Camera module, electronic equipment, photosensitive component and manufacturing method thereof

Abstract

The present invention relates to a photosensitive component, which includes a combination of a circuit board and a photosensitive chip, a heat dissipation rib arranged on the back of the combination, and at least a part of the heat dissipation rib is located on the back of the photosensitive chip or on the back of the circuit board in an area overlapping with the photosensitive chip. The present invention also provides a corresponding camera module, an electronic device, and a method for manufacturing a photosensitive component. The present invention can avoid or suppress the deformation of the photosensitive chip and improve the imaging quality of the camera module at a relatively small spatial size cost.

Description

Technical Field

[0001] The present invention relates to the technical field of camera modules, and in particular to a camera module, a photosensitive component used in a camera module and a manufacturing method thereof, and corresponding electronic equipment. Background Art

[0002] With the popularization of mobile electronic devices, the relevant technologies of camera modules used in mobile electronic devices to help users obtain images (such as videos or images) have been rapidly developed and improved, and in recent years, camera modules have been widely used in many fields such as medical treatment, security, industrial production, etc.

[0003] In order to meet the increasingly broad market demand, high pixel, large chip, small size and large aperture are the irreversible development trend of existing camera modules. However, it is very difficult to achieve the four requirements of high pixel, large chip, small size and large aperture in the same camera molding. For example, first, the market has put forward higher and higher requirements for the imaging quality of camera modules. How to obtain higher imaging quality with a smaller camera module volume has become a major problem in the field of compact camera modules (such as camera modules for mobile phones), especially based on the technical development trends of high pixel, large aperture and large chip in the mobile phone industry; second, the compact development of mobile phones and the increase in the screen-to-body ratio of mobile phones have made the space inside the mobile phone that can be used for the front camera module smaller and smaller; the number of rear camera modules is increasing, and the area occupied is also increasing, resulting in the corresponding reduction of other configurations of mobile phones such as battery size and motherboard size. In order to avoid the sacrifice of other configurations, the market hopes that the volume of the rear camera module can be reduced, that is, to achieve small-size packaging; third, with the popularization of high-pixel chips and the gradual improvement of functions such as video shooting, chip energy consumption and heat dissipation have become important issues that need to be solved in the module design and manufacturing process.

[0004] The above market demand is the development bottleneck of the camera module packaging industry. The reasons why the above demand has not been solved are mainly analyzed as follows:

[0005] (1) High pixel and large chip size: As the chip size gradually increases, for example, the more common 48-megapixel chip at this stage is 1 / 2 inch in size. In the future, 1 / 1.7-inch chips and even larger chips will become popular, resulting in a rapid increase in chip size. However, since the photosensitive chip is thinner than ordinary chips, only about 0.15mm thick, large chips are more likely to have field curvature problems. At the same time, since the chip and the circuit board are generally connected by glue, the glue coating generally presents a shape with low edges and high middle, such as the cross-shaped glue, which causes the middle of the chip to bulge slightly. Furthermore, when the chip is attached, the nozzle sucks the chip from the top, causing the chip to be imaged in a curved shape with the edges lower than the center. In addition, the coefficient of thermal expansion (CTE) index of the chip, glue, and circuit board is different. For example, the CTE of the chip is 6ppm / C, while that of the PCB is 14ppm / C. The module assembly process generally has a baking process. The different CTE coefficients of various materials will cause the chip to bend. The soft and hard combination boards commonly used in the industry have serious warping due to the lamination process, which will also aggravate the chip bending problem. The above chip bending problem will cause the chip field curvature problem in the final module imaging, and ultimately affect the imaging quality.

[0006] Furthermore, under the current trend of device miniaturization, in the current mainstream compact camera modules (such as camera modules for mobile phones), most of the circuit boards tend not to add additional heat dissipation components to avoid increasing the size of the camera module, but at the same time, the heat dissipation performance of the circuit board itself is not enough to match the heat dissipation performance requirements of the module. However, on the other hand, the current high-end camera modules have developed to 48 million pixels and above, and the demand for video shooting has gradually become prominent, such as 4K high-definition video shooting, slow motion capture, etc. In the future, there will be more high-pixel and high-frame-rate camera modules, and the corresponding photosensitive chip power will be greatly improved. The inventors of this case have found that as the heat generated by the photosensitive chip increases during operation, this heat accumulation causes the photosensitive chip to deform, which is one of the important factors leading to the decline in imaging quality. Specifically, under working conditions, as the temperature inside the camera module increases, the circuit board and the photosensitive chip will bend, thereby reducing the imaging quality. In other words, for high-pixel and high-frame-rate photosensitive chips, even if they are not packaged by molding, they will be affected by temperature and bend. That is, neither molded nor non-molded packaging can solve the bending problem of high-pixel and large chips.

[0007] (2) Miniaturization / small size: In the field of compact camera modules, in order to reduce the size of the camera module and improve manufacturing efficiency, a molding process is adopted to directly form a bracket for the lens assembly or other components on the circuit board (such as MOB or MOC process solutions). Specifically, the camera module may include a photosensitive component and a lens assembly, and the lens group and other optical elements of the lens assembly are arranged on the photosensitive path of the photosensitive element (usually a photosensitive chip) of the photosensitive component. It should be noted that in some solutions, the color filter can be directly installed on the photosensitive component to form a part of the photosensitive component, but in other solutions, the photosensitive component may not contain a color filter, but the color filter is made into an independent color filter assembly or installed in other forms on the light-transmitting path. Therefore, the lens assembly can sometimes be understood as a combination of light-transmitting elements such as a lens group, a color filter and their supporting structural parts. This combination can sometimes also be called a light-transmitting component. Canceling or lowering the position of the color filter can further reduce the height of the module.

[0008] Furthermore, the photosensitive component may include a circuit board and a molded body integrally molded on the circuit board. Since the molded body eliminates the advantage of the avoidance space of the traditional lens holder attached module, the advantages of the module in terms of length, width and height can be further realized. In addition, the molded body can reinforce the strength of the circuit board, and can reduce the thickness requirement of the circuit board while ensuring the flatness of the module, so the circuit board can be thinned. For example, in the MOC packaging process, the photosensitive element is pre-attached to the circuit board, and then a molded body is formed on the circuit board through a molding process. The molded body can wrap the non-photosensitive area of ​​part of the photosensitive element. In the camera module, the combination of the circuit board and the molded body, and the combination of the molded body and the photosensitive chip are both rigid combinations, which are very strong and often require destructive methods to be removed. But at the same time, the circuit board and the photosensitive chip are combined by glue, which is a relatively flexible combination. In addition, the coefficient of thermal expansion (CTE) of the circuit board, molded body, and photosensitive chip is different. When the ambient temperature changes greatly during the manufacturing process (for example, the molding material needs to be raised to above 150 degrees Celsius during the molding process, and the module baking stage needs to be raised to above 80 degrees Celsius. In the subsequent manufacturing process of the camera module, the ambient temperature may change many times), the expansion degree of the circuit board, chip, and molded body is different, and the expansion speed is also different. Among them, the shrinkage degree of the photosensitive chip is often the smallest. However, since the combination of the circuit board and the molded body is a rigid combination, the circuit board and the molded body will generate stress, causing the circuit board and the molded body to bend. This bending will cause the photosensitive chip to deform, especially the upward bending deformation of the photosensitive chip will cause a significant decrease in the imaging quality of the module. Fig.24 The schematic diagram shows the principle of the bending of the circuit board and the molded body causing the deformation of the photosensitive chip. Fig.24The curvature shown is exaggerated. In reality, the curvature may only be a dozen or twenty microns, but this degree of curvature is enough to have a negative impact on the image quality. For example, this curvature may cause the field curvature of the camera module to be too large, and the image obtained by the camera module will appear to be normal in the center but poor in the periphery.

[0009] (3) Large aperture

[0010] As large-pixel chips become more popular, the corresponding improvement of optical performance is also an inevitable trend. For example, the optical parameters of lenses such as large aperture and wide angle will be gradually improved to maximize the resolution performance of photosensitive chips. However, large aperture and wide angle modules have higher requirements for the flatness of the modules.

[0011] Therefore, there is an urgent need for a solution that can avoid or suppress the deformation of the photosensitive chip at a smaller spatial size cost, and there is an urgent need for a solution that can ensure the imaging quality of the camera module (especially the imaging quality under long-term working conditions) at a smaller spatial size cost. Summary of the invention

[0012] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a solution for a photosensitive component and a camera module.

[0013] In order to solve the above technical problems, the present invention provides a photosensitive component, which includes: a combination of a circuit board and a photosensitive chip, wherein the side to which the photosensitive surface of the photosensitive chip faces is the front side of the combination, and the side opposite to the front side is the back side of the combination; and a heat dissipation rib, which is arranged on the back side of the combination, and at least a part of the heat dissipation rib is located on the back side of the photosensitive chip or on the back side of the circuit board in an area overlapping with the photosensitive chip.

