Deformable image sensor, manufacturing method thereof, and camera module including same

Abstract

The present invention relates to a deformable image sensor, a manufacturing method thereof, and a camera module including same, the deformable image sensor comprising: an image sensor layer including an image sensor region in which a photoelectric conversion element is formed; a ground layer formed in contact with one side of the image sensor layer, which is opposite to the other side of the image sensor layer on which the image sensor region is formed; and a piezoelectric layer formed in contact with the other side of the ground layer, which is opposite to the side in contact with the image sensor layer, wherein the shape of the image sensor region is deformed according to the voltage applied to the ground layer and the piezoelectric layer. The present invention can mitigate tilt defects of the image sensor caused by incorrect calibration, peripheral light fall-off and focal shift of the image sensor due to the curvature of the upper surface of a lens unit, and warpage of the image sensor generated in the manufacturing process of the camera module.

Description

Deformable image sensor, manufacturing method thereof, and camera module including the same

[0001] The present invention relates to a deformable image sensor, a manufacturing method thereof, and a camera module including the same. More specifically, the invention relates to improving tilt defects in the image sensor, peripheral light reduction and focus distortion in the image sensor, and warping of the image sensor that occurs during the camera module manufacturing process.

[0002] Recently, as optical lenses and image sensors have become smaller and lighter, electronic devices incorporating miniaturized camera modules, such as those found in mobile terminals equipped with digital cameras, have become more common. This has led to a fierce competition to improve the functionality of camera modules. Consequently, there is a growing demand for technologies that can simultaneously miniaturize and enhance camera functionality.

[0003] Fig. 1 is an exploded perspective view showing a conventional camera module, and Fig. 2 is a cross-sectional view showing a conventional camera module.

[0004] Referring to FIGS. 1 and 2, a conventional camera module (10) may include a lens unit (200) composed of multiple lenses, a VCM (300) that controls the focal length of the lens unit (200), an IRCF (Infra-Red Cut off Filter, 400) that blocks infrared rays, an image sensor (100), an FPCB (Flexible PCB, 190), and an HTCC (High Temperature Co-fired Ceramic, 180) that fixes the image sensor (100) and connects the image sensor (100) to the FPCB (Flexible PCB, 190).

[0005] HTCC (180) is a multilayer microelectronic component manufactured using co-fired ceramics formed at high temperatures (approximately 1,600°C). It has a fixed mechanical shape and conduction, resistance, and dielectric materials are simultaneously fired, so it is used as a support structure and a hybrid integrated circuit connecting signal lines.

[0006] Referring to FIG. 2, the first connection part (181) of the HTCC (180) and the sensor pad (113) of the image sensor (100) are connected, and the second connection part (182) and the connection pad of the FPCB (190) are connected.

[0007] The lens unit (200) of the above camera module (10) guides the image light (incident light) received from the subject to the image sensor (100) having a photoelectric conversion element formed therein. At this time, the image light (incident light) passes through an IRCF (infrared blocking filter, 400) to exclude infrared light that is not recognized by the human eye, thereby reducing the difference between the image formed by the image sensor (100) and the recognition value by the human eye.

[0008] The above lens unit (200) may be composed of a plurality of optical lenses.

[0009] Conventional camera modules configured in this way have the following three problems.

[0010] First, during the adjustment process of aligning the planes of the lens unit (200) and the image sensor (100) parallel to each other, an incorrect adjustment may occur, resulting in a tilt defect in the light-receiving plane of the image sensor (100).

[0011] In the final inspection process performed after the camera module (10) is assembled, if the tilt defect is found, the assembled camera module (10) must be disassembled, which increases the manufacturing cost.

[0012] Second, light intensity reduction and focus distortion occur around the image sensor due to the curvature of the upper surface of the lens unit (200).

[0013] In image processing systems such as camera modules, a spherical camera lens is positioned on the light-receiving side of the image sensor. Due to spherical aberration of this camera lens, the pixels on the image sensor receive different amounts of light. For example, central and peripheral pixels have different focal lengths and experience peripheral light reduction, a phenomenon that occurs in almost all lenses.

[0014] To improve this, an image sensor with a concavely curved upper surface corresponding to the curve of the camera lens or a lens unit with an additional number of lenses in the lens unit or a light-receiving surface of the image sensor has been proposed.

[0015] However, the lens section, which has an increased number of lenses, has the problem of making it difficult to miniaturize the camera module and increasing manufacturing costs. Furthermore, image sensors with curved surfaces require the formation of photoelectric conversion elements on the concave surface, which increases the manufacturing cost of the image sensor. Furthermore, after being manufactured with a fixed curvature, it is impossible to compensate for deviations from the matching lens, which reduces the production yield of the camera module.

