CN118016686A - Image sensor and method for manufacturing the same - Google Patents

Abstract

The invention provides an image sensor and a manufacturing method thereof. The bonding pads on the substrate are correspondingly and electrically connected with the bonding pads of the photosensitive chip through wires; the optical filter and the substrate are enclosed into an accommodating space, and the photosensitive chip is arranged in the accommodating space. A first shading layer is arranged on the surface of one side of the optical filter, which is far away from the photosensitive chip; the projection of the first shading layer on the substrate covers a first annular area between the periphery of the photosensitive area and the side wall of the accommodating space; a second shading layer is arranged on the surface of one side of the optical filter, which is close to the photosensitive chip; the projection of the second shading layer on the photosensitive chip at least covers a second annular area between the periphery of the photosensitive area and the pressure welding point of the lead wire on the welding pad. Under the condition that the size of the photosensitive chip is not increased and the packaging size of the image sensor is not increased, the invention effectively shields the flare light and noise light through the double-sided shading layer, improves the imaging quality of the product and improves the reliability of the product.

Description

Image sensor and method for manufacturing the same

Technical Field

The invention belongs to the technical field of image sensor manufacturing, and particularly relates to an image sensor and a manufacturing method thereof.

Background

Image sensors are widely used in digital still cameras, cellular telephones, security cameras, and medical, automotive, and other applications. An image sensor includes a photosensitive chip, which is encapsulated in a cavity formed by a substrate and an optical filter. The bonding pad on the photosensitive chip is electrically connected with the bonding pad on the substrate through a gold wire. The high-temperature reliability test is carried out on the image sensor, and the binding force between the gold wire and the bonding pad on the photosensitive chip and the binding force between the gold wire and the bonding pad on the substrate are good before the high-temperature test, but after the high-temperature test (such as placing the bonding test for 1000 hours at high temperature), the binding force between the gold wire and the bonding pad are poor, and when severe, the cracking phenomenon occurs at the pressure welding points of the gold wire on the bonding pad and the bonding pad, so that the high-temperature reliability test is unqualified, and the reliability of the image sensor product is affected.

Disclosure of Invention

The invention aims to provide an image sensor and a manufacturing method thereof, which can effectively shield flare light and noise light through a double-sided shading layer under the conditions of not increasing the self size of a photosensitive chip and not increasing the whole packaging size of the image sensor, thereby improving the imaging quality of a product and improving the reliability of the product.

The present invention provides an image sensor including:

The back of the photosensitive chip is fixed on the substrate; the front surface of the photosensitive chip is provided with a photosensitive area and a welding pad area surrounding the photosensitive area; the welding pad area is provided with a plurality of welding pads; the substrate is provided with a plurality of bonding pads, and the bonding pads are correspondingly and electrically connected with the bonding pads through wires;

the optical filter and the substrate enclose an accommodating space, and the photosensitive chip is arranged in the accommodating space;

A first shading layer is arranged on the surface of one side, far away from the photosensitive chip, of the optical filter; the projection of the first shading layer on the substrate covers a first annular area between the periphery of the photosensitive area and the side wall of the accommodating space;

A second shading layer is arranged on the surface of one side, close to the photosensitive chip, of the optical filter; and the projection of the second shading layer on the photosensitive chip at least covers a second annular area between the periphery of the photosensitive area and the pressure welding point of the lead wire on the welding pad.

Further, the materials of the first light shielding layer and the second light shielding layer may include at least one of black photoresist, plastic, metal and black paint.

Further, the substrate comprises a printed circuit board or a ceramic circuit board.

Further, the substrate comprises an integral structure formed by a bottom plate and side walls extending upwards from the periphery of the bottom plate, the optical filter is contacted with the top of the side walls of the substrate to form an accommodating space, and the side walls of the substrate are light-tight.

Further, the substrate is of a flat plate structure, the image sensor further comprises a frame, the frame is matched and adhered between the substrate and the optical filter, and the substrate, the frame and the optical filter are enclosed into an accommodating space; the frame is opaque.