[0014] Among them, the circuit board has a first surface for attaching a photosensitive chip and a second surface opposite to the first surface, wherein the first surface has a chip attachment area; the back side of the photosensitive chip is attached to the first surface; the heat dissipation ribs are directly made on the second surface or attached to the second surface, wherein at least a portion of the heat dissipation ribs are located in the area of ​​the second surface corresponding to the back of the chip attachment area.

[0015] In which, the photosensitive component also includes a back side packaging portion, which covers the second surface and fills the gaps between the heat dissipation ribs, wherein the gaps between the heat dissipation ribs are gaps between multiple heat dissipation ribs or gaps between different parts of a single heat dissipation rib, and the back side molding portion is integrated with the heat dissipation ribs.

[0016] Wherein, the bottom surface of the heat dissipation rib is exposed outside the back side packaging part; and the bottom surface of the back side packaging part is flush with the bottom surface of the heat dissipation rib.

[0017] Among them, the back side packaging part is a back side molding part made on the second surface by a molding process, the back side molding part covers the second surface and the bottom surface of the heat dissipation rib, and the distance between the bottom surface of the back side molding part and the bottom surface of the heat dissipation rib is not greater than 0.1 mm.

[0018] Among them, the heat dissipation ribs are multiple parallel straight strip heat dissipation ribs; or multiple heat dissipation ribs arranged in a scattered array; or a single strip heat dissipation rib, and the single strip heat dissipation rib is spiral or "M" shaped, or other strip shapes that can be connected into one but still have gaps between different parts; or the heat dissipation rib is any combination of two or more of the above two.

[0019] Wherein, the heat dissipation ribs are metal heat dissipation ribs or heat dissipation ribs formed by hardening of heat-conducting colloidal material.

[0020] Among them, the photosensitive component also includes a secondary heat dissipation part, the top surface of the secondary heat dissipation part is connected to the bottom surface of the heat dissipation rib, the bottom surface of the back packaging part is flush with the bottom surface of the secondary heat dissipation part, the bottom surface of the secondary heat dissipation part is exposed outside the back packaging part, and the area of ​​the bottom surface of the secondary heat dissipation part is larger than the area of ​​the bottom surface of the heat dissipation rib.

[0021] Wherein, the heat dissipation ribs are attached to the second surface by bonding or welding.

[0022] Among them, the photosensitive component also includes metal wires, and the metal wires electrically connect the photosensitive chip and the circuit board through a wire bonding process, and the circuit board is a PCB circuit board.

[0023] Wherein, the photosensitive component also includes electronic components installed on the circuit board, wherein at least a portion of the electronic components are installed on the second surface and covered by the back side packaging part.

[0024] Wherein, the photosensitive component also includes a front molding part, which is manufactured on the first surface through a molding process and surrounds the photosensitive chip, and the top surface of the front molding part is suitable for installing a lens assembly; wherein there is a gap between the front molding part and the photosensitive chip, or the front molding part extends toward the photosensitive chip and contacts the photosensitive chip.

[0025] Wherein, the photosensitive component also includes a lens holder, which is installed on the first surface and surrounds the photosensitive chip, and the top surface of the lens holder is suitable for installing the lens assembly; wherein the lens holder is formed and then installed on the first surface.

[0026] Wherein, the photosensitive component also includes a lens holder, the lens holder is installed on the front molding part, and the top surface of the lens holder is suitable for installing the lens assembly; wherein the lens holder is formed and then installed on the front molding part.

[0027] Among them, the circuit board has a main through hole, the photosensitive chip is located in the main through hole, and the back side of the combination includes the back side of the circuit board and the photosensitive chip, and at least a part of the heat dissipation rib is located on the back side of the photosensitive chip.

[0028] Wherein, the thickness of the heat dissipation rib is 0.05mm-0.4mm.

[0029] According to another aspect of the present application, a camera module is also provided, which includes: any one of the aforementioned photosensitive components; and a lens assembly, wherein the lens assembly is installed on the photosensitive component.

[0030] According to another aspect of the present application, a method for manufacturing a photosensitive component is also provided, which includes: 1) preparing a circuit board, the circuit board having a first surface for attaching a photosensitive chip and a second surface opposite to the first surface, wherein the first surface has a chip attachment area; 2) manufacturing or attaching heat dissipation ribs on the second surface; 3) covering the second surface with a back side packaging portion, wherein the back side packaging portion covers the second surface and fills the gaps between the heat dissipation ribs, wherein the gaps between the heat dissipation ribs are gaps between multiple heat dissipation ribs or gaps between different parts of a single heat dissipation rib; the bottom surface of the heat dissipation rib is exposed outside the back side packaging portion and the bottom surface of the back side packaging portion is flush with the bottom surface of the heat dissipation rib; and 4) mounting a photosensitive chip on the first surface, thereby manufacturing the photosensitive component.

[0031] Wherein, in the step 2), the heat dissipation ribs are attached by welding or bonding.

[0032] Wherein, in the step 1), the circuit board has a seed layer, and in the step 2), a metal layer is implanted on the seed layer so that the metal layer grows and exceeds the second surface, thereby forming the heat dissipation ribs.

[0033] Wherein, in the step 2), a heat-conductive colloid substance is coated on the second surface, and then the heat-conductive colloid substance is hardened to form the heat dissipation ribs.

[0034] Wherein, in the step 2) and the step 3), the back side packaging part is formed on the second surface by a molding process.

[0035] Wherein, the step 2) is performed first and then the step 3).

[0036] Wherein, the step 3) is performed first and then the step 2); wherein in the step 3), the back side packaging part is formed on the second surface by a molding process, and during the molding process, a through hole is left in the back side packaging part by a pressing head, and the through hole exposes a part of the second surface outside the back side packaging part; then, in the step 2), the heat dissipation rib is made in the through hole of the packaging part.

[0037] The photosensitive component manufacturing method further includes the following steps performed after step 3): 3a) manufacturing a secondary packaging portion on the bottom surface of the back packaging portion through a molding process, wherein the secondary packaging portion has a secondary through hole, and the secondary through hole exposes the bottom surface of the heat dissipation rib and the adjacent area of ​​the bottom surface of the back packaging portion around the heat dissipation rib; and 3b) manufacturing a heat dissipation extension portion in the secondary through hole, wherein the top surface of the heat dissipation extension portion is connected to the bottom surface of the heat dissipation rib, and the bottom surface of the heat dissipation extension portion is flush with the bottom surface of the secondary packaging portion; wherein the heat dissipation extension portion is manufactured by implanting a metal layer or injecting a heat-conductive colloidal substance and hardening it, or by bonding or welding a formed component.

[0038] Wherein, the step 4) also includes installing at least a portion of electronic components on the second surface; and performing the step 4) first and then performing the step 3); and in the step 3), the back side packaging layer covers at least a portion of the electronic components installed on the second surface.

[0039] Wherein, the step 4) also includes: making a front molding part on the first surface, the front molding part is made on the first surface by a molding process and surrounds the photosensitive chip, and the top surface of the front molding part is suitable for installing a lens assembly.

[0040] Wherein, in the step 3), the back side packaging part is a back side molding part, and the front side molding part and the back side molding part are simultaneously formed on the circuit board through the same molding process.

[0041] Among them, in the step 1), the circuit board is a circuit board panel in which multiple single circuit boards are connected into one; in the step 2), heat dissipation ribs corresponding to the multiple single circuit boards are made on the circuit board panel; in the step 3), the back packaging part corresponding to the multiple single circuit boards is made by one-time molding; in the step 4), photosensitive chips are respectively installed on the first surfaces corresponding to the multiple single circuit boards to obtain a photosensitive component panel; and the photosensitive component manufacturing method also includes the step: 5) cutting the photosensitive component panel to obtain separated single photosensitive components.

[0042] According to another aspect of the present application, an electronic device is provided, which includes any one of the camera modules described above.

[0043] Compared with the prior art, the present invention has at least one of the following technical effects:

[0044] 1. The photosensitive component and camera module of the present application can avoid or suppress the deformation of the photosensitive chip at the cost of a smaller space size.

[0045] 2. The photosensitive component and camera module of the present application improve the structural strength of the circuit board.

[0046] 3. The photosensitive component and camera module of the present application improve the heat dissipation efficiency of the photosensitive chip.

[0047] 4. The photosensitive component and camera module of the present application can ensure the imaging quality of the camera module at the cost of a smaller space size.

[0048] 5. The photosensitive component and camera module of the present application are particularly suitable for high-pixel, high-frame-rate camera modules.

[0049] 6. The photosensitive component and camera module of the present application are particularly suitable for combination with MOC and MOB technologies.

