WO2019153219A1

WO2019153219A1 - Optical path modulator and manufacturing method therefor, fingerprint recognition apparatus, and terminal device

Info

Publication number: WO2019153219A1
Application number: PCT/CN2018/075924
Authority: WO
Inventors: 王红超; 沈健
Original assignee: 深圳市为通博科技有限责任公司
Priority date: 2018-02-09
Filing date: 2018-02-09
Publication date: 2019-08-15
Also published as: CN110366730A

Abstract

An optical path modulator (300) and a manufacturing method therefor, a fingerprint recognition apparatus, and a terminal device. The optical path modulator (300) comprises a substrate, a through-hole array formed by a plurality of through holes penetrating the substrate, and a sealing thin film located on an upper surface of the substrate. The sealing thin film seals the through-hole array on the upper surface of the substrate, and the sealing thin film is used for performing surface bonding with the display screen (120). The sealing thin film is provided on the upper surface of the optical path modulator (300) , so that the through-hole array in the optical path modulator (300) is sealed on the upper surface of the optical path modulator (300), and therefore in the process of bonding with the display screen (120), the sealing thin film can achieve surface bonding with the display screen (120), preventing glue from entering the through holes of the optical path modulator (300) during bonding, ensuring the accuracy of the relative position of the optical path modulator (300) and the display screen (120), and also improving the bonding strength.

Description

Optical path modulator and manufacturing method thereof, fingerprint identification device and terminal device

Technical field

The present application relates to the field of biometrics, and more particularly to an optical path modulator, a method of fabricating the same, a fingerprint identification device, and a terminal device.

Background technique

With the wide application of the full screen with large screen ratio, the design requirements of the screen for fingerprint recognition are increasing. The traditional capacitive fingerprint recognition technology is limited by the penetrating ability and is difficult to apply to the screen fingerprint recognition system. Optical fingerprint recognition technology can better break through the limitations of display screen and glass thickness, so it has a good application prospect.

The optical fingerprint recognition system usually uses an optical path modulator (hereinafter referred to as an optical path modulator) to guide the downwardly transmitted light to guide the reflected light reflected by the finger to the optical detecting unit, so that the optical detecting unit uses the fingerprint path to align the light. The difference in reflection can obtain a fingerprint image, and based on the matching verification of the fingerprint feature points, fingerprint recognition is implemented on a terminal device such as a mobile phone. However, when the optical path modulator is attached to the display screen, the glue easily enters the through hole in the optical path modulator, and the relative position between the optical path modulator and the display screen cannot be ensured during the bonding process, and the bonding strength is also Relatively weak.

Summary of the invention

The embodiment of the present application provides an optical path modulator, a manufacturing method thereof, a fingerprint identification device, and a terminal device, which can implement surface bonding between the optical path modulator and the display screen, thereby avoiding glue entering the optical path modulator during the bonding process. In the through hole, the accuracy of the relative position of the optical path modulator and the display screen is ensured, and the bonding strength is improved.

In a first aspect, an optical path modulator is provided, the optical path modulator comprising: a substrate, an array of through holes formed by a plurality of through holes extending through the substrate, and a sealing film on an upper surface of the substrate. Wherein the sealing film seals the array of through holes on the upper surface of the substrate, and the sealing film is used for surface bonding with the display screen.

Therefore, the upper surface of the optical path modulator of the embodiment of the present application has a sealing film, so that the through-hole array in the optical path modulator is sealed on the upper surface of the optical path modulator, so that in the process of bonding with the display screen, The sealing film and the display screen can be surface-fitted.

Since the surface fitting method is used instead of the original frame fitting method, in the process of bonding the optical path modulator and the display screen, the glue caused by the original frame bonding process can be prevented from entering the optical path modulator. The through hole ensures the accuracy of the relative position of the optical path modulator to the display screen while avoiding possible gaps between the upper surface of the optical path modulator and the display screen during the frame fitting process. Moreover, the sealing film is bonded to the display screen to improve the bonding strength, or the thinner adhesive layer can be used to realize the connection between the optical path modulator and the display screen under the condition of ensuring the same bonding strength. To get a thinner optical modulator.

The optical path modulator according to the embodiment of the present application may be applied to a fingerprint identification device for guiding reflected light emitted from a display screen and reflected back on a finger surface to an optical detecting unit disposed under the optical path modulator. The optical detecting unit is configured to detect the received reflected light.

In some possible implementations, the sealing film is a silicon dioxide film or an organic film.

In some possible implementations, the transmittance of the sealing film to the band used by the fingerprint recognition device is greater than or equal to 85%.

In some possible implementations, the sealing film is used for surface bonding with the display screen by a thermosetting process.

In some possible implementations, the optical path modulator further includes: a coating between the upper surface of the substrate and the sealing film, the coating for suppressing entering an optical signal of the optical modulator Noise signal.

In some possible implementations, the material of the coating is black glue or titanium.

In some possible implementations, the transmittance of the black plastic material to the wavelength band used by the fingerprint recognition device is less than or equal to 10%.

In some possible implementations, the through holes in the through hole array are vertical through holes or inclined through holes, wherein the inclined through holes have an inclination angle greater than 0°, and the inclined angle is the inclined through holes An angle between an axial direction and a normal direction perpendicular to the surface of the optical path modulator, the oblique angle of the vertical through hole being equal to 0°.

In a second aspect, a method of fabricating an optical path modulator is provided, the method comprising: forming a sealing film on a first surface of an etched sheet, the sealing film being used for face-to-face bonding with a display screen; The etched sheet of the sealing film is inverted; a mask layer is formed on the second surface of the etched sheet according to the etched pattern, and the second surface is an upper surface of the etched sheet after the inversion; Etching the etched sheet to form an array of vias having a plurality of vias on the etched sheet, wherein the sealing film causes the via array to be in the etch The second surface of the sheet is sealed; the optical path modulator is formed based on the etched sheet having the array of vias.

Therefore, in the method of fabricating the optical path modulator of the embodiment of the present application, a sealing film is formed on the first surface of the etched sheet, and the etched sheet having the sealing film is inverted, on the etched sheet after the inversion Forming a mask layer on the second surface of the surface, etching the etched sheet with the mask layer, and stopping etching when etching the sealing film, thereby forming a plurality of through holes on the etched sheet The through hole array is sealed by the sealing film on the second surface of the etched sheet, so that the optical path modulator and the display screen can be surface-bonded by the sealing film.

