Photosensitive component, camera module and method for assembling photosensitive component

Abstract

The present invention provides a photosensitive component, a camera module and an assembly method of the photosensitive component, wherein the photosensitive chip has a relative photosensitive surface and a non-photosensitive surface; the metal foil has a relative front and back, the front of the metal foil is in contact with the non-photosensitive surface of the photosensitive chip, and the surface area of ​​the front of the metal foil is larger than the surface area of ​​the non-photosensitive surface of the photosensitive chip; the circuit board is electrically connected to the photosensitive surface of the photosensitive chip, and the circuit board is in contact with the back of the metal foil; the package is at least partially located at the periphery of the photosensitive chip, and the package covers the front of the metal foil. The present application solves the problem in the prior art that the heat of the camera module cannot be dissipated in time and the camera module is miniaturized.

Description

Technical Field

[0001] The present invention relates to the technical field of camera modules, and in particular to a photosensitive component, a camera module and an assembling method of the photosensitive component. Background Art

[0002] In recent years, electronic products, smart devices, etc. have been increasingly moving towards miniaturization and high performance. This development trend of electronic products and smart devices has put forward more stringent requirements on the size and imaging capabilities of camera modules, which are one of the standard configurations of electronic products and smart devices, resulting in the development trend of compact camera modules and large image surfaces of photosensitive chips, thereby providing better image quality and higher resolution. In the design of compact camera modules, heat is not easy to dissipate. At the same time, although the increase in the size of the photosensitive chip can capture more light, it will cause the camera module to generate more heat when working. The heat continues to accumulate inside the camera module, and the circuit board and photosensitive chip are prone to warping and deformation, causing the imaging of the camera module to produce field curvature and reduce the imaging quality.

[0003] That is to say, the camera module in the prior art has the problem that heat cannot be dissipated in time.

[0004] Patent CN115700924A discloses a photosensitive component, including a circuit board, a photosensitive chip, a first heat-conducting element, a second heat-conducting element and a mounting seat, wherein the photosensitive chip is mounted on the front side of the annular circuit board and electrically connected to the circuit board, the first heat-conducting element is at least partially accommodated in the central hole of the circuit board and in contact with the back side of the photosensitive chip, the back side of the circuit board is provided with electronic components, the second heat-conducting element is arranged on the back side of the circuit board and covers the electronic components, the mounting seat is arranged on the back sides of the first heat-conducting element and the second heat-conducting element and in contact with the first heat-conducting element and the second heat-conducting element, so that the heat generated by the photosensitive chip is conducted to the mounting seat through the first heat-conducting element for heat dissipation, and the heat generated by the electronic component is conducted to the mounting seat through the second heat-conducting element for heat dissipation, and at the same time, the mounting seat can also act as a reinforcement plate to support the circuit board to enhance the overall structural strength of the photosensitive chip packaging structure.

[0005] In the above-mentioned scheme of the photosensitive component, on the one hand, whether it is the heat dissipation of the photosensitive chip or the heat dissipation of the electronic components on the circuit board (the heat dissipation path of the electronic components and the heat dissipation path of the photosensitive chip are two independent heat dissipation paths), both are achieved by setting a heat conductor on the back of the heat source to dissipate the heat. Even if the heat conductor can increase the heat transfer area, the heat dissipation path is unidirectional, resulting in slow heat dissipation. In addition, the heat source, the heat transfer element and the heat dissipation element are stacked in sequence, resulting in a thick photosensitive component, which is not conducive to the miniaturization of the camera module. For example, the circuit board is about 400µm thick and the photosensitive chip is about 200µm thick. The thickness of the second heat-conducting element is about 500µm, the thickness of the mounting base is about 700µm (500µm is the portion overlapping with the second heat-conducting element in the thickness direction, and 200µm is the portion on the back of the second heat-conducting element), and the thickness of the photosensitive component is about 1300µm; on the other hand, the circuit board is annular. Since circuits and electronic components need to be arranged on the circuit board, it is necessary to increase the circumferential size of the circuit board to allow the circuit board to have sufficient space to meet the electronic design requirements on the circuit board, resulting in a larger circumferential size of the photosensitive component, which is not conducive to the miniaturization design of the camera module. Summary of the invention

[0006] The main purpose of the present invention is to provide a photosensitive component, a camera module and an assembly method of the photosensitive component to solve the problem in the prior art that the heat of the camera module cannot be dissipated in time.

[0007] The main purpose of the present invention is to provide a photosensitive component, a camera module and an assembly method of the photosensitive component, which can reduce the size of the camera module. In order to achieve the above purpose, according to one aspect of the present invention, a photosensitive component is provided, including: a photosensitive chip having a relative photosensitive surface and a non-photosensitive surface; a metal foil having a relative front and back, the front of the metal foil is in contact with the non-photosensitive surface of the photosensitive chip, and the surface area of ​​the front of the metal foil is greater than the surface area of ​​the non-photosensitive surface of the photosensitive chip; a circuit board, which is electrically connected to the photosensitive surface of the photosensitive chip, and the circuit board is in contact with the back of the metal foil; a package, which is at least partially located on the periphery of the photosensitive chip, and the package covers the front of the metal foil.

[0008] Furthermore, the metal foil includes a first area and a second area surrounding the first area, the inner edge of the package body coincides with the outer edge of the first area, at least a portion of the first area contacts the photosensitive chip, and the package body contacts at least a portion of the second area.

[0009] Furthermore, there is a gap between the inner edge of the package body and the peripheral edge of the photosensitive chip, so that the metal foil has an exposed area, and the exposed area has at least one hollow area.

[0010] Furthermore, the circuit board has at least one pad electrically connected to the photosensitive chip, and the pad is exposed through the hollow area.

[0011] Furthermore, a first gap is formed between the outer edge of the hollow area and the inner edge of the package body.

[0012] Furthermore, a second gap is formed between the pad and the edge of the hollow area.