[0016] Third, warping of the image sensor occurs during the manufacturing process of the camera module.

[0017] Referring to FIG. 2, the image sensor (100) includes a number of sensor pads (113) to connect image signals and control signals to the HTCC (180).

[0018] In order to connect the sensor pad (113) and the first connection portion (181) of the HTCC (180), a flip chip process is used. Flip chip is a technology that directly fuses a semiconductor chip to a substrate at high temperature using a bump ball instead of the existing method of using a metal wire when mounting the semiconductor chip on the substrate. Compared to existing products, it is possible to make it smaller and lighter, has excellent thermal stability, low resistance, and a faster response speed, so it is being used more and more. However, in the process of fuse-welding the sensor pad (113) of the image sensor (100) and the first connection portion of the HTCC (180) at high temperature using a bump ball, warping of the image sensor (100) occurs.

[0019] Research and development of image sensors that can improve these problems is necessary.

[0020] The technical problem to be solved by the present invention is to resolve a tilt defect of an image sensor caused by misadjustment during an adjustment process to align the planes of a lens unit and an image sensor parallel to each other, to prevent a decrease in peripheral light quantity and focus distortion of an image sensor due to curvature of the upper surface of the lens unit, and to flatten a warpage of an image sensor caused during a process of mounting the image sensor to a camera module.

[0021] The deformable image sensor of the present invention for solving the above technical problem includes an image sensor layer including an image sensor region in which a photoelectric conversion element is formed, a ground layer formed in contact with a surface opposite to a surface on which the image sensor region is formed, and a piezoelectric layer formed in contact with the other surface of the ground layer, and the shape of the image sensor region can be deformed depending on a voltage applied to the ground layer and the piezoelectric layer.

[0022] In some embodiments of the present invention, the image sensor layer, the ground layer, and the piezoelectric layer may include a through hole formed by connecting openings installed in each of the image sensor layer, the ground layer, and the piezoelectric layer.

[0023] In some embodiments of the present invention, the opening may be formed around the perimeter of the image sensor area.

[0024] In some embodiments of the present invention, the image sensor layer may include a sensor pad that connects an image signal and a control signal.

[0025] In some embodiments of the present invention, the ground layer may be connected to a ground pad formed on the piezoelectric layer through a through hole.

[0026] In some embodiments of the present invention, the piezoelectric layer may include a tilt electrode that changes the tilt of the image sensor area.

[0027] In some embodiments of the present invention, the tilt electrode may be formed adjacent to the outside of the image sensor area.

[0028] In some embodiments of the present invention, the piezoelectric layer may include a deformable electrode that deforms the gradient inside the image sensor area.

[0029] In some embodiments of the present invention, the deformable electrodes may be arranged in a plurality of annular shapes sequentially surrounding the center of the image sensor area.

[0030] In some embodiments of the present invention, the number of deformable electrodes within the annular shape may be characterized by increasing as it moves away from the center.

[0031] The method for manufacturing a deformable image sensor of the present invention for solving the above technical problem may include the steps of preparing an image sensor layer including an image sensor region in which a photoelectric conversion element is formed and a piezoelectric wafer formed with a piezoelectric material, the step of depositing a ground layer on the image sensor layer and the piezoelectric wafer, the step of bonding the ground layer formed on the image sensor layer and the piezoelectric wafer, and the step of forming a piezoelectric layer including an electrode and a pad on the piezoelectric wafer.

[0032] In some embodiments of the present invention, the step of forming a through hole in the piezoelectric wafer may be further included prior to the step of depositing a ground layer on the piezoelectric wafer.

[0033] In some embodiments of the present invention, after the step of forming a piezoelectric layer including electrodes and pads on the piezoelectric wafer, the step of forming a through hole penetrating the image sensor layer, the ground layer, and the piezoelectric layer may be further included.

[0034] The camera module of the present invention for solving the above technical problem includes a lens unit, a VCM for moving the focal length of the lens unit, an image sensor for receiving light from the lens unit, a signal processing unit for performing a signal processing operation on a signal output from the image sensor, and a control unit for controlling the VCM, the image sensor, and the signal processing unit, wherein the control unit can control the image sensor to change the image sensor area.

[0035] In some embodiments of the present invention, the control unit can operate the tilt electrode of the image sensor to correct the inclination of the image sensor area.

[0036] In some embodiments of the present invention, the control unit may operate the deformable electrode of the image sensor to form the image sensor area to be concavely curved.

[0037] In some embodiments of the present invention, the control unit can operate the deformable electrode of the image sensor to correct warpage of the image sensor area.

[0038] In some embodiments of the present invention, the control unit can drive the tilt electrode and the deformation electrode using a test image formed by the same tilt test pattern corresponding to each of the tilt electrodes and the same deformation test pattern corresponding to each of the deformation electrodes.

