Manufacturing method of curved surface image sensor chip

Abstract

The invention provides a manufacturing method of a curved surface image sensor, which comprises the following steps of: forming a plurality of separated photosensitive unit arrays on a bendable substrate, forming a bending part by metal wires communicated with the photosensitive unit arrays through pre-pressing treatment, and forming a curved surface by the plurality of separated pixel unit arrays through bending the substrate. Therefore, metal wire breakage caused by inconsistent spacing of the photosensitive unit arrays of different view fields is avoided, the method can be uniformly applied to the manufacturing process of concave chips and convex chips, the process difficulty of the curved surface image sensor chip is effectively reduced, the product yield is improved, the manufacturing cost is reduced, and the production efficiency is improved. The light can be substantially vertically irradiated to the photosensitive unit array, so that field curvature aberration is avoided, and the imaging performance of the camera module is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and more specifically, to a method for manufacturing a curved image sensor chip. Background Art

[0002] Currently, image sensors have been widely used in various fields that require digital imaging, such as mobile phones, laptops, tablet computers and other portable electronic devices, as imaging elements in camera modules.

[0003] As portable electronic devices become increasingly thinner and lighter, the distance between the lens and the image sensor in the camera module is designed to be closer and closer in order to reduce the size or thickness. However, if the distance between the lens and the image sensor is too close, the incident light cannot be refracted by the lens and irradiated vertically on the flat image sensor, that is, the refracted light and the normal of the photosensitive unit in the image sensor are at a certain angle, which is particularly obvious at the edge of the image sensor. In other words, when shooting an object on a plane perpendicular to the optical axis, the image formed by the lens is not in an image plane, but on a curved surface symmetrical with the optical axis. This imaging defect is called field curvature. Field curvature is a kind of aberration. When taking pictures with a lens with field curvature, when the image is focused to the center of the picture, the image will be blurred around the picture, and when the image is focused to the surroundings, the image in the center of the picture will be blurred. Therefore, it is impossible to obtain a clear image at the center and around the picture on a flat image plane. In the field of image sensors, the vast majority of chips are planar chips, which cannot solve the optical field curvature problem, preventing light from vertically incident on the chip's non-central field of view, causing the light received by the chip to become weaker, and the overall optical performance of the lens to deteriorate.

[0004] like Figure 1The curved image sensor chip 102 shown can adapt to the optical path difference problem of each field of view, so that the light passing through the lens 101 is generally vertically incident on the photosensitive area, basically avoiding the field curvature aberration, so that the camera module can play a better performance. However, the curved image sensor chip is not popular, mainly due to the difficulty in manufacturing. The existing manufacturing method usually forms a plurality of separate photosensitive unit arrays 104 on a bendable substrate 103, and the photosensitive unit arrays 104 are connected to each other through metal wires 105 for signal transmission, and then the substrate 103 is bent so that the plurality of separate pixel unit arrays 104 form a concave surface facing the lens 101. When the chip 102 is bent, the distance between the photosensitive unit arrays 104 of different fields of view cannot be kept consistent, the spacing of the photosensitive unit arrays of the central field of view is too wide, and the spacing of the photosensitive unit arrays of the edge field of view is too narrow. In the process of chip bending, the existing metal material cannot adapt to the stress of different bending angles, which can easily cause the metal wire 105 to break, thereby making the chip scrapped. Therefore, the existing curved image sensor chip manufacturing method faces technical problems that need to be solved urgently, such as greater process difficulty, lower product yield, and higher manufacturing cost. Summary of the invention

[0005] The object of the present invention is to provide a method for manufacturing a curved image sensor, thereby reducing the process difficulty of the curved image sensor chip, improving the product yield, and reducing the manufacturing cost.

[0006] Based on the above considerations, the present invention provides a method for manufacturing a curved image sensor chip, comprising: forming a plurality of separate photosensitive unit arrays on a flexible substrate, wherein the photosensitive unit arrays are connected to each other through metal wires; forming a bending portion of the metal wires through a pre-pressing treatment; and forming a curved surface by bending the substrate.