[0050] 7. The photosensitive assembly and camera module of the present application can reduce the radial size of the camera module by placing some electronic components on the back of the circuit board, where the radial size refers to the size in the direction perpendicular to the optical axis.

[0051] 8. The back side of the photosensitive component of the present application can be a flat surface, which is convenient for subsequent manufacturing processes and for adapting to other components of the terminal device (such as a mobile phone).

[0052] 9. The back side of the photosensitive component of the present application can be a flat surface, which is more suitable for large-scale mass production.

[0053] 10. The photosensitive component and camera module of the present application have high production efficiency.

[0054] 11. In the photosensitive component of the present application, the heat dissipation ribs on the back are combined with the packaging part, which on the one hand improves the structural strength of the circuit board, and on the other hand improves the heat dissipation efficiency of the photosensitive chip, avoids excessive heat accumulation, and reduces the stress that causes the bending of the circuit board due to different thermal expansion coefficients. Therefore, the photosensitive component of the present application can suppress the bending of the photosensitive chip from two aspects.

[0055] 12. The photosensitive component of the present application can suppress the bending of the photosensitive chip by preventing excessive heat accumulation and increasing structural strength. Therefore, the thickness of the packaging part and the heat dissipation ribs on the back of the circuit board can be relatively reduced. In other words, the present application can achieve the effect of suppressing the bending of the photosensitive chip at a lower thickness cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A cross-sectional schematic diagram of a composite substrate 1000 for a camera module in one embodiment of the present application is shown;

[0057] Figure 2 Shows Figure 1 A three-dimensional schematic diagram of a composite substrate 1000 is shown;

[0058] Figure 3 A front schematic diagram of a composite substrate 1000 on which a photosensitive chip 50 is mounted in one embodiment of the present application is shown;

[0059] Figure 4 A cross-sectional schematic diagram of a photosensitive component 2000 including a composite substrate 1000 in one embodiment of the present application is shown;

[0060] Figure 5 A schematic diagram of the back side of a composite substrate in a modified embodiment of the present application is shown;

[0061] Figure 6 A schematic diagram of the back side of a composite substrate in another modified embodiment of the present application is shown;

[0062] Figure 7 A photosensitive component 2000 based on a composite substrate according to another embodiment of the present application is shown;

[0063] Figure 8 A photosensitive component 2000 based on a composite substrate according to another embodiment of the present application is shown;

[0064] Fig. 9 A cross-sectional schematic diagram of a photosensitive component according to another modified embodiment of the present application is shown;

[0065] Fig.10 A cross-sectional schematic diagram of a photosensitive component according to a modified embodiment of the present application is shown;

[0066] Fig.11The circuit board 10 in step S10 is shown;

[0067] Fig.12 A schematic diagram showing the process of making heat dissipation ribs 20 on the second surface 15 of the circuit board 10 in step S20 is shown;

[0068] Fig.13 A schematic diagram showing the step S30 of placing the circuit board 10 in a mold to form a molding cavity in one embodiment of the present application is shown;

[0069] Fig.14 A schematic diagram showing a method of injecting liquid molding material into a molding cavity and molding a packaging portion 30 in one embodiment of the present application is shown;

[0070] Fig.15 The composite substrate obtained after the mold is opened is shown, and the composite substrate includes a circuit board 10, a heat dissipation rib 20 and a packaging part 30;

[0071] Fig.16A A circuit board panel including a connector portion is shown;

[0072] Fig. 16B A circuit board panel without a connector portion is shown;

[0073] Fig.17 A schematic diagram showing the formation of a molding cavity after mold closing in step S30 of one embodiment of the present application is shown;

[0074] Fig.18 A schematic diagram showing the molding process in step S30 of one embodiment of the present application is shown;

[0075] Fig.19 A schematic diagram after mold opening in step S30 of one embodiment of the present application is shown;

[0076] Fig. 20 A schematic diagram showing the formation of a molding cavity after mold closing in step S31 of one embodiment of the present application is shown;

[0077] Fig.21 A schematic diagram showing the molding process in step S31 of one embodiment of the present application is shown;

[0078] Fig. 22 A schematic diagram after mold opening in step S31 of one embodiment of the present application is shown;

[0079] Fig.23 A composite substrate with a heat dissipation extension portion in one embodiment of the present application is shown;

[0080] Fig.24 The schematic diagram shows the principle that the bending of the circuit board and the molded body causes the deformation of the photosensitive chip;

[0081] Fig.25 A cross-sectional schematic diagram of a camera module in one embodiment of the present application is shown;

[0082] Fig.26 A cross-sectional schematic diagram of a camera module in another embodiment of the present application is shown;

[0083] Fig. 27 A cross-sectional schematic diagram of a camera module in another embodiment of the present application is shown;

[0084] Fig.28 A cross-sectional schematic diagram of a camera module in another embodiment of the present application is shown;

[0085] Fig.29 A cross-sectional schematic diagram of a camera module in another embodiment of the present application is shown;

[0086] Fig.30 A cross-sectional schematic diagram of a camera module in another embodiment of the present application is shown;

[0087] Fig.31 A cross-sectional schematic diagram of a camera module in another embodiment of the present application is shown;

[0088] Fig.32 A cross-sectional schematic diagram of a composite substrate 1000 in another embodiment of the present application is shown;

[0089] Fig.33 A schematic diagram showing the step S30 of placing the circuit board 10 in a mold to form a molding cavity in another embodiment of the present application is shown;

[0090] Fig.34 A schematic diagram showing another embodiment of the present application in which liquid molding material is injected into a molding cavity to form a packaging portion 30 is shown. DETAILED DESCRIPTION

[0091] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0092] It should be noted that in this specification, the expressions of first, second, etc. are only used to distinguish one feature from another feature, and do not represent any limitation on the feature. Therefore, without departing from the teaching of this application, the first subject discussed below can also be referred to as the second subject.

[0093] In the drawings, the thickness, size and shape of objects have been slightly exaggerated for ease of explanation. The drawings are only examples and are not drawn strictly to scale.

[0094] It should also be understood that the terms "comprises", "including", "having", "includes" and / or "comprising", when used in this specification, indicate the presence of the stated features, wholes, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, parts and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0095] As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation, not degree, and are intended to account for the inherent variations in measurements or calculations that would be recognized by those of ordinary skill in the art.

[0096] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as commonly understood by ordinary technicians in the field to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having the same meaning as their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0097] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0098] As mentioned above, as mobile phone camera modules develop towards high pixels and high frame rates, the heat generated by photosensitive chips during operation is getting larger and larger. The inventors of this case have found that the accumulation of heat and the increase in the size of the photosensitive chip (high pixels lead to an increase in the size of the photosensitive chip) make the photosensitive chip prone to deformation, and the deformation is sufficient to cause the imaging quality of the camera module to decline. Specifically, under the current development trend of the mobile phone market (mobile phone camera module market), first, the photosensitive chip itself has a large area and high power, generating a large amount of heat; second, the photosensitive chip has a large area and a small thickness. This ratio makes the chip itself easily affected by foreign objects; third, the photosensitive chip is affected by the force generated by foreign objects such as circuit boards and molding deformation, making the photosensitive chip more prone to deformation. Based on this, the applicant proposed a composite substrate that can suppress the above-mentioned deformation, as well as a photosensitive component and a camera module based on the composite substrate. The following will refer to the accompanying drawings and combine with the embodiments to describe the present application in detail.

[0099] Figure 1 FIG. 1 is a cross-sectional schematic diagram of a composite substrate 1000 for a camera module in one embodiment of the present application. Figure 1 In this embodiment, the composite substrate 1000 includes a circuit board 10, heat dissipation ribs 20 and a back packaging portion 30. The circuit board 10 has a first surface 14 for attaching a photosensitive chip and a second surface 15 opposite to the first surface 14. The heat dissipation ribs 20 are directly made on the second surface 15. The material used to make the heat dissipation ribs has good thermal conductivity. In this embodiment, the thermal conductivity coefficient of the material used for the heat dissipation ribs is 10-1000W / mK. The specific material can be copper, aluminum, silver, metal alloys or thermal conductive silicone grease and other materials. The back packaging portion 30 covers the second surface 15 and fills the gaps between the heat dissipation ribs 20. Furthermore, Figure 2 Shows Figure 1 The three-dimensional schematic diagram of the composite substrate 1000 is shown. Figure 2 The circuit board 10 may include a circuit board body 11 , a connector 12 and a flexible connecting tape 13 . Figure 1 Only the circuit board body 11 is shown in the figure. In this embodiment, the heat dissipation ribs 20 are actually attached to the back of the circuit board body 11, so the connector 12 and the flexible connecting belt 13 are omitted in some drawings. In this embodiment, the circuit board body 11 can be a PCB board. The heat dissipation ribs 20 are a plurality of parallel linear strip heat dissipation ribs 21. Correspondingly, the back packaging part 30 is filled between the plurality of parallel linear strip heat dissipation ribs 21 and covers the second surface 15. For the sake of clarity, Figure 2 The back side packaging part 30 is shown separately from the circuit board 10. The back side packaging part 30 can be made on the second surface 15 by a molding process. Of course, in other embodiments, the back side packaging part 30 can also be implemented by other packaging processes such as injection molding and molding, as long as the second surface 15 can be covered and the gap between the heat dissipation ribs 20 can be filled to achieve packaging.

