WO2021139510A1

WO2021139510A1 - Photosensitive chip assembly, camera module, and terminal device

Info

Publication number: WO2021139510A1
Application number: PCT/CN2020/137753
Authority: WO
Inventors: 蒋恒; 孟楠
Original assignee: 宁波舜宇光电信息有限公司
Priority date: 2020-01-10
Filing date: 2020-12-18
Publication date: 2021-07-15
Also published as: CN115336245A

Abstract

Provided by the present application are a photosensitive chip assembly, a camera module, and a terminal device. The chip assembly comprises: a photosensitive chip, comprising a substrate, an active region located on the substrate, and a microlens array located on said active region; a stress layer, arranged on the back side of the photosensitive chip, such that the photosensitive chip is deformed toward the substrate of the photosensitive chip. By means of arranging a stress layer on the back of a conventional photosensitive chip, the direction and degree of bending of the photosensitive chip are controlled, thus controlling the field curvature of the photosensitive chip, causing the direction of bending of the photosensitive chip to be consistent with the direction of field curvature of the lens, thereby improving the clarity of imaging.

Description

Photosensitive chip components, camera modules and terminal equipment

Technical field

This application relates to the field of camera technology, and in particular to a photosensitive chip assembly, camera module and terminal equipment.

Background technique

The camera is an indispensable input device in electronic products such as mobile phones and tablets. As users continue to improve the image quality of the camera, the pixels of the camera are also getting larger and larger, and the area of the photosensitive chip inside it is required to be larger and larger.

The camera imaging process is mainly the optical signal digitization process, which is mainly completed by the camera module. The camera module mainly includes a lens, a photosensitive chip and a circuit board. The photosensitive chip is the main component of the camera module. Its working principle is: external light passes through the lens and irradiates the surface of the photosensitive chip, and the photosensitive chip uploads the light from the lens. It is converted into an electrical signal, and then converted into a digital signal through analog-to-digital conversion.

Among them, the quality of the photosensitive chip is an important factor that affects the imaging quality. However, as the pixels of the camera become larger and larger, the area of the photosensitive chip becomes larger and larger. However, due to the increasingly thinner and lighter market demand for mobile phones and other electronic products, the thickness of the photosensitive chip cannot be increased accordingly. As a result, the ratio of the area to the thickness of the photosensitive chip gradually increases.

The ratio of the area of the photosensitive chip to the thickness gradually increases, so that during the manufacturing of the photosensitive chip, especially during the heating and curing process of the photosensitive chip, deformation is more likely to occur when the temperature rises, as shown in Figure 1.

As the central area of the photosensitive chip protrudes upward, the photosensitive area forms a curved surface, which leads to an increase in the curvature of field of the photosensitive chip. The direction of the increase in the curvature of field is opposite to the direction of field curvature of the lens (ie, the curvature of field of the lens), as shown in FIG. The direction in which the photosensitive chip deforms is opposite to the image surface of the lens, causing the camera to take pictures with a clear center and blurry surroundings, resulting in poor picture quality.

In order to solve the above problems, the commonly used method is to bend the photosensitive chip itself into a cylindrical shape, a spherical shape, or a curved shape required by the lens group. However, in the method of bending the photosensitive chip, the method usually used is the extrusion of the die. For example, as shown in FIG. 3, for a spherical photosensitive chip 1100, a lower mold 002 with a spherical curved surface is set, and the filmed photosensitive chip 1100 is pressed onto the curved surface of the lower mold through the upper mold 001 with a spherical curved surface, so that the entire photosensitive chip 1100 is pressed onto the curved surface of the lower mold. The chip 1100 is bent into a spherical shape. In addition, some chips are made into a curved shape when they are molded. However, this method is difficult to process and is not conducive to batch molding.

Summary of the invention

Based on this, this application aims to provide a photosensitive chip assembly that keeps the photosensitive chip bent during the assembly process and is consistent with the bending direction of the actual imaging surface of the lens, and controls the curvature of the photosensitive chip by controlling the degree of curvature of the photosensitive chip. In order to improve the photographic quality of the photosensitive chip assembly.

According to the first aspect of the present application, a photosensitive chip assembly is provided, including:

The photosensitive chip includes a substrate, an active area on the substrate, and a microlens array on the active area;

The stress layer is arranged on the back side of the photosensitive chip, so that the photosensitive chip deforms toward the substrate of the photosensitive chip.

According to some embodiments of the present application, the thickness of the stress layer is 0.1um-10um.

According to some embodiments of the present application, the thickness of the photosensitive chip is 100 um to 200 um.

According to some embodiments of the present application, the stress layer includes:

Compensation film, the thermal expansion coefficient of the compensation film is greater than or equal to the thermal expansion coefficient of the microlens array.

According to some embodiments of the present application, the thickness of the compensation film is greater than or equal to the thickness of the microlens array.

According to some embodiments of the present application, the material of the compensation film includes at least one of silicon oxide, magnesium fluoride, aluminum oxide, and titanium oxide.

According to some embodiments of the present application, the compensation film includes a PVD film and/or a CVD film.

According to some embodiments of the present application, the PVD film includes at least one of a vacuum vapor deposition film, a magnetron sputtering film, and an atomic layer deposition film.

According to some embodiments of the present application, the active area further includes a photosensitive area, which is disposed under the microlens array and receives light from the outside reaching the front surface of the photosensitive chip;

The stress layer includes a stress film, the stress film has a predetermined thickness, and the stress generated during the coating process causes the photosensitive area of the photosensitive chip to deform toward the substrate of the photosensitive chip.