[0039] According to the present invention, when a tilt defect of an image sensor occurs due to misadjustment, the assembled state is maintained and a simple correction process is performed to resolve the defect, thereby increasing production efficiency and reducing manufacturing costs. In addition, by preventing peripheral light reduction and focus distortion due to the curvature of the lens surface, the increase in cost can be minimized and the camera module can be made more high-performance. In addition, the yield in the production of a camera module can be increased by flattening the warpage of the image sensor that occurs during the manufacturing process of the camera module.

[0040] Figure 1 is an exploded perspective view showing a conventional camera module.

[0041] Fig. 2 is a cross-sectional view showing a conventional camera module.

[0042] FIG. 3 is a cross-sectional view showing a camera module according to one embodiment of the present invention.

[0043] FIG. 4 is a perspective view showing an image sensor according to one embodiment of the present invention.

[0044] FIG. 5 is a plan view of an image sensor according to one embodiment of the present invention.

[0045] Figure 6 is a cross-sectional view taken along the AA' cutting line of Figure 5.

[0046] Figure 7 is a cross-sectional view taken along the BB' cutting line of Figure 5.

[0047] Figure 8 is a rear view of an image sensor according to one embodiment of the present invention.

[0048] FIG. 9 is a rear view of an image sensor according to another embodiment of the present invention.

[0049] FIG. 10 is a drawing showing a method for assembling an image sensor according to one embodiment of the present invention.

[0050] FIG. 11 is a block diagram of a camera module including an image sensor according to one embodiment of the present invention.

[0051] Figure 12 is a test image that can be used to correct warpage in the image sensor area.

[0052] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0053] “And / or” includes each and every combination of one or more of the items mentioned.

[0054] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, operations, and / or elements mentioned.

[0055] Additionally, throughout the specification, when a part is said to be "connected" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly" or "electrically connected" with other members or components in between.

[0056] Additionally, throughout the specification, the description that each layer (film), region, pattern or structure is formed "on" or "under" the substrate, each layer (film), region, pad or pattern includes both being formed directly or through the interposition of another layer. The criteria for being on / over or under / under each layer are explained based on the drawings.

[0057] Additionally, expressions such as 'first, second', etc. are used only to distinguish between multiple components, and do not limit the order or other characteristics between the components.

[0058] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0059] A deformable image sensor according to the present invention, a method for manufacturing the same, and a camera module including the same are described with reference to drawings.

[0060] FIG. 3 is a cross-sectional view showing a camera module according to one embodiment of the present invention.

[0061] Referring to FIG. 3, a camera module according to one embodiment of the present invention has a structure in which a ground layer (120) and a piezoelectric layer (130) are added to an image sensor layer (110) including components of a conventional image sensor (100).

[0062] The electrode formed to drive the piezoelectric layer (130) is connected to a piezoelectric pad (133), and the piezoelectric pad (133) can be connected to the HTCC (180) via a wire (134).

[0063] The above piezoelectric layer (130) can be formed using a piezoelectric crystal having a piezoelectric effect. The piezoelectric effect is a mechanical change that occurs in an object when an electrical signal is applied. As a piezoelectric crystal having this piezoelectric effect, quartz, Roselle salt, barium titanate (BaTiO3), artificial ceramics, etc. can be used to form the piezoelectric layer (130).

[0064] Among the artificial ceramic materials that are widely used, especially those called piezoelectric ceramics, PZT (lead zirconium titanate) or PMN-PT (lead magnesium niobate-lead titanate) are preferable.

[0065] The piezoelectric effect is expressed as follows:

[0066] D = εE

[0067] Here, D is the electric displacement field, ε is the permittivity, and E is the magnitude of the electric field. Therefore, the displacement can change depending on the magnitude of the voltage applied to the piezoelectric layer (130).

[0068] The above HTCC (180) is a multilayer microelectronic component manufactured using co-fired ceramic formed at a high temperature (approximately 1,600°C). Since it has a fixed mechanical shape and conductive, resistive, and dielectric materials are simultaneously fired, it is used as a hybrid integrated circuit connecting a support structure and signal lines.

[0069] In one embodiment of the present invention, the image sensor (100) is used for support and connection, but is not limited thereto, and may be replaced with other electronic components capable of performing the above-described support and connection functions.

[0070] FIG. 4 is a perspective view showing an image sensor according to one embodiment of the present invention, wherein (a) is a perspective view of the image sensor, and (b) is a bottom exploded perspective view.

