and the transfer shaping device 5. By rotating the half-wave plate, polarized light in a specific polarization direction is obtained.

[0090] The photodiode, the broadband filter, the dichroic mirror 6, the broadband polarization beam splitter prism, the broadband quarter-wave plate and the focusing mirror 33 are located on the same optical path.

[0091] The method of using the above-mentioned online detection device for the thickness of the donor film for laser induced transfer comprises the following steps:

[0092] A. Prepare a donor film; wherein the donor film includes a donor substrate 9 and a donor film, and the donor film is attached to the lower surface of the donor substrate 9.

[0093] B. Turn on monitoring laser 1;

[0094] The monitoring laser emitted by the monitoring laser 1 first passes through the monitoring shaping device 2 for collimation, spot expansion and polarization direction adjustment in sequence; then enters the polarization splitting and focusing device 3, and is first reflected to the broadband quarter-wave plate by the broadband polarization splitting prism in the polarization splitting and focusing device 3, and is adjusted from linear polarization to circular polarization light or elliptically polarized light by the broadband quarter-wave plate, and finally is focused by the focusing mirror 33 and acts on the upper surface of the donor substrate 9. After the monitoring laser acts on the upper surface of the donor substrate 9, it passes through the donor substrate 9 and irradiates the interface where the donor film contacts the donor substrate 9, thereby being reflected to form a reflected laser.

[0095] The reflected laser then passes through the donor substrate 9 and the focusing lens 33 in sequence, and then passes through a broadband quarter-wave plate to be adjusted to a linearly polarized light that is perpendicular to the polarization direction of the monitoring laser when it enters the broadband quarter-wave plate, and then passes through a broadband polarization splitter prism, and then passes through a dichroic mirror 6 to be reflected to a broadband filter, and finally enters a photodetector 7.

[0096] C. Keep monitoring laser 1 turned on and turn on transfer laser 4 at the same time;

[0097] The transfer laser emitted by the transfer laser 4 first passes through the transfer shaping device 5 for collimation, spot expansion, polarization direction adjustment and two-dimensional scanning in sequence; then passes through the dichroic mirror 6 to enter the polarization splitting and focusing device 3, and first passes through the broadband polarization splitting prism in the polarization splitting and focusing device 3, and then passes through the broadband quarter-wave plate to adjust the linear polarization to circular polarization or elliptically polarized light, and finally is focused by the focusing mirror 33 and acts on the upper surface of the donor substrate 9. After the transfer laser acts on the upper surface of the donor substrate 9, it passes through the donor substrate 9 and irradiates the interface where the donor film contacts the donor substrate 9, causing the partial melting and shedding of the donor film, thereby realizing the material transfer of the donor film.

[0098] D. The photodiode receives the reflected laser formed after the monitoring laser is reflected by the donor film, and calculates the time consumed by the monitoring laser to drop from 80% of the highest reflectivity to 20% of the highest reflectivity through the reflected laser, and obtains the current actual thickness of the donor film.