[0013] Furthermore, the circuit board includes a first mounting area for arranging the metal foil and a second mounting area located outside the first mounting area, the outer edge of the metal foil overlaps with the outer edge of the first mounting area, and the second mounting area is covered by the packaging body.

[0014] Furthermore, the second mounting area is provided with an electronic component, and a third gap is formed between the electronic component and the outer edge of the metal foil.

[0015] Furthermore, the packaging body has at least one set of connected first packaging parts and second packaging parts, the extension directions of the first packaging parts and the second packaging parts are perpendicular, the width of the first packaging part is greater than the width of the second packaging part, and the first packaging part covers the electronic component.

[0016] Furthermore, there is a gap between the inner edge of the packaging body and the peripheral edge of the photosensitive chip, so that the metal foil has an exposed area, the exposed area has at least one hollow area, the circuit board has at least one solder pad electrically connected to the photosensitive chip, the solder pad is exposed through the hollow area, and the hollow area is located at the position where the second packaging part is located.

[0017] Furthermore, the surface area of ​​the front side of the metal foil is 1.43 to 2 times the surface area of ​​the non-photosensitive side of the photosensitive chip. It is understandable that the more the area of ​​the metal foil exceeds the surface area of ​​the photosensitive chip, the better the heat transfer effect. However, considering the limitation of the circuit board size due to the miniaturization design requirements of the camera module, as well as the requirements for heat transfer rate, the surface area of ​​the front side of the metal foil is designed to be 1.43 to 2 times the surface area of ​​the non-photosensitive side of the photosensitive chip, which can achieve both heat dissipation efficiency and miniaturization of the photosensitive component.

[0018] Furthermore, at least one side surface of the metal foil is a rough surface.

[0019] According to another aspect of the present invention, a camera module is provided, comprising the above-mentioned photosensitive component, a motor and a lens installed in the motor, wherein the motor and the photosensitive component are assembled together, and the lens is located on the photosensitive path of the photosensitive chip of the photosensitive component.

[0020] Furthermore, the circuit board of the photosensitive component also has a third installation area, and the third installation area is provided with a connecting terminal. The outer edge of the first packaging part of the packaging body of the photosensitive component has a notch, and the notch is used to make way for the third installation area, and the motor is electrically connected to the connecting terminal.

[0021] According to another aspect of the present invention, there is provided a method for assembling a photosensitive component, and the method for assembling a photosensitive component is used to assemble the above-mentioned photosensitive component, and the method for assembling a photosensitive component comprises: mounting a metal foil of the photosensitive component on a first mounting area of ​​a circuit board of the photosensitive component, the metal foil having a first area and a second area located outside the first area, and the first area is provided with a hollow area; covering the hollow area of ​​the first area of ​​the metal foil with a shielding layer; forming a package of the photosensitive component on the second mounting area of ​​the circuit board and the second area of ​​the metal foil; removing the shielding layer; mounting a photosensitive chip of the photosensitive component on the first area, with the photosensitive chip avoiding the hollow area; and electrically connecting the photosensitive chip to the circuit board.

[0022] Furthermore, the package body is formed by a molding process or a compression molding process.

[0023] According to the technical solution of the present invention, a photosensitive chip has a relative photosensitive surface and a non-photosensitive surface; a metal foil has a relative front and back, the front side of the metal foil is in contact with the non-photosensitive surface of the photosensitive chip, and the surface area of ​​the front side of the metal foil is larger than the surface area of ​​the non-photosensitive surface of the photosensitive chip; a circuit board is electrically connected to the photosensitive surface of the photosensitive chip, and the circuit board is in contact with the back side of the metal foil; and a package is at least partially located on the periphery of the photosensitive chip, and the package covers the front side of the metal foil.

[0024] The present application provides a photosensitive component, in which the circuit board is the basis of the photosensitive component and is electrically connected to the photosensitive chip, so that the photosensitive component can connect to the circuit and process signals. The photosensitive chip is a heat source, and a metal foil in contact with the non-photosensitive surface of the photosensitive chip is provided as a heat transfer element, and the surface area of ​​the front side of the metal foil is limited to be larger than the surface area of ​​the non-photosensitive surface of the photosensitive chip to increase the heat transfer area. At the same time, the back side of the metal foil is in contact with the circuit board, and the front side of the metal foil is in contact with the package body, so as to form two heat dissipation paths of the photosensitive chip-metal foil-circuit board, and the photosensitive chip-metal foil-package body. This not only realizes the two-way heat dissipation of the photosensitive chip, thereby enabling the photosensitive chip to dissipate heat faster, but also makes the thickness of the photosensitive component thinner. On the one hand, this is because the thickness of the metal foil of the heat-conducting element is much smaller than the thickness of the first heat transfer element in the background technology (equivalent to the thickness of the circuit board). Thickness), for example, the thickness of the circuit board is 400µm, and the thickness of the metal foil is 40µm. On the other hand, because at least part of the package is located at the periphery of the photosensitive chip, that is, the space occupied by the package and the photosensitive chip in the thickness direction of the photosensitive component overlaps, the photosensitive chip, the metal foil and the package are not stacked in sequence. Moreover, because the space occupied by the heat-conducting metal foil and the circuit board in the thickness direction of the photosensitive component does not overlap, there is enough space on the circuit board for electronic design, and there is no need to increase the circumferential size of the circuit board, which can avoid the circumferential size of the photosensitive component being too large. The control of the circumferential size of the photosensitive component and the thinning of the thickness are conducive to the miniaturization of the photosensitive component. In addition, the package is usually formed by a mold, and the mold itself has a leveling effect on the circuit board. On the other hand, when the package is made of resin material, since the thermal expansion coefficient of the package is closer to that of the circuit board, the photosensitive component is not easy to warp during the curing process of the package, which can make the overall flatness of the photosensitive component higher and can further improve the imaging effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 A partial structural schematic diagram of a photosensitive component according to Embodiment 1 of the present invention is shown;

[0027] Figure 2 Shows Figure 1 The schematic diagram of the structure after the encapsulation is added;

[0028] Figure 3 A cross-sectional view at one angle of the camera module according to the first embodiment of the present invention is shown;

[0029] Figure 4 Shows Figure 3 A cross-sectional view of the camera module from another angle;

[0030] Figure 5 A flow chart showing a method for assembling a photosensitive component according to a first embodiment of the present invention;

[0031] Figure 6 A schematic diagram showing the thermal imaging intensity distribution of the photosensitive chip region according to the first embodiment of the present invention is shown;

[0032] Figure 7 A schematic diagram of thermal imaging intensity distribution of a photosensitive chip region according to the second embodiment of the present invention is shown.

