Image sensor packaging structure and preparation method thereof

Abstract

The invention relates to an image sensor packaging structure and a preparation method thereof, and relates to the technical field of chip packaging, the image sensor packaging structure comprises a substrate, a structural chip, a heat dissipation shielding cover, a sensing chip and a protection shading cover, the structural chip is mounted on the substrate; the heat dissipation shielding cover is arranged outside the structural chip in a covering manner; the sensing chip is attached to the middle of the side, away from the substrate, of the heat dissipation shielding cover and is provided with a photosensitive area. The protective shading cover is arranged on the substrate. Compared with the prior art, by arranging the heat dissipation shielding cover, electromagnetic shielding can be achieved between different chips in the packaging structure, the sensing chip is prevented from being interfered by electromagnetic waves, meanwhile, the heat dissipation effect can be achieved, and the heat dissipation effect on the structural chip is improved. In addition, by arranging the protective shading cover, external light can be shielded, poor light sensing of the sensing chip caused by refraction or diffraction of the external light is avoided, and the light sensing effect of the sensing chip is further improved.

Description

Technical Field

[0001] The present application relates to the field of chip packaging technology, and in particular to an image sensor packaging structure and a preparation method thereof. Background Art

[0002] With the rapid development of the semiconductor industry, image sensor packaging technology mainly involves packaging image sensor chips, where image sensor chips include charge coupled device image sensors (CCD: charge couple device), CMOS chip graphics processors or photoelectric sensors (CIS: contact image sensor). Therefore, image sensor chips can receive light signals and convert them into electrical signals, making image sensor chips used in various electronic products such as digital cameras, automotive image sensor modules, surveillance cameras, etc.

[0003] However, as the functions and performance of image sensors improve, higher processing performance is required for image sensors, so more chips (such as logic chips, flash memory and DRAM) need to be installed on the image sensor to obtain enhanced memory capacity to improve its image sensor performance. Due to the improvement of packaging integration performance, multiple chips are integrated together, and image sensor chips are easily interfered by other chips and external electromagnetic waves, which affects its image sensing effect and produces ghost or double images. Summary of the invention

[0004] The purpose of the present application is to provide an image sensor packaging structure and a preparation method thereof, which can reduce electromagnetic wave interference and improve image sensing effect.

[0005] In order to achieve the above object, the present invention adopts the following scheme: In a first aspect, the present invention provides an image sensor packaging structure, comprising: substrate; A structural chip, wherein the structural chip is mounted on the substrate; A heat dissipation shielding cover, wherein the heat dissipation shielding cover is arranged outside the structural chip, and the middle part of the heat dissipation shielding cover is attached to a side of the structural chip away from the substrate, and the edge of the heat dissipation shielding cover is connected to the substrate; A sensor chip, the sensor chip is mounted on the middle part of the side of the heat dissipation shielding cover away from the substrate and is electrically connected to the substrate, and a photosensitive area is also provided on the side of the sensor chip away from the substrate; A protective light shielding cover, which is arranged on the substrate and covers the sensor chip and the structure chip, and the protective light shielding cover is provided with a photosensitive opening, and the photosensitive opening corresponds to the photosensitive area; The heat dissipation shielding cover is configured to dissipate heat and provide electromagnetic shielding for the structural chip, and the protective light shielding cover is configured to block external light.

[0006] In an optional embodiment, a receiving groove is provided on the substrate, the structural chip is mounted in the receiving groove, and the edge of the heat dissipation shielding cover is connected to the opening periphery of the receiving groove.

[0007] In an optional embodiment, the heat dissipation shielding cover includes a cover body and a plurality of legs, the cover body is attached to a surface of the structural chip on a side away from the substrate, and the plurality of legs are spaced apart at an edge of the cover body and connected to the opening periphery of the accommodating groove.

[0008] In an optional embodiment, a first connecting pad is provided on the side of the sensor chip facing away from the substrate, the first connecting pad is provided around the photosensitive area, the first connecting pad is provided with a first connecting wire, and the first connecting wire is connected to the substrate to electrically connect the sensor chip to the substrate.

[0009] In an optional embodiment, an electromagnetic shielding adhesive layer is further provided on the substrate, the electromagnetic shielding adhesive layer is arranged in the protective shading cover and covers the sensor chip, the heat dissipation shielding cover and the structural chip, and the photosensitive area is exposed to the electromagnetic shielding adhesive layer.