Further, the center of the first annular region and the center of the second annular region are coincident with the center of the photosensitive region.

Further, the material of the optical filter comprises any one of glass, plastic or sapphire.

Further, the two side surfaces of the optical filter along the thickness direction are plated with an infrared filter film and/or an optical antireflection film.

Further, the wire includes at least one of gold wire, copper wire, aluminum wire, silver wire, or alloy wire.

The invention also provides a manufacturing method of the image sensor, which comprises the following steps:

Providing a substrate and a photosensitive chip, and fixing the back surface of the photosensitive chip on the substrate; the front surface of the photosensitive chip is provided with a photosensitive area and a welding pad area surrounding the photosensitive area; the welding pad area is provided with a plurality of welding pads; the substrate is provided with a plurality of bonding pads, and the bonding pads are correspondingly and electrically connected with the bonding pads through wires;

Providing a light filter, and forming a first light shielding layer and a second light shielding layer on two surfaces of the light filter in the thickness direction;

Enclosing the optical filter and the substrate into an accommodating space, and placing the photosensitive chip in the accommodating space; the projection of the first shading layer on the substrate covers a first annular area between the periphery of the photosensitive area and the side wall of the accommodating space; the second shading layer is positioned in the accommodating space, and the projection of the second shading layer on the photosensitive chip at least covers a second annular area between the periphery of the photosensitive area and the pressure welding point of the lead wire on the welding pad.

Compared with the prior art, the invention has the following beneficial effects:

The invention provides an image sensor and a manufacturing method thereof, wherein the image sensor comprises: the back of the photosensitive chip is fixed on the substrate; the front surface of the photosensitive chip is provided with a photosensitive area and a welding pad area surrounding the photosensitive area; the welding pad area is provided with a plurality of welding pads; a plurality of bonding pads are arranged on the substrate, and the bonding pads are correspondingly and electrically connected with the bonding pads through leads; the optical filter and the substrate enclose an accommodating space, and the photosensitive chip is arranged in the accommodating space; a first shading layer is arranged on the surface of one side of the optical filter, which is far away from the photosensitive chip; the projection of the first shading layer on the substrate covers a first annular area between the periphery of the photosensitive area and the side wall of the accommodating space; a second shading layer is arranged on the surface of one side of the optical filter, which is close to the photosensitive chip; the projection of the second shading layer on the photosensitive chip at least covers a second annular area between the periphery of the photosensitive area and the pressure welding point of the lead wire on the welding pad. Under the condition of not increasing the size of the photosensitive chip and the packaging size of the image sensor, the invention effectively shields the flare light and noise light through the double-sided shading layer, improves the imaging quality of the product and improves the reliability of the product.

Drawings

Fig. 1 is a schematic diagram of an image sensor according to a first embodiment of the present invention.

Fig. 2 is a schematic diagram of an image sensor according to a second embodiment of the invention.

Fig. 3 is a schematic diagram of an image sensor.

Fig. 4 is a schematic diagram of another image sensor structure.

Fig. 5 is a flowchart illustrating a manufacturing method of an image sensor according to an embodiment of the invention.

Wherein, the reference numerals are as follows:

10-a substrate; 10 a-a bottom plate; 10 b-sidewalls; 11-bonding pads; 20-a photosensitive chip; 20 a-a photosensitive region; 20 b-pad area; 21-a bonding pad; 30-an optical filter; 31-a first light-shielding layer; 32-a second light-shielding layer; b-width of the first nonfunctional light-shielding region; c-filter thickness; d-second light shielding layer width; θ—maximum angle of incidence; w-conducting wires; 41-a substrate; 42-frame; 02-a second black photoresist layer; 01-a first black photoresist layer; the distance between the optical filter and the photosensitive chip; e-second nonfunctional light-shielding region width.

Detailed Description

The invention is described in further detail below with reference to the drawings and the specific examples. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are not to scale precisely, but rather merely for the purpose of facilitating and clearly aiding in the description of the embodiments of the invention.