[0071] Referring to FIG. 4, a deformable image sensor (100) according to one embodiment of the present invention includes an image sensor layer (110) including an image sensor region (111) in which a photoelectric conversion element is formed, a ground layer (120) formed in contact with a surface opposite to a surface on which the image sensor region (111) is formed, and a piezoelectric layer (130) formed in contact with the other surface of the ground layer (120), and the shape of the image sensor region can be deformed depending on a voltage applied to the ground layer (120) and the piezoelectric layer (130).

[0072] In addition, a deformable image sensor (100) according to one embodiment of the present invention may include a through hole (150) formed by connecting openings (115, 125, 135) installed in the image sensor layer (110), the ground layer (120), and the piezoelectric layer (130), respectively.

[0073] The first opening (115) may be formed around the perimeter of the image sensor region (111) of the image sensor layer (110). Accordingly, the second opening (125) of the ground layer (120) and the third opening (135) of the piezoelectric layer (130) may also be formed around the perimeter of a position surrounding the image sensor region (111).

[0074] In this way, since the image sensor area (111) is not completely fixed to the periphery of the image sensor (100) but is partially separated, the shape of the image sensor area (111) can be easily modified.

[0075] FIG. 5 is a plan view of an image sensor according to one embodiment of the present invention, FIG. 6 is a cross-sectional view taken along line AA' of FIG. 4, and FIG. 7 is a cross-sectional view taken along line BB' of FIG. 4.

[0076] Referring to FIGS. 5 to 7, the image sensor layer (110) may include a sensor pad (113) that connects an image signal and a control signal.

[0077] The above sensor pad (113) can be formed on the same surface as the surface on which the image sensor region (111) is formed in order to connect the photoelectric conversion element formed on the image sensor layer (110) and the circuit that controls the photoelectric conversion element to the HTCC (180).

[0078] At this time, since the sensor pad (113) should not interfere with the path of incident light while being connected to the HTCC (180), it can be formed on the outer side of the image sensor layer (110) while avoiding the image sensor region (111). That is, the image sensor region (111) can be formed in the center of the image sensor layer (110), the first opening (115) can be formed in a shape that surrounds the periphery of the image sensor region (111), and the sensor pad (113) can be formed in a shape that surrounds the first opening (115).

[0079] At this time, the image sensor area (111) may be fixed, and the first opening (115) may be disconnected without completely covering the image sensor area (111) so that it can be connected to the sensor pad (113). A pattern connecting the image sensor area (111) and the sensor pad (113) may be formed in the disconnected area.

[0080] The above ground layer (120) can be connected to the ground pad (133c) of the piezoelectric layer (130) through a through hole (137) formed in the piezoelectric layer (130).

[0081] Referring to Fig. 6, a ground pad (133c) may be formed on the piezoelectric layer (130). The ground pad (133c) may be connected to the ground layer (120) through a through hole (137) formed in the piezoelectric layer (130).

[0082] The above ground pad (133c) can be connected to the ground terminal of the HTCC (180) by a wire (134) so ​​that the ground layer (120) can be at ground potential.

[0083] Figure 8 is a rear view of an image sensor according to one embodiment of the present invention.

[0084] Referring to FIGS. 7 and 8, the piezoelectric layer (130) may include a tilt electrode (132a) that changes the tilt of the image sensor area (111), and the tilt electrode (132a) may be formed adjacent to the outside of the image sensor area (111).

[0085] The above tilt electrode (132a) can be connected to a tilt pad (133a) formed around the piezoelectric layer (130) and a pattern formed on the piezoelectric layer (130). For example, a tilt electrode (132a) indicated by Q11 can be connected to a tilt pad (133a) indicated by P11.

[0086] In this way, a piezoelectric layer (130) can be formed between the tilt electrode (132a) and the ground layer (120). The displacement of the piezoelectric layer (130) can vary due to the piezoelectric effect that occurs depending on the voltage applied to the tilt electrode (132a).

[0087] Since the tilt electrode (132a) is formed to correct the overall inclination of the image sensor area (111) of the image sensor (100), it is preferably installed on the outside of the image sensor area (111). In one embodiment of the present invention, it is formed adjacent to the outside of the four corners of the image sensor area (111) to avoid the third opening (135) for forming the through hole (150).

[0088] When formed in this manner, each side of the rectangular image sensor area (111) can be tilted separately. For example, in order to tilt the left side of the image sensor area (111) in the vertical direction based on FIG. 8, the tilting can be controlled by varying the voltage applied to the tilt electrodes (132a) indicated by Q41 and Q31 at two corners of the left side.

[0089] The above piezoelectric layer (130) may include a deformation electrode (132b) that deforms the gradient inside the image sensor area (111).

[0090] In addition, the above-described deformation electrode (132b) can be arranged in a plurality of annular shapes that sequentially surround the center of the image sensor area (111).