[0033] The above drawings include the following reference numerals:

[0034] 10. Circuit board; 01. First gap; 02. Second gap; 03. Third gap; 11. First mounting area; 12. Second mounting area; 121. Third area; 122. Fourth area; 123. Third mounting area; 124. Electronic component; 13. Connecting terminal; 14. Solder pad; 20. Photosensitive chip; 30. Metal foil; 31. First area; 311. Hollow area; 32. Second area; 40. Package; 41. First packaging part; 411. Notch; 42. Second packaging part; 50. Motor; 51. Terminal block; 60. Lens; 70. Base; 80. Color filter; 90. Adhesive. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0037] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0038] In order to solve the problem in the prior art that the heat of the camera module cannot be dissipated in time, the present invention provides a photosensitive component, a camera module and an assembling method of the photosensitive component.

[0039] The main purpose of the present invention is to provide a photosensitive component, a camera module and an assembly method of the photosensitive component to solve the problem in the prior art that the heat of the camera module cannot be dissipated in time.

[0040] like Figures 1 to 7 As shown, the photosensitive component includes a circuit board 10, a metal foil 30, a photosensitive chip 20 and a package 40. The photosensitive chip 20 has a relative photosensitive surface and a non-photosensitive surface. The metal foil 30 has a relative front and back. The front of the metal foil 30 is in contact with the non-photosensitive surface of the photosensitive chip 20, and the surface area of ​​the front of the metal foil 30 is greater than the surface area of ​​the non-photosensitive surface of the photosensitive chip 20. The circuit board 10 is electrically connected to the photosensitive surface of the photosensitive chip 20, and the circuit board 10 is in contact with the back of the metal foil 30, so that the photosensitive chip 20, the metal foil 30 and the circuit board 10 are stacked in sequence in the thickness direction of the photosensitive component. The package 40 is at least partially located on the periphery of the photosensitive chip 20, and the package 40 covers the front of the metal foil 30.

[0041] The present application provides a photosensitive component, in which a circuit board 10 is the basis of the photosensitive component and is electrically connected to a photosensitive chip 20, so that the photosensitive component can connect to circuits and process signals. The photosensitive chip 20 is a heat source, and a metal foil 30 in contact with the non-photosensitive surface of the photosensitive chip 20 is provided as a heat transfer member, and the surface area of ​​the front side of the metal foil 30 is limited to be larger than the surface area of ​​the non-photosensitive surface of the photosensitive chip 20 to increase the heat transfer area, so that the heat of the photosensitive chip 20 can be quickly conducted away. At the same time, the back side of the metal foil 30 is in contact with the circuit board 10, and the front side of the metal foil 30 is in contact with the package body 40, so as to form two heat dissipation paths of the photosensitive chip 20-metal foil 30-circuit board 10, and the photosensitive chip 20-metal foil 30-package body 40, which not only realizes the two-way heat dissipation of the photosensitive chip 20, thereby enabling the photosensitive chip 20 to dissipate heat faster, but also makes the thickness of the photosensitive component thinner, on the one hand because the thickness of the heat-conducting metal foil 30 is much smaller than that in the background technology. The thickness of the first heat transfer element (equivalent to the thickness of the circuit board) is, for example, 400µm for the circuit board and 40µm for the metal foil. On the other hand, because at least part of the package 40 is located outside the photosensitive chip 20, that is, the space occupied by the package 40 and the photosensitive chip 20 in the thickness direction of the photosensitive component overlaps, and the photosensitive chip 20, the metal foil 30 and the package 40 are not stacked in sequence. Moreover, because the space occupied by the heat conductive metal foil 30 and the circuit board 10 in the thickness direction of the photosensitive component does not overlap, there is enough space on the circuit board 10 for electronic design, and there is no need to increase the circumferential size of the circuit board 10, which can avoid the circumferential size of the photosensitive component being too large. The control of the circumferential size of the photosensitive component and the thinning of the thickness are conducive to the miniaturization of the photosensitive component. Optionally, the material of the metal foil 30 can be stainless steel or copper foil.

[0042] It should be noted that the package body 40 is usually made by molding or compression molding. On the one hand, the mold of the package body 40 has a leveling effect on the circuit board 10 during the molding process. On the other hand, the package body 40 is usually made of resin material, which has a similar thermal expansion coefficient to the circuit board 10. During the curing and cooling process of the package body 40, the shrinkage degree of the package body 40 and the circuit board 10 is similar, so that the circuit board 10 is not prone to warping, and the overall flatness of the photosensitive component is higher. It is precisely because the package body 40 can improve the overall flatness of the photosensitive component that it can allow the metal foil 30 to be designed to be thinner while meeting the thermal conductivity and processability requirements of the metal foil 30, avoiding the photosensitive component from being too thick.

[0043] If the heat dissipation of the photosensitive chip 20 and the flatness of the circuit board 10 are both achieved by the metal interlayer between the photosensitive chip 20 and the circuit board 10, the metal interlayer is thicker in order to meet the support performance, usually more than 150μm, which is not conducive to the miniaturization of the photosensitive component. In contrast, the thickness of the metal foil 30 of the present application can reach 10~50μm, so that the photosensitive component can be made thinner.