For ease of description, some embodiments of the application may use spatially relative terms such as "above …," "below …," "top," "below," and the like to describe one element or component's relationship to another element(s) or component(s) as illustrated in the figures of the embodiments. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or components described as "below" or "beneath" other elements or components would then be oriented "above" or "over" the other elements or components. The terms "first," "second," and the like, herein below, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that such terms so used are interchangeable under appropriate circumstances.

An embodiment of the present invention provides an image sensor, as shown in fig. 1, including:

a substrate 10 and a photosensitive chip 20, the back of the photosensitive chip 20 being fixed on the substrate 10; the front surface of the photosensitive chip 20 is provided with a photosensitive area 20a and a welding pad area 20b surrounding the photosensitive area 20 a; the bonding pad area 20b is provided with a plurality of bonding pads 21; a plurality of bonding pads 11 are arranged on the substrate 10, and the bonding pads 11 are correspondingly and electrically connected with the bonding pads 21 through wires W;

The optical filter 30, the optical filter 30 and the substrate 10 are enclosed into an accommodating space, and the photosensitive chip 20 is arranged in the accommodating space;

a first shading layer 31 is arranged on the surface of one side of the optical filter 30 away from the photosensitive chip 20; the projection of the first light shielding layer 31 on the substrate 10 covers a first annular region between the periphery of the photosensitive region 20a and the side wall of the accommodating space;

The surface of one side of the optical filter 30, which is close to the photosensitive chip 20, is provided with a second shading layer 32; the projection of the second light shielding layer 32 on the photosensitive chip 20 covers at least a second annular region between the periphery of the photosensitive region 20a and the bonding point of the wire W on the bonding pad 21.

Specifically, in the first embodiment, as shown in fig. 1, the base plate 10 includes a structure having an intermediate accommodating cavity integrally formed by a bottom plate 10a and a side wall 10b extending upward from the periphery of the bottom plate 10 a. The substrate 10 is, for example, a printed circuit board or a ceramic circuit board. The substrate 10 is provided with pads 11 in a peripheral region of the photosensitive chip 20. The wire W may electrically connect the pad 11 and the pad 21 by bonding. The photo-sensing chip 20 is packaged on the substrate 10, and the photo-sensing chip 20 is packaged by a ceramic substrate planar grid array or an organic substrate planar grid array, for example. The wire W includes at least one of gold wire, copper wire, aluminum wire, silver wire, or alloy wire. The optical filter 30 contacts with the top of the sidewall 10b of the substrate 10 and encloses an accommodating space, and the back surface of the photosensitive chip 20 can be adhered and fixed with the bottom plate 10a to fix the photosensitive chip 20 in the accommodating space. The side wall forming the accommodating space is opaque, in this example, the side wall 10b of the substrate 10 is the side wall forming the accommodating space, and the side wall 10b of the substrate 10 is opaque to prevent light from entering the side wall of the accommodating space to cause interference to the photosensitive chip 20.

In the second embodiment, as shown in fig. 2, the substrate 41 is a flat plate structure, and the substrate 41 is, for example, a printed circuit board or a ceramic circuit board. The image sensor further comprises a frame 42, wherein the frame 42 is bonded between the substrate 41 and the optical filter 30 in a matching way, and the substrate 41, the frame 42 and the optical filter 30 are enclosed into an accommodating space; the photosensitive chip 20 is disposed in the accommodation space. The side walls forming the accommodation space are opaque, in this example, the frame 42 forms the side walls of the accommodation space, and the frame 42 is opaque to prevent light from entering the side walls of the accommodation space to cause interference with the photosensitive chip 20. The frame 42 may be formed by curing a frame glue or other suitable material that is opaque to light.

The photosensitive chip 20 is an image sensor chip, and the working principle of the photosensitive chip 20 is as follows: image light from an external scene is generally incident on the photo-sensing chip 20 from directly above the photo-sensing region 20 a. The photo-sensing chip 20 includes a plurality of pixel units including photosensitive elements such that each photosensitive element absorbs a portion of incident image light. The photosensitive elements included in the photosensitive chip 20 each generate an image charge immediately after absorbing image light, the generated image charge being proportional to the intensity of the image light, the generated image charge being usable to generate an image representing an external scene.