[0007] Preferably, after the step of forming the curved surface, the curvature of the bent portion of the metal wire in the central field of view of the chip is smaller than the curvature of the bent portion of the metal wire in the edge field of view.

[0008] Preferably, in the pre-pressing step, the pre-pressing pressures of the central field of view and the edge field of view are controlled so that the curvature of the bent portion of the metal wire in the central field of view is smaller than the curvature of the bent portion of the metal wire in the edge field of view.

[0009] Preferably, in the step of bending the substrate, the curvature of the metal wire bending portion in the central field of view is smaller than the curvature of the metal wire bending portion in the edge field of view by controlling the stretching of the metal wire bending portion in the central field of view and / or the retraction of the metal wire bending portion in the edge field of view.

[0010] Preferably, the angle between the normals of any two photosensitive unit arrays in the central field of view is no greater than 5°.

[0011] Preferably, the normal angle between any two photosensitive unit arrays in the edge field of view is no more than 3°.

[0012] Preferably, the pre-pressing step includes: performing hydraulic pressure treatment on the surface of the chip.

[0013] Preferably, the step of bending the substrate comprises: bending and shaping the substrate by a mold.

[0014] Preferably, after the step of forming the curved surface, the length of the metal wires between adjacent photosensitive unit arrays is greater than 1.5 times the spacing between adjacent photosensitive unit arrays.

[0015] Preferably, the bending direction of the metal wire bending portion is towards the substrate or away from the substrate.

[0016] Preferably, the bending directions of all the metal wire bending portions between the photosensitive unit arrays are consistent.

[0017] Preferably, the metal lines between the photosensitive unit arrays in each row and the metal lines between the photosensitive unit arrays in each column are not in the same metal layer.

[0018] Preferably, the extension direction of the metal lines between the photosensitive unit arrays in each row is perpendicular to the extension direction of the metal lines between the photosensitive unit arrays in each column.

[0019] Preferably, after the step of forming the curved surface, the method further includes: filling a medium with low light transmittance between the plurality of separated photosensitive unit arrays.

[0020] Preferably, each of the photosensitive unit arrays includes at least one photosensitive unit.

[0021] Preferably, the photosensitive unit includes a pixel unit, a filter film located on the pixel unit, and a microlens located on the filter film.

[0022] Preferably, the step of forming a plurality of separate photosensitive unit arrays includes: a. preparing a plurality of pixel unit arrays, a dielectric layer located on the plurality of pixel unit arrays, and metal wires distributed in the dielectric layer for connecting the plurality of pixel unit arrays on a first surface of a first substrate; b. forming a second substrate on the dielectric layer, the second substrate comprising a bendable material; c. thinning the first substrate to a predetermined thickness from the second surface of the first substrate; d. forming a filter film array and a microlens array corresponding to the plurality of pixel unit arrays from the second surface of the first substrate, each pixel unit array and the corresponding filter film array and microlens array together constitute a photosensitive unit array; and e. etching the first substrate from the second surface of the first substrate, so that the first substrate does not exist between the plurality of pixel unit arrays, and the remaining thickness of the dielectric layer is within a predetermined thickness range; wherein the order of step d and step e is interchangeable.

[0023] Preferably, the curved surface image sensor chip is a back-illuminated image sensor chip.

[0024] Preferably, the curved surface is a concave surface facing the lens or a convex surface facing the lens.

[0025] Preferably, the curved surface is a spherical surface or an aspherical surface.