[0100] Here, based on different packaging methods, the setting of the back packaging part is based on different packaging processes, and the setting of the heat dissipation ribs has different requirements. If it is processed by transfer molding, since the mold needs to press the surface of the circuit board to form a flow channel, the direction of the heat dissipation ribs should preferably be parallel to the molding pressing edge (that is, the exposed edge of the circuit board), or at a certain angle, such as 45 degrees or less to the pressing edge, to facilitate the injection of molding fluid and prevent "under-injection". The compression molding process mainly uses molding powder for packaging. There is a certain gap in the surface flatness of the compression molding package compared to the molded package.

[0101] Further, Figure 3FIG. 1 is a front view of a composite substrate 1000 with a photosensitive chip 50 mounted thereon in one embodiment of the present application. For ease of understanding, the side facing the photosensitive surface is uniformly referred to as the front side, and the side facing away from the photosensitive surface is uniformly referred to as the back side. Figure 3 In this embodiment, the photosensitive chip 50 is attached to the center of the circuit board 10. The area of ​​the first surface 14 of the circuit board 10 for attaching the photosensitive chip 50 is called a chip attachment area. Figure 4 FIG. 2 is a cross-sectional schematic diagram of a photosensitive component 2000 including a composite substrate 1000 in one embodiment of the present application. Figure 3 and Figure 4 , it can be seen that in this embodiment, a part of the heat dissipation rib 20 is located in the area corresponding to the back of the chip attachment area of ​​the second surface. Among them, part of the linear strip heat dissipation ribs 21 are located in the area behind the chip attachment area and the two ends of these linear strip heat dissipation ribs 21 extend to the part outside the chip attachment area. Another part of the linear strip heat dissipation ribs 21 are located in the edge area of ​​the circuit board 10, that is, all of these linear strip heat dissipation ribs 21 are located outside the chip attachment area. In this embodiment, since at least a part of the heat dissipation ribs 20 are arranged in the area overlapping with the photosensitive chip, the distance between the photosensitive chip and the heat dissipation ribs can be shortened, and the heat dissipation efficiency can be increased. In this embodiment, the bottom surface of the heat dissipation ribs is exposed outside the back packaging part to improve the heat dissipation effect. In this embodiment, the back heat dissipation ribs are combined with the packaging part, which, on the one hand, improves the structural strength of the circuit board, and on the other hand, improves the heat dissipation efficiency of the photosensitive chip, avoids excessive heat accumulation, and reduces the stress that causes the circuit board to bend due to different thermal expansion coefficients. Therefore, the photosensitive component of the present application can suppress the bending of the photosensitive chip from two aspects.

[0102] Further, still refer to Figure 1In one embodiment of the present application, the bottom surface of the back packaging portion is flush with the bottom surface of the heat dissipation rib. In this way, the back of the photosensitive component in this embodiment can be a flat surface, which is convenient for the subsequent manufacturing process, convenient for adaptation with other components of the terminal device (such as a mobile phone), and more suitable for large-scale mass production. Further, in this embodiment, the thickness of the heat dissipation rib 20 can be 0.05mm-0.4mm, ensuring that the strength of the photosensitive component can be effectively enhanced without increasing the thickness of the camera module too much, and the bending effect of the photosensitive chip can be suppressed by the dual effects of enhancing structural strength and improving heat dissipation, thereby effectively preventing the imaging quality of the camera module (such as field curvature performance) from decreasing. In addition, since the molded body can play the role of reinforcing the circuit board, the circuit board selected in the present technical solution can be thinner than the circuit board of the conventional design solution, and generally reduces the thickness of the circuit board by 0.1mm, so in some cases, the module height will not be increased. Conventional circuit boards are generally 0.35mm or thicker (e.g., 0.35mm-0.45mm), while MOB modules can be made less than 0.3mm thick, and ideally less than 0.25mm. Note that in this embodiment, thickness refers to the axial dimension, i.e., the dimension in the optical axis direction of the camera module. The axial direction can also be understood as the normal direction of the photosensitive surface or the first surface.

[0103] It should be noted that, although in the above embodiment, the bottom surface of the back packaging portion is flush with the bottom surface of the heat dissipation rib, the present application is not limited thereto. Fig.32A cross-sectional schematic diagram of a composite substrate 1000 in another embodiment of the present application is shown. In this embodiment, the back side encapsulation part 30 is a back side molding part directly formed on the second surface 15 (i.e., the back side) of the circuit board by a molding process, and the back side molding part covers the bottom surface of the heat dissipation rib 20, rather than being flush with the bottom surface of the heat dissipation rib 20. This solution can help improve the product yield. Since the incoming material consistency of the molding material may be insufficient, if the back side encapsulation part that is flush with the bottom surface and the heat dissipation rib is to be directly made during molding, the problem of uneven molding bottom surface may sometimes be encountered. Therefore, in this embodiment, the back side molding part covers the bottom surface of the heat dissipation rib 20, so that a bottom surface 38 completely composed of molding material can be obtained, and this bottom surface 38 can have a very high flatness, and the process difficulty is reduced, and the requirements for the quality of the molding material can be reduced, which is conducive to improving the product yield and reducing production costs. Furthermore, in one embodiment of the present application, on the basis that the back molding portion covers the second surface and the bottom surface of the heat dissipation rib, the spacing between the bottom surface 38 of the back molding portion and the bottom surface of the heat dissipation rib may be no greater than 0.1 mm, and the spacing between the bottom surface 38 of the back molding portion and the second surface 15 may be no greater than 0.2 mm (i.e., the thickness of the back molding portion is no greater than 0.2 mm). The composite substrate thus obtained still has a relatively small thickness. Furthermore, in one embodiment of the present application, when the back molding portion covers the second surface 15 and the bottom surface of the heat dissipation rib 20, the thickness of the circuit board can be further reduced to 0.25 mm or less.

[0104] Further, still refer to Figure 3 In one embodiment of the present application, the photosensitive chip 50 is rectangular, and the rectangle has a long side L and a short side W. The heat dissipation ribs 20 are composed of a plurality of parallel straight strip heat dissipation ribs. The plurality of parallel straight strip heat dissipation ribs can be parallel to the long side L of the photosensitive chip 50. A typical photosensitive chip is a 16:9 rectangle, and the chip usually has different degrees of warping on the long side and the short side. The direction of the heat dissipation ribs used in this embodiment is more conducive to suppressing and preventing the photosensitive chip from bending, so it is preferred to arrange the heat dissipation ribs in a direction parallel to the long side of the photosensitive chip.

[0105] In another embodiment of the present application, the circuit board 10 (actually the circuit board body 11) is rectangular, the rectangle has a long side and a short side, and the plurality of linear strip heat dissipation ribs are parallel to the long side of the circuit board 10. The direction of the heat dissipation ribs used in this embodiment is more conducive to suppressing and preventing the photosensitive material from bending. Figure 3 In the embodiment, the long side direction of the photosensitive chip is consistent with the long side direction of the circuit board, but the present application is not limited to this, because sometimes the long side of the photosensitive chip and the long side of the circuit board can be perpendicular.

[0106] Further, Figure 5 FIG. 1 is a schematic diagram showing the back side of a composite substrate in a modified embodiment of the present application. Figure 5 In this embodiment, the heat dissipation rib 20 adopts another shape, that is, the heat dissipation rib 20 is composed of a single connected strip heat dissipation rib. When viewed from an upward angle, the heat dissipation rib 20 is generally in the shape of a "M". At this time, the gap between the heat dissipation ribs can be understood as the gap between different parts of a single heat dissipation rib. The back packaging part 30 fills the gap to achieve packaging. This embodiment can strengthen the structural strength of the circuit board in the diagonal direction, horizontal direction, and vertical direction, support the circuit board in multiple directions, suppress the warping of the four corners of the photosensitive component, strengthen the ability to hinder the bending of the photosensitive component, and alleviate the bending of the photosensitive component. In some cases, because the glue (i.e., glue material) inside the chip is coated and concentrated in the middle, or because the suction nozzle adsorbs the chip from the top to attach it to the circuit board, the chip is prone to bend upward in the center, and the degree of the above-mentioned bending may be aggravated in subsequent processes. In a preferred embodiment of the present invention, the M-shaped, X-shaped or cross-shaped heat dissipation ribs, whose center position of the heat dissipation rib structure corresponds to the center area of ​​the chip, reinforce and fix the center part of the chip, which is beneficial to suppress the upward warping of the center of the chip and the warping of the four corners of the photosensitive component, thereby suppressing the field curvature of the chip.