As shown in fig. 1 and 2, the material of the filter 30 includes any one of glass, plastic, or sapphire. Both side surfaces of the optical filter 30 in the thickness direction thereof may be coated with an infrared filter film and/or an optical antireflection film as needed.

The material of the first light shielding layer 31 and the second light shielding layer 32 may include at least one of black photoresist, plastic, metal and black paint. The materials of the first light shielding layer 31 and the second light shielding layer 32 are, for example, black photoresist, which is a material having a photosensitive effect and capable of being opaque after curing. The black photoresist is exposed to form a preset size, the first light shielding layer 31 and the second light shielding layer 32 can be formed by using an exposure process, the process is simple and easy to control, and the shape and size of the first light shielding layer 31 and the second light shielding layer 32 can be very accurate. Of course, the materials of the first light shielding layer 31 and the second light shielding layer 32 are not limited to be black photoresist, and can be plastic or metal materials, so that the wear resistance and the stability are stronger; the material of the first light shielding layer 31 and the second light shielding layer 32 may also be black paint, which may be formed by spraying and baking processes. The process of forming the first light shielding layer 31 and the second light shielding layer 32 is not limited to the exposure process, and may be a process such as coating or sputtering.

A first shading layer 31 is arranged on the surface of one side of the optical filter 30 away from the photosensitive chip 20; the projection of the first light shielding layer 31 on the substrate 10 covers a first annular region between the periphery of the photosensitive region 20a and the side wall of the accommodating space. Illustratively, the first light-shielding layer 31 is rectangular or square in plan view. The center sum of the first annular region coincides with the center of the photosensitive region 20 a.

The surface of one side of the optical filter 30, which is close to the photosensitive chip 20, is provided with a second shading layer 32; the projection of the second light shielding layer 32 on the photosensitive chip 20 covers at least a second annular region between the periphery of the photosensitive region 20a and the bonding point of the wire W on the bonding pad 21. Illustratively, the second light shielding layer 32 is rectangular or square in plan view. The periphery of the photosensitive region 20a is regarded as the inner periphery of the second annular region in plan view, and the second annular region extends in a direction away from the center of the photosensitive region 20a to cover at least the press-bonding pad of the wire W on the pad 21, so as to prevent, for example, incident light from entering and irradiating the non-photosensitive region (region other than the photosensitive region 20a on the photosensitive chip 20) and the wire W from causing interference such as reflection, noise light, and the like within the thickness range of the optical filter 30. The center sum of the second annular region coincides with the center of the photosensitive region 20 a.

Fig. 3 is a schematic diagram of an image sensor. In fig. 3, a second black photoresist layer 02 is disposed on a side surface (lower surface) of the optical filter 30 adjacent to the photosensitive chip 20, and no black photoresist layer is disposed on an upper surface of the optical filter 30. The second black photoresist layer 02 is disposed on the lower surface of the optical filter 30, and the second black photoresist layer 02 is encapsulated in a cavity enclosed by the substrate 10 and the optical filter 30. The second black photoresist layer 02 effectively absorbs and blocks the light reflection, flare and noise inside the cavity. Flare and noise refer to some reflected and/or refracted light that affects the imaging quality; inside the image sensor, reflection light and/or refraction light of different materials, such as gold wires, mirrors of adhesive glue, glass corners, often need to be masked. Intensive researches show that as the black photoresist of the material of the second black photoresist layer 02 has certain hygroscopicity, the wet gas is sealed in the cavity, and corrosive gas is separated out or cracked under the high temperature condition, so that the cracking of the gold wire W pressure welding spot is accelerated, the reliability of the image sensor is affected (the binding force of the gold wire W and the welding pad 21 or the welding pad 11 is affected after the moisture passes through the high temperature reliability test in the cavity); and there is a gap between the second black photoresist layer 02 and the sidewall 10b, and there is a defect of light leakage at the outer edge gap. The second black photoresist layer 02 is arranged on the lower surface of the optical filter 30, and has better light-emitting and noise light shielding capability, but has poorer high-temperature reliability, and the test cannot pass the verification of 1000 hours at high temperature.