[0099] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. An online detection device for the thickness of a donor film for laser induced transfer, characterized in that: It includes a monitoring laser, a monitoring shaping device, a polarization beam splitting and focusing device, a transfer laser, a transfer shaping device, a dichroic mirror, a photodetector and a filter; The polarization beam splitting and focusing device comprises a polarization beam splitting prism, a quarter wave plate and a focusing lens which are arranged in sequence; The transfer laser, the transfer shaping device, the dichroic mirror, the polarization beam splitter prism, the quarter wave plate and the focusing mirror are located on the same optical path, and the transfer laser is used to emit the transfer laser, the transfer shaping device is used to shape the transfer laser, the dichroic mirror is used to transport the transfer laser from the transfer shaping device to the polarization beam splitter prism, the polarization beam splitter prism is used to transmit the transfer laser, the quarter wave plate is used to adjust the polarization state of the transfer laser, and the focusing mirror is used to focus the transfer laser; The monitoring laser, the monitoring shaping device, the polarization beam splitter prism, the quarter-wave plate and the focusing mirror are located on the same optical path, and the monitoring laser is used to emit the monitoring laser, the monitoring shaping device is used to shape the monitoring laser, the polarization beam splitter prism is also used to reflect the monitoring laser, the quarter-wave plate is also used to adjust the polarization state of the monitoring laser, and the focusing mirror is also used to focus the monitoring laser; The photodetector, the filter, the dichroic mirror, the polarization beam splitter prism, the quarter wave plate and the focusing mirror are located on the same optical path, and the focusing mirror, the polarization beam splitter prism and the filter are all used to transmit the reflected laser light formed after the monitoring laser light is reflected by the donor film, and the dichroic mirror is used to transmit the reflected laser light from the polarization beam splitter prism to the filter, the quarter wave plate is also used to adjust the polarization state of the reflected laser light, and the photodetector is used to receive the reflected laser light and convert the light intensity of the reflected laser light into an electrical signal; The transfer shaping device and the monitoring shaping device both include a polarization light processor, which is used to adjust the incident light to a specific single polarization direction, and the polarization direction of the transfer laser entering the polarization beam splitter prism is perpendicular to the polarization direction of the monitoring laser entering the polarization beam splitter prism; The online detection method of the online detection device for the thickness of the donor film for laser induced transfer comprises the following steps: A. preparing a donor film; wherein the donor film comprises a donor substrate and a donor film, and the donor film is attached to the lower surface of the donor substrate; B. Turning on the monitoring laser and irradiating the upper surface of the donor substrate with the monitoring laser emitted by the monitoring laser; C. Keeping the monitoring laser turned on, the transfer laser is turned on at the same time, and the transfer laser emitted by the transfer laser irradiates the upper surface of the donor substrate; D. The photoelectric detector receives the reflection information of the reflected laser formed after the monitoring laser is reflected by the donor film, and determines the thickness of the donor film according to the reflection information.

2. The on-line detection device for the thickness of the donor film for laser induced transfer according to claim 1, characterized in that: The photodetector includes any one of a photodiode and a photomultiplier tube, and the polarized light processor includes any one of a half-wave plate, a polarization beam splitter prism, a Glan-Taylor prism, a Wollaston polarizing prism and a Rochon polarizing prism.

3. The on-line detection device for the thickness of the donor film for laser induced transfer according to claim 1, characterized in that: The monitoring and shaping device also includes any one or more combinations of a collimator, a beam expander, a beam reducer and an optical shutter.

4. The on-line detection device for the thickness of a donor film for laser induced transfer according to claim 1, characterized in that: The transfer shaping device also includes any one or more combinations of a collimator, a beam expander, a beam reducer, an optical shutter, an acousto-optic modulator, a scanning galvanometer and a fast-reflection mirror.

5. The on-line detection device for the thickness of a donor film for laser induced transfer according to claim 1, characterized in that: The filter is a broadband filter, the polarization beam splitter prism is a broadband polarization beam splitter prism, and the quarter wave plate is a broadband quarter wave plate.

6. The on-line detection device for the thickness of a donor film for laser induced transfer according to claim 1, characterized in that: The reflection information is the time consumed for the maximum reflectivity of the monitoring laser to drop from 80% to 20%.

7. The on-line detection device for the thickness of a donor film for laser induced transfer according to claim 1, characterized in that: The difference between the central wavelength of the monitoring laser and the central wavelength of the transfer laser is ≥50nm.

8. The on-line detection device for the thickness of a donor film for laser induced transfer according to claim 1, characterized in that: The thickness of the donor film is ≥2 μm.

9. The on-line detection device for the thickness of a donor film for laser induced transfer according to claim 1, characterized in that: The transmittance of the donor substrate to the monitoring laser and the transfer laser is ≥90%.

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