[0026] The manufacturing method of the curved image sensor of the present invention forms a plurality of separated photosensitive unit arrays on a bendable substrate, firstly forms a bending portion of the metal wires connecting the photosensitive unit arrays through a pre-pressing process, and then forms a curved surface by bending the substrate, thereby avoiding the breakage of the metal wires caused by the inconsistent spacing of the photosensitive unit arrays in different fields of view. The method can be uniformly applied to the manufacturing process of concave chips and convex chips, effectively reducing the process difficulty of the curved image sensor chip, improving the product yield, reducing the manufacturing cost, and realizing that the light can be irradiated roughly vertically to the photosensitive unit array, thereby avoiding the field curvature aberration and improving the imaging performance of the camera module. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0028] Figure 1 is a schematic diagram of a curved image sensor chip in the prior art; Figure 2 It is a flow chart of the method for manufacturing a curved image sensor chip of the present invention; Figure 3 is a schematic diagram of a curved image sensor chip according to an embodiment of the present invention; Figure 4is a schematic diagram of a curved image sensor chip according to another embodiment of the present invention; Figure 5 for Figure 3 Partial stereogram of area A in the middle edge field of view; Figure 6 for Figure 3 Partial side view of area A in the middle edge field of view; Figure 7 for Figure 3 A partial stereogram of the central field of view B area; Figure 8 for Figure 3 Partial side view of area B in the central field of view; Fig. 9 for Figure 4 A local stereogram of the A' region in the middle edge field of view; Fig.10 for Figure 4 Partial side view of the A' region in the middle edge field of view; Fig.11 for Figure 4 A partial stereogram of the central field of view B' area; Fig.12 for Figure 4 Partial side view of the B' area in the center field of view.

[0029] In the drawings, the same or similar reference numerals denote the same or similar devices (modules) or steps throughout different drawings. Implementation

[0030] In order to solve the above-mentioned problems in the prior art, the present invention provides a method for manufacturing a curved image sensor. After forming a plurality of separate photosensitive unit arrays on a flexible substrate, a pre-pressing treatment is first performed to form a bending portion of the metal wire connecting the photosensitive unit arrays, and then the substrate is bent to form a curved surface of the plurality of separate pixel unit arrays.

[0031] In the following specific description of the preferred embodiments, reference will be made to the attached drawings which constitute a part of the present invention. The attached drawings show by way of example specific embodiments that can implement the present invention. The illustrative embodiments are not intended to be exhaustive of all embodiments according to the present invention. It will be appreciated that other embodiments may be utilized, and structural or logical modifications may also be made without departing from the scope of the present invention. Therefore, the following specific description is not restrictive, and the scope of the present invention is limited by the appended claims.

[0032] like Figure 2As shown, the present invention provides a method for manufacturing a curved image sensor chip, comprising: forming a plurality of separate photosensitive unit arrays on a bendable substrate, wherein the photosensitive unit arrays are connected to each other through metal wires; forming a bending portion of the metal wires through a pre-pressing process; and forming a curved surface by bending the substrate.

[0033] Figure 3 The structure and principle of a curved image sensor chip according to an embodiment of the present invention are shown. The curved image sensor chip 202 includes a substrate 203 and a plurality of separate photosensitive unit arrays 204 located on the substrate 203, wherein each of the plurality of separate photosensitive unit arrays 204 includes at least one photosensitive unit 207 (see Figure 5-Figure 8 ).

[0034] Specifically, the substrate 203 includes a bendable material, such as a flexible organic polymer material such as polyimide, and therefore, the substrate 203 is bendable, thereby allowing the plurality of separated photosensitive unit arrays 204 to form a curved surface, and the concave surface facing the lens 201 is taken as an example. It should be noted that the bendable referred to herein means that under a certain external force, the substrate 203 is prone to appropriate deformation, so as to drive the relative positions of the plurality of separated photosensitive unit arrays 204 on the substrate 203 to change, while the structural connection between the substrate 203 and each photosensitive unit array 204 remains basically unchanged.

[0035] Field of View (FOV) refers to the maximum area that the image sensor in the imaging system can sense. The area close to the optical axis of the lens can be called the central field of view, and the area far from the optical axis of the lens can be called the peripheral field of view. There is no uniform standard for the division of the central field of view and the peripheral field of view. For example, the 1 / 2 area close to the optical axis of the lens, that is, the 0.5 field of view, can be called the central field of view, and the 1 / 2 area far from the optical axis of the lens, that is, the 0.5-1.0 field of view, can be called the peripheral field of view. Figure 3 In the illustrated embodiment, the edge viewing field A region and the center viewing field B region are only approximate divisions, which are used as examples for detailed description. Figure 5 , Figure 6 They are Figure 3 Partial stereogram and side view of area A in the middle edge field of view; Figure 7 , Figure 8 They are Figure 3 Partial stereoscopic and side views of area B in the central field of view.