Fig. 4 is a schematic diagram of another image sensor structure. In fig. 4, a first black photoresist layer 01 is disposed on a side surface (upper surface) of the optical filter 30 away from the photosensitive chip 20, and no black photoresist layer is disposed on a lower surface of the optical filter 30. The maximum incidence angle of the light is also θ, tan θ= (a+c)/E (a is the distance between the filter and the non-photosensitive region of the photosensitive chip, C is the thickness of the filter, and E is the width of the second non-functional light-shielding region). Intensive studies have found that, compared with the design of the lower surface of the optical filter 30 in fig. 3, the design of the upper surface of the optical filter 30 in fig. 4, in which the first black photoresist layer 01 is provided, has a higher requirement on the size of the photosensitive chip 20, and causes light transmission within the range of the thickness C of the optical filter, resulting in a larger width E of the second nonfunctional light-shielding region. The photosensitive chip 20 is rectangular or square, and correspondingly, the photosensitive chip 20 extends outwards from the photosensitive area 20a to the front, back, left and right directions, so that the size of the photosensitive chip 20 and the whole packaging size of the image sensor are larger, and the whole cost is higher. Therefore, in order to solve the problem of light leakage caused by the thickness C of the optical filter, the size of the non-photosensitive area of the photosensitive chip 20 must be increased, resulting in a larger final size of the photosensitive chip 20. The first black resist layer 01 is disposed on the upper surface of the optical filter 30, and thus has poor light and noise shielding performance, and requires a larger size of the photo-sensing chip 20. Because the first black photoresist layer 01 is not arranged in the cavity formed by the substrate 10 and the optical filter 30, the first black photoresist layer 01 is not affected by hygroscopicity and high temperature, the scheme has stable high-temperature reliability, and the test can be verified by high temperature for 2000 hours.

As further shown in fig. 1 and 2, the present invention provides a first light shielding layer 31 on the upper surface of the optical filter 30, and a second light shielding layer 32 on the lower surface of the optical filter 30. The design of light shielding layer is set up on the light filter 30 double-sided, and most light shielding layer is at light filter 30 upper surface, only leaves a small amount of light shielding layer at light filter 30 lower surface, is convenient for keep original shading function, and humidity in the cavity can significantly reduce to such structure, satisfies the demand of product high temperature reliability.

The first light shielding layer 31 and the second light shielding layer 32 are used for shielding interference of flare light and noise light on imaging. Under the condition that the size and performance of the photosensitive chip 20 and the whole packaging size of the image sensor are not changed, the design that the light shielding layers are arranged on the upper surface and the lower surface of the optical filter 30 is adopted, the maximum incident angle of light is the same θ, tan θ=c/D, (C is the thickness of the optical filter, and D is the width of the second light shielding layer). The second light shielding layer width D is reduced in size compared to the second black photoresist layer 02 in fig. 3.

The invention is provided with a first shading layer 31 on the upper surface of the optical filter 30, and a second shading layer 32 on the lower surface of the optical filter 30. The second light shielding layer 32 is arranged in the product cavity in a smaller size, so that less moisture is absorbed, the reliability of the image sensor product package under the high-temperature condition is improved, the influence of corrosive gas separated or cracked by the second light shielding layer 32 on the product welding spots is reduced, and the quality and performance of the product are improved. Also, light leakage in the range of the filter thickness C due to the first light shielding layer 31 being disposed on the upper surface of the filter 30 is exactly shielded by the second light shielding layer 32, so that the size of the first nonfunctional light shielding region width B is not increased while maintaining the light shielding performance. The lower surface of the optical filter 30 has a small amount of second light shielding layer 32 to make up for the shortage of light shielding of the first light shielding layer 31 on the upper surface of the optical filter 30. The invention has better shielding characteristics of flare light and noise light, and also gives consideration to the design of a small amount of second shading layers 32 on the lower surface part, thereby improving the reliability of the product. In addition, since the first light shielding layer 31 is disposed on the upper surface of the optical filter 30 and is located outside the accommodating space surrounded by the optical filter 30 and the substrate 10, the outer boundary of the first light shielding layer 31 is not limited or interfered by the sidewall of the accommodating space, and the first light shielding layer 31 can extend outwards, so that the inner wall of the sidewall of the accommodating space is ensured to be light-proof, and better light shielding performance is obtained.