In some possible implementations, the method further includes: thinning the etched sheet to make the etched sheet thickness before the sealing film is formed on the upper surface of the etched sheet The target thickness of the optical path modulator to be fabricated is equal.

In some possible implementations, the method further includes: forming a coating on the first surface before the sealing film is formed on the first surface of the etched sheet, the coating being used for suppressing a noise signal in the optical signal of the optical path modulator; wherein the sealing film is formed on the first surface of the etched sheet, comprising: forming the sealing film on the coating; Etching the etched sheet by the mask layer comprises: etching the etched sheet and the coating layer by using the mask layer.

In some possible implementations, the material of the coating is black rubber, and the coating on the first surface comprises: preparing the coating on the first surface by spraying.

In some possible implementations, the material of the coating is titanium, and the coating on the first surface comprises: forming the coating on the first surface by metal sputtering.

In some possible implementations, the etching the etched sheet by using the mask layer comprises: anisotropically etching the etched sheet by using the mask layer.

In a third aspect, a method for fabricating an optical path modulator is provided, the method comprising: forming a mask layer on an upper surface of the etched sheet according to the etched pattern; and performing the etched sheet on the etched sheet by using the mask layer Etching to form a via array having a plurality of via holes on the etched sheet; forming a sealing film on the upper surface of the etched sheet, wherein the sealing film causes the via array to be in the etch The upper surface of the sheet is sealed, and the sealing film is used for face-to-face bonding with the display screen; the optical path modulator is formed based on the etched sheet having the array of through holes.

Therefore, in the method of fabricating the optical path modulator of the embodiment of the present application, the etched sheet is etched by using the mask layer, and a sealing film is formed on the upper surface of the etched etched sheet to be etched. An array of through holes having a plurality of through holes is formed on the sheet such that the array of through holes is sealed by the sealing film on the upper surface of the etched sheet, so that the optical path modulator and the display screen can be surface-bonded by a sealing film .

In some possible implementations, the etching the etched sheet with the mask layer to form an array of vias having a plurality of via holes on the etched sheet, including: using the Masking the etched sheet and performing a thinning process to form the via array having a plurality of via holes on the etched sheet, wherein the etched sheet is thinned The thickness is equal to the target thickness of the optical path modulator.

In some possible implementations, the method further includes: forming a coating on a non-via region of an upper surface of the etched sheet before the sealing film is formed on an upper surface of the etched sheet, The coating is for suppressing a noise signal in an optical signal entering the optical path modulator; wherein forming the sealing film on an upper surface of the etched sheet comprises: forming the sealing film on the coating.

In some possible implementations, the etching the etched sheet by using the mask layer comprises: fixing the etched sheet to an inclined groove of the slide, and the inclined surface of the inclined groove is opposite to The surface of the carrier has a predetermined inclination angle; the etched sheet is etched by the mask layer, so that the through hole in the through hole array formed on the etched sheet is a slanted through hole, wherein An inclined angle of each inclined through hole is the same as a predetermined inclination angle of the inclined surface, the inclination angle being an angle between an axial direction of the inclined through hole and a normal direction perpendicular to a surface of the optical path modulator .

In some possible implementations, the fixing the etched sheet to the inclined groove of the slide comprises: fixing the etched sheet to the inclined groove by temporary bonding or silicone oil bonding Inclined surface.

According to a fourth aspect, there is provided a fingerprint recognition apparatus comprising the optical path modulator of the first aspect or any of the possible implementations of the first aspect, and an optical detection unit disposed under the optical path modulator.

According to a fifth aspect, a terminal device is provided, the terminal device comprising a display screen, and the fingerprint recognition device in any of the possible implementations of the fourth aspect or the fourth aspect, wherein the fingerprint recognition device is disposed on the display Below the screen, a sealing film on the surface of the optical path modulator in the fingerprint recognition device is attached to the display screen surface.

In some possible implementations, the sealing film is surface-contacted with the display screen by a thermosetting process.

DRAWINGS

FIG. 1 is a schematic structural diagram of a terminal device applicable to an embodiment of the present application.

2 is a detailed schematic view of the optical fingerprint device of FIG. 1.

3a and 3b are schematic structural views of an optical path modulator according to an embodiment of the present application.

4a and 4b are schematic views of vertical through holes and inclined through holes, respectively, according to an embodiment of the present application.

FIG. 5 is a schematic diagram of the bonding of the optical path modulator and the display screen in the embodiment of the present application.

FIG. 6 is a schematic flowchart of a method of fabricating an optical path modulator according to an embodiment of the present application.

7a to 7g are schematic views showing a method of fabricating an optical path modulator according to an embodiment of the present application.

FIG. 8 is a schematic flowchart of a method of fabricating an optical path modulator according to another embodiment of the present application.

9a to 9g are schematic views showing a method of fabricating an optical path modulator according to another embodiment of the present application.

FIG. 10 is a schematic view of making a slanted through hole according to an embodiment of the present application.

FIG. 11 is a schematic block diagram of a fingerprint identification apparatus according to an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

It should be understood that the embodiments of the present application may be applied to an optical fingerprinting system, including but not limited to an optical fingerprinting system and a medical diagnostic product based on optical fingerprint imaging. The embodiment of the present application only uses an optical fingerprinting system as an example, but should not The embodiments of the present application constitute any limitation, and the embodiments of the present application are equally applicable to other systems using optical imaging technologies and the like.

As a common application scenario, the fingerprint identification method, the fingerprint identification device, and the fingerprint identification chip according to the embodiments of the present application may be applied to a smart phone, a tablet computer, and other mobile terminals or other terminal devices having a display screen; more specifically, In the above terminal device, the fingerprint recognition system may be specifically an optical fingerprint system, which may be disposed in a partial area or an entire area below the display screen, thereby forming an under-display optical fingerprint system.