According to some embodiments of the present application, the stress film includes at least one of a silicon dioxide film, a magnesium fluoride film, a silicon nitride film, and an aluminum nitride film.

According to some embodiments of the present application, before the stress film is coated, the back surface of the photosensitive chip is a flat surface.

According to some embodiments of the present application, the part of the photosensitive chip corresponding to the photosensitive area is substantially flush with the back surface of the photosensitive chip.

According to some embodiments of the present application, a part of the photosensitive chip corresponding to the photosensitive area is convex toward the direction of the stress film, and the distance of the convexity ranges from 2 μm to 10 μm.

According to some embodiments of the present application, the stress film is attached to the entire back surface of the photosensitive chip.

According to some embodiments of the present application, the photosensitive chip has an area of 5 mm2-40 mm2.

According to some embodiments of the present application, the photosensitive chip assembly further includes:

The first intermediate layer is disposed between the photosensitive chip and the stress layer, and the bonding performance between the first intermediate layer and the substrate and the stress layer is better than that of the substrate and the stress layer Binding performance between.

The second intermediate layer is arranged on the opposite side of the stress layer to the photosensitive chip, and the second intermediate layer adheres the photosensitive chip assembly to the carrier board on which the photosensitive chip assembly is mounted through an adhesive .

According to some embodiments of the present application, the bonding performance between the second intermediate layer and the stress layer and the adhesive is better than the bonding performance between the stress layer and the adhesive.

According to some embodiments of the present application, the material of the first intermediate layer includes one or more of silicon and silicon dioxide.

According to some embodiments of the present application, the material of the second intermediate layer includes one or more of porous silicon dioxide, titanium dioxide, and hydrophilic silicon coating solution.

According to some embodiments of the present application, the thickness of the first intermediate layer or the second intermediate layer is 10-20 nm.

According to some embodiments of the present application, the first intermediate layer or the second intermediate layer includes a physical vapor deposition layer and/or a chemical vapor deposition layer.

According to the second aspect of the present application, a camera module is provided, including:

Lens components, including lenses;

The above-mentioned photosensitive chip assembly is connected to the lens assembly, and the field curvature of the photosensitive chip assembly is in the same direction with the field curvature of the lens and the difference is within ±10um.

According to some embodiments of the present application, the camera module further includes:

A carrier board, the photosensitive chip assembly is arranged on the carrier board;

Electronic components are arranged on the carrier board.

The package component is arranged on the carrier board, the package component and the carrier board enclose a cavity for accommodating the photosensitive chip assembly and the electronic component, and the package component has a cavity exposing the photosensitive chip The window of the microlens array of the component;

or

A packaging component covering the photosensitive chip assembly and the electronic component, and the packaging component has a window exposing the microlens array of the photosensitive chip assembly; and

The packaging component is integrally formed on the carrier board by transfer molding, injection molding, or compression molding;

or

The package component includes a molded part, which is disposed on the carrier board and covers the electronic component; and

The supporting portion is provided on the molding portion, the molding portion and the supporting portion surround a cavity for accommodating the photosensitive chip assembly and the electronic component, and the supporting portion has a cavity that exposes the The window of the micro lens array of the photosensitive chip assembly.

The filter element is arranged on the packaging component and covers the window;

The lens assembly is mounted on the packaging component.

According to some embodiments of the present application, the carrying board includes:

A circuit board, the electronic component and the photosensitive chip assembly are electrically connected to the carrier board;

or

A flexible circuit board, the electronic components and the photosensitive chip assembly are arranged on the flexible circuit board and electrically connected to the flexible circuit board; and

A reinforcing plate is arranged under the flexible circuit board to support the flexible circuit board;

or

A circuit board having an opening, and the electronic components are arranged on the circuit board; and

A reinforcing plate is arranged under the circuit board, the photosensitive chip assembly is arranged on the reinforcing plate and located in the opening, and the electronic component and the photosensitive chip assembly are electrically connected to the circuit board.

According to a third aspect of the present application, a terminal device is provided, including the above-mentioned camera module.

The additional aspects and advantages of the present application will be partly given in the following description, and part of them will become obvious from the following description, or be understood through the practice of the present application.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings, without exceeding the scope of protection claimed in this application.

Figure 1 shows a schematic diagram of the deformation of the photosensitive chip;

Figure 2 shows a schematic diagram of the deformation direction of the photosensitive chip and the image plane of the lens;

Figure 3 shows a schematic diagram of the process of die extrusion and bending of the photosensitive chip;

Figure 4 shows a schematic diagram of the structure of a conventional photosensitive chip;

Figure 5 shows a schematic diagram of the bending principle during the bonding and curing process of a conventional photosensitive chip;

Figure 6 shows a schematic diagram of the bending process during the bonding and curing process of a conventional photosensitive chip;

Fig. 7 shows a schematic structural diagram of a photosensitive chip assembly according to a first exemplary embodiment of the present application;

Fig. 8 shows a schematic diagram of a bending process of a photosensitive chip assembly according to an exemplary embodiment of the present application;

FIG. 9 shows a schematic diagram of the protrusion distance of the corresponding part of the photosensitive area of the photosensitive chip according to the exemplary embodiment of the present application.

FIG. 10 shows a schematic diagram in which the bending direction of the photosensitive chip is the same as the bending direction of the image surface of the lens;

Fig. 11 shows a schematic structural diagram of a photosensitive chip assembly according to a second exemplary embodiment of the present application;

FIG. 12 shows the second structural diagram of the photosensitive chip assembly according to the third exemplary embodiment of the present application;

FIG. 13 shows the third structural diagram of the photosensitive chip assembly according to the fourth exemplary embodiment of the present application;

FIG. 14 shows a schematic diagram of a fixing structure of a photosensitive chip assembly according to an exemplary embodiment of the present application.