[0107] Further, Figure 6 FIG. 2 shows a schematic diagram of the back side of a composite substrate in another variant embodiment of the present application. Figure 6 In this embodiment, the heat dissipation rib 20 adopts another shape, that is, the heat dissipation rib 20 is composed of a single strip heat dissipation rib connected in one body. When viewed from above, the heat dissipation rib 20 is generally in the shape of a square spiral. Figure 5 Similar to the embodiment of FIG. 1 , in this embodiment, the gap between the heat dissipation ribs can be understood as the gap between different parts of a single heat dissipation rib. The back packaging part 30 fills the gap to achieve packaging. This embodiment can enhance the structural strength of the circuit board, support the circuit board in multiple directions, enhance the ability to prevent the bending of the photosensitive component, and alleviate the bending of the photosensitive component.

[0108] It should be noted that the present application may also use heat dissipation ribs 20 of other shapes, such as "X"-shaped heat dissipation ribs, "circular"-shaped or ring-shaped heat dissipation ribs, etc. The heat dissipation ribs 20 may also be a plurality of small heat dissipation ribs arranged in a scattered array. The heat dissipation ribs 20 may also be a combination of two or more of the aforementioned types. For example, on the back of the same circuit board, a plurality of parallel straight-line strip heat dissipation ribs and a "rice"-shaped heat dissipation rib may be arranged at the same time. Various combinations may be flexibly arranged, and will not be described one by one in this article.

[0109] Furthermore, in one embodiment of the present application, the heat dissipation ribs can be made of metal material. For example, a multi-layer PCB board can be used as a circuit board. The multi-layer PCB board has multiple layers, and each layer can be arranged with circuits and designed functional circuits. The different layers can be connected through copper pillars (or other metal pillars) to connect the entire circuit board (electrically) into a whole. In this embodiment, a copper seed layer can be made in a certain layer of the circuit board, and then copper pillars can be planted on the seed layer by electroplating and grown to the second surface (i.e., the back surface) of the circuit board, thereby forming the required heat dissipation ribs. In this embodiment, the manufacturing process of the heat dissipation ribs can be compatible with the process in the production of the circuit board, easy to mass produce, and the obtained composite substrate has a high structural strength. The layer of the multi-layer PCB board used to make the seed layer may not be used for circuit conduction, but is dedicated to strengthening the structural strength of the circuit board.

[0110] In another embodiment of the present application, the heat dissipation ribs may be formed by using a heat-conducting colloid substance. For example, the heat-conducting colloid substance may be coated on the second surface (i.e., the back surface) of the circuit board in a desired shape, and then the heat-conducting colloid substance is hardened to form the heat dissipation ribs. The heat-conducting colloid substance may be, for example, heat-conducting silicone grease.

[0111] In another embodiment of the present application, the heat dissipation ribs may be formed first and then attached to the second surface (i.e., the back surface) of the circuit board by bonding or welding. The preformed heat dissipation ribs may be made of metal or hardened thermally conductive colloid, such as thermally conductive silicone grease.

[0112] Further, still refer to Figure 4 According to an embodiment of the present application, a photosensitive component 2000 based on a composite substrate is provided. The photosensitive component 2000 includes a composite substrate. The composite substrate may include a circuit board 10, a heat dissipation rib 20 and a back packaging unit 30. The photosensitive chip 40 is attached to the first surface 14 of the circuit board 10. The heat dissipation rib 20 is directly made on the second surface 15 of the circuit board 10. The back packaging unit 30 is on the second surface 15 and fills the gap between the heat dissipation ribs 20 to achieve a packaging effect. The photosensitive component 2000 also includes an electronic component 50, which can be mounted on the first surface 14 and arranged around the photosensitive chip 40. The electronic component 50 can be, for example, a passive device such as a capacitor or an inductor, or an active device such as a memory chip or an image processor chip. The photosensitive component can also include a metal wire 60, which can electrically connect the photosensitive chip and the circuit board through a wire bonding (its English name is Wire Bonding, which can also be called "wire bonding", "binding", "binding" or "wire bonding") process. The metal wire 60 can be a metal wire with good conductivity, such as a gold wire, an aluminum wire or a copper wire.

[0113] Further, Figure 7 Another embodiment of the present invention is a photosensitive component 2000 based on a composite substrate. Figure 4 ) is that the electronic component 50 is arranged on the back side of the circuit board 10, that is, the electronic component 50 is installed on the second surface 15. The back packaging unit 30 can wrap the electronic component 50 or fill it around the electronic component 50, so as to realize the packaging of the back side of the circuit board. In this embodiment, since the electronic components can be arranged on the back side of the circuit board, the space on the front side of the circuit board for arranging the electronic components can be omitted, which helps to reduce the radial dimension of the photosensitive component. In this embodiment, the radial dimension refers to the dimension in the direction perpendicular to the optical axis of the camera module. The thickness direction of the circuit board can be called the axial direction, which is parallel to the optical axis of the camera module. It should be noted that the electronic components can be arranged entirely on the back side of the circuit board, or partially on the back side of the circuit board and the other part on the front side of the circuit board.

[0114] Further, Figure 8 FIG. 2 shows a photosensitive component 2000 based on a composite substrate according to another embodiment of the present application. Figure 4 Compared with the embodiment, the difference of this embodiment is that a secondary heat dissipation part 22 is added. Among them, the top surface of the secondary heat dissipation part 22 is connected to the bottom surface of the heat dissipation rib 20. The bottom surface of the back packaging part 30 can be flush with the bottom surface of the secondary heat dissipation part 22, and the bottom surface of the secondary heat dissipation part 22 is exposed outside the back packaging part 30. The area of ​​the bottom surface of the secondary heat dissipation part 22 is larger than the area of ​​the bottom surface of the heat dissipation rib 20. In this way, the surface area of ​​the heat dissipation component can be increased and the heat dissipation efficiency can be improved. It should be noted that Figure 8 The above is not the only implementation form of the secondary heat dissipation part 22. For example, in another embodiment, the longitudinal section of the secondary heat dissipation part 22 may be trapezoidal, so that the cross-sectional area of ​​the secondary heat dissipation part gradually increases from the top surface to the bottom surface. This implementation method can also increase the surface area of ​​the heat dissipation component and improve the heat dissipation efficiency.

[0115] Further, Fig. 9 A cross-sectional schematic diagram of a photosensitive component according to another variant embodiment of the present application is shown. Fig. 9 In this embodiment, the back packaging part of the photosensitive component is cancelled, that is, the heat dissipation rib 20 is made on (or attached to) the second surface (back side) of the circuit board 10. The bottom and side surfaces of the heat dissipation rib 20 are exposed. The heat dissipation rib 20 can be a plurality of parallel linear strip heat dissipation ribs, or a plurality of heat dissipation ribs arranged in a scattered array, or a single strip heat dissipation rib, and the single strip heat dissipation rib is spiral or "M" shaped, or other strip shapes that can be connected into one but still have gaps between different parts; the rib can also be any combination of two or more of the above two items.

[0116] Furthermore, in one embodiment of the present application, the photosensitive component may also include a front molding portion, which may be manufactured on the first surface by a molding process and surround the photosensitive chip. In this embodiment, there is a gap between the front molding portion and the photosensitive chip, i.e., MOB process. Moreover, in this embodiment, the top surface of the front molding portion is suitable for installing a lens assembly. Here, the lens assembly may be a lens assembly with a motor or a lens assembly without a motor.

[0117] Furthermore, in another embodiment of the present application, the photosensitive component may also include a front molding portion, which may be manufactured on the first surface by a molding process and surround the photosensitive chip, and the front molding portion extends toward the photosensitive chip and contacts the photosensitive chip (for example, the front molding portion may cover the edge area of ​​the photosensitive chip), i.e., an MOC process. Moreover, in this embodiment, the top surface of the front molding portion is suitable for installing a lens assembly. Here, the lens assembly may be a lens assembly with a motor or a lens assembly without a motor. The lens assembly and the photosensitive component are assembled together to obtain a camera module.