FIG. 1 is a schematic structural diagram of a terminal device applicable to an embodiment of the present application. The optical fingerprint system of the terminal device 100 includes a display screen 120 and an optical fingerprint device 130. The optical fingerprint device 130 is configured at least in the A partial area below the display screen 120. The optical fingerprint device 130 may be an optical fingerprint sensor, which includes a sensing array having a plurality of optical sensing units, and the sensing array is located in the fingerprint identification area 103 of the optical fingerprint device 130. As shown in FIG. 1 , the fingerprint identification area 103 is located in the display area 102 of the display screen 120. Therefore, when the user needs to unlock the terminal device or perform other fingerprint verification, the user only needs to press the finger. Fingerprint input can be implemented in the fingerprint recognition area 103 of the display screen 120. Since the fingerprint detection can be implemented in the screen, the terminal device 100 adopting the above structure does not need to reserve a space for setting a fingerprint button (such as a Home button) on the front side, so that a full screen scheme, that is, a display area of the display screen 120 can be adopted. The 102 can be substantially extended to the front of the entire terminal device 100.

In a preferred embodiment, the display screen 120 may be a self-illuminating display screen, which adopts a self-luminous display unit as a display pixel, such as an Organic Light-Emitting Diode (OLED) display or a miniature Light-emitting diode (Micro-LED) display. Taking an OLED display as an example, the optical fingerprint device 130 can utilize an OLED display unit (ie, an OLED light source) of the OLED display 120 located in the fingerprint recognition area 103 as an excitation light source for optical fingerprint detection. Moreover, the sensing array of the optical fingerprint device 130 is specifically a photo detector array including a plurality of photodetectors distributed in an array, and the photodetectors can be used as the optical sensing unit as described above. When a finger touches, presses, or approaches (collectively referred to as touch for convenience of description) in the fingerprint recognition area 103, the light emitted by the display unit of the fingerprint recognition area 103 reflects on the fingerprint of the finger surface and forms reflected light. The reflected light of the ridges and valleys of the fingerprint of the finger is different, and the reflected light is received from the display screen 120 and received by the photodetector array and converted into a corresponding electrical signal, that is, a fingerprint detection signal. Fingerprint image data can be obtained based on the fingerprint detection signal, and fingerprint matching verification can be further performed, thereby implementing an optical fingerprint recognition function at the terminal device 100.

In other alternative embodiments, the optical fingerprint device 130 may also be disposed over the entire area below the display screen 120, thereby extending the fingerprint identification area 103 to the entire display area 102 of the display screen 120, Full screen fingerprint detection. Alternatively, the optical fingerprint device 130 may also be disposed in a predetermined area inside the terminal device 100, such as an edge region of the terminal device 100, and a light guiding structure is disposed under the display screen 120 to reflect the surface of the finger. Light is directed to the sensing array of the optical fingerprint device 130.

It should be understood that, in a specific implementation, the terminal device 100 further includes a transparent protective cover 110, and the cover plate 110 may be a transparent cover plate, such as a glass cover or a sapphire cover, which is located on the display screen. Above the 120 and covering the front side of the terminal device 100. Therefore, in the embodiment of the present application, the so-called finger touch, press or proximity on the display screen 120 actually refers to the finger touching, pressing or approaching the cover plate 110 above the display screen 120 or covering the cover plate 110. The surface of the protective layer. In addition, the terminal device 100 may further include a touch sensor, which may be specifically a touch panel, which may be disposed on the surface of the display screen 120, or may be partially or integrally integrated into the display screen 120, that is, The display screen 120 is specifically a touch display screen.

As an alternative implementation, as shown in FIG. 1, the optical fingerprint device 130 includes an optical detecting unit 134 and an optical component 132, and the optical detecting unit 134 includes the sensing array and the sensing array electrical Connected read circuits and other auxiliary circuits, which may be fabricated on a chip by a semiconductor process; the optical components 132 may be disposed above the sensing array of the optical detecting unit 134, which may specifically include filtering Filters, optical path modulators, and other optical components, the filters can be used to filter out ambient light that penetrates the finger, and the optical modulator can use a through-hole array with a high aspect ratio, mainly for The light that propagates downward is collimated and modulated, and the reflected light reflected from the surface of the finger is guided to the sensing array for optical detection.

2 illustrates one possible configuration of the optical fingerprint device 130 of FIG. 1, wherein the optical fingerprint device 130 can include an optical assembly 132 and an optical detection unit 134, the optical assembly 132 including an optical path modulator and a filter, The light emitted by the display screen is reflected on the surface of the finger to be detected above the display screen, and the optical path modulator collimates and modulates the reflected light reflected from the surface of the finger through its through-hole array, and guides the reflected light to the filter. The light is received by the optical detection unit 134 after being filtered by the filter, and the optical detection unit 134 can further detect the received reflected light to implement fingerprint recognition.

In a specific implementation, the optical component 132 may be packaged in the same optical fingerprint chip as the optical detecting unit 134, or may be installed inside the optical fingerprint module as a component independent of the optical detecting unit 134. The optical path modulator may be specifically a collimator layer or a lens (Lens) layer made of a semiconductor silicon wafer or a silicon oxide (such as silicon dioxide) or a nitride (such as silicon nitride). It has a plurality of collimating units or lens units, and the collimating unit or the lens unit can be used as a modulating unit of the optical path modulator. Specifically, the modulating unit can be specifically a small hole having a high aspect ratio, reflected from the finger. In the reflected light, the light incident on the modulation unit can pass through and be received by the optical sensing unit below, and each optical sensing unit can basically receive the reflected light of the fingerprint pattern guided by the small hole above it. Thus, the sensing array can detect the fingerprint image of the finger.

In the optical fingerprint device 130, each modulation unit of the optical path modulator may respectively correspond to one of the optical sensing units of the sensing array; alternatively, the modulation unit and the optical sensing unit of the sensing array A non-one-to-one correspondence may also be used to reduce the occurrence of moiré interference. For example, an optical sensing unit may correspond to a plurality of modulation units, or the modulation unit may also be implemented in an irregular arrangement. There is no specific correspondence between the optical sensing units of the array. When the modulation unit of the optical path modulator adopts an irregular arrangement, the optical fingerprint device 130 can correct the reflected light detected by each sensing unit by a post-software algorithm.

3a and 3b are a cross-sectional view and a bottom view, respectively, of an optical path modulator 300 of an embodiment of the present application, which may be applied to a fingerprint recognition device such as the optical fingerprint device 130 shown in FIGS. 1 and 2. As the optical path modulator between the display screen 120 and the optical detecting unit 134. The optical path modulator 300 is configured to direct reflected light emitted from the display screen 120 and reflected back from the surface of the finger to an optical detecting unit 134 disposed under the optical path modulator 300, the optical detecting unit 134 for receiving the received The reflected light is detected to acquire a fingerprint image of the finger.