[0044] like Figure 1 As shown, the metal foil 30 includes a first area 31 and a second area 32 surrounding the first area 31, the inner edge of the package body 40 coincides with the outer edge of the first area 31, at least a portion of the first area 31 contacts the photosensitive chip 20, and the package body 40 contacts at least a portion of the second area 32. In other words, the metal foil 30 is divided into the first area 31 and the second area 32, and the photosensitive chip 20 covers the first area 31 of the metal foil 30. Among them, the second area 32 is the area of ​​the metal foil 30 outside the first area 31, and the package body 40 covers the second area 32 of the metal foil 30 during the packaging process. By contacting the first area 31 of the metal foil 30 with the photosensitive chip 20, it is ensured that the heat generated by the photosensitive chip 20 can be conducted to the first area 31 to the greatest extent, and further conducted to the second area 32, and the heat generated by the photosensitive chip 20 can be conducted outward in the circumferential direction, which is conducive to accelerating the heat dissipation of the photosensitive chip 20.

[0045] It is understandable that the larger the contact area between the metal foil 30 and the photosensitive chip 20, the better the heat dissipation effect of the photosensitive chip 20. "Contact" can be direct contact, such as the photosensitive chip 20 can be bonded to the area of ​​the circuit board 10 not covered by the metal foil 30 through the adhesive 90 on the side, so that the bottom surface ( Figure 3 The metal foil 30 may be in contact with the metal foil 30 (in the direction shown), or may be in contact with the metal foil 30 through a third substance, such as an adhesive 90.

[0046] It should be noted that "the package body 40 is at least partially located at the periphery of the photosensitive chip 20" means that the package body 40 may include a first part and a second part, the first part is located at the periphery of the photosensitive chip 20 and covers at least the front of the metal foil 30, and the second part covers the non-photosensitive area on the photosensitive surface of the photosensitive chip 20. Since the package body 40 is in direct contact with the photosensitive chip 20, the shrinkage of the package body 40 during the curing process will directly act on the photosensitive chip 20, making the photosensitive chip 20 more prone to warping. The package body 40 can also be completely located at the periphery of the photosensitive chip 20 and in contact with the side wall of the photosensitive chip 20. Although the shrinkage of the package body 40 during the curing process will also directly act on the photosensitive chip 20, the force-bearing surface of the photosensitive chip 20 is the side wall, and the degree of warping will be reduced.

[0047] More preferably, the metal foil such as Figure 1 and Figure 2 As shown, there is a gap between the inner edge of the package body 40 and the peripheral edge of the photosensitive chip 20, so that the first area 31 has an exposed area, and the exposed area has at least one hollow area 311. This means that the local area of ​​the metal foil 30 in the gap is hollow, and the metal foil 30 in the local area is used to connect the part of the first area 31 that contacts the photosensitive chip 20 and the second area 32 of the metal foil 30. The design of the gap between the inner edge of the package body 40 and the peripheral edge of the photosensitive chip 20 can prevent the package body 40 from contacting the photosensitive chip 20. When the package body 40 is a resin material, the package body 40 will shrink during the heating, curing and cooling process, thereby pulling the photosensitive chip in contact with it, which can easily cause the photosensitive chip 20 to warp.

[0048] like Figure 1 and Figure 2 As shown, the circuit board 10 has at least one pad 14 electrically connected to the photosensitive chip 20, and the exposed area has at least one hollow area 311, and the pad 14 is exposed through the hollow area 311. In other words, the metal foil 30 is provided with at least one hollow area 311, and the hollow areas 311 are all located within the first area 31. The hollow area 311 exposes the positions of several pads 14 on the circuit board 10, and the circuit board 10 and the photosensitive chip 20 can achieve the shortest electrical connection path through the pad 14, simplifying the circuit design of the photosensitive component, saving space cost, and facilitating the compact connection of the photosensitive component.

[0049] like Figure 1 to Figure 2As shown, a first gap 01 is formed between the outer edge of the hollow area 311 and the inner edge of the package body 40. That is to say, in the direction away from the center of the circuit board 10, the outer edge of the hollow area 311 and the inner edge of the package body 40 are left at a distance to form the first gap 01. In the assembly process of the photosensitive component, there is a sequence of first molding the package body 40 and then assembling the photosensitive chip 20. The molding edge of the mold needs to be reserved. At the same time, considering the processing and assembly tolerances, the molding liquid or molding powder in the molding process of the package body 40 may overflow into the hollow area 311, or even cover the pad 14, affecting the subsequent electrical connection between the circuit board 10 and the photosensitive chip 20.

[0050] Specifically, the width of the first gap 01 is greater than or equal to 0.132 mm and less than or equal to 5 mm. By properly setting the width range of the first gap 01, the pad 14 is prevented from being covered by the molding liquid or molding powder overflowing from the package body 40, which is conducive to the smooth installation and connection of the subsequent photosensitive chip 20.

[0051] like Figure 1 to Figure 2 As shown, a second gap 02 is formed between the pad 14 and the edge of the hollow area 311. In the direction away from the center of the circuit board 10, the pad 14 closest to the edge of the hollow area 311 is selected as a reference, and the distance between the pad 14 and the edge of the hollow area 311 is the second gap 02. The second gap 02 is used as a processing gap for electrically connecting the circuit board 10 and the photosensitive chip 20, and needs to be reserved.

[0052] Specifically, the width of the second gap 02 is greater than or equal to 0.1 mm and less than or equal to 0.3 mm. By reasonably setting the width of the second gap 02, a processing gap for the electrical connection between the circuit board 10 and the photosensitive chip 20 is reserved, forming an operating space for the electrical connection between the circuit board 10 and the photosensitive chip 20. In addition, the distance between the pad 14 and the package body 40 can be further controlled to prevent the pad 14 from being covered by the molding liquid or molding powder of the package body 40.