[0118] It should be noted that when the photosensitive component is packaged using the MOC process, the photosensitive chip may be more prone to bending because the molded body is integrally formed with the photosensitive chip. For example, for photosensitive components packaged using the MOC process, the photosensitive chip may bend not only after long-term use, but also during the manufacturing process. For another example, for photosensitive components packaged using the MOC or MOB process, not only high-pixel and high-frame-rate camera modules may bend after long-term use, but this bending phenomenon may also occur in camera modules with relatively low pixel numbers and frame rates. This is because during the molding process, the temperature change in the manufacturing environment is relatively large (for example, from room temperature to more than 150 degrees, and then back to room temperature), and the molding material and the circuit board have different thermal expansion coefficients, so stress is easily generated between the two, and the photosensitive components of the MOC / MOB module are more prone to bending. Therefore, for the photosensitive components packaged by MOC / MOB process, the heat dissipation ribs in the above embodiment are arranged on the back of the circuit board, which can achieve a more obvious effect in suppressing the bending of the photosensitive chip. Furthermore, the combination of the molded body and the heat dissipation ribs can also reduce the thickness requirement of the circuit board, and at the same time can have good flatness, and the heat dissipation performance is significantly improved compared with the existing products.

[0119] Further, in another embodiment of the present application, the front molded portion can be replaced by a lens holder (sometimes also referred to as a lens holder). The lens holder is formed and then mounted on the first surface. Specifically, the lens holder is mounted on the first surface and surrounds the photosensitive chip, and the top surface of the lens holder is suitable for mounting a lens assembly.

[0120] Further, in another embodiment of the present application, the photosensitive component may further include a color filter, which may be mounted on the front molding portion or the lens holder. When the color filter is mounted on the front molding portion, the top surface of the front molding portion may form a step structure, and the color filter is mounted on the step structure.

[0121] Further, in another embodiment of the present application, the photosensitive component may not include a color filter. A color filter component may be added to the camera module, and the color filter component includes a lens holder and a color filter mounted on the lens holder. The photosensitive component may have a front molding portion, and the bottom of the lens holder is mounted on the top surface of the front molding portion. The lens assembly is mounted on the top surface of the lens holder.

[0122] It should be noted that in the above embodiments, the photosensitive chips are attached to the front side of the circuit board, that is, the first surface, but the present application is not limited to this. In a modified embodiment, the center of the circuit board may have a main through hole that can accommodate the photosensitive chip, and the photosensitive chip can be installed in the main through hole. This manufacturing process helps to reduce the axial size of the photosensitive component. That is, reduce the size of the optical axis direction (referring to the optical axis of the camera module or lens assembly). Fig.10 A cross-sectional schematic diagram of a photosensitive component of a modified embodiment of the present application is shown. Fig.10 It can be seen that in this embodiment, the circuit board and the photosensitive chip form a combination, wherein the side to which the photosensitive surface of the photosensitive chip faces is the front side of the combination, and the side opposite to the front side is the back side of the combination. The heat dissipation ribs are located on the back side of the combination, wherein the heat dissipation ribs are directly made on or attached to the back side of the combination. Moreover, in this embodiment, the back side of the combination includes the back side of the circuit board and the photosensitive chip, and at least a portion of the heat dissipation ribs are located on the back side of the photosensitive chip.

[0123] Furthermore, according to another embodiment of the present application, a method for manufacturing a photosensitive component is also provided, which includes the following steps S10-S40 performed in sequence.

[0124] Step S10, preparing a circuit board 10. Fig.11The circuit board 10 in step S10 is shown. The circuit board 10 has a first surface 14 for attaching a photosensitive chip and a second surface 15 opposite to the first surface 14, wherein the first surface 14 has a chip attachment area. The circuit board 10 in this step can be a PCB board, which can be made by itself or ordered on the market (note that there is no such product on the market at present, in other words, the structure of the circuit board 10 itself described in this step is not prior art).

[0125] Step S20 , manufacturing heat dissipation ribs 20 on the second surface 15 (ie, the back side) of the circuit board 10 . Fig.12 FIG. 2 is a schematic diagram showing the process of making heat dissipation ribs 20 on the second surface 15 of the circuit board 10 in step S20. At least a portion of the heat dissipation ribs 20 is located directly below the chip attachment area (note that Fig.12 The circuit board 10 is turned upside down, so that Fig.12 The heat dissipation rib 20 is located above the circuit board 10), that is, the area on the second surface 15 that overlaps with the chip attachment area. In this embodiment, the heat dissipation rib 20 can be set to a preset shape. For example, the heat dissipation rib can be composed of a plurality of parallel linear strip heat dissipation ribs.

[0126] Step S30, covering the second surface with a back side encapsulation part, wherein the back side encapsulation part covers the second surface and fills the gaps between the heat dissipation ribs, wherein the gaps between the heat dissipation ribs are gaps between multiple heat dissipation ribs or gaps between different parts of a single heat dissipation rib; the bottom surface of the heat dissipation rib is exposed outside the back side encapsulation part and the bottom surface of the back side encapsulation part is flush with the bottom surface of the heat dissipation rib. In this embodiment, the back side encapsulation part can be formed on the second surface by a molding process. Specifically, Fig.13 A schematic diagram showing the process of placing the circuit board 10 in a mold to form a molding cavity in step S30 in one embodiment of the present application is shown. Fig.14 FIG. 1 is a schematic diagram showing a process of injecting liquid molding material into a molding cavity and molding the packaging portion 30 in one embodiment of the present application. Fig.13 , the circuit board 10 is placed in a mold, which includes an upper mold 91 and a lower mold 92. The second surface 15 of the circuit board 10 faces upward, and the second surface 15 has heat dissipation ribs 20. There is a gap between the heat dissipation ribs 20, the bottom surface of the upper mold 91 presses on the end surface of the heat dissipation ribs 20, and the lower mold 92 bears against the first surface 14 of the circuit board 10. After the upper and lower molds are closed, a molding cavity is formed between the upper mold 91, the circuit board 10 and the heat dissipation ribs 20. Then, refer to Fig.14 ,exist Fig.13 The liquid molding material is injected into the molding cavity, and the liquid molding material is solidified to form the packaging part 30. Further, Fig.15The composite substrate obtained after the mold is opened is shown, and the composite substrate includes a circuit board 10, a heat dissipation rib 20 and a packaging part 30. It should be noted that although the above embodiment adopts a solution in which the bottom surface of the back molding part is flush with the bottom surface of the heat dissipation rib, the present application is not limited to this. For example, in another embodiment of the present application, the back molding part can cover the second surface 15 and the bottom surface of the heat dissipation rib 20 at the same time (refer to Fig.32 In this embodiment, the upper mold 91 and the bottom surface of the heat dissipation rib 20 (at Figure 13-14 The bottom surface of the middle heat dissipation rib 20 is facing upwards) and a gap 39 (reference Fig.33 , Fig.33 Schematic diagram showing the step S30 in another embodiment of the present application of placing the circuit board 10 in the mold to form a molding cavity). The gap 39 can be 0.1 mm (or other values, such as 0.06 mm, generally not greater than 0.1 mm). Further, Fig.34 A schematic diagram of another embodiment of the present application is shown in which liquid molding material is injected into the molding cavity and formed into a packaging portion 30. Since the incoming consistency of the molding material may be insufficient, if a back packaging portion that is flush with the bottom surface and the heat dissipation rib is to be directly made during molding, the problem of uneven molding bottom surface may sometimes be encountered. By making the back molding portion cover the bottom surface of the heat dissipation rib, a bottom surface completely composed of molding material can be obtained. This bottom surface can have a very high flatness, and the process difficulty is reduced, and the requirements for the quality of the molding material can be reduced, which is beneficial to improving product yield and reducing production costs. Furthermore, in one embodiment of the present application, when the back molding portion covers the second surface and the bottom surface of the heat dissipation rib, the thickness of the circuit board can be further reduced to 0.25 mm or less.

[0127] Step S40, installing a photosensitive chip and other components (such as electronic components, metal wires, lens holders, color filters, etc.) on the first surface (i.e., the front side) of the circuit board to produce the photosensitive assembly. The photosensitive chip can be attached to the chip attachment area of ​​the first surface.

[0128] Furthermore, in one embodiment, in step S20, the heat dissipation ribs can be directly made on the second surface of the circuit board. For example, the circuit board can have a seed layer, and a metal layer is planted on the seed layer so that the metal layer grows and exceeds the second surface, thereby forming the heat dissipation ribs. For another example, in a modified embodiment, a heat conductive colloid can be coated on the second surface, and then the heat conductive colloid is hardened to form the heat dissipation ribs.

[0129] Furthermore, in another embodiment, the heat dissipation rib may be pre-formed and then attached to the second surface of the heat dissipation rib by welding or bonding.