Wherein, as shown in the cross-sectional view of FIG. 3a and the bottom view of FIG. 3b, the optical path modulator 300 includes a substrate, an array of through holes composed of a plurality of through holes penetrating the substrate, and a sealing film on the upper surface of the substrate. . Wherein, the sealing film seals the array of through holes on the upper surface of the substrate, and the sealing film is used for surface bonding with the display screen.

The material of the substrate is opaque to the corresponding wavelength band used by the fingerprint recognition device. For example, the material of the substrate may be silicon, silicon carbide, silicon oxide or nitride, or the like.

In the via array of the optical path modulator 300, each via may serve as a modulation unit of the optical path modulator 300 for collimating and modulating the reflected light propagating to the optical detecting unit below the optical path modulator 300. .

Optionally, the through holes in the through hole array may be vertical through holes or inclined through holes.

Specifically, if the through hole in the through hole array is a vertical through hole, such as the cross-sectional view shown in FIG. 4a, the axial direction of the inclined through hole is the same as the normal direction perpendicular to the surface of the optical path modulator.

If the through hole in the through hole array is an inclined through hole, for example, the cross-sectional view shown in FIG. 4b, the inclined angle a of the inclined through hole is greater than 0°, and the inclined angle is the axial direction of the inclined through hole and perpendicular to The angle between the normal directions of the surface of the optical path modulator. At this time, it should be understood that the above collimation actually means guiding the light so that the reflected light passing through each of the through holes of the optical path modulator 300 is at a predetermined angle (i.e., the above-described inclination angle a, preferably, 0°). <a < 40°) obliquely incident on the sensing array of the optical detecting unit.

In addition, the inclined through hole in the through-hole array of the optical path modulator 300 may be a circular through hole, an elliptical through hole or a square through hole; or any other shape of the through hole, which is not limited in the present application.

The upper surface of the optical path modulator 300 has a sealing film which is sealed on the upper surface of the optical path modulator 300 to form a plane, thereby enabling surface-to-face placement between the optical path modulator and the display screen. Hehe. For example, the sealing film can be bonded to the display screen by a thermosetting process, and during the bonding process using the thermosetting process, it is necessary to control the thermosetting temperature so that the sealing film is closely attached to the display screen to ensure the sealing. The film does not soften into the through holes.

For example, the optical fingerprint device shown in FIG. 5 has a sealing film disposed on the upper surface of the optical path modulator and is closely attached to the display screen. Since the upper surface of the optical path modulator is covered with the sealing film, the optical path modulator and the display screen can be surface-bonded by the sealing film. The original method is only to adhere the non-through-hole area on the upper surface of the optical path modulator and the display screen by glue bonding. The manner in which the frame is attached can easily cause the glue to enter the through-hole of the optical path modulator. And if the paste is not flat, there may be gaps between some non-through-hole areas and the display screen to affect imaging. In addition, the fitting strength of the frame fitting method is low, and it is difficult to ensure the accuracy of the relative position of the optical path modulator and the display screen, which may cause a positional deviation between the through hole and the sensing unit below it.

The upper surface of the optical path modulator of the embodiment of the present application has a sealing film such that the array of through holes in the optical path modulator is sealed on the upper surface of the optical path modulator, so that the sealing is performed during the bonding with the display screen. A face fit can be achieved between the film and the display. Since the surface fitting method is used instead of the original frame fitting method, in the process of bonding the optical path modulator and the display screen, the glue caused by the original frame bonding process can be prevented from entering the optical path modulator. The through hole ensures the accuracy of the relative position of the optical path modulator to the display screen while avoiding possible gaps between the upper surface of the optical path modulator and the display screen during the frame fitting process. Moreover, the sealing film is bonded to the display screen to improve the bonding strength, or the thinner adhesive layer can be used to realize the connection between the optical path modulator and the display screen under the condition of ensuring the same bonding strength. To get a thinner optical modulator.

The sealing film may be, for example, an inorganic film such as a silicon oxide film, or may be an organic film.

The sealing film should have a good transmittance for the wavelength band used by the fingerprint recognition device, for example, the transmittance of the sealing film to the band used by the fingerprint recognition device is greater than or equal to 85%.

Optionally, the upper surface of the substrate further comprises a coating between the substrate and the sealing film for suppressing noise signals in the optical signal entering the optical modulator.

Optionally, the material of the coating is black glue or titanium. When the coating is a black rubber layer, the black glue on the upper surface of the substrate can absorb the light incident on the non-via region of the surface of the optical path modulator, thereby improving the signal-to-noise ratio of the optical signal entering the optical modulator, the black plastic The band used by the fingerprint recognition device should have a low transmittance, for example, the transmittance of the black plastic material to the band used by the fingerprint recognition device is less than or equal to 10%. When the coating is a titanium layer, the titanium layer on the upper surface of the substrate is capable of reflecting light incident on the non-via region of the surface of the optical modulator, as well as improving the signal-to-noise ratio of the optical signal entering the optical modulator.

For the optical path modulator described above, the embodiment of the present application further provides two methods for fabricating the optical path modulator, which are specifically described below.

method 1

6 shows a schematic flow chart of a method 600 of fabricating an optical path modulator according to an embodiment of the present application, which can fabricate the optical path modulator 300 shown in FIGS. 3a and 3b, wherein the optical path modulator 300 includes a base. A sheet, an array of through holes composed of a plurality of through holes penetrating the substrate, and a sealing film on the upper surface of the substrate. The sealing film seals the array of through holes on the upper surface of the substrate for sealing the display screen. The optical path modulator 300 fabricated by the method 600 provided by the embodiment of the present application can be applied to a fingerprint recognition device such as the optical fingerprint device 130 shown in FIGS. 1 and 2.

Specifically, as shown in FIG. 6, the method 600 for fabricating the optical path modulator may include:

In step 610, a sealing film is formed on the first surface of the etched sheet, and the sealing film is used for surface bonding with the display screen.

Specifically, an etched sheet is first prepared, which is a substrate for fabricating an optical path modulator, and may be, for example, an etched sheet as shown in FIG. 7a. Alternatively, the material of the etched sheet may be silicon, silicon carbide, silicon oxide or silicon nitride.