[0053] like Figure 1As shown, the circuit board 10 includes a first mounting area 11 for arranging a metal foil 30 and a second mounting area 12 located at the periphery of the first mounting area 11. The outer edge of the metal foil 30 coincides with the outer edge of the first mounting area 11, and the second mounting area 12 is covered by the package body 40. In other words, the first mounting area 11 is used to lay the metal foil 30. The second mounting area 12 is formed along the periphery of the metal foil 30, that is, the circuit board 10 is formed along the periphery of the first mounting area 11. At the same time, the second mounting area 12 is covered by the package body 40, and the edge of the metal foil 30 is not exposed. In other words, the package body 40 covers at least a portion of the metal foil 30 and the second mounting area 12. The package body 40 covers both the metal foil 30 and the circuit board 10, thereby enhancing the connectivity between the metal foil 30 and the circuit board 10. The package body 40 is simultaneously formed in the second area 32 of the metal foil 30 and the second mounting area 12 of the circuit board 10. The good affinity between the package body 40 and the circuit board 10 makes the interface bonding between the package body 40 and the circuit board 10 more solid, stabilizes the connection relationship between the package body 40, the metal foil 30 and the circuit board 10, and avoids the risk of separation of the package body 40 and the metal foil 30 due to the large difference in thermal expansion coefficients.

[0054] like Figure 1 As shown, the second installation area 12 is provided with an electronic component 124, and a third gap 03 is formed between the electronic component 124 and the outer edge of the metal foil 30. That is to say, along the circumference of the metal foil 30, any electronic component 124 is required to form a certain distance, i.e., the third gap 03, from the metal foil 30. The arrangement of the metal foil 30 will not affect the installation and use of the electronic component 124, and the second installation area 12 can also be covered with the package 40 to protect the electronic component 124. The processing and assembly of the electronic component 124 and the metal foil 30 inevitably have tolerances, and the third gap 03 can prevent the electronic component 124 and the metal foil 30 from interfering with each other due to the tolerances, thereby avoiding damage to the electronic component 124.

[0055] Specifically, the width of the third gap 03 is greater than or equal to 0.204 mm and less than or equal to 0.5 mm. It should be noted that the first gap 01, the second gap 02 and the third gap 03 in the present application are all distances within the board surface where the circuit board 10 is located, that is, the lateral distance (in Figure 3 It should be noted that, since the package body 40 can cover part of the electronic component 124 for protection, compared with the existing arrangement of a base on the circuit board 10, the gap space between the base and the electronic component 124 can be effectively saved, thereby reducing the volume of the photosensitive component.

[0056] like Figure 2As shown, the package body 40 has at least one group of connected first packaging parts 41 and second packaging parts 42, the extension directions of the first packaging parts 41 and the second packaging parts 42 are perpendicular, the width of the first packaging parts 41 is greater than the width of the second packaging parts 42, and the first packaging parts 41 cover the electronic components 124. That is to say, the circumferential area of ​​the package body 40 is divided into at least one group of first packaging parts 41 and second packaging parts 42, and the first packaging parts 41 are vertically connected to the second packaging parts 42. Specifically, the second mounting area 12 has a group of third areas 121 and a group of fourth areas 122, and the adjacent third areas 121 and fourth areas 122 extend vertically, the first packaging part 41 covers the third area 121, and the second packaging part 42 covers part of the fourth area 122. By concentrating the electronic components 124 in the third area 121 and the first packaging part 41 covering the electronic components 124, the electronic components 124 are protected, and accordingly, the fourth area 122 can be designed to be narrower, thereby reducing the width of the circuit board 10. In addition, the second packaging part 42 is narrower in width, which is convenient for avoiding the hollow area 311, and further leaves more design space for the hollow area 311 to avoid the pad 14, which is also conducive to avoiding the position of the pad 14 to widen the circuit board 10, thereby avoiding the second packaging part 42 from widening with the circuit board 10, which is conducive to the miniaturization design of the photosensitive component. At the same time, the wider width of the first packaging part 41 is also conducive to protecting the electronic components 124.

[0057] like Figure 2 As shown, the hollow area 311 is located at the position where the second packaging part 42 is located, and the setting positions of the pad 14 and the electronic component 124 are staggered, which not only ensures that the pad 14 and the electronic component 124 have sufficient setting space to reduce the risk of interference between the two, but also avoids increasing the length of the circuit board 10, which is conducive to miniaturization.

[0058] Specifically, the surface area of ​​the front side of the metal foil 30 is 1.43 to 2 times the surface area of ​​the non-photosensitive surface of the photosensitive chip 20. It is understandable that the more the area of ​​the metal foil 30 exceeds the surface area of ​​the photosensitive chip 20, the better the heat transfer effect. However, considering the restrictions on the size of the circuit board due to the miniaturization design requirements of the camera module, as well as the requirements for the heat transfer rate, the surface area of ​​the front side of the metal foil 30 is designed to be 1.43 to 2 times the surface area of ​​the non-photosensitive surface of the photosensitive chip 20, which can achieve both the heat dissipation efficiency and miniaturization of the photosensitive component. In some embodiments, the surface area of ​​the front side of the metal foil 30 is 1.92 times the surface area of ​​the non-photosensitive surface of the photosensitive chip 20.

[0059] like Figures 1 to 5As shown, at least one side of the metal foil 30 is a rough surface. The design of the rough surface can increase the interface bonding force of the adhesive layer between the metal foil 30 and the package 40, the metal foil 30 and the circuit board 10, or the metal foil 30 and the photosensitive chip 20, so that the metal foil 30, the package 40, and the circuit board 10 are firmly assembled together, further improving the reliability of the photosensitive component. The upper surface of the metal foil 30 can be designed as a rough surface, which can make the metal foil 30 and the adhesive have a stronger bonding ability when the metal foil 30 is bonded to the photosensitive chip 20. The lower surface of the metal foil 30 can be designed as a rough surface, which can make the metal foil 30 and the adhesive have a stronger bonding ability when the metal foil 30 is bonded to the circuit board 10, or when the metal foil 30 is embedded in the insulating material of the circuit board 10, the metal foil 30 and the circuit board 10 have a stronger bonding ability.

[0060] Specifically, the surface roughness of the metal foil 30 is in the range of 50-100 μm.