The invention also provides a manufacturing method of the image sensor, as shown in fig. 1 and 5, comprising the following steps:

Step S1, providing a substrate 10 and a photosensitive chip 20, and fixing the back surface of the photosensitive chip 20 on the substrate 10; the front surface of the photosensitive chip 20 is provided with a photosensitive area 20a and a welding pad area 20b surrounding the photosensitive area 20 a; the bonding pad area 20b is provided with a plurality of bonding pads 21; a plurality of bonding pads 11 are arranged on the substrate 10, and the bonding pads 11 are correspondingly and electrically connected with the bonding pads 21 through wires W;

Step S2, providing a light filter 30, and forming a first light shielding layer 31 and a second light shielding layer 32 on two surfaces of the light filter 30 in the thickness direction;

Step S3, enclosing the optical filter 30 and the substrate 10 into an accommodating space, and placing the photosensitive chip 20 in the accommodating space; the projection of the first light shielding layer 31 on the substrate 10 covers a first annular region between the periphery of the photosensitive region 20a and the side wall of the accommodating space; the second light shielding layer 32 is located in the accommodating space, and the projection of the second light shielding layer 32 on the photosensitive chip 20 covers at least a second annular area between the periphery of the photosensitive area 20a and the bonding point of the wire W on the bonding pad 21.

The wire W includes at least one of gold wire, copper wire, aluminum wire, silver wire, or alloy wire. The wire W may be bonded (or pressure bonded) on the pad 11 or the pad 21 by thermosonic bonding. The filter 30 and the substrate 10 may be bonded together by an adhesive to form an accommodating space. The materials of the first light shielding layer 31 and the second light shielding layer 32 are, for example, black photoresist, which is a material having a photosensitive effect and capable of being opaque after curing. The black photoresist is exposed to form a preset size, the first light shielding layer 31 and the second light shielding layer 32 can be formed by using an exposure process, the process is simple and easy to control, and the shape and size of the first light shielding layer 31 and the second light shielding layer 32 can be very accurate. The material of the first light shielding layer 31 and the second light shielding layer 32 may also be black paint, which may be formed by spraying and baking processes. The process of forming the first light shielding layer 31 and the second light shielding layer 32 is not limited to the exposure process, and may be a process such as coating or sputtering.

In summary, the present invention provides an image sensor and a method for manufacturing the same, the image sensor includes: the back of the photosensitive chip is fixed on the substrate; the front surface of the photosensitive chip is provided with a photosensitive area and a welding pad area surrounding the photosensitive area; the welding pad area is provided with a plurality of welding pads; a plurality of bonding pads are arranged on the substrate, and the bonding pads are correspondingly and electrically connected with the bonding pads through leads; the optical filter and the substrate enclose an accommodating space, and the photosensitive chip is arranged in the accommodating space; a first shading layer is arranged on the surface of one side of the optical filter, which is far away from the photosensitive chip; the projection of the first shading layer on the substrate covers a first annular area between the periphery of the photosensitive area and the side wall of the accommodating space; a second shading layer is arranged on the surface of one side of the optical filter, which is close to the photosensitive chip; the projection of the second shading layer on the photosensitive chip at least covers a second annular area between the periphery of the photosensitive area and the pressure welding point of the lead wire on the welding pad. Under the condition of not increasing the size of the photosensitive chip and the packaging size of the image sensor, the invention effectively shields the flare light and noise light through the double-sided shading layer, improves the imaging quality of the product and improves the reliability of the product.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the method disclosed in the embodiment, the description is relatively simple since it corresponds to the device disclosed in the embodiment, and the relevant points refer to the description of the method section.