[0010] In an optional implementation, an adhesive layer is further provided between the sensor chip and the heat dissipation shielding cover.

[0011] In an optional embodiment, a positioning groove is further provided on a side of the protective light shielding cover away from the substrate, and the positioning groove is provided on at least two sides of the photosensitive opening.

[0012] In an optional embodiment, a protective adhesive layer is further disposed on the substrate, and the protective adhesive layer is disposed outside the protective light-shielding cover and covers the protective light-shielding cover.

[0013] In an optional implementation, the protective adhesive layer is a transparent adhesive layer, and the protective adhesive layer seals and covers the photosensitive opening.

[0014] In an optional embodiment, a first grounding pad and a second grounding pad are provided on the substrate, the bottom end of the protective light shielding cover is connected to the first grounding pad through a first conductive adhesive layer, the second grounding pad is located on a side of the first grounding pad close to the heat dissipation shielding cover, a second connecting wire is also provided on a side of the sensor chip away from the substrate, the second connecting wire is connected to the second grounding pad, and the first conductive adhesive layer extends beyond the second grounding pad to ground the protective light shielding cover and the sensor chip.

[0015] In an optional embodiment, a grounding pin is further provided at the bottom end of the protective light shielding cover, and the grounding pin extends to the first conductive adhesive layer and is electrically connected to the second grounding pad.

[0016] In an optional implementation, a third connecting wire is further disposed on the second grounding pad, and the third connecting wire is connected to the heat dissipation shielding cover.

[0017] In an optional embodiment, a conductive column is further provided on the edge of the heat dissipation shielding cover, and the conductive column is extended and connected to the protective light shielding cover.

[0018] In an optional embodiment, a second conductive adhesive layer is further provided on the edge of the heat dissipation shielding cover, and the second conductive adhesive layer covers the root of the conductive column and extends to the substrate.

[0019] In an optional embodiment, the conductive column is connected to the periphery of the photosensitive opening, and a supporting cross column is provided at one end of the conductive column close to the protective light shielding cover, the supporting cross column extends toward the center of the photosensitive opening, and a light-transmitting cover plate is also provided on the supporting cross column, the light-transmitting cover plate blocks the photosensitive opening.

[0020] In an optional embodiment, a side of the light-transmitting cover plate away from the substrate is flush with a side of the protective light-shielding cover away from the substrate.

[0021] In an optional embodiment, the supporting cross column and the protective light shielding cover are spaced apart to form a heat dissipation gap.

[0022] In a second aspect, the present invention provides a method for preparing an image sensor packaging structure, which is used to prepare the image sensor packaging structure as described in the above embodiment, and the preparation method comprises: Mounting the structural chip on the substrate; A heat dissipation shielding cover is mounted on the substrate, wherein the heat dissipation shielding cover is arranged outside the structural chip, and the middle part of the heat dissipation shielding cover is mounted on a side of the structural chip away from the substrate, and the edge of the heat dissipation shielding cover is connected to the substrate; A sensor chip is mounted on the middle of the side of the heat dissipation shielding cover away from the substrate, the sensor chip is electrically connected to the substrate, and a photosensitive area is also arranged on the side of the sensor chip away from the substrate; Mounting a protective light shielding cover on the substrate, wherein the protective light shielding cover is arranged outside the sensor chip and the structural chip, and the protective light shielding cover is provided with a photosensitive opening, and the photosensitive opening corresponds to the photosensitive area; The heat dissipation shielding cover is configured to dissipate heat and provide electromagnetic shielding for the structural chip, and the protective light shielding cover is configured to block external light.

[0023] Through the above technical scheme, the image sensor packaging structure provided by the embodiment of the present invention mounts the structural chip on the substrate, and then sets the heat dissipation shielding cover outside the structural chip, and mounts the sensor chip on the heat dissipation shielding cover, while the photosensitive area of ​​the sensor chip is away from the substrate, and the protective light shielding plate is set on the substrate and covers the sensor chip and the structural chip, and the protective light shielding cover is provided with a photosensitive opening corresponding to the photosensitive area. Among them, the heat dissipation shielding cover is configured to dissipate heat and electromagnetically shield the structural chip, and the protective light shielding cover is configured to block external light. Compared with the prior art, the present invention can achieve electromagnetic shielding between different chips inside the packaging structure by setting the heat dissipation shielding cover, avoid the sensor chip from being interfered by electromagnetic waves, and at the same time can play a role in heat dissipation, thereby improving the heat dissipation effect of the structural chip. In addition, by setting the protective light shielding cover, external light can be blocked to avoid the refraction or diffraction of external light causing poor photosensitivity of the sensor chip, thereby further improving the photosensitivity effect of the sensor chip.