FIG. 15 shows a schematic diagram of a fixing structure of a photosensitive chip assembly according to another exemplary embodiment of the present application;

FIG. 16 shows a schematic structural diagram of a camera module photosensitive chip assembly package according to an exemplary embodiment of the present application;

FIG. 17 shows a schematic structural diagram of a camera module photosensitive chip assembly package according to another exemplary embodiment of the present application;

FIG. 18 shows the second schematic diagram of the structure of a camera module photosensitive chip assembly package according to another exemplary embodiment of the present application;

Fig. 19 shows a schematic structural diagram of a camera module according to an exemplary embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative work shall fall within the protection scope of this application.

First, the structure and connection process of the existing photosensitive chip will be combined to explain the reason why the deformation direction of the photosensitive chip is opposite to the image surface of the lens.

Fig. 4 shows a schematic diagram of the structure of a conventional photosensitive chip.

As shown in FIG. 4, the structure of the photosensitive chip 1100 from top to bottom is a microlens array 111, a Bayer color filter array 112, a photosensitive area 113, a non-sensitive area 114 such as a circuit layer, and a silicon substrate 115, respectively. The non-photosensitive areas 114 such as the Bayer color filter array 112, the photosensitive area 113, and the circuit layer are also referred to as active areas. For ease of description, the photosensitive area 113, the non-sensitive area 114 such as the circuit layer, and the silicon substrate 115 are referred to as the silicon layer 116 below.

The microlens array 111 is generally made of an organic film, such as propylene-based thermosetting resin, propylene-based thermoplastic resin, and the like. The photosensitive area 113, the circuit layer and other non-photosensitive areas 114, and the silicon substrate 115 are mainly made of inorganic materials, mainly silicon. The photosensitive chip 1100 and the circuit board are usually fixed by applying an adhesive and curing after heating.

FIG. 5 shows a schematic diagram of the bending principle during the bonding and curing process of the conventional photosensitive chip.

As shown in FIG. 5, the photosensitive chip 1100 needs to be heated during the bonding and curing process. The thermal expansion coefficient of the microlens array 111 is relatively large, about 30 PPM. The thermal expansion coefficient of the silicon layer 116 is about 3 PPM. The expansion coefficients of the microlens array 111 and the silicon layer 116 are too different. During the temperature increase, the expansion speed of the microlens array 111 is greater than the expansion speed of the silicon layer, which causes the photosensitive chip 1100 to bend downwards, that is, the central area of the photosensitive chip 1100 protrudes upwards.

FIG. 6 shows a schematic diagram of the bending process during the bonding and curing process of the conventional photosensitive chip.

In the process of adhering and fixing the photosensitive chip 1100 and the carrier board 1200, the adhesive 900 is first coated on the carrier board 1200. Then, the photosensitive chip 1100 is attached to the carrier board 1200 through the adhesive 900. Next, the temperature is raised to 100-120 degrees Celsius to cure the adhesive 900. During this process, the photosensitive chip 1100 is heated due to the aforementioned reasons, and the central area of the photosensitive chip 1100 protrudes upward, and the adhesive 900 is gradually solidified in this process. After the photosensitive chip 1100 is bent to a certain degree, it is fixed by the adhesive 900 and cannot be restored to flatness. Eventually, the photosensitive chip 1100 produces a convex upward curvature in this process, which is inconsistent with the curvature direction of the imaging surface of the lens assembly.

To solve this problem, the inventor proposes a photosensitive chip assembly. By providing a stress layer on the back side of the photosensitive chip, the photosensitive chip is deformed toward the substrate of the photosensitive chip, so that the bending direction of the photosensitive chip is aligned with the imaging surface of the lens. The bending direction is consistent and stable bending is maintained, thereby improving the sharpness of imaging.

Fig. 7 shows a schematic structural diagram of a photosensitive chip assembly according to a first exemplary embodiment of the present application.

As shown in FIG. 7, the photosensitive chip assembly 1100 includes a photosensitive chip 1100 and a stress layer 130. The stress layer 130 is disposed on the back side of the photosensitive chip 1100. According to the first example implementation of the present application, the stress layer 130 may be a compensation film with a thermal expansion coefficient greater than or equal to that of the microlens array 111. Therefore, during the assembly process, the expansion speed of the compensation film 130 after being heated is greater than the expansion speed of the microlens array 111, the periphery of the photosensitive chip 1100 will slightly bend upwards, and the central area of the photosensitive chip 1100 is recessed downwards, thereby making the photosensitive area of the photosensitive chip 1100 The bending direction of the lens is the same as the bending direction of the lens imaging surface.

According to some embodiments, the material of the compensation film 130 may be silicon oxide, aluminum oxide, titanium oxide, etc., and may also be magnesium fluoride or the like. The compensation film 130 may include, but is not limited to, a PVD film and/or a CVD film. The PVD film includes but is not limited to at least one of a vacuum vapor deposition film, a magnetron sputtering film, and an atomic layer deposition film. The thickness of the compensation film 130 is 0.1um-10um. The thickness of the photosensitive chip 1100 is generally 100 um to 200 um. The thickness of the microlens array 111 of the photosensitive chip 1100 is generally equivalent to or smaller than the thickness of the compensation film 130.

In order to ensure that the thickness of the photosensitive chip assembly 1100 after adding the compensation film 130 meets the chip requirements of the usual specifications, the thickness of the silicon substrate 115 on the bottom side of the photosensitive chip 1100 can be ground first to ensure the thickness of the photosensitive chip assembly 1100 after the stress layer 130 is increased. Will not increase.