Thereafter, a sealing film is formed on the upper surface (ie, the first surface) of the etched sheet, and the sealing film is used for surface-contacting with the display screen. For example, the sealing film can be bonded to the display screen by a thermosetting process, and during the bonding process using the thermosetting process, it is necessary to control the thermosetting temperature to make the sealing film closely fit the display screen.

Optionally, in step 610, before the sealing film is formed on the first surface of the etched sheet, the etched sheet may be thinned to modulate the thickness of the etched sheet and the optical path to be fabricated. The target thickness of the device is equal, for example, the etched sheet after the thinning treatment as shown in Fig. 7b is obtained. Thereafter, the sealing film can be formed on the etched sheet after thinning.

Optionally, in step 610, before the sealing film is formed on the first surface of the etched sheet, a coating may be formed on the first surface, and then the sealing film is formed on the coating, for example, As shown in 7c, the coating is formed on the first surface of the etched sheet, and the sealing film is formed on the coating. The coating can suppress noise signals in the optical signal entering the optical modulator.

The material of the coating can be, for example, black glue or titanium.

When the coating is a black rubber layer, the black glue on the first surface of the etched sheet can absorb the light incident on the non-via region of the surface of the optical modulator, thereby improving the signal of the optical signal entering the optical modulator. The noise ratio, the black gel should have a lower transmittance for the band used by the fingerprint recognition device, for example, the transmittance of the black plastic material to the band used by the fingerprint recognition device is less than or equal to 10%. The black glue layer can be formed on the first surface of the etched sheet, for example, by spraying.

When the coating layer is a titanium layer, the titanium layer of the first surface of the etched sheet can reflect the light incident on the non-via region of the surface of the optical path modulator, and can also improve the optical signal entering the optical path modulator. Signal to noise ratio. The titanium layer can be formed on the first surface of the etched sheet by, for example, metal sputtering.

In step 620, the etched sheet having the sealing film is inverted.

Specifically, the etched sheet having the sealing film obtained in step 610 is inverted such that the first surface faces downward and the second surface faces upward, and the second surface is the inverted upper surface of the etched sheet, for example, Shown in 7d.

Step 630, forming a mask layer on the second surface of the etched sheet according to the etched pattern.

The etched pattern may specifically refer to a planar pattern corresponding to the array of vias to be fabricated, such as the via pattern shown in Figure 3b.

For example, as shown in FIG. 7e, the mask layer may be formed with a plurality of etching openings, and the plurality of etching openings are arranged in an array, and each of the etching openings respectively corresponds to an array of through holes formed in the etching sheet. A through hole. The etch opening of the etch stop layer may be a via hole perpendicular to the surface of the mask layer. The etched opening has an opening region formed on the surface of the etched sheet that coincides with its corresponding etched pattern.

Optionally, the etched sheet may be a silicon wafer, and the mask layer may be a silicon dioxide layer or a silicon nitride layer grown on the surface of the etched sheet, and the silicon dioxide layer or silicon nitride layer The layer is formed by the etching process to form the above etched opening.

Step 640, etching the etched sheet by using the mask layer to form an array of via holes having a plurality of via holes on the etched sheet.

Wherein, the sealing film seals the etched array of via holes on the second surface of the etched sheet and is used for surface bonding with the display screen.

Specifically, as shown in FIG. 7f, the etched sheet is etched from the second surface of the etched sheet, and the etching process is performed until the sealing film is stopped to etch at the etch. An array of via holes having a plurality of via holes is formed on the wafer, and the sealing film on the surface of the etched sheet is not etched. For example, as shown in FIG. 7g, the etched sheet and the coating of the first surface thereof are etched, and the sealing film is not etched. In this way, the sealing film can seal the through-hole array on the second surface of the etched sheet to form a plane, so that the optical path modulator and the display screen can be surface-bonded through the sealing film.

When the sealing film is adhered to the display screen by a thermosetting process, in the process of bonding using a thermosetting process, it is necessary to control the thermosetting temperature so that the sealing film closely adheres to the display screen, and ensures the The sealing film does not soften into the above-mentioned through holes.

The etched sheet may be etched by an anisotropic etch, and the etch direction may be specifically perpendicular to the surface of the etched sheet.

When the etched sheet is etched by using the mask layer and perpendicular to the surface of the carrier, the portion of the etched sheet that is blocked by the region outside the etched opening of the mask layer is not etched. Only the opening region (the via pattern shown in Fig. 3b) formed on the surface of the etched sheet with the etched opening can be etched. Therefore, under the blocking of the mask layer, after the etched sheet is etched, a via hole corresponding to the etched pattern, such as the through hole shown in FIG. 4a, can be formed.

In step 640, during the etching of the etched sheet by the mask layer, an anisotropic etching method is preferably used to etch the via holes in the etched sheet. The anisotropic etch refers to an etch process in which the etch rate in the vertical direction is greater than the etch rate in the horizontal direction, including but not limited to dry plasma etching. The etching method of the anisotropic strips can ensure the etching precision of the inclined via holes formed in the etched sheet, and the internal properties of the inclined via holes are prevented from affecting the optical performance due to the lateral etching.

It should be understood that the sequence of steps for fabricating the optical path modulator of Figures 7a through 7g is merely an example. In this embodiment, in the step of fabricating the optical path modulator, the position of the step of the thinning process is not limited in any way. For example, the etched sheet may be thinned at first to obtain a thinned etched sheet as shown in FIG. 7b, and a coating and a sealing film may be formed on the etched sheet after thinning; or The coating and the sealing film are first formed on the etched sheet, and then subjected to a thinning treatment to obtain the etched sheet shown in Fig. 7c. This application does not limit this as long as the thickness of the finally fabricated optical path modulator can satisfy the desired target thickness.

Step 650, forming the optical path modulator based on the etched sheet having the via array.

Specifically, after the etched sheet is etched and formed into an array of vias having a plurality of via holes, the mask layer on the surface thereof may be removed to obtain an optical path modulator such as that shown in FIG. 7g; and, alternatively, may be The etched sheet can be further cut to obtain an optical path modulator that satisfies the size and shape requirements.