The foregoing description is only illustrative of the preferred embodiments of the present invention, and is not intended to limit the scope of the claims, and any person skilled in the art may make any possible variations and modifications to the technical solution of the present invention using the method and technical content disclosed above without departing from the spirit and scope of the invention, so any simple modification, equivalent variation and modification made to the above embodiments according to the technical matter of the present invention fall within the scope of the technical solution of the present invention.

Claims (10)

1. An image sensor, comprising:

The back of the photosensitive chip is fixed on the substrate; the front surface of the photosensitive chip is provided with a photosensitive area and a welding pad area surrounding the photosensitive area; the welding pad area is provided with a plurality of welding pads; the substrate is provided with a plurality of bonding pads, and the bonding pads are correspondingly and electrically connected with the bonding pads through wires;

the optical filter and the substrate enclose an accommodating space, and the photosensitive chip is arranged in the accommodating space;

A first shading layer is arranged on the surface of one side, far away from the photosensitive chip, of the optical filter; the projection of the first shading layer on the substrate covers a first annular area between the periphery of the photosensitive area and the side wall of the accommodating space; a second shading layer is arranged on the surface of one side, close to the photosensitive chip, of the optical filter; and the projection of the second shading layer on the photosensitive chip at least covers a second annular area between the periphery of the photosensitive area and the pressure welding point of the lead wire on the welding pad.

2. The image sensor of claim 1, wherein the first light shielding layer and the second light shielding layer each comprise at least one of black photoresist, plastic, metal, and black paint.

3. The image sensor of claim 1, wherein the substrate comprises a printed circuit board or a ceramic circuit board.

4. The image sensor of claim 1, wherein the substrate comprises an integral structure of a bottom plate and a side wall extending upward from a periphery of the bottom plate, the optical filter contacts a top of the side wall of the substrate to form an accommodating space, and the side wall of the substrate is opaque.

5. The image sensor of claim 1, wherein the substrate is a flat panel structure, the image sensor further comprising a frame matingly bonded between the substrate and the optical filter; the substrate, the frame and the optical filter are enclosed to form an accommodating space; the frame is opaque.

6. The image sensor of claim 1, wherein a center of the first annular region and a center of the second annular region each coincide with a center of the photosensitive region.

7. The image sensor of claim 1, wherein the filter comprises any one of glass, plastic, or sapphire.

8. The image sensor of claim 7, wherein both side surfaces of the optical filter in the thickness direction thereof are coated with an infrared filter film and/or an optical antireflection film.

9. The image sensor of claim 1, wherein the wire comprises at least one of gold wire, copper wire, aluminum wire, silver wire, or alloy wire.

10. A method for manufacturing an image sensor, comprising:

Providing a substrate and a photosensitive chip, and fixing the back surface of the photosensitive chip on the substrate; the front surface of the photosensitive chip is provided with a photosensitive area and a welding pad area surrounding the photosensitive area; the welding pad area is provided with a plurality of welding pads; the substrate is provided with a plurality of bonding pads, and the bonding pads are correspondingly and electrically connected with the bonding pads through wires;

Providing a light filter, and forming a first light shielding layer and a second light shielding layer on two surfaces of the light filter in the thickness direction;

Enclosing the optical filter and the substrate into an accommodating space, and placing the photosensitive chip in the accommodating space; the projection of the first shading layer on the substrate covers a first annular area between the periphery of the photosensitive area and the side wall of the accommodating space; the second shading layer is positioned in the accommodating space, and the projection of the second shading layer on the photosensitive chip at least covers a second annular area between the periphery of the photosensitive area and the pressure welding point of the lead wire on the welding pad.