FIG. 8 shows a schematic diagram of a bending process of a photosensitive chip assembly according to an exemplary embodiment of the present application.

As shown in FIG. 8, during the heating and fixing process of the photosensitive chip assembly 1100, since the thermal expansion coefficient of the compensation film 130 is greater than or equal to the thermal expansion coefficient of the microlens array 111 of the photosensitive chip 1100, and the compensation film 130 It is located on the back of the photosensitive chip 1100, and the micro lens array 111 is located on the front of the photosensitive chip 1100. When the photosensitive chip assembly 1100 is heated, the expansion speed of the compensation film 130 is greater than or equal to the micro lens array 111.

Referring to FIG. 8, when the thermal expansion coefficient of the compensation film 130 is equal to the thermal expansion coefficient of the microlens array 111, the expansion speeds of the two are basically the same. Therefore, the photosensitive chip assembly 1100 basically does not bend. Since the thickness of the compensation film 130 is slightly greater than the thickness of the microlens array 111, the expansion amount of the compensation film 130 is slightly greater than the expansion amount of the microlens array 111. At this time, the periphery of the photosensitive chip assembly 1100 will be slightly upwardly curved, and its central area will be slightly downwardly recessed, or substantially no curvature will occur. Therefore, the photosensitive chip basically does not bend here, and it should be understood that the photosensitive chip assembly 1100 is flat or the center area is recessed downward.

As shown in FIG. 8, when the thermal expansion coefficient of the compensation film 130 is greater than the thermal expansion coefficient of the microlens array 111, the expansion rate of the compensation film 130 is greater than the expansion rate of the microlens array 111. The periphery of the photosensitive chip assembly 1100 is bent upward, and the central area is recessed downward. At this time, the bending direction of the photosensitive chip 1100 is consistent with the bending direction of the imaging surface of the lens.

According to other embodiments of the present application, as shown in FIG. 7, the stress layer 130 may also be a stress film and have a predetermined thickness. The stress film 130 can generate stress during the molding process, so that the photosensitive area of the photosensitive chip 110 is deformed toward the substrate (back). That is, the stress film 130 is plated on the backside surface of the silicon substrate, and stress is generated on the photosensitive chip 110 during the coating process, so that the photosensitive area of the photosensitive chip 110 is deformed toward the back surface. At this time, the predetermined thickness of the stress film 130 may be determined according to the size of the photosensitive chip 110 and the size to be deformed.

The stress film 130 generates stress during the coating process, which is different from the prior art. The coating process can be understood as the atoms or molecules are plated layer by layer on the surface of the plating body, and stress is generated during the coating process. Instead of only providing a finished product of stress film, the finished product of stress film is attached to the back of the photosensitive chip 110 to generate stress on the photosensitive chip 110.

Because the photosensitive chip 110 mainly produces field curvature during the heating and curing process. As shown in Figure 1, the middle area of the traditional photosensitive chip is arched toward the front, and both sides are curved toward the back. Therefore, if the stress film 130 is plated on the photosensitive chip 110 before the photosensitive chip 110 is heated and cured, compressive stress will be generated on the back surface of the photosensitive chip 110, and the photosensitive chip 110 will be deformed toward the back in advance, that is, the photosensitive area of the photosensitive chip 110 and its The lower area bends and arches downward. If after the photosensitive chip 110 is heated and cured, the photosensitive chip 110 has already undergone field curvature deformation, and the stress film 130 is plated on the photosensitive chip 110 at this time, a tensile stress opposite to the deformation of the photosensitive chip 110 will be generated. In principle, it can, but in actual production, the process of heating and curing is the process of pasting the photosensitive chip on the circuit board or reinforcing board, and the coated side needs to be pasted on the circuit board or reinforcing board, so in actual operation, it is often Choose to coat first and then heat to cure.

The reason why the stress film 130 generates stress on the photosensitive chip 110 can be explained microscopically. During the coating process of the photosensitive chip 110, as the thin film crystallites grow, the effect of surface tension weakens, and the lattice constant of the crystallites, that is, the edge length of the unit cell, should have gradually increased to the maximum lattice constant of the film. However, due to the binding effect of the film on the back of the photosensitive chip 110, the increase in the lattice constant of the crystallites is hindered. Even if the thickness of the film continues to increase, the lattice constant of the crystallites is smaller than the maximum lattice constant of the film. Therefore, the stress of the stress film 130 on the photosensitive chip 110 is caused, and the stress causes the photosensitive chip to bulge toward one side of the film. The distance between the photosensitive chip 110 and the photosensitive area corresponding to the photosensitive area (that is, the portion of the photosensitive area within the vertical projection of the photosensitive chip 110), which is raised toward the side of the stress film 130, can be achieved by controlling the temperature and pressure during the coating process .

The distance h that the corresponding part of the photosensitive area of the photosensitive chip protrudes in the direction of the stress film is defined as: the height of the periphery of the photosensitive area minus the height of the center of the photosensitive area, as shown in FIG. 9. (The microlens array is omitted in FIG. 9) In this exemplary embodiment, by controlling the temperature and pressure during the coating process, the distance h that a specific part of the photosensitive chip protrudes toward the stress film is controlled to range from 2 μm to 10 μm. In this embodiment, the stress film 130 is attached to the entire back surface of the photosensitive chip 110 to generate as much stress as possible on the photosensitive chip 110. The specific size of the photosensitive chip, the thickness of the coating film, and the thickness of the protrusions of the corresponding part of the photosensitive area in the photosensitive chip can be set according to the actual situation, and this is not a limitation of this embodiment.