[0061] It should be noted that the smooth surface of the metal foil 30 has insufficient bonding strength with the circuit board 10 and the package body 40. At least one surface of the metal foil 30 needs to be roughened by means of a corresponding process. Preferably, the metal foil 30 is made of copper foil. The use of copper foil is based on the excellent thermal conductivity and ductility of copper materials. Good thermal conductivity helps copper to quickly conduct heat away, and good ductility gives copper a certain toughness, which is not easy to tear when impacted, thereby reducing the possibility of breakage of the photosensitive chip 20 and the circuit board 10. In addition, the surface roughening of the copper can be achieved by browning treatment, that is, immersing the copper plate in a browning solution prepared by hydrogen peroxide, sulfuric acid and additives to roughen the copper surface and generate a layer of brown organic metal film on the copper surface.

[0062] The present application also provides a camera module, including the above-mentioned photosensitive component, a motor 50 and a lens 60 installed in the motor 50, the motor 50 is assembled with the photosensitive component, and the lens is located on the photosensitive path of the photosensitive chip 20 of the photosensitive component. In other words, the camera module includes a photosensitive component, a motor 50 and a lens 60. Of course, the photosensitive component can also include a base 70 and a color filter 80. The base 70 provides a light path for the annular structure, one side of which is pressed against the package body 40, and the other side supports the color filter 80. The motor 50 is bonded to the surface of the side of the base 70 away from the package body 40, and the motor 50 is also provided with a lens 60 and a position sensor. By reasonably setting the architecture of the photosensitive component, the motor 50 and the lens 60 installed in the motor 50, the camera module has a compact structure, can more effectively utilize the heat dissipation measures of the photosensitive component, is conducive to the heat dissipation between the various components, and ensures the image quality while greatly increasing the portability and aesthetics of the photographic module.

[0063] It should be noted that the base 70 and the package body 40 are bonded together by the adhesive 90, and the motor 50 is provided with a lens 60 and a position sensor. When the motor 50 is overheated, the lens is easily deformed, and the sensing accuracy of the position sensor is reduced, thereby affecting the actuation accuracy of the motor 50 and ultimately affecting the imaging quality. By properly selecting an adhesive 90 with a low thermal conductivity, the heat of the package body 40 is difficult to be transferred to the motor 50 through the adhesive 90, thereby avoiding the heat transfer to the motor 50 affecting the imaging quality.

[0064] like Figure 2 As shown, the circuit board 10 of the photosensitive component also has a third mounting area 123, and the third mounting area 123 is provided with a connecting terminal 13. The outer edge of the first packaging part 41 of the packaging body 40 of the photosensitive component has a notch 411, and the notch 411 is used to make room for the third mounting area 123, and the motor 50 is electrically connected to the connecting terminal 13. The outer edge of one of the first packaging parts 41 of the packaging body 40 has a notch 411, and the notch 411 is used to make room for the third mounting area 123 of the circuit board 10 of the photosensitive component, and the motor 50 is electrically connected to the connecting terminal 13 on the third mounting area 123. In other words, the outer edge of one of the first packaging parts 41 has a notch 411, the circuit board 10 has a third mounting area 123 exposed at the notch 411, and the motor 50 has a connecting terminal 51 electrically connected to the third mounting area 123. By reasonably setting the notch 411 and the third installation area 123, the connection between the wiring terminal 51 and the connecting terminal 13 can connect the motor 50 and the circuit board 10, realize the circuit connection, ensure the normal operation of the camera module, and facilitate subsequent disassembly and maintenance.

[0065] The present application also provides an assembly method of a photosensitive component, which is used to assemble the above-mentioned photosensitive component. The assembly method of the photosensitive component is as follows: Step S10: Mounting the metal foil 30 of the photosensitive component on the first installation area 11 of the circuit board 10 of the photosensitive component; Step S20: Covering the hollow area 311 of the first area 31 of the metal foil 30 with a shielding layer; Step S30: Forming a package 40 of the photosensitive component on the second installation area 12 and the second area 32 of the metal foil 30; Step S40: Removing the shielding layer; Step S50: Mounting the photosensitive chip 20 of the photosensitive component on the first area 31, and the photosensitive chip 20 avoids the hollow area 311; Step S60: Electrically connecting the photosensitive chip 20 to the circuit board 10. That is to say, the assembly of the photosensitive component needs to follow reasonable steps. First, a circuit board 10 is provided through step S10. The circuit board 10 is provided with a first mounting area 11 and a second mounting area 12 located outside the first mounting area 11. The first mounting area 11 is provided with a soldering pad 14, and the second mounting area 12 is provided with an electronic component 124. Then, a metal foil 30 is mounted on the first mounting area 11 of the circuit board 10. The metal foil 30 has a first area 31 and a second area 32 located outside the first area 31. The first area 31 is provided with a hollow area 311 for exposing the soldering pad 14. Then, a shielding layer is covered in step S20 in the hollow area 311. After forming the package body 40 on the second mounting area 12 and the second area 32 in step S30, the shielding layer is removed in step S40. Finally, a photosensitive chip 20 is mounted on the first area 31 of the circuit board 10 through steps S50 and S60, and the photosensitive chip 20 is electrically connected to the soldering pad 14 exposed in the hollow area 311. By assembling the package body 40 first and then mounting the photosensitive chip 20, it is effectively avoided that the mold crushes the photosensitive chip 20 and the electrical connection structure between the photosensitive chip 20 and the circuit board 10 when the package body 40 is formed, thereby reducing assembly losses.

[0066] Optionally, the masking layer can be selected from tape, film or glue. After the package body 40 is cured, the glue will shrink and warp, and separate from the circuit board 10, which is convenient for subsequent removal by a centrifugal cleaning process. Among them, the glue can be acrylic resin-HD430, which is cured by UV, and the subsequent stripping machine's glue removal unit uses a high-pressure columnar or fan-shaped nozzle to remove the glue on the product surface. Of course, the glue also selects materials including but not limited to modified acrylic resins such as Vitralit® MASK 20100, which can be removed by a centrifugal cleaning process.