[0036] It can be understood by those skilled in the art that Figure 3The number of photosensitive unit arrays 204 is only an example. In actual applications, the number of photosensitive unit arrays 204 in the curved image sensor chip, the number of photosensitive units 207 in each photosensitive unit array 204, and the arrangement thereof may also vary depending on the resolution of the curved image sensor chip. Figure 5-Figure 8 In the illustrated embodiment, the number and internal arrangement of the photosensitive cells 207 in each photosensitive cell array 204 are the same (each photosensitive cell array 204 includes 4×4 photosensitive cells 207), and the plurality of separated photosensitive cell arrays 204 are regularly arranged in an array on the substrate 203. In other embodiments not shown, the number of photosensitive cells 207 included in the plurality of photosensitive cell arrays 204 on the substrate 203 may not be completely the same, for example, the photosensitive cell array 204 in the central field of view B region has a larger area and includes a larger number of photosensitive cells 207, while the photosensitive cell array 204 in the edge field of view A region has a smaller area and includes fewer photosensitive cells 207.

[0037] It should be noted that the separation referred to here means that the semiconductor substrate regions forming photodiodes, MOS transistors, etc. in each photosensitive unit array 204 are separated from each other; however, different photosensitive unit arrays 204, such as adjacent photosensitive unit arrays 204 in the same row and / or the same column of the array-arranged photosensitive unit arrays 204, can still be connected through metal wires 205 (such as copper wires, aluminum wires or other metal interconnection materials) therebetween for signal transmission. According to the different numbers of photosensitive units 207 included in the photosensitive unit arrays 204 and the different arrangements of the photosensitive units 207, the number and length of the metal wires 205 between adjacent photosensitive unit arrays 204 may also be different. The length of the metal wire 205 referred to in this article refers to the length of the metal wire 205 located between different photosensitive unit arrays 204, and does not include the area where the metal wire 205 is located within the photosensitive unit array 204. Preferably, the length of the metal wire 205 between adjacent photosensitive unit arrays 204 is greater than 1.5 times the spacing between adjacent photosensitive unit arrays 204 after the curved surface is formed, to ensure that the bending space of the metal wire 205 is not too small during subsequent bending of the metal wire and the substrate.

[0038] The manufacturing method of the curved image sensor chip of the present invention, after forming a plurality of separated photosensitive unit arrays 204 on a bendable substrate 203, firstly performs a pre-pressing process (for example, hydraulic processing is performed on the surface of the chip 202) to form a bending portion 206 on the metal wire 205 connecting the photosensitive unit arrays 204, and then applies a certain external force to the substrate 203 to bend the substrate 203 (for example, bending and shaping the substrate 203 by a mold), so that the photosensitive surfaces of the plurality of separated photosensitive unit arrays 204 on the substrate 203 converge toward the direction of the lens 201, forming a concave surface facing the lens 201. On the image sensor chip 202 after the curved surface is formed, the spacing of the photosensitive unit arrays 204 in the central field of view B area is relatively large, and the spacing of the photosensitive unit arrays 204 in the edge field of view A area is relatively small, that is, the photosensitive unit arrays 204 in the central field of view B area are more sparsely distributed, and the photosensitive unit arrays 204 in the edge field of view A area are more compactly distributed. In the process of bending the substrate 203 to form a curved surface with multiple separated photosensitive unit arrays 204, the bent portion 206 of the metal wire 205 has good toughness and can be stretched and retracted within a certain range, thereby avoiding the breakage of the metal wire 205 caused by the inconsistent spacing of the photosensitive unit arrays 204 in different fields of view, thereby effectively reducing the process difficulty of the curved image sensor chip, improving the product yield, reducing the manufacturing cost, and achieving the light being able to irradiate the photosensitive unit array roughly vertically, thereby avoiding field curvature aberration and improving the imaging performance of the camera module.