[0091] Referring to FIG. 8, four deformable electrodes (132b) indicated as Q12, Q22, Q32 and Q42 may be formed inside the shape of the first circle surrounding the center of the image sensor area (111), and deformable electrodes (132b) indicated as Q13, Q23, Q33 and Q43 may be formed inside the shape of the second circle surrounding the shape of the first circle.

[0092] The above-described deformation electrode (132b) can be connected to a deformation pad (133b) formed around the piezoelectric layer (130) and a pattern formed on the piezoelectric layer (130). For example, the deformation electrodes (132b) indicated by Q12 and Q13 can be connected to the deformation pads (133b) indicated by P12 and P13, respectively.

[0093] When the voltage of the four deformation electrodes (132b) indicated as Q12, Q22, Q32 and Q42 within the shape of the first circle is fixed and the voltage is applied to the deformation electrodes (132b) indicated as Q13, Q23, Q33 and Q43 within the shape of the second circle, only the displacement of the periphery of the image sensor area (111) changes, so that the gradient can be deformed into a protruding shape. If only the periphery of the image sensor area (111) protrudes, a light-receiving surface of a concave shape can be formed.

[0094] Additionally, the number of deformation electrodes (132b) within the above-mentioned annular shape may increase as it moves away from the center.

[0095] FIG. 9 is a rear view of an image sensor according to another embodiment of the present invention.

[0096] Referring to FIG. 9, one deformable electrode (132b) may be formed inside the shape of the first circle surrounding the center of the image sensor area (111), four deformable electrodes (132b) may be formed inside the shape of the second circle surrounding the shape of the first circle, and eight deformable electrodes (132b) may be formed inside the shape of the third circle surrounding the shape of the second circle.

[0097] The voltage of the deformation electrode (132b) inside the shape of the first circle is fixed, and by controlling the voltage of the deformation electrode (132b) inside the shape of the second circle and the deformation electrode (132b) inside the shape of the third circle, only the displacement of the periphery of the image sensor area (111) changes, so that a gradient can be formed in a protruding shape. In this way, if only the periphery of the image sensor area (111) protrudes, a light-receiving surface in a concave shape can be formed.

[0098] In this way, compensating for tilting of the image sensor area (111) and forming a concave light-receiving surface can be achieved by controlling the tilt electrode (132a) and the deformation electrode (132b) as described above.

[0099] In addition to the above tilt compensation and concave deformation of the light-receiving surface, the deformation electrode (132b) can be formed more densely to compensate for warpage occurring within the image sensor area (111).

[0100] In order to correct for warpage occurring in a specific area within the image sensor area (111), it is desirable to ensure that the deformation electrode (132b) is evenly distributed within the image sensor area (111).

[0101] Referring to FIG. 9, the number of deformation electrodes (132b) formed within the second annular shape is 4 and the number of deformation electrodes (132b) formed within the third annular shape is 8, so the number of deformation electrodes (132b) formed within the third annular shape is doubled, and at this time, the area of ​​each deformation electrode (132b) can be similar.

[0102] In this way, when the deformation electrode (132b) is formed evenly with a similar area within the image sensor region (111), when bending occurs within the image sensor region (111), the deformation electrode (132b) formed in the part where the bending occurs can be controlled and corrected.

[0103] FIG. 10 is a drawing showing a method for assembling an image sensor according to one embodiment of the present invention.

[0104] First, referring to (a) of FIG. 10, a method for assembling an image sensor according to the present invention may include a step of preparing an image sensor layer (110) including an image sensor region in which a photoelectric conversion element is formed and a piezoelectric wafer formed of a piezoelectric material.

[0105] The above image sensor layer (110) can be prepared by performing the same steps as the process of forming a conventional image sensor (100).

[0106] The above piezoelectric wafer may use a piezoelectric crystal having a piezoelectric effect. Such piezoelectric crystals may include quartz, Roselle salt, barium titanate (BaTiO3), and artificial ceramics. Among the artificial ceramic materials widely used as piezoelectric ceramics, PZT (lead zirconium titanate) and PMN-PT (lead magnesium niobate-lead titanate) are preferred.

[0107] At this time, a through hole (137) can be formed in the piezoelectric wafer.

[0108] Referring to Fig. 6, the ground pad (133c) formed on the piezoelectric layer (130) and the ground layer (120) can be connected through the through hole (137).

[0109] Referring to (b) of the following Figure 10, the method for assembling an image sensor according to the present invention may include a step of depositing a ground layer (120) on the image sensor layer (110) and the piezoelectric wafer, respectively.

[0110] After the above ground layer (120) is deposited, a polishing process can be performed to achieve an appropriate thickness and reduce surface roughness.