[0067] Specifically, the package body 40 is formed by a molding process or a compression molding process. That is, the metal foil 30 is mounted on the first mounting area 11 of the circuit board 10, and the metal foil 30 has a first area 31 and a second area 32 located outside the first area 31. The first area 31 is provided with a hollow area 311 for the pad 14 to be exposed. Specifically, the second area 32 and the second mounting area 12 together form a packaging area. Subsequently, the package body 40 is formed in the packaging area by molding or compression molding. This effectively improves the assembly efficiency and avoids assembly loss.

[0068] It should be noted that the maximum size of the pressed edge during the packaging process will cause glue overflow. When there is a lot of glue overflow, the hollow area 311 will be contaminated, the appearance will be poor, and even the electrical connection will be affected. Preferably, the material of the package body 40 is epoxy molding compound (EMC). Before the package body 40 is formed, ultraviolet (UV) glue is applied inside the metal material of the circuit board 10 corresponding to the hollow area 311 to be flush with the metal material layer, and finally peeled off after the package body 40 is formed.

[0069] Specifically, if the EMC reaches the limit size of the pressing edge during the packaging process, the packaging of the package body 40 is carried out according to the following process. The first step is to use surface mounting technology (SMT) to directly mount the electronic component 124 on the surface of the circuit board 10 to reduce the space occupied by the component. The second step is to mount the metal foil 30 on the first mounting area 11 of the circuit board 10 of the photosensitive component. The third step is to use plasma technology (Plasma) to clean and activate the packaging material, improve the bonding performance of the package body 40, the metal foil 30, and the circuit board 10, and improve the stability of the package. The fourth step is to apply ultraviolet (UV, Ultraviolet) glue in the hollow area 311 before the package body 40 is formed, flush with the metal foil 30. The fifth step is to cure the UV glue. The sixth step is to use EMC to mold the package body 40. The seventh step is to cut and arrange each photosensitive component after the package body 40 is formed. The eighth step is to peel off and remove the UV glue. The ninth step is to put it into storage after the appearance inspection is normal.

[0070] Embodiment 1

[0071] like Figures 1 to 6As shown, the photosensitive component includes a circuit board 10, a metal foil 30, a photosensitive chip 20 and a package 40. The metal foil 30 is made of copper foil. The copper foil of the photosensitive component is mounted on the first mounting area 11 of the circuit board 10 of the photosensitive component with the help of copper backing adhesive; the hollow area 311 of the first area 31 of the copper foil is covered with acrylic resin-HD430, and UV curing is used to form a shielding layer; the package 40 of the photosensitive component is formed on the circuit board 10 and the copper foil; the degumming unit of the stripping machine uses a high-pressure columnar or fan-shaped nozzle to remove the colloid on the surface of the product; the package 40 is formed by the EMC molding process; the photosensitive chip 20 of the photosensitive component is mounted in the first area 31; and the photosensitive chip 20 is electrically connected to the circuit board 10.

[0072] In this embodiment, the metal foil 30 is a whole copper foil, such as Figure 6 As shown, the temperature of the photosensitive component is 62.82°C, which is much lower than that of the prior art (i.e., the solution without the metal foil 30, in which the temperature of the photosensitive component is 87.2°C), indicating that the photosensitive component of this solution has good heat dissipation.

[0073] Optionally, the thickness of the metal foil 30 is between 10 and 50 μm.

[0074] Table 1 below shows some parameters of the photosensitive component of this embodiment.

[0075] Table 1

[0076] Structure / Parameters thickness Thermal conductivity W / (m·℃) Package 500μm 1.1 Photosensitive chip 200μm - Circuit Board 0.4mm 1.4 DA glue 20μm 0.6 copper 40μm 401 Copper backing adhesive 10μm 0.6

[0077] It can be seen from Table 1 that in the photosensitive component, the stacking height of the package + circuit board is greater than the stacking height of the circuit board + DA glue + copper back glue + photosensitive chip. Therefore, the thickness of the photosensitive component is determined by the stacking height of the package + circuit board, and the thickness of the photosensitive component is 900μm.

[0078] Embodiment 2

[0079] like Figure 7 As shown, the difference from the first embodiment is that the material of the metal foil 30 is different.

[0080] In this embodiment, the material of the metal foil 30 is 316 stainless steel. Figure 7 As shown, the temperature of the photosensitive component is 69.542°C, which is also much lower than the prior art (i.e., the solution without the metal foil 30, in which the temperature of the photosensitive component is 87.2°C), indicating that the photosensitive component of this solution has good heat dissipation.

[0081] Embodiment 3

[0082] In a specific embodiment not shown in the figure, the difference from the first embodiment is that the connection method between the metal foil 30 and the circuit board 10 is different.

[0083] In this embodiment, the metal foil 30 and the circuit board 10 are formed on the circuit board 10 by encapsulating the metal foil 30 with glue.

[0084] Embodiment 4

[0085] In a specific embodiment not shown in the figure, the difference from the first embodiment is that the contact area between the photosensitive chip 20 and the metal foil 30 is different.

[0086] In this embodiment, only a portion of the photosensitive chip 20 is in contact with the metal foil 30 , and another portion of the photosensitive chip 20 is directly disposed on the circuit board 10 .

[0087] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0088] 1. The photosensitive chip 20 is a heat source. A metal foil 30 in contact with the non-photosensitive surface of the photosensitive chip 20 is provided as a heat transfer element, and the surface area of ​​the front side of the metal foil 30 is limited to be larger than the surface area of ​​the non-photosensitive surface of the photosensitive chip 20 to increase the heat transfer area, so that the heat of the photosensitive chip 20 can be quickly transferred out.

[0089] 2. The back side of the metal foil 30 is in contact with the circuit board 10, and the front side of the metal foil 30 is in contact with the package body 40, so as to form two heat dissipation paths of the photosensitive chip 20-metal foil 30-circuit board 10, and the photosensitive chip 20-metal foil 30-package body 40, which not only realizes the two-way heat dissipation of the photosensitive chip 20, but also enables the photosensitive chip 20 to dissipate heat faster.