[0039] See also Figure 5 , Figure 6 and Figure 7 , Figure 8 By comparison, after the step of forming the curved surface, the curvature of the metal wire bending portion 206 in the central field of view B region is smaller than the curvature of the metal wire bending portion 206 in the edge field of view A region, so as to adapt to the distribution mode in which the spacing of the photosensitive unit array 204 in the central field of view B region is larger than the spacing of the photosensitive unit array 204 in the edge field of view A region. Specifically, in the step of pre-pressing treatment, the curvature of the metal wire bending portion in the central field of view B region can be made smaller than the curvature of the metal wire bending portion in the edge field of view A region by controlling the pre-pressing pressure of the central field of view B region and the edge field of view A region. It is also possible that in the step of bending the substrate, the curvature of the metal wire bending portion in the central field of view B region can be made smaller than the curvature of the metal wire bending portion in the edge field of view A region by controlling the stretching of the metal wire bending portion in the central field of view B region and / or the retraction of the metal wire bending portion in the edge field of view A region. Of course, the above two methods can also be used in combination. When the curvature of the bent portion of the metal wire obtained by pre-pressing cannot meet the requirements, a secondary bending process is performed through mold shaping to further adjust the curvature of the bent portion of the metal wire.

[0040] Preferably, after the step of forming the curved surface, the normal angle between any two photosensitive unit arrays 204 in the central field of view B is not greater than 5° to ensure that the resolution of the central field of view is not too small. The normal angle between any two photosensitive unit arrays 204 in the edge field of view A is not greater than 3° to ensure that the photosensitive area of ​​the entire chip is not too large.

[0041] In addition, see Figure 5-Figure 8 In this embodiment, adjacent photosensitive unit arrays 204 in the same row are connected through metal wires 205a therebetween, and the metal wires 205a have a bending portion 206a; adjacent photosensitive unit arrays 204 in the same column are connected through metal wires 205b therebetween, and the metal wires 205b have a bending portion 206b. The metal wires 205a between the photosensitive unit arrays 204 in each row and the metal wires 205b between the photosensitive unit arrays 204 in each column are not in the same metal layer, and the extension direction of the metal wires 205a between the photosensitive unit arrays 204 in each row is perpendicular to the extension direction of the metal wires 205b between the photosensitive unit arrays 204 in each column. Whether it is the metal wires 205a between the photosensitive unit arrays 204 in each row or the metal wires 205b between the photosensitive unit arrays 204 in each column, the bending directions of the bending portions 206a and 206b are consistent, and are shown here as bending in a direction away from the substrate 203 (i.e., bending upward).

[0042] In such Figure 4 , Figure 9-12 In another embodiment shown, the bending direction of the bending portion 306 of the metal wire 305 is to bend in the direction of the substrate 203 (i.e., bend downward). Those skilled in the art can select the bending direction of the metal wire according to different manufacturing processes, and form a bending portion of the metal wire connecting the photosensitive unit array through pre-pressing treatment. It should be noted that in the case of bending downward, especially for the edge field of view A area, it is necessary to ensure that there is enough distance between the substrate 303 and the metal wire 305, and they cannot interfere with each other.

[0043] The above embodiments are all described by taking the concave chip facing the lens as an example. Those skilled in the art can understand that the manufacturing method of the curved image sensor chip of the present invention can be uniformly applied to the manufacturing process of concave chips and convex chips. That is to say, in other embodiments not shown, the curved surface of the image sensor chip can also be a convex surface facing the lens. In addition, the curved surface can be a spherical surface or an aspherical surface, so as to flexibly adjust the chip curvature to meet the requirements of different shooting needs for chip curvature, so that the light can be roughly vertically irradiated to the photosensitive unit array, thereby avoiding field curvature aberrations and improving the imaging performance of the camera module.