[0111] Referring to (c) of the following Figure 10, the ground layer (120) of the image sensor layer (110) and the ground layer (120) of the piezoelectric wafer can be bonded. At this time, the ground layers (120) formed on the image sensor layer (110) and the piezoelectric wafer, respectively, can be formed into a single combined ground layer (120).

[0112] Referring to (d) of the following Figure 10, a piezoelectric layer (130) including electrodes and pads can be formed on the piezoelectric wafer.

[0113] A piezoelectric layer (130) according to the present invention can be formed by forming two piezoelectric electrodes (132), namely a tilt electrode (132a) and a deformation electrode (132b), and three piezoelectric pads (133), namely a tilt pad (133a), a deformation pad (133b), and a ground pad (133c) on the above piezoelectric wafer.

[0114] The above piezoelectric electrode (132) and piezoelectric pad (133) can be formed by performing a deposition process and a lift-off process.

[0115] After the step of forming a piezoelectric layer (130) including electrodes and pads on the piezoelectric wafer, a step of forming a through hole (150) penetrating the image sensor layer (110), the ground layer (120), and the piezoelectric layer (130) may be further included. The through hole (150) may be formed by performing a laser processing process.

[0116] The above deformable image sensor can be used in a camera module according to one embodiment of the present invention.

[0117] FIG. 11 is a block diagram of a camera module including an image sensor according to one embodiment of the present invention.

[0118] Referring to FIG. 11, a camera module (10) applying an image sensor (100) according to one embodiment of the present invention includes a lens unit (200), a VCM (300) that moves the focal length of the lens unit (200), an image sensor (100) that receives light from the lens unit (200), a signal processing unit (193) that performs a signal processing operation on a signal output from the image sensor (100), and a control unit (195) that controls the VCM (300), the image sensor (100), and the signal processing unit (193), and the control unit (195) can control the image sensor (100) to change the image sensor area (111).

[0119] The lens unit (200) can guide image light (incident light) from a subject to the image sensor area (111) of the image sensor (100) and can be composed of a plurality of optical lenses.

[0120] The above control unit (195) may include a CPU (central processing unit), a storage device including memory, and peripheral circuits. The control unit (195) may control the operation of the camera module (10) by the CPU executing a program stored in the storage device.

[0121] The signal processing unit (193) can perform various types of signal processing using image data acquired from the image sensor (100), and can analyze and process the image signal according to the specifications required by the control unit (195) of the camera module (10).

[0122] The signal processing unit (193) may include a DSP (Digital Signal Processor) that processes digital signals and a memory.

[0123] Referring to FIG. 4, an image sensor (100) included in a camera module (10) according to one embodiment of the present invention includes an image sensor layer (110) including an image sensor region (111) in which a photoelectric conversion element is formed, a ground layer (120) formed in contact with a surface on the other side opposite to a surface on which the image sensor region (111) is formed, and a piezoelectric layer (130) formed in contact with the other surface of the ground layer (120), and the shape of the image sensor region can be deformed depending on a voltage applied to the ground layer (120) and the piezoelectric layer (130).

[0124] The step of obtaining a control value that appropriately transforms the image sensor area (111) in advance is defined as a setting step.

[0125] Figure 12 is a test image according to one embodiment of the present invention.

[0126] A test image (500) can be used to perform the setting step of the camera module (10) according to the present invention.

[0127] Referring to FIG. 12, the test image (500) can be formed of identical tilt test patterns (510) each corresponding to the tilt electrode (132a) and identical deformation test patterns (520) each corresponding to the deformation electrode (132b).

[0128] The tilt test pattern (510) may be formed in the same shape at positions corresponding to the four corners where the tilting electrodes (132a) are formed, and the deformation test pattern (520) may be formed in the same shape at positions corresponding to the deformation electrodes (132b) formed by arranging a plurality of annular shapes.

[0129] The above control unit (195) can perform a setting mode by controlling the tilt electrode (132a) and the deformation electrode (132b) using the test image (500).

[0130] First, the control unit (195) can operate the tilt electrode (132a) of the image sensor (100) to correct the inclination of the image sensor area (111).

[0131] First, the camera module (10) can be assembled by performing the assembly and inspection steps of the camera module (10) in the same manner as the manufacturing method of the conventional camera module (10).

[0132] When assembled as described above, the components on the path of incident light, including the lens unit (200) and the image sensor (100), are adjusted, and the image sensor (100) can also be aligned at an angle parallel to a plane perpendicular to the path of incident light.

[0133] In addition, the above control unit (195) can appropriately control the VCM (300) to focus on the subject.

[0134] However, during the adjustment process to align the planes of the lens unit (200) and the image sensor (100) parallel to each other, an incorrect adjustment may occur, resulting in a tilt defect in the light-receiving plane of the image sensor (100).