[0090] 3. The photosensitive component is thinner and has a smaller circumferential size, making the camera module smaller.

[0091] 4. The package body 40 also covers a local area of ​​the circuit board 10 located outside the metal foil 30. The good affinity between the package body 40 and the circuit board 10 makes the interface bonding between the package body 40 and the circuit board 10 more firm, thus avoiding the separation of the metal foil 30 and the circuit board 10.

[0092] 5. During the packaging and molding process of the package body 40, the mold has a leveling effect on the circuit board 10. Moreover, when the package body 40 is made of resin material, since the thermal expansion coefficient of the package body 40 is close to that of the circuit board 10, during the curing and cooling process of the package body 40, the shrinkage degree of the package body 40 and the circuit board 10 is close, making it less likely for the circuit board 10 to warp. The overall flatness of the photosensitive component is higher, thus avoiding warping and deformation of the photosensitive component, thereby greatly reducing the field curvature of the imaging.

[0093] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0094] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0095] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A photosensitive component, It is characterized in that include: A photosensitive chip (20) having a photosensitive surface and a non-photosensitive surface opposite to each other; A metal foil (30) having a front side and a back side opposite to each other, the front side of the metal foil (30) being in contact with the non-photosensitive side of the photosensitive chip (20), and the surface area of ​​the front side of the metal foil (30) being greater than the surface area of ​​the non-photosensitive side of the photosensitive chip (20); A circuit board (10) is electrically connected to the photosensitive surface of the photosensitive chip (20), and the circuit board (10) is in contact with the back surface of the metal foil (30); A packaging body (40) at least partially located on the periphery of the photosensitive chip (20), and the packaging body (40) covers the front surface of the metal foil (30); There is a gap between the inner edge of the package body (40) and the peripheral edge of the photosensitive chip (20), so that the metal foil (30) has an exposed area, and the exposed area has at least one hollow area (311); the circuit board (10) has at least one solder pad (14) electrically connected to the photosensitive chip (20), and the solder pad (14) is exposed through the hollow area (311).

2. The photosensitive component according to claim 1, It is characterized in that A first gap (01) is formed between the outer edge of the hollow area (311) and the inner edge of the packaging body (40).

3. The photosensitive component according to claim 1, It is characterized in that A second gap (02) is formed between the solder pad (14) and the edge of the hollow area (311).

4. The photosensitive component according to claim 1, It is characterized in that The circuit board (10) comprises a first mounting area (11) for arranging a metal foil (30) and a second mounting area (12) located at the periphery of the first mounting area (11), the outer edge of the metal foil (30) coincides with the outer edge of the first mounting area (11), and the second mounting area (12) is covered by the packaging body (40).

5. The photosensitive component according to claim 4, It is characterized in that The second installation area (12) is provided with an electronic component (124), and a third gap (03) is formed between the electronic component (124) and the outer edge of the metal foil (30).

6. The photosensitive component according to claim 5, It is characterized in that The packaging body (40) comprises at least one group of connected first packaging parts (41) and second packaging parts (42); the extension directions of the first packaging parts (41) and the second packaging parts (42) are perpendicular; the width of the first packaging parts (41) is greater than the width of the second packaging parts (42); and the first packaging parts (41) cover the electronic component (124).

7. The photosensitive component according to claim 6, It is characterized in that There is a gap between the inner edge of the packaging body (40) and the peripheral edge of the photosensitive chip (20), so that the metal foil (30) has an exposed area, and the exposed area has at least one hollow area (311). The circuit board (10) has at least one pad (14) electrically connected to the photosensitive chip (20), and the pad (14) is exposed through the hollow area (311), and the hollow area (311) is located at the position where the second packaging part (42) is located.

8. The photosensitive component according to any one of claims 1 to 7, It is characterized in that The surface area of ​​the front side of the metal foil (30) is 1.43 to 2 times the surface area of ​​the non-photosensitive side of the photosensitive chip (20).

9. The photosensitive component according to any one of claims 1 to 7, It is characterized in that At least one side surface of the metal foil (30) is a rough surface.

10. A camera module, It is characterized in that The invention comprises a photosensitive component according to any one of claims 1 to 9, a motor (50), and a lens (60) installed in the motor (50), wherein the motor (50) is assembled with the photosensitive component, and the lens (60) is located on the photosensitive path of the photosensitive chip (20) of the photosensitive component.

11. The camera module according to claim 10, It is characterized in that The circuit board (10) of the photosensitive component further has a third mounting area (123), and the third mounting area (123) is provided with a connecting terminal (13). The outer edge of the first packaging portion (41) of the packaging body (40) of the photosensitive component has a notch (411), and the notch (411) is used to make way for the third mounting area (123). The motor (50) is electrically connected to the connecting terminal (13).

12. A method for assembling a photosensitive component, It is characterized in that The photosensitive component assembly method is used to assemble the photosensitive component according to any one of claims 1 to 9, and the photosensitive component assembly method comprises: The metal foil (30) of the photosensitive component is mounted on the first mounting area (11) of the circuit board (10) of the photosensitive component, wherein the metal foil (30) comprises a first area (31) and a second area (32) located outside the first area (31), and the first area (31) is provided with a hollow area (311); Covering the hollow area (311) of the first area (31) of the metal foil (30) with a shielding layer; Forming a packaging body (40) of the photosensitive component on the second mounting area (12) of the circuit board (10) and the second area (32) of the metal foil (30); removing the shielding layer; A photosensitive chip (20) of the photosensitive component is attached to the first area (31), and the photosensitive chip (20) avoids the hollow area (311); The photosensitive chip (20) is electrically connected to the circuit board (10).

13. The method for assembling a photosensitive component according to claim 12, It is characterized in that The packaging body (40) is formed by a molding process or a compression molding process.

Images