[0130] In the above embodiments, heat dissipation ribs are first made and then molded to form a back packaging portion. However, the present application is not limited to this. For example, in another embodiment of the present application, another method for making a photosensitive component is also provided. Different from the manufacturing method of the aforementioned embodiment, in this embodiment, the back packaging portion can be first molded on the back of the circuit board to form a back packaging portion, and then the heat dissipation ribs are made or attached to the second surface (i.e., the back) of the circuit board. Specifically, in this embodiment, the execution order of step S30 and step S20 is reversed, that is, step S30 is executed first and then step S20. Among them, in step S30, the back packaging portion can be formed on the second surface by a molding process, and during the molding process, a through hole can be left in the back packaging portion by using a pressure head (or a raised structure of an upper mold), and the through hole exposes a portion of the second surface outside the back packaging portion. Fig.17 FIG. 1 is a schematic diagram showing a molding cavity formed after mold closing in step S30 of an embodiment of the present application. Fig.17 It can be seen that the upper mold 91 has a plurality of downward protruding structures 93 , which press against the second surface 15 of the circuit board 10 , and a molding cavity surrounding the protruding structures 93 can be formed between the upper mold 91 and the circuit board 10 . Fig.18 FIG. 1 is a schematic diagram showing the molding process in step S30 of an embodiment of the present application. Fig.18 It can be seen that the liquid molding material is injected into the molding cavity and solidified to obtain the backside encapsulation part 30 . Fig.18 As can be seen in the figure, the back side packaging part 30 can surround the protruding structures 93, or the back side packaging part 30 can fill the gaps between the protruding structures 93 and the gaps between the protruding structures 93 and the mold. Fig.19 FIG. 1 is a schematic diagram showing the process of opening the mold (sometimes also referred to as demoulding) in step S30 of an embodiment of the present application. Fig.19 After the mold is opened, the back packaging part 30 is reserved with a through hole 31, which can be in a strip shape. Step S20 is performed on the circuit board with the back packaging part 30. In the step S20, the heat dissipation rib is made in the through hole of the back packaging part, so as to obtain Fig.15 The composite substrate shown.

[0131] Furthermore, in one embodiment, after the steps S20 and S30, the following steps S31 and S32 may also be performed.

[0132] Step S31, making a secondary packaging part on the bottom surface of the back packaging part through a molding process, the secondary packaging part has a secondary through hole, and the secondary through hole exposes the bottom surface of the heat dissipation rib and the adjacent area of ​​the bottom surface of the back packaging part around the heat dissipation rib. Fig. 20 FIG. 1 is a schematic diagram showing a molding cavity formed after mold closing in step S31 of an embodiment of the present application. Fig. 20 It can be seen that in this embodiment, the upper mold 91 can have a plurality of downward protrusion structures 93, and these protrusion structures 93 support the upper surface of the composite substrate (referring to the composite substrate obtained after completing steps S20 and S30 (the composite substrate can be composed of a circuit board 10, a heat dissipation rib 20 and a back packaging portion 30), in this embodiment, the composite substrate is actually still a semi-finished product) (note that due to Fig. 20 The composite substrate is inverted, and its upper surface is actually the back surface), and a molding cavity surrounding the protruding structure 93 can be formed between the upper mold 91 and the composite substrate. Fig.21 FIG. 1 is a schematic diagram showing the molding process in step S31 of an embodiment of the present application. Fig.21 It can be seen that by injecting liquid molding material into the molding cavity and solidifying it, the reserved secondary through hole ( Fig. 22 The secondary molding part (shown in FIG. 1 ) is the secondary packaging part 32. Further, Fig. 22 FIG. 1 is a schematic diagram showing the process of opening the mold (sometimes also referred to as demoulding) in step S31 of an embodiment of the present application. Fig. 22 After the mold is opened, a composite substrate having a secondary packaging portion 32 can be obtained. The secondary packaging portion 32 has a secondary through hole 33, and the secondary through hole 33 exposes the bottom surface of the heat dissipation rib 20 ( Fig. 22 The middle bottom surface faces upward) and an adjacent area 34 of the bottom surface of the back packaging portion around the heat dissipation rib 20.

[0133] Step S32, making a heat dissipation extension portion in the secondary through hole to obtain a composite substrate with the heat dissipation extension portion. Fig.23 A composite substrate with a heat dissipation extension portion in one embodiment of the present application is shown. The composite substrate can be used to manufacture Figure 8 The photosensitive component shown. Figure 8 and Fig.23 The top surface of the heat dissipation extension portion 22 is connected to the bottom surface of the heat dissipation rib 20, and the bottom surface of the heat dissipation extension portion 22 is flush with the bottom surface of the secondary packaging portion 32 (note that Fig.23 The bottom surface is placed upwards.) The heat dissipation extension part 22 is made by implanting a metal layer or injecting a heat-conducting colloid material and hardening it, or by bonding or welding a formed component.

[0134] Further, in one embodiment of the present application, the step S40 may further include: mounting at least a portion of electronic components on the second surface of the circuit board. The step of mounting electronic components on the second surface may be performed prior to the step S30. Thus, in the step S30, the backside encapsulation layer may cover the electronic components mounted on the second surface (or fill the gaps around the electronic components) to achieve an encapsulation effect.

[0135] Furthermore, in one embodiment, the step S40 may also include: making a front molding portion on the first surface of the circuit board, the front molding portion is made on the first surface by a molding process and surrounds the photosensitive chip, and the top surface of the front molding portion is suitable for installing a lens assembly.

[0136] Furthermore, in one embodiment, in step S30, the back side encapsulation part is a back side molding part, and the front side molding part and the back side molding part can be simultaneously molded on the circuit board by the same molding process, which will help improve production efficiency and save costs.

[0137] Furthermore, in one embodiment, in step S10, the prepared circuit board may be a circuit board panel formed by connecting a plurality of single circuit boards together. Fig.16A A circuit board panel with a connector part is shown. The circuit board panel can be a rigid-flexible board. Fig. 16B A circuit board panel without a connector part is shown. The circuit board panel may be a PCB board, or a hard board. Further, in the present embodiment, in the step S20, the heat dissipation ribs are made on the second surface (i.e., the back surface) of the circuit board panel. That is, heat dissipation ribs corresponding to a plurality of individual circuit boards are made at one time. In the step S30, the back side packaging portion corresponding to a plurality of individual circuit boards may be made by molding at one time, and the back side packaging portion may be integrally covered on the second surface of the circuit board panel. In the step S40, photosensitive chips may be respectively pasted (or installed in other ways) on the first surfaces corresponding to the plurality of individual circuit boards, thereby obtaining a photosensitive component panel. Further, the photosensitive component manufacturing method of the present embodiment also includes a step S50: cutting the photosensitive component panel to obtain separated individual photosensitive components.

[0138] Based on the photosensitive component manufacturing method of the above embodiment, the obtained photosensitive component can be further assembled with the lens assembly to obtain a complete camera module. The lens assembly here can be a lens assembly with a motor or a lens assembly without a motor. The assembled camera module can be an autofocus camera module or a fixed-focus camera module.

[0139] Further, Fig.25FIG. 1 is a cross-sectional schematic diagram of a camera module in an embodiment of the present application. Fig.25 The camera module includes a lens assembly 3000 and a photosensitive assembly 2000. In this embodiment, the photosensitive assembly is Figure 1 The photosensitive assembly of the embodiment is further provided with a lens support 2001 and a color filter 2002 mounted on the lens support 2001. The lens assembly 3000 may have a motor 3001, the bottom surface of the motor being mounted on the top surface of the lens support.

[0140] Further, Fig.26 FIG. 2 shows a cross-sectional schematic diagram of a camera module in another embodiment of the present application. Fig.25 The difference between the embodiment of FIG. 1 and FIG. 2 is that the electronic component 50 is mounted on the back side of the circuit board 10 , and the electronic component 50 is covered and wrapped by the back molding portion 30 .

[0141] Further, Fig. 27 FIG. 2 shows a cross-sectional schematic diagram of a camera module in another embodiment of the present application. Fig.25 The difference between the embodiments is that the composite substrate of the photosensitive component 2000 is added with a heat dissipation extension portion 22.

[0142] Further, Fig.28 FIG. 2 shows a cross-sectional schematic diagram of a camera module in another embodiment of the present application. Fig.25 The difference between the embodiments is that the back molding part is eliminated in the composite substrate of the photosensitive component.

[0143] Further, Fig.29 FIG. 2 shows a cross-sectional schematic diagram of a camera module in another embodiment of the present application. Fig.28 The difference between the embodiments is that the upper surface of the circuit board 10 of the photosensitive component 2000 is made with a front molding part 2003. The bottom surface of the motor can be installed on the top surface of the front molding part 2003, and the lens holder 2001 (corresponding to the lens holder in the previous embodiments) is only used to install the color filter 2002, and the lens holder 2001 is located on the inner side of the front molding part 2003 and the outer side of the electronic component 50.

[0144] Further, Fig.30 FIG. 2 shows a cross-sectional schematic diagram of a camera module in another embodiment of the present application. Fig.28 The difference between the embodiment of the present invention and the embodiment of the present invention is that the upper surface of the circuit board 10 of the photosensitive component 2000 is made with a front molding part 2003. The lens holder 2001 is mounted on the top surface of the front molding part 2003, the color filter 2002 is mounted on the lens holder 2001, and the lens assembly 3000 (the bottom surface of the motor) is mounted on the top surface of the lens holder 2001.