[0135] To resolve this tilting defect, a test image (500) such as FIG. 12 can be used.

[0136] The control unit (195) can analyze the difference between each tilt test pattern (510) in the image data of the test image (500) acquired from the image sensor area (111) by controlling the signal processing unit (193).

[0137] Since the above tilt test pattern (510) is formed corresponding to the four corners where the tilt electrodes (132a) are formed, the tilt electrodes (132a) can be controlled so that the images of the four tilt test patterns (510) are analyzed and the respective analysis data are matched.

[0138] Since the corner portion where tilt defect occurs in the image sensor area (111) has a different focus compared to the corner portion where no defect occurs, the tilt electrode (132a) can be controlled to compensate for the changed focus.

[0139] The displacement of the piezoelectric layer (130) can vary due to the piezoelectric effect that occurs depending on the voltage applied to each tilt electrode (132a).

[0140] In this way, the tilt electrode (132a) can correct the overall inclination of the image sensor area (111).

[0141] Second, the control unit (195) can operate the deformation electrode (132b) of the image sensor (100) to form the image sensor area (111) to be concavely curved.

[0142] First, the camera module (10) can be assembled by performing the assembly and inspection steps of the camera module (10) in the same manner as the manufacturing method of the conventional camera module (10).

[0143] When assembled as described above, the components on the path of incident light, including the lens unit (200) and the image sensor (100), are adjusted so that the image sensor (100) can also be aligned at an angle parallel to a plane perpendicular to the path of incident light.

[0144] In addition, the above control unit (195) can appropriately control the VCM (300) to focus on the subject.

[0145] However, peripheral light reduction and focus distortion may occur due to the curvature of the top surface of the shooting lens (200).

[0146] To solve this, the light-receiving surface of the image sensor area (111) can be formed to be concavely curved so as to have a curved shape.

[0147] To transform it into such a curved shape, a test image (500) such as FIG. 12 can be used.

[0148] The control unit (195) can analyze the difference between each deformation test pattern (520) in the image data of the test image (500) acquired from the image sensor area (111) by controlling the signal processing unit (193).

[0149] Since the above deformation test pattern (520) is formed in the same shape at positions corresponding to the deformation electrodes (132b) that are formed by being arranged in a plurality of circular shapes, the deformation electrodes (132b) can be controlled by analyzing the images of the pieces in the center and the pieces in the peripheral portion of the deformation test pattern (520).

[0150] Since peripheral light quantity reduction and focus distortion occur due to surface curvature, the deformation electrode (132b) can be controlled to compensate for this so that the fragment images of the peripheral and central parts have the same light quantity and focus.

[0151] The piezoelectric layer (130) can shrink or expand due to the piezoelectric effect that occurs depending on the voltage applied to each deformation electrode (132b).

[0152] In this way, the above-mentioned deformation electrode (132b) can be formed so that the image sensor area (111) is concavely curved.

[0153] Third, the control unit (195) can operate the deformation electrode (132b) of the image sensor (100) to correct the warpage of the image sensor area (111).

[0154] First, the camera module (10) can be assembled by performing the assembly and inspection steps of the camera module (10) in the same manner as the manufacturing method of the conventional camera module (10).

[0155] When the assembly is completed as described above, the parts on the path of the incident light, including the lens unit (200) and the image sensor (100), are adjusted so that the image sensor (100) can also be aligned at an angle parallel to the plane perpendicular to the path of the incident light.

[0156] In addition, the above control unit (195) can appropriately control the VCM (300) to focus on the subject.

[0157] However, warping of the image sensor area (111) may occur during the manufacturing process of the camera module (10).

[0158] To correct the warpage of the image sensor area (111) that occurs in this way, a test image (500) such as FIG. 12 can be used.

[0159] The control unit (195) can analyze the difference between each deformation test pattern (520) in the image data of the test image (500) acquired from the image sensor area (111) by controlling the signal processing unit (193).

[0160] Since the above deformation test pattern (520) is formed in the same shape at a position corresponding to the deformation electrode (132b) formed in a plurality of shapes of similar size, the deformation electrode (132b) can be controlled so that the analysis data of each piece of the deformation test pattern (520) matches by analyzing the adjacent image.

[0161] The piezoelectric layer (130) can shrink or expand due to the piezoelectric effect that occurs depending on the voltage applied to each deformation electrode (132b).

[0162] In this way, the above-described deformation electrode (132b) can correct the bending of the image sensor area (111).

[0163] Depending on the environment in which the image sensor according to the present invention is applied, all three of the above setting modes may be performed, some may be omitted, or may be performed in a changed order.