[0044] The manufacturing method of the curved image sensor chip of the present invention can be applied to the manufacturing of back-illuminated image sensor chips. The so-called back-illuminated image sensor means that the pixel unit 208 for photosensing in the photosensitive unit array 204 is located above the interconnection layer composed of the metal wire 205 and the dielectric layer (not shown) relative to the substrate 203, so that the light can first irradiate the photodiode of the pixel unit 208, which avoids the interconnection layer affecting the incident light, thereby increasing the amount of photosensitivity and improving the sensitivity of the image sensor.

[0045] Specifically, each of the photosensitive unit arrays 204 includes at least one photosensitive unit 207 , and each photosensitive unit 207 includes a pixel unit 208 , a filter film 209 located on the pixel unit 208 , and a microlens 210 located on the filter film. The steps of forming a plurality of separated photosensitive unit arrays 204 include: a. preparing a plurality of pixel unit 208 arrays, a dielectric layer (not shown) located on the plurality of pixel unit arrays, and metal wires 205 distributed in the dielectric layer for connecting the plurality of pixel unit arrays on a first surface of a first substrate (i.e., a semiconductor substrate); b. forming a second substrate (i.e., a bendable substrate 203) on the dielectric layer, the second substrate comprising a bendable material; c. thinning the first substrate to a predetermined thickness from a second surface of the first substrate; d. forming a filter film 209 array and a microlens 210 array corresponding to the plurality of pixel unit arrays from the second surface of the first substrate, each pixel unit 208 array and the corresponding filter film 209 array and microlens 210 array together constitute a photosensitive unit array 204; and e. etching the first substrate from the second surface of the first substrate, so that the first substrate does not exist between the plurality of pixel unit arrays 204, and the remaining thickness of the dielectric layer is within a predetermined thickness range; wherein the order of step d and step e is interchangeable. The pixel unit 208 , the metal line 205 , and the substrate 203 are all connected by pins.

[0046] The manufacturing method of the curved image sensor chip of the present invention further includes: after the step of forming the curved surface, a medium with low light transmittance is filled between the plurality of separated photosensitive unit arrays 204 to reduce the light transmission flux, and the medium with low light transmittance is, for example, a material with a light transmittance of less than 10%. The medium with low light transmittance is used to fill the gaps between the mutually separated photosensitive unit arrays 204, further preventing or reducing the light crosstalk that may occur between different photosensitive unit arrays 204. In particular, for the case where each photosensitive unit array 204 includes only one photosensitive unit, the medium with low light transmittance further reduces or substantially eliminates the light crosstalk between adjacent photosensitive units.

[0047] In summary, the manufacturing method of the curved image sensor of the present invention, after forming multiple separate photosensitive unit arrays on a flexible substrate, first performs a pre-pressing treatment to form a bending portion of the metal wire connecting the photosensitive unit arrays, and then bends the substrate to form a curved surface for the multiple separate pixel unit arrays, thereby avoiding the breakage of the metal wires caused by the inconsistent spacing of the photosensitive unit arrays in different fields of view. It can be uniformly applied to the manufacturing process of concave chips and convex chips, effectively reducing the process difficulty of curved image sensor chips, improving product yield, reducing manufacturing costs, and achieving that light can be roughly vertically irradiated to the photosensitive unit array, thereby avoiding field curvature aberrations and improving the imaging performance of the camera module.

[0048] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, in any case, the embodiments should be considered exemplary and non-restrictive. Furthermore, it is apparent that the term "comprising" does not exclude other elements and steps, and the wording "a" does not exclude the plural. Multiple elements stated in a device claim may also be implemented by one element. The words first, second, etc. are used to indicate names and do not indicate any particular order.

Claims

1. A method for manufacturing a curved image sensor chip, characterized in that: include: A plurality of separate photosensitive unit arrays are formed on a flexible substrate, wherein the photosensitive unit arrays are connected to each other through metal wires; The metal wire is formed into a bent portion by pre-pressing; The substrate is bent so that a plurality of separated photosensitive unit arrays form a curved surface.

2. The method for manufacturing a curved image sensor chip according to claim 1, wherein: After the step of forming the curved surface, the curvature of the bent portion of the metal wire in the central field of view of the chip is smaller than the curvature of the bent portion of the metal wire in the edge field of view.