[0145] Further, Fig.31FIG. 2 shows a cross-sectional schematic diagram of a camera module in another embodiment of the present application. Fig.30 The difference between the embodiment of the present invention and the embodiment of the present invention is that the front molding part 2003 covers the electronic components 50 and the metal wires and contacts the photosensitive chip 40. In this embodiment, the front molding part 2003 may cover the edge area of ​​the photosensitive chip, and the edge area may be a non-photosensitive area.

[0146] Furthermore, according to an embodiment of the present application, an electronic device is provided, which has a camera module according to any of the above embodiments. The electronic device may be, for example, a smart phone, a tablet computer, etc.

[0147] In this article, heat dissipation ribs can be understood as reinforcing ribs with heat dissipation function.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A photosensitive component, characterized in that: include: A combination of a circuit board and a photosensitive chip, wherein the circuit board has a first surface for attaching the photosensitive chip and a second surface opposite to the first surface, wherein the first surface has a chip attaching area; the back side of the photosensitive chip is attached to the first surface; a heat dissipation rib disposed on the back side of the assembly, the heat dissipation rib being directly made on the second surface or attached to the second surface, wherein at least a portion of the heat dissipation rib is located in a region of the second surface corresponding to the back side of the chip attaching region, and the heat dissipation rib is a plurality of parallel linear strip heat dissipation ribs, and the direction of the heat dissipation rib is parallel to the second surface; as well as A back side encapsulation part, wherein the back side encapsulation part is a back side molding part made on the second surface by a molding process, and the back side molding part covers the second surface and fills the gaps between the heat dissipation ribs; The bottom surface of the heat dissipation rib is exposed outside the back side packaging part, and the bottom surface of the back side packaging part is flush with the bottom surface of the heat dissipation rib; or the back side packaging part covers the second surface and the bottom surface of the heat dissipation rib, and the distance between the bottom surface of the back side packaging part and the bottom surface of the heat dissipation rib is not greater than 0.1 mm; The heat dissipation ribs are metal heat dissipation ribs or heat dissipation ribs formed by hardening of heat-conducting colloid material.

2. The photosensitive component according to claim 1, characterized in that: The photosensitive component also includes a secondary heat dissipation part, the top surface of the secondary heat dissipation part is connected to the bottom surface of the heat dissipation rib, the bottom surface of the back packaging part is flush with the bottom surface of the secondary heat dissipation part, the bottom surface of the secondary heat dissipation part is exposed outside the back packaging part, and the area of ​​the bottom surface of the secondary heat dissipation part is larger than the area of ​​the bottom surface of the heat dissipation rib.

3. The photosensitive component according to claim 1, characterized in that: The heat dissipation ribs are attached to the second surface by bonding or welding.

4. The photosensitive component according to claim 1, characterized in that: The photosensitive component also includes metal wires, which electrically connect the photosensitive chip and the circuit board through a wire bonding process, and the circuit board is a PCB circuit board.

5. The photosensitive component according to claim 1, characterized in that: The photosensitive component also includes electronic components mounted on the circuit board, wherein at least a portion of the electronic components are mounted on the second surface and covered by the back side packaging portion.

6. The photosensitive component according to claim 1, characterized in that: The photosensitive component also includes a front molding portion, which is manufactured on the first surface through a molding process and surrounds the photosensitive chip, and the top surface of the front molding portion is suitable for installing a lens assembly; wherein there is a gap between the front molding portion and the photosensitive chip, or the front molding portion extends toward the photosensitive chip and contacts the photosensitive chip.

7. The photosensitive component according to claim 1, characterized in that: The photosensitive component also includes a lens holder, which is installed on the first surface and surrounds the photosensitive chip, and the top surface of the lens holder is suitable for installing the lens assembly; wherein the lens holder is formed and then installed on the first surface.

8. The photosensitive component according to claim 6, characterized in that: The photosensitive component also includes a lens holder, which is installed on the front molding part, and the top surface of the lens holder is suitable for installing the lens assembly; wherein the lens holder is molded and then installed on the front molding part.

9. The photosensitive component according to claim 1, characterized in that: The thickness of the heat dissipation rib is 0.05mm-0.4mm.

10. A camera module, characterized in that: include: The photosensitive component according to any one of claims 1 to 9; as well as A lens assembly is installed on the photosensitive assembly.

11. A method for manufacturing a photosensitive component, characterized in that: include: 1) preparing a circuit board, wherein the circuit board has a first surface for attaching a photosensitive chip and a second surface opposite to the first surface, wherein the first surface has a chip attaching area; 2) manufacturing or attaching heat dissipation ribs on the second surface, wherein at least a portion of the heat dissipation ribs is located in an area of ​​the second surface corresponding to the back of the chip attachment area, and the heat dissipation ribs are a plurality of parallel straight strip heat dissipation ribs, and the direction of the heat dissipation ribs is parallel to the second surface; the heat dissipation ribs are metal heat dissipation ribs or heat dissipation ribs formed by hardening a heat-conductive colloid material; 3) a back molding portion is formed on the second surface by a molding process, wherein the back molding portion covers the second surface and fills the gaps between the heat dissipating ribs; wherein the bottom surface of the heat dissipating ribs is exposed outside the back molding portion, and the bottom surface of the back molding portion is flush with the bottom surface of the heat dissipating ribs; or the back molding portion covers the second surface and the bottom surface of the heat dissipating ribs, and the distance between the bottom surface of the back molding portion and the bottom surface of the heat dissipating ribs is not greater than 0.1 mm; and 4) Installing a photosensitive chip on the first surface to produce the photosensitive component.

12. The method for manufacturing a photosensitive component according to claim 11, characterized in that: In the step 2), the heat dissipation ribs are attached by welding or bonding.

13. The method for manufacturing a photosensitive component according to claim 11, characterized in that: In the step 1), the circuit board has a seed layer, and in the step 2), a metal layer is implanted on the seed layer so that the metal layer grows and exceeds the second surface, thereby forming the heat dissipation ribs.

14. The method for manufacturing a photosensitive component according to claim 11, characterized in that: In the step 2), a heat-conducting colloid substance is coated on the second surface, and then the heat-conducting colloid substance is hardened to form the heat dissipation ribs.

15. The method for manufacturing a photosensitive component according to claim 11, characterized in that: Execute step 2) first and then execute step 3).

16. The method for manufacturing a photosensitive component according to claim 11, characterized in that: The photosensitive component manufacturing method further includes the following steps performed after step 3): 3a) manufacturing a secondary packaging portion on the bottom surface of the back molding portion by a molding process, wherein the secondary packaging portion has a secondary through hole, and the secondary through hole exposes the bottom surface of the heat dissipation rib and an adjacent area of ​​the bottom surface of the back molding portion around the heat dissipation rib; as well as 3b) A heat dissipation extension portion is made in the secondary through hole, the top surface of the heat dissipation extension portion is connected to the bottom surface of the heat dissipation rib, and the bottom surface of the heat dissipation extension portion is flush with the bottom surface of the secondary packaging portion; wherein the heat dissipation extension portion is made by implanting a metal layer or injecting a heat-conductive colloidal material and hardening it, or by bonding or welding a formed component.

17. The method for manufacturing a photosensitive component according to claim 11, characterized in that: The step 4) also includes mounting at least a portion of electronic components on the second surface; and performing the step 4) first and then the step 3); and in the step 3), the back molding portion covers the at least a portion of the electronic components mounted on the second surface.

18. The method for manufacturing a photosensitive component according to claim 11, characterized in that: The step 4) also includes: making a front molding part on the first surface, the front molding part is made on the first surface by a molding process and surrounds the photosensitive chip, and the top surface of the front molding part is suitable for installing a lens assembly.

19. The method for manufacturing a photosensitive component according to claim 18, characterized in that: In the step 3), the front molding part and the back molding part are simultaneously formed on the circuit board through the same molding process.

20. The method for manufacturing a photosensitive component according to claim 11, characterized in that: In the step 1), the circuit board is a circuit board panel formed by connecting a plurality of individual circuit boards into one; in the step 2), heat dissipation ribs corresponding to the plurality of individual circuit boards are made on the circuit board panel; in the step 3), the back molding parts corresponding to the plurality of individual circuit boards are made by one-time molding; in the step 4), photosensitive chips are respectively installed on the first surfaces corresponding to the plurality of individual circuit boards, thereby obtaining a photosensitive component panel; and The photosensitive component manufacturing method also includes the steps of: 5) Cutting the photosensitive component panels to obtain separated single photosensitive components.

21. An electronic device, characterized in that: Including the camera module described in claim 10.

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