It should be noted that the film coating method includes but is not limited to physical vapor deposition methods such as vacuum evaporation, magnetron sputtering, or other chemical vapor deposition methods. The preferred method is vacuum evaporation and magnetron sputtering. The material for the coating needs to choose a material with good adhesion and large surface energy (that is, the energy that the surface of the material has relative to the inside) is large, so that the film is firmly attached to the photosensitive chip 110 and can generate greater stress. Therefore, the material of the stress film 130 may include at least one of silicon dioxide, magnesium fluoride, silicon nitride, and aluminum nitride. The specific method and material of the coating are not a limitation to this embodiment.

Before the stress film 130 is coated, the back surface of the photosensitive chip 110, that is, the substrate, needs to be polished. In this embodiment, the thickness of the photosensitive chip can be polished to a range of 100 μm-200 μm. Correspondingly, the coating thickness of the stress film 130 is 0.1 μm-10 μm, and the area of the photosensitive chip 110 is 5 mm ² -40 ^{mm 2} .

By placing a stress layer on the back side of the photosensitive chip, after the final deformation of the photosensitive chip, there can be two situations: one is that the part of the photosensitive chip corresponding to the photosensitive area and the part corresponding to the non-sensitive area are basically flush, that is, the whole The back of the photosensitive chip assembly forms a plane (as shown on the left side of Figure 8). Second, the portion corresponding to the photosensitive area in the photosensitive chip is convex toward the direction of the stress layer, and the convex direction is the same as the direction of curvature of the image plane of the lens (as shown on the right side of FIG. 8).

FIG. 10 shows a schematic diagram in which the bending direction of the photosensitive chip is the same as the bending direction of the lens field.

As shown in FIG. 10, for example, the image surface J of the lens is in the shape of a smiling face with an upward mouth. It is precisely because the image surface of the lens is a smiling face, the shape of the chip should also be made into a smiling face, that is, the photosensitive chip or the photosensitive area of the photosensitive chip is convex downwards, so that the shape of the photosensitive chip corresponds to the shape of the image surface of the lens, receiving more In order to avoid the shooting situation that is clear in the middle and blurred on both sides.

Assuming that the actual field curvature of the lens assembly is A, when the stress layer adopts the compensation film, the field curvature of the photosensitive chip 1100 can be controlled to B by adjusting the thermal expansion coefficient, heating temperature, heating time and other parameters of the compensation film, so that B is close to A and the same direction. When the stress film is used as the stress film, the field curvature of the photosensitive chip can be controlled to B by adjusting the heating temperature, heating time, heating pressure and other parameters of the stress film during the coating process, so that B is close to A and in the same direction. According to some embodiments of the present application, the difference between B and A can be controlled within ±10um. According to other embodiments of the present application, the difference between B and A can be controlled within ±5um. Therefore, the field curvature of the photosensitive chip 1100 can be matched with the field curvature of the lens, so that the overall field curvature of the camera module can be reduced, and the photographing quality of the camera module can be improved.

Further, according to some embodiments of the present application, the thickness of the stress layer is 0.1 μm-10 μm, and the stress layer may be formed by a coating process such as physical vapor deposition and chemical vapor deposition. The traditional photosensitive chip needs to bond the compensation layer and then attach it to the circuit board. In contrast, the provision of a stress layer can save a gluing process, thereby reducing field curvature caused by the difference in thermal expansion coefficients between multiple layers of different media, reducing the risk of chip bumps caused by uneven adhesive coating, and not Significantly increase the chip thickness.

In addition, the traditional compensation layer generally uses metal materials. The thermal expansion coefficient of metal materials is generally 10-20ppm/℃, and it is easy to cause thermal mismatch with photosensitive chips, circuit boards and other materials, which will lead to problems such as mechanical fracture between the compensation layer and the chips and circuit boards. In the embodiments of the application, the thermal expansion coefficient of the compensation film is greater than or equal to the thermal expansion coefficient of the microlens array, and the thermal expansion coefficient of the stress film is close to the thermal expansion coefficient of the microlens array, and both can compensate the field curvature caused by the difference in the thermal expansion coefficient inside the photosensitive chip. At the same time, it can also effectively alleviate the problems of warpage and field curvature of the photosensitive chip during the subsequent process of attaching the photosensitive chip to the circuit board.

According to some embodiments of the present application, during use, the stress layer and the photosensitive chip may have a large performance difference and poor "affinity", that is, the adhesion between the two is poor, causing the stress layer to separate from the photosensitive chip. The upper fall off is not conducive to maintaining the bending direction. Therefore, the inventor of the present invention proposes a second photosensitive chip assembly structure based on the photosensitive chip assembly of the first exemplary embodiment described above.

Fig. 11 shows a schematic structural diagram of a photosensitive chip assembly according to a second exemplary embodiment of the present application.

As shown in FIG. 11, the photosensitive chip assembly 1100 includes a photosensitive chip 110, a stress layer 130 and a first intermediate layer 120. The stress layer 130 is disposed on the back side of the photosensitive chip 110. The first intermediate layer 120 is disposed between the photosensitive chip 110 and the stress layer 130. The material properties of the first intermediate layer 120 are between the bottom layer material of the photosensitive chip 110 and the material of the stress layer 130, which can neutralize the incompatible properties of the two, acting as a “bridge” and increasing The adhesion between the two.

The material of the first intermediate layer 120 has little or no influence on the bending of the photosensitive chip assembly 1100, or is consistent with the influence of the stress layer 130 on the bending of the chip. Specifically, the material of the first intermediate layer 120 may be one or more of silicon and silicon dioxide, but the application is not limited thereto.