In the method for fabricating the optical path modulator of the embodiment of the present application, a sealing film is formed on the first surface of the etched sheet, and the etched sheet having the sealing film is inverted, and the upper surface of the etched sheet after the inversion is Forming a mask layer on the second surface, etching the etched sheet with the mask layer, and stopping etching when etching the sealing film, thereby forming a pass having a plurality of through holes on the etched sheet The array of holes is sealed by the sealing film on the second surface of the etched sheet, so that the optical path modulator and the display screen can be surface-bonded by the sealing film.

Method 2

8 shows a schematic flow diagram of a method 800 of fabricating an optical path modulator that can fabricate the optical path modulator 300 shown in FIGS. 3a and 3b, wherein the optical path modulator 300 includes a base, in accordance with an embodiment of the present application. A sheet, an array of through holes composed of a plurality of through holes penetrating the substrate, and a sealing film on the upper surface of the substrate. The sealing film seals the array of through holes on the upper surface of the substrate for sealing the display screen. The optical path modulator 300 fabricated by the method 800 provided by the embodiment of the present application can be applied to a fingerprint recognition device such as the optical fingerprint device 130 shown in FIGS. 1 and 2.

Step 810, forming a mask layer on the upper surface of the etched sheet according to the etched pattern.

Specifically, an etched sheet is first prepared, which is a substrate for fabricating an optical path modulator, and may be, for example, an etched sheet as shown in FIG. 9a. Optionally, the material of the etched sheet may be silicon, silicon carbide, silicon oxide or silicon nitride.

Then, a mask layer is formed on the etched sheet. For example, as shown in FIG. 9b, the mask layer may be formed with a plurality of etch openings, and the plurality of etch openings are arranged in an array, and each of the etch openings respectively corresponds to a required One of the through holes in the array of via holes fabricated in the etched sheet. The etch opening of the etch stop layer may be a via hole perpendicular to the surface of the mask layer. The etched opening has an opening region formed on the surface of the etched sheet that coincides with its corresponding etched pattern.

If the through hole in the through hole array of the optical path modulator to be fabricated is an oblique through hole, the opening shape of the etching opening of the mask layer may be designed such that when the etched piece is placed at an oblique angle a, The effective opening area of the horizontal projection of the etched opening on the surface of the etched sheet coincides with its corresponding etched pattern.

Step 820, etching the etched sheet by using the mask layer to form an array of via holes having a plurality of via holes on the etched sheet.

Specifically, for example, as shown in FIG. 9c, the etched sheet may be etched by an anisotropic etching, and the etching direction may be specifically perpendicular to the surface of the etched sheet. When the etched sheet is etched by using the mask layer and perpendicular to the surface of the carrier, the portion of the etched sheet that is blocked by the region outside the etched opening of the mask layer is not etched. Only the opening region (the via pattern shown in Fig. 3b) formed on the surface of the etched sheet with the etched opening can be etched. Therefore, under the blocking of the mask layer, after the etched sheet is etched, a via hole corresponding to the etched pattern, such as the through hole shown in FIG. 4a, can be formed.

If the through hole in the through hole array of the optical path modulator to be fabricated is a slanted through hole, then in step 820, a slide having an inclined groove having an inclined surface with respect to the surface of the slide may be provided The inclination angle a is predetermined. The etched sheet having the mask layer is fixed on the inclined groove of the slide, so that the etched sheet can be kept inclined during the etching process, so that the etched through hole is an inclined through hole.

For example, the slide carrying the inclined groove shown in FIG. 10 fixes the etched sheet in the inclined groove of the slide, for example, by temporarily bonding or silicone-bonding the etched piece to the inclined groove. Inclined surface. Afterwards, the etched sheet is etched by using the mask layer, so that the through holes in the through hole array formed on the etched sheet are inclined through holes, wherein the axial direction of each inclined through hole is perpendicular to the The normal direction of the surface of the etched sheet has the same angle a as the inclination angle a of the inclined surface.

As shown in FIG. 10, when the etched sheet is etched by using the mask layer in a direction perpendicular to the surface of the carrier, the etched sheet is blocked by the region outside the etched opening of the mask layer. It is not etched, and since the mask layer is in an inclined state, the opening direction of the etching opening of the mask layer is not perpendicular to the surface of the carrier, so the edge of the etching opening and part of the inner sidewall will The vertical etching of the etched sheet causes a certain blockage, and only the effective opening area of the horizontal projection of the etched opening on the surface of the etched sheet can be etched. Therefore, under the blocking of the mask layer, after the etched sheet fixed to the inclined groove is etched, the inclined through hole corresponding to the etched pattern can be formed.

In step 820, during the etching of the etched sheet by the mask layer, an anisotropic etching method is preferably used to etch the via holes in the etched sheet. The etching method of the anisotropic strips can ensure the etching precision of the inclined via holes formed in the etched sheet, and the internal properties of the inclined via holes are prevented from affecting the optical performance due to the lateral etching.

In step 820, optionally, in the process of etching the etched sheet by using the mask layer to form a via array having a plurality of via holes on the etched sheet, the etching may be directly performed in the etching A through hole is formed on the chip, that is, the etched piece is etched by using the mask layer until the etched piece is penetrated to form a through hole, and then other operations such as thinning are performed to make the etched piece after thinning The thickness of the optical path modulator is equal to the target thickness of the optical path modulator to be fabricated; or the etched sheet may be etched and thinned by the mask layer to form the plurality of through holes on the etched sheet. a via array, such as shown in FIG. 9d, is etched by the mask layer to a depth that is greater than or equal to a target thickness of the optical modulator to be fabricated, and then The etched sheet is subjected to a thinning treatment to obtain an etched sheet having a via hole as shown in FIG. 9f, and the etched sheet is etched by removing the portion of the etched sheet that is not etched by the thinning treatment. Hole with a certain depth becomes a through hole It is equal to the target thickness of the sheet after etching and thinning of the optical path modulator.

In step 830, a sealing film is formed on the upper surface of the etched sheet.

Specifically, after etching the etched sheet to form an array of vias having a plurality of via holes, the mask layer on the surface thereof can be removed, and a sealing film can be formed on the etched sheet. Wherein, the sealing film seals the array of through holes on the upper surface of the etched sheet, and the sealing film is used for surface bonding with the display screen.

For example, the sealing film can be adhered to the display screen by a thermosetting process, and during the bonding process using the thermosetting process, it is necessary to control the thermosetting temperature to make the sealing film closely fit with the display screen, and to ensure The sealing film does not soften into the through holes.