[0164] However, it is desirable that the first slope correction, the second curved shape formation, and the third bending correction are performed sequentially in the order of the area to be deformed being large.

[0165] The amount and range of deformation of the shape of the image sensor area according to the voltage applied to the ground layer (120) and the piezoelectric layer (130) is first simulated for each voltage of each electrode, and the data obtained is then libraryized and used in the setting mode.

[0166] Data corresponding to the voltage magnitude and displacement amount for each piezoelectric electrode (132) can be generated. In this case, in order to efficiently include cases where multiple piezoelectric electrodes (132) are driven simultaneously, the deformed shape can be mathematically calculated using Zernike polynomials.

[0167] Zernike polynomials are used in the expression and correction of wavefront errors, and can be used to effectively model and analyze complex characteristics of optical systems.

[0168] As described above, the image sensor layer includes an image sensor region in which a photoelectric conversion element is formed, a ground layer formed in contact with a surface opposite to one surface in which the image sensor region is formed, and a piezoelectric layer formed in contact with the other surface of the ground layer, and the shape of the image sensor region is deformed according to a voltage applied to the ground layer and the piezoelectric layer, thereby improving tilt defects of the image sensor, reduction in the amount of light and focus distortion in the peripheral portion of the image sensor due to curvature of the upper surface of the lens portion, and warping of the image sensor that occurs during the manufacturing process of the camera module.

[0169] In particular, by not using the existing methods used to resolve the field curvature of the lens section, such as adding the number of lenses in the lens section or manufacturing the image sensor itself in a concave curved shape, it is possible to manufacture a high-quality camera module capable of responding to field curvature without increasing the size and at a low cost.

[0170] Although the present invention has been described as above, those skilled in the art will recognize that the present invention can be implemented in other forms while maintaining the technical spirit and essential features of the present invention.

[0171] The scope of the present invention will be defined by the patent claims, but it should be interpreted that not only the configuration directly derived from the description of the patent claims, but also all changes or modified forms derived from equivalent configurations are included in the scope of the present invention.

Claims

1. An image sensor layer including an image sensor region in which a photoelectric conversion element is formed; A ground layer formed in contact with the other side of the surface opposite to the one side where the image sensor area is formed; and Including a piezoelectric layer formed in contact with the other surface of the above ground layer, A deformable image sensor in which the shape of the image sensor area is deformed according to the voltage applied to the ground layer and the piezoelectric layer.

2. In paragraph 1, A deformable image sensor comprising a through hole formed by connecting openings formed in each of the image sensor layer, the ground layer, and the piezoelectric layer.

3. In paragraph 1, A deformable image sensor, wherein the piezoelectric layer includes at least one of a tilt electrode that changes the tilt of the image sensor area and a deformation electrode that changes the gradient inside the image sensor area.

4. In paragraph 3, A deformable image sensor in which the above-mentioned deformable electrodes are arranged in a plurality of annular shapes sequentially surrounding the center of the image sensor area.

5. In paragraph 4, A deformable image sensor, characterized in that the number of deformable electrodes within the above annular shape increases as it moves away from the center.

6. A step of preparing an image sensor layer including an image sensor region in which a photoelectric conversion element is formed and a piezoelectric wafer formed of a piezoelectric material; A step of depositing a ground layer on each of the image sensor layer and the piezoelectric wafer; A step of bonding the image sensor layer and the ground layer formed on the piezoelectric wafer; A method for manufacturing a deformable image sensor, comprising a step of forming a piezoelectric layer including electrodes and pads on the piezoelectric wafer.

7. In paragraph 6, A method for manufacturing a deformable image sensor, further comprising a step of forming a through hole in the piezoelectric wafer prior to the step of depositing a ground layer on the piezoelectric wafer.

8. Lens section; VCM for moving the focal length of the above lens unit; An image sensor that receives light from the lens unit; A signal processing unit that performs a signal processing operation on a signal output from the image sensor; and It includes a control unit that controls the VCM, the image sensor, and the signal processing unit, A camera module in which the control unit controls the image sensor to transform the image sensor area.

9. In paragraph 8, The above image sensor, An image sensor layer including an image sensor region in which a photoelectric conversion element is formed; A ground layer formed in contact with the other side of the surface opposite to the one side where the image sensor area is formed; and Including a piezoelectric layer formed in contact with the other surface of the above ground layer, A camera module in which the shape of the image sensor area is deformed according to the voltage applied to the ground layer and the piezoelectric layer.

10. In the 8th paragraph, the control unit operates the tilt electrode of the image sensor to correct the inclination of the image sensor area, or operates the deformation electrode of the image sensor to form the image sensor area to be concavely curved or correct the warpage of the image sensor area, a camera module.

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