According to some embodiments, the thickness of the first intermediate layer 120 is 10-20 nm, and can be formed by a coating process such as physical vapor deposition, chemical vapor deposition, etc., such as vacuum evaporation, magnetron sputtering, etc., or atomic layer deposition. And other processes are formed.

Similarly, when the photosensitive chip assembly is attached to the circuit board with an adhesive, the stress layer and the adhesive may have inappropriate properties and are difficult to bond. For this reason, the inventors of the present invention propose the third and fourth types of photosensitive chip assembly structures in the photosensitive chip assemblies implemented in the first and second exemplary embodiments described above.

Fig. 12 shows the second structural schematic diagram of the photosensitive chip assembly according to the third exemplary embodiment of the present application; Fig. 13 shows the third structural schematic diagram of the photosensitive chip assembly according to the fourth exemplary embodiment of the present application.

The photosensitive chip assembly structure shown in FIG. 12 does not include the first intermediate layer 120; the photosensitive chip assembly structure shown in FIG. 13 includes the first intermediate layer 120. Hereinafter, Figures 120 and 13 are combined together for description.

As shown in FIG. 12, the photosensitive chip assembly 1100 includes a photosensitive chip 110, a stress layer 130 and a second intermediate layer 140. The stress layer 130 is disposed on the back side of the photosensitive chip 110. The second intermediate layer 140 is disposed on the opposite side of the stress layer 130 to the photosensitive chip 110. As shown in FIG. 13, the photosensitive chip assembly 1100 includes a photosensitive chip 110, a stress layer 130, a first intermediate layer 120 and a second intermediate layer 140. The stress layer 130 is disposed on the back side of the photosensitive chip 110. The first intermediate layer 120 is disposed between the photosensitive chip 110 and the stress layer 130. The second intermediate layer 140 is disposed on the opposite side of the stress layer 130 to the photosensitive chip 110.

The material of the second intermediate layer 140 is suitable for stable bonding between the stress layer 130 and the adhesive, wherein the adhesive functions to bond the photosensitive chip 110 to the circuit board. At the same time, it does not affect the bending of the photosensitive chip 110 and the stress layer 130, or its influence is consistent with the influence of the stress layer 130 on the bending of the photosensitive chip 110. At this time, the bending of the photosensitive chip assembly 1100 is the result of the comprehensive influence of the stress layer 130 and the second intermediate layer 140.

Specifically, the bonding performance between the second intermediate layer 140 and the stress layer 130 and the adhesive is better than the bonding performance between the stress layer 130 and the adhesive. The material of the second intermediate layer 140 may be a nano-coating that increases the adhesion between the stress layer 130 and the adhesive, and is generally a hydrophilic material, such as porous silicon dioxide, titanium dioxide, hydrophilic silicon coating solution, etc. , But this application is not limited to this.

According to some embodiments, the thickness of the second intermediate layer is 10-20 nm, which can be formed by physical vapor deposition, chemical vapor deposition and other coating processes, such as vacuum evaporation, magnetron sputtering, etc., or atomic layer deposition, etc. The process forms the second intermediate layer 140.

As shown in FIGS. 10-13, due to the addition of the stress layer 130, the first intermediate layer 120, and the second intermediate layer 140, the thickness of the photosensitive chip assembly 1100 will increase. Therefore, before forming the stress layer 130, the first intermediate layer 120, and the second intermediate layer 140, the thickness of the silicon substrate on the bottom side of the photosensitive chip 110 may be ground to reduce the thickness of the formed chip and meet the general chip requirements.

When the above-mentioned photosensitive chip assembly is used in a camera module, it is usually fixed on a carrier board together with electronic components. According to some embodiments of the present application, the carrier board may be a separate circuit board, and the electronic components and the photosensitive chip assembly are electrically connected to the carrier board. According to other embodiments of the present application, as shown in FIG. 14, the carrier board 1200 may further include a flexible circuit board 1210 and a reinforcing board 1220. The electronic component 1300 and the photosensitive chip assembly 1100 are disposed on the flexible circuit board 1210 and electrically connected to the flexible circuit board 1210, and the stress layer 130 is located between the sensor chip 110 and the flexible circuit board 1210. The reinforcing plate 1220 is disposed under the flexible circuit board 1210 to support the flexible circuit board 1210.

Optionally, as shown in FIG. 15, the carrier board 1200 further includes a circuit board 1210 and a reinforcement board 1220, the circuit board 1210 has an opening 1211, and the electronic component 1300 is disposed on the circuit board 1210. The reinforcing plate 1220 is disposed under the circuit board 1210, and the photosensitive chip assembly 1100 is disposed on the reinforcing plate 1220 and located in the opening 1211. The electronic component 1300 and the photosensitive chip assembly 1100 are electrically connected to the circuit board 1220, and the stress layer 1300 is located between the sensing chip 110 and the circuit board 1210. In this embodiment, the photosensitive chip assembly 1100 is disposed on the reinforcing plate 1220 and located in the opening 1211. Such a configuration can reduce the thickness of the entire camera module.

The above-mentioned fixing solution is introduced by taking the photosensitive chip assembly of the first exemplary embodiment of the present application as an example, and it is also applicable to photosensitive chip assemblies in other exemplary embodiments.

FIG. 16 shows a schematic structural diagram of a photosensitive component package of a camera module according to an exemplary embodiment of the present application.

As shown in FIG. 16, the camera module photosensitive component package 1000 includes a photosensitive chip component 1100, a carrier board 1200, an electronic component 1300, a packaging component 1400, and a filter component 1500.