3. The method for manufacturing a curved image sensor chip according to claim 2, wherein: In the pre-pressing step, the pre-pressing pressures of the central field of view and the edge field of view are controlled so that the curvature of the bent portion of the metal wire in the central field of view is smaller than the curvature of the bent portion of the metal wire in the edge field of view.

4. The method for manufacturing a curved image sensor chip according to claim 2, wherein: In the step of bending the substrate, the curvature of the metal wire bending portion in the central field of view is made smaller than the curvature of the metal wire bending portion in the edge field of view by controlling the extension of the metal wire bending portion in the central field of view and / or the retraction of the metal wire bending portion in the edge field of view.

5. The method for manufacturing a curved image sensor chip according to claim 2, wherein: The normal angle between any two photosensitive unit arrays in the central field of view is no greater than 5°.

6. The method for manufacturing a curved image sensor chip according to claim 2, wherein: The normal angle between any two photosensitive unit arrays in the edge field of view is no greater than 3°.

7. The method for manufacturing a curved image sensor chip according to claim 1, wherein: The pre-pressing step includes: performing hydraulic pressure treatment on the surface of the chip.

8. The method for manufacturing a curved image sensor chip according to claim 1, wherein: The step of bending the substrate includes bending and shaping the substrate by a mold.

9. The method for manufacturing a curved image sensor chip according to claim 1, wherein: After the step of forming the curved surface, the length of the metal wires between adjacent photosensitive unit arrays is greater than 1.5 times the spacing between adjacent photosensitive unit arrays.

10. The method for manufacturing a curved image sensor chip according to claim 1, wherein: The bending direction of the metal wire bending portion is toward the substrate or away from the substrate.

11. The method for manufacturing a curved image sensor chip according to claim 10, wherein: The bending directions of all the metal wire bending portions between the photosensitive unit arrays are consistent.

12. The method for manufacturing a curved image sensor chip according to claim 10, wherein: The metal lines between the photosensitive unit arrays in each row and the metal lines between the photosensitive unit arrays in each column are not in the same metal layer.

13. The method for manufacturing a curved image sensor chip according to claim 10, wherein: An extension direction of the metal lines between the photosensitive unit arrays in each row is perpendicular to an extension direction of the metal lines between the photosensitive unit arrays in each column.

14. The method for manufacturing a curved image sensor chip according to claim 1, wherein: After the step of forming the curved surface, the method further includes: filling a medium with low light transmittance between the plurality of separated photosensitive unit arrays.

15. The method for manufacturing a curved image sensor chip according to claim 1, wherein: Each of the photosensitive unit arrays includes at least one photosensitive unit.

16. The method for manufacturing a curved image sensor chip according to claim 15, wherein: The photosensitive unit includes a pixel unit, a filter film located on the pixel unit, and a microlens located on the filter film.

17. The method for manufacturing a curved image sensor chip according to claim 16, wherein: The step of forming a plurality of separated photosensitive unit arrays comprises: a. preparing a plurality of pixel unit arrays, a dielectric layer located on the plurality of pixel unit arrays, and metal lines distributed in the dielectric layer for connecting the plurality of pixel unit arrays on the first surface of the first substrate; b. forming a second substrate on the dielectric layer, wherein the second substrate comprises a bendable material; c. thinning the first substrate to a predetermined thickness from the second surface of the first substrate; d. forming a filter film array and a microlens array corresponding to the plurality of pixel unit arrays from the second surface of the first substrate, wherein each pixel unit array and the corresponding filter film array and microlens array together constitute a photosensitive unit array; and e. etching the first substrate from the second surface of the first substrate, so that the first substrate does not exist between the plurality of pixel unit arrays, and the remaining thickness of the dielectric layer is within a predetermined thickness range; The order of step d and step e is interchangeable.

18. The method for manufacturing a curved image sensor chip according to claim 1, wherein: The curved surface image sensor chip is a back-illuminated image sensor chip.

19. The method for manufacturing a curved image sensor chip according to claim 1, wherein: The curved surface is a concave surface facing the lens or a convex surface facing the lens.

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