Optionally, in step 830, before the sealing film is formed on the upper surface of the etched sheet, a coating may be formed on the non-via region of the upper surface of the etched sheet to obtain, for example, as shown in FIG. 9e. The etched sheet is coated and the sealing film is formed on the coating to obtain, for example, a sealed film optical path modulator as shown in Fig. 9g. It can be seen that the upper surface of the etched sheet forms a coating on which the sealing film is formed. Wherein, the coating can suppress a noise signal in an optical signal entering the optical path modulator.

The material of the coating can be, for example, black glue or titanium.

When the coating is a black rubber layer, the black glue on the upper surface of the etched sheet can absorb the light incident on the non-via region of the surface modulator surface, thereby improving the signal noise of the optical signal entering the optical path modulator. In contrast, the black gel should have a lower transmittance for the band used by the fingerprint recognition device, for example, the transmittance of the black plastic material to the band used by the fingerprint recognition device is less than or equal to 10%. The black glue layer can be formed, for example, by spraying on the upper surface of the etched sheet.

When the coating is a titanium layer, the titanium layer on the upper surface of the etched sheet can reflect the light incident on the non-via region of the surface of the optical modulator, and can also improve the signal of the optical signal entering the optical modulator. Noise ratio. The titanium layer can be formed on the upper surface of the etched sheet by, for example, metal sputtering.

It should be understood that the steps of fabricating the optical path modulator of Figures 9a through 9g are merely examples. In this embodiment, in the step of fabricating the optical path modulator, the position of the step of the thinning process is not limited in any way. For example, the etched etched sheet shown in FIG. 9d may be subjected to a thinning treatment, and the etched sheet after the thinning treatment may be used to form a coating layer and a sealing film; or, as shown in FIG. 9d, A coating is formed on the etched etched sheet to obtain the coated etched sheet shown in FIG. 9e, and the etched sheet having the coating is thinned to form the etch shown in FIG. 9f. a film, and finally the sealing film is formed on the etched sheet shown in FIG. 9f; or, the coating and the sealing film may be formed on the etched etched sheet shown in FIG. 9d, and finally thinned; or It is also possible to perform a thinning operation before performing the etching step shown in Fig. 9c. This application does not limit this as long as the thickness of the finally fabricated optical path modulator can satisfy the desired target thickness.

Step 840, forming the optical path modulator based on the etched sheet having the through hole array.

Alternatively, the etched sheet may be further cut to obtain an optical path modulator that satisfies the size and shape requirements.

In the method for fabricating the optical path modulator of the embodiment of the present application, the etched sheet is etched by using the mask layer, and a sealing film is formed on the upper surface of the etched etched sheet to be fabricated on the etched sheet. An array of through holes having a plurality of through holes is formed such that the array of through holes is sealed by the sealing film on the upper surface of the etched sheet, so that the optical path modulator and the display screen can be surface-bonded by the sealing film.

FIG. 11 shows a schematic block diagram of a fingerprint identification apparatus 1100 of an embodiment of the present application. The fingerprint identification device 1100 can be applied to a mobile terminal device as shown in FIG. 1 or FIG. 2, as shown in FIG. 11, the fingerprint recognition device 1100 includes an optical path modulator 1110 and an optical detection unit disposed under the optical path modulator 1110. 1120. The optical path modulator 1110 can be the optical path modulator 300 shown in the aforementioned FIGS. 3a and 3b.

The optical path modulator 1110 is configured to guide the reflected light reflected from the surface of the finger to an optical detecting unit 1120 disposed under the optical path modulator 1110, and the optical detecting unit 1120 is configured to detect the received reflected light. Wherein, the optical path modulator 1110 includes: a substrate; an array of through holes formed by a plurality of through holes penetrating the substrate; and a sealing film on an upper surface of the substrate, wherein the sealing film causes the through hole array to be at the base The upper surface of the sheet is sealed and the sealing film is used to face the display screen.

It should be understood that the fingerprint identification device in the embodiment of the present application may include a fingerprint identification chip, which may be a push-type fingerprint recognition chip, a scratch-type fingerprint recognition chip, or a touch-type fingerprint recognition chip. Limited to this. The fingerprint identification device can be applied to a terminal device, such as a mobile terminal device such as a smart phone, a tablet computer, or a notebook computer.

The embodiment of the present application further provides a terminal device, which may include a display screen and any of the above-mentioned fingerprint recognition devices in the embodiment of the present application, wherein the fingerprint recognition device is disposed below the display screen.

It should be understood that the terminal device in the embodiment of the present application may be an electronic device equipped with a fingerprint identification device, such as a mobile phone, a tablet computer, a notebook computer, or the like, and may be, for example, a mobile phone with a fingerprint identification chip.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present application.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or may be Integrate into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separate, and the components displayed as the units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one detecting unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The above is only a specific embodiment of the present application, but the scope of protection of the embodiments of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the embodiments of the present application. , should be covered in the scope of protection of this application for personal gain. Therefore, the scope of protection of the embodiments of the present application should be determined by the scope of protection of the claims.

Claims

An optical path modulator, characterized in that the optical path modulator comprises:

Substrate

An array of vias formed through a plurality of vias of the substrate;

a sealing film on an upper surface of the substrate, wherein the sealing film seals the array of through holes on an upper surface of the substrate, the sealing film being used for face-to-face bonding with a display screen.
The optical path modulator according to claim 1, wherein the sealing film is a silicon dioxide film or an organic film.
The optical path modulator according to claim 1 or 2, wherein the transmittance of the sealing film to the band used by the fingerprint recognition device is greater than or equal to 85%.
The optical path modulator according to any one of claims 1 to 3, wherein the sealing film is used for surface bonding with the display screen by a thermosetting process.
The optical path modulator according to any one of claims 1 to 4, further comprising:

a coating between the upper surface of the substrate and the sealing film for suppressing noise signals in an optical signal entering the optical modulator.
The optical path modulator according to claim 5, wherein the coating material is black rubber or titanium.
The optical path modulator according to claim 6, wherein the transmittance of the black plastic material to the wavelength band used by the fingerprint recognition device is less than or equal to 10%.
The optical path modulator according to any one of claims 1 to 7, wherein the through hole in the through hole array is a vertical through hole or an inclined through hole, wherein the inclined through hole has an inclination angle greater than 0°, the inclination angle is an angle between an axial direction of the inclined through hole and a normal direction perpendicular to a surface of the optical path modulator, and the inclination angle of the vertical through hole is equal to 0°.
The optical path modulator according to any one of claims 1 to 8, wherein the optical path modulator is applied to a fingerprint recognition device for guiding reflected light that is emitted from a display screen and reflected back on a finger surface And an optical detecting unit disposed under the optical path modulator, the optical detecting unit configured to detect the received reflected light.
A fingerprint recognition apparatus comprising the optical path modulator according to any one of claims 1 to 8 and an optical detection unit disposed under the optical path modulator.
A terminal device, comprising: a display screen and the fingerprint recognition device according to claim 9, wherein the fingerprint recognition device is disposed under the display screen, and the optical path modulator in the fingerprint recognition device A sealing film of the surface is attached to the display surface.
The terminal device according to claim 11, wherein the sealing film is surface-contacted with the display screen by a thermosetting process.
A method for fabricating an optical path modulator, characterized in that the method comprises:

Forming a sealing film on the first surface of the etched sheet, the sealing film being used for surface bonding with the display screen;

Inverting the etched sheet having the sealing film;

Forming a mask layer on the second surface of the etched sheet according to the etched pattern, the second surface being an upper surface of the etched sheet after being inverted;

Etching the etched sheet with the mask layer to form a via array having a plurality of via holes on the etched sheet, wherein the sealing film causes the via array to be The second surface of the etched sheet is sealed;

The optical path modulator is formed based on the etched sheet having the through hole array.
The method according to claim 13, wherein the sealing film is a silicon dioxide film or an organic film.
The method according to claim 13 or 14, wherein the transmittance of the sealing film to the band used by the fingerprint recognition device is greater than or equal to 85%.
The method according to any one of claims 13 to 15, wherein the sealing film is used for surface bonding with the display screen by a thermosetting process.
The method according to any one of claims 13 to 16, wherein the method further comprises:

Before the sealing film is formed on the upper surface of the etched sheet, the etched sheet is subjected to a thinning treatment so that the thickness of the etched sheet is equal to the target thickness of the optical path modulator to be fabricated.
The method according to any one of claims 13 to 17, wherein the method further comprises:

Before the sealing film is formed on the first surface of the etched sheet, a coating is formed on the first surface for suppressing a noise signal in an optical signal entering the optical path modulator;

Wherein the sealing film is formed on the first surface of the etched sheet, comprising:

Forming the sealing film on the coating;

The etching the etched sheet by using the mask layer comprises:

The etched sheet and the coating are etched using the mask layer.
The method according to any one of claims 13 to 18, characterized in that the material of the coating is black glue or titanium.
The method according to claim 19, wherein the transmittance of the black plastic material to the wavelength band used by the fingerprint recognition device is less than or equal to 10%.
The method according to claim 19 or 20, wherein the material of the coating is black glue, and the coating on the first surface comprises:

The coating is made on the first surface by spraying.
The method according to claim 19, wherein the material of the coating is titanium, and the coating on the first surface comprises:

The coating is made on the first surface by metal sputtering.
The method according to any one of claims 13 to 22, wherein the etching the etched sheet by using the mask layer comprises:

The etched sheet is anisotropically etched using the mask layer.
A method for fabricating an optical path modulator, characterized in that the method comprises:

Forming a mask layer on the upper surface of the etched sheet according to the etched pattern;

Etching the etched sheet with the mask layer to form an array of via holes having a plurality of via holes on the etched sheet;

Forming a sealing film on the upper surface of the etched sheet, wherein the sealing film seals the array of through holes on the upper surface of the etched sheet, and the sealing film is used for surface bonding with the display screen;

The optical path modulator is formed based on the etched sheet having the through hole array.
The method according to claim 24, wherein the sealing film is a silicon dioxide film or an organic film.
The method according to claim 24 or 25, wherein the transmittance of the sealing film to the band used by the fingerprint recognition device is greater than or equal to 85%.
The method according to any one of claims 24 to 26, wherein the sealing film is used for surface bonding with the display screen by a thermosetting process.
The method according to any one of claims 24 to 27, wherein the etched sheet is etched by the mask layer to form a plurality of passes on the etched sheet A through hole array of holes, including:

Etching the etched sheet with the mask layer and performing a thinning process to form the via array having a plurality of via holes on the etched sheet, wherein the thinned layer is The thickness of the etched sheet is equal to the target thickness of the optical path modulator.
The method according to any one of claims 24 to 28, wherein the method further comprises:

Before the sealing film is formed on the upper surface of the etched sheet, a coating is formed on the non-via region of the upper surface of the etched sheet, and the coating is used to suppress an optical signal entering the optical modulator Noise signal in;

Wherein the sealing film is formed on the upper surface of the etched sheet, comprising:

The sealing film is formed on the coating.
The method according to claim 29, wherein the material of the coating is black rubber or titanium.
The method according to claim 30, wherein the material of the coating is black glue, and the coating on the first surface comprises:

The coating is made on the first surface by spraying.
The method according to claim 30 or 31, wherein the transmittance of the black plastic material to the wavelength band used by the fingerprint recognition device is less than or equal to 10%.
The method according to claim 30, wherein the material of the coating is titanium, and the coating on the first surface comprises:

The coating is made on the first surface by metal sputtering.
The method according to any one of claims 24 to 33, wherein the etching the etched sheet by using the mask layer comprises:

Fixing the etched sheet on the inclined groove of the slide, the inclined surface of the inclined groove has a predetermined inclination angle with respect to the surface of the slide;

Etching the etched sheet with the mask layer such that the through holes in the through hole array formed on the etched sheet are oblique through holes, wherein the inclined angle of each inclined through hole is The predetermined inclination angle of the inclined surface is the same, and the inclination angle is an angle between an axial direction of the inclined through hole and a normal direction perpendicular to a surface of the optical path modulator.
The method according to claim 34, wherein the fixing the etched sheet to the inclined groove of the slide comprises:

The etched sheet is fixed to the inclined surface of the inclined groove by temporary bonding or silicone oil bonding.
The method according to any one of claims 24 to 35, wherein the etching the etched sheet by using the mask layer comprises:

The etched sheet is anisotropically etched using the mask layer.