The photosensitive chip assembly 1100 is adhered to the carrier board 1200 by an adhesive 900. The carrier board 1200 is electrically connected to the photosensitive chip assembly 1100 to transmit digital signals. The electronic component 1300 is disposed on the carrier board 1200, is electrically connected to the carrier board 1200, and provides auxiliary circuits for the transmission and processing of digital signals.

The packaging component 1400 is disposed on the carrier board 1200. The packaging component 1400 and the carrier board 1200 surround a cavity 1441 for accommodating the photosensitive chip assembly 1100 and the electronic component 1300, and the packaging component 1400 has a microlens array 111 exposing the photosensitive chip assembly 1100 Light-transmitting window 1442. The filter element 1500 is disposed on the packaging component 1400 and covers the light-transmitting window 1442, and is used to filter out infrared light to improve the imaging effect.

When the photosensitive chip assembly 1100 is attached to the carrier board 1200 by the adhesive 900, and heating is required to cure the adhesive 900, the central area of the photosensitive chip 110 remains flat or recessed, which is similar to that of the photosensitive chip 110 in the prior art. Compared with the upward protrusion of the central area, curvature of field can be improved. As a result, the camera module can be clearer around the camera when the center of the camera is clear. The package body has a simple structure and a simple packaging process.

The package structure provided in this embodiment can prevent contamination of photosensitive chips, electronic components, circuit boards, and the like.

FIG. 17 shows a schematic structural diagram of a photosensitive component package of a camera module according to another exemplary embodiment of the present application.

Optionally, the packaging component 1400 is integrally formed on the carrier board 1200 by transfer molding, injection molding, or compression molding. The packaging component 1400 covers the photosensitive chip assembly 1100 and the electronic components 1300, and the packaging component 1400 has a light-transmitting window 1442 exposing the micro lens array 111 of the photosensitive chip assembly 1100.

The size of the package body structure is reduced in all directions of length, width, and height to prevent the adhesive from separating out, and the package component 1400 further protects the electronic components and the connecting wires.

FIG. 18 shows the second structural diagram of a photosensitive component package of a camera module according to another exemplary embodiment of the present application.

Optionally, the packaging component 1400 includes a molding part 1443 and a supporting part 1444. The molding part 1443 is disposed on the carrier board 1200 and covers the electronic component 1300. The supporting portion 1444 is disposed on the molding portion 1443. The molding portion 1443 and the supporting portion 1444 enclose a cavity for accommodating the photosensitive chip assembly 1100 and the electronic component 1300, and the supporting portion 1444 has a microlens array exposing the photosensitive chip assembly 1100 111 of the light-transmitting window 1442.

The packaging process of the package body structure is simple, the warpage generated during the packaging process is small, the dirt is small, and the dimensions in the length and width directions are reduced.

It should be noted that the structural schematic diagrams of the photosensitive component package shown in FIGS. 16-18 are described by taking the photosensitive chip assembly of the first exemplary embodiment of the present application as an example, and are also applicable to photosensitive chips of other exemplary embodiments of the present application. Components.

In addition, the present application also provides a camera module including the above-mentioned photosensitive chip assembly package.

FIG. 19 shows a schematic structural diagram of a camera module according to an exemplary embodiment of the present application

As shown in FIG. 19, the camera module 2000 further includes a lens assembly 1600 configured and installed on the packaging component 1400 for capturing and focusing a target object to be photographed to be transferred to the photosensitive chip assembly 1100. The lens assembly 1600 includes a lens 1610, a lens carrier or a motor 1620. The field curvature of the photosensitive chip assembly 1100 and the field curvature of the lens 1610 are in the same direction and the difference is controlled within ±10um.

It should be noted that the schematic structural diagram of the camera module shown in FIG. 19 is described by taking the photosensitive chip assembly of the first exemplary embodiment of the present application as an example, and is also applicable to the photosensitive chip assembly of other exemplary embodiments of the present application.

The photosensitive chip assembly provided by the present application controls the bending direction and degree of the photosensitive chip by providing a stress layer on the back of the traditional photosensitive chip to control the field curvature of the photosensitive chip so that the bending direction of the photosensitive chip is consistent with the field curvature direction of the lens. Thereby improving the clarity of imaging. In addition, in order to ensure a good combination between the stress layer and the photosensitive chip or between the circuit board, a first intermediate layer and/or a second intermediate layer are provided in the photosensitive chip assembly, so that the bending of the photosensitive chip can be maintained for a long time.

The embodiments of the present application are described in detail above, and specific examples are used in this article to illustrate the principles and implementation manners of the present application. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present application. At the same time, any changes or deformations made by those skilled in the art based on the ideas of the application, the specific implementation and the scope of application of the application, are all within the protection scope of the application. In summary, the content of this specification should not be construed as a limitation on this application.

Claims

A photosensitive chip assembly, including:

The photosensitive chip includes a substrate, an active area on the substrate, and a microlens array on the active area;

The stress layer is arranged on the back side of the photosensitive chip, so that the photosensitive chip deforms toward the substrate of the photosensitive chip.
The photosensitive chip assembly of claim 1, wherein the stress layer has a thickness of 0.1um-10um.
3. The photosensitive chip assembly of claim 2, wherein the photosensitive chip has a thickness of 100um to 200um.
The photosensitive chip assembly of claim 3, wherein the stress layer comprises:

Compensation film, the thermal expansion coefficient of the compensation film is greater than or equal to the thermal expansion coefficient of the microlens array.
The photosensitive chip assembly according to claim 3, wherein the thickness of the compensation film is greater than or equal to the thickness of the microlens array.
The photosensitive chip assembly according to claim 3, wherein the material of the compensation film includes at least one of silicon oxide, magnesium fluoride, aluminum oxide, and titanium oxide.
The photosensitive chip assembly according to claim 3, wherein the compensation film includes a PVD film and/or a CVD film.
8. The photosensitive chip assembly according to claim 7, wherein the PVD film comprises at least one of a vacuum vapor deposition film, a magnetron sputtering film, and an atomic layer deposition film.
The photosensitive chip assembly according to claim 3, wherein:

The active area also includes a photosensitive area, which is arranged under the microlens array and receives light from the outside reaching the front surface of the photosensitive chip;

The stress layer includes a stress film, the stress film has a predetermined thickness, and the stress generated during the coating process causes the photosensitive area of the photosensitive chip to deform toward the substrate of the photosensitive chip.
9. The photosensitive chip assembly of claim 9, wherein the stress film includes at least one of a silicon dioxide film, a magnesium fluoride film, a silicon nitride film, and an aluminum nitride film.
9. The photosensitive chip assembly of claim 9, before the stress film is coated, the back surface of the photosensitive chip is a flat surface.
9. The photosensitive chip assembly according to claim 9, wherein a part of the photosensitive chip corresponding to the photosensitive area is substantially flush with the back surface of the photosensitive chip.
The photosensitive chip assembly according to claim 9, wherein a part of the photosensitive chip corresponding to the photosensitive area is convex toward the direction of the stress film, and the distance of the convexity ranges from 2 m to 10 m.
9. The photosensitive chip assembly of claim 9, wherein the stress film is attached to the entire back surface of the photosensitive chip.
The photosensitive chip assembly of claim 9, wherein the area of the photosensitive chip is 5 mm 2 -40 mm 2 .
15. The photosensitive chip assembly according to any one of claims 1-15, wherein the photosensitive chip assembly further comprises:

The first intermediate layer is disposed between the photosensitive chip and the stress layer, and the bonding performance between the first intermediate layer and the substrate and the stress layer is better than that of the substrate and the stress layer Binding performance between.
The photosensitive chip assembly according to claim 16, wherein the photosensitive chip assembly further comprises:

The second intermediate layer is arranged on the opposite side of the stress layer to the photosensitive chip, and the second intermediate layer adheres the photosensitive chip assembly to the carrier board on which the photosensitive chip assembly is mounted through an adhesive .
8. The photosensitive chip assembly according to any one of claims 4-8, wherein the photosensitive chip assembly further comprises:

The second intermediate layer is arranged on the opposite side of the stress layer to the photosensitive chip, and the second intermediate layer adheres the photosensitive chip assembly to the carrier board on which the photosensitive chip assembly is mounted through an adhesive .
The photosensitive chip assembly according to claim 17 or 18, wherein the bonding performance between the second intermediate layer and the stress layer and the adhesive is better than that between the stress layer and the adhesive The combination of performance between.
The photosensitive chip assembly according to claim 16, wherein the material of the first intermediate layer includes one or more of silicon and silicon dioxide.
The photosensitive chip assembly according to claim 17 or 18, wherein the material of the second intermediate layer includes one or more of porous silicon dioxide, titanium dioxide, and hydrophilic silicon coating solution.
The photosensitive chip assembly according to claim 16 or 18, wherein the thickness of the first intermediate layer or the second intermediate layer is 10-20 nm.
18. The photosensitive chip assembly according to any one of claims 16-18, wherein the first intermediate layer or the second intermediate layer comprises a physical vapor deposition layer and/or a chemical vapor deposition layer.
A camera module includes:

Lens components, including lenses;

The photosensitive chip assembly according to any one of claims 1 to 23, which is connected to the lens assembly, and the field curvature of the photosensitive chip assembly is in the same direction as the field curvature of the lens and the difference is within ±10um.
The camera module according to any one of claims 24, wherein the camera module further comprises:

A carrier board, the photosensitive chip assembly is arranged on the carrier board;

Electronic components are arranged on the carrier board.
The camera module according to claim 25, wherein the camera module further comprises:

The package component is arranged on the carrier board, the package component and the carrier board surround a cavity for accommodating the photosensitive chip assembly and the electronic component, and the package component has a cavity exposing the photosensitive chip The window of the microlens array of the component;

or

A packaging component covering the photosensitive chip assembly and the electronic component, and the packaging component has a window exposing the microlens array of the photosensitive chip assembly; and

The packaging component is integrally formed on the carrier board by transfer molding, injection molding, or compression molding;

or

The package component includes a molded part, which is disposed on the carrier board and covers the electronic component; and

The supporting portion is provided on the molding portion, the molding portion and the supporting portion surround a cavity for accommodating the photosensitive chip assembly and the electronic component, and the supporting portion has a cavity that exposes the The window of the micro lens array of the photosensitive chip assembly.
The camera module according to claim 26, wherein the camera module further comprises:

The filter element is arranged on the packaging component and covers the window;

The lens assembly is mounted on the packaging component.
The camera module according to claim 25, wherein the carrier board comprises:

A circuit board, the electronic component and the photosensitive chip assembly are electrically connected to the carrier board;

or

A flexible circuit board, the electronic components and the photosensitive chip assembly are arranged on the flexible circuit board and electrically connected to the flexible circuit board; and

A reinforcing plate is arranged under the flexible circuit board to support the flexible circuit board;

or

A circuit board having an opening, and the electronic components are arranged on the circuit board; and

A reinforcing plate is arranged under the circuit board, the photosensitive chip assembly is arranged on the reinforcing plate and located in the opening, and the electronic component and the photosensitive chip assembly are electrically connected to the circuit board.
A terminal device, comprising the camera module according to any one of claims 24-28.