[0024] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of a first image sensor packaging structure provided in an embodiment of the present application; Figure 2 A top view of a first image sensor packaging structure provided in an embodiment of the present application; Figure 3 A schematic diagram of a second image sensor packaging structure provided in an embodiment of the present application; Figure 4A schematic diagram of a third image sensor packaging structure provided in an embodiment of the present application; Figure 5 A schematic diagram of a fourth image sensor packaging structure provided in an embodiment of the present application; Figure 6 A schematic diagram of a fifth image sensor packaging structure provided in an embodiment of the present application; Figure 7a A schematic diagram of a sixth image sensor packaging structure provided in an embodiment of the present application; Figure 7b A schematic diagram of a seventh image sensor packaging structure provided in an embodiment of the present application; Figures 8 to 11 This is a process flow chart of a method for preparing an image sensor packaging structure provided in an embodiment of the present application.

[0027] Icon: 100-image sensor packaging structure; 110-substrate; 111-accommodating groove; 112-first grounding pad; 113-second grounding pad; 114-first conductive adhesive layer; 120-structural chip; 130-heat dissipation shielding cover; 131-cover body; 132-support foot; 133-third connecting wire; 140-sensor chip; 141-photosensitive area; 142-first connecting pad; 143-first connecting wire; 144-adhesive layer; 145-second connecting pad; 146-second connecting wire; 150-protective shading cover; 151-photosensitive opening; 152-positioning groove; 153-grounding foot; 160-electromagnetic shielding layer; 170-protective adhesive layer; 180-conductive column; 181-second conductive adhesive layer; 182-supporting cross column; 183-heat dissipation fin; 190-transparent cover plate. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] In the description of this application, it should be noted that the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0030] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] As disclosed in the background technology, the image sensor packaging structure in the prior art usually integrates and packages multiple chips together, and there is no electromagnetic shielding between the chips. In this case, the image sensor chip is easily interfered by the electromagnetic waves of other chips, thereby affecting the image sensing effect and producing ghost or double imaging phenomena.

[0032] In addition, the existing image sensor packaging structure usually directly uses a plastic package to seal the packaging structure. Since the image sensor chip needs to be sensitive to external light, external electromagnetic waves are also likely to interfere with the chip's sensitivity. For example, external electromagnetic waves are refracted or diffracted into the image sensing area, which also affects the image sensing effect.

[0033] In addition, the existing image sensor packaging structure has poor heat dissipation effect and is prone to static electricity inside, which causes an internal and external potential difference, which may cause the chip to be broken down and affect the chip performance.

[0034] In order to solve the above technical problems, the embodiments of the present invention provide a novel image sensor packaging structure and a preparation method thereof. It should be noted that the features in the embodiments of the present application can be combined with each other in the absence of conflict.

[0035] See also Figure 1 and Figure 2 The embodiment of the present invention provides an image sensor packaging structure 100, which can reduce electromagnetic wave interference, improve image sensing effect, and also has better heat dissipation effect.

[0036] The embodiment of the present invention provides an image sensor packaging structure 100, including a substrate 110, a structure chip 120, a heat dissipation shielding cover 130, a sensor chip 140 and a protective light shielding cover 150, wherein the structure chip 120 is mounted on the substrate 110; the heat dissipation shielding cover 130 is arranged outside the structure chip 120, and the middle part of the heat dissipation shielding cover 130 is mounted on the side of the structure chip 120 away from the substrate 110, and the edge of the heat dissipation shielding cover 130 is connected to the substrate 110; the sensor chip 140 is mounted on the heat dissipation shielding cover 130 away from the substrate 110; The protective light shielding cover 150 is arranged on the substrate 110 and covers the sensor chip 140 and the structure chip 120, and the protective light shielding cover 150 is provided with a light sensitive opening 151, and the light sensitive opening 151 corresponds to the light sensitive area 141; wherein, the heat dissipation shielding cover 130 is configured to dissipate heat and electromagnetically shield the structure chip 120, and the protective light shielding cover 150 is configured to block external light.

[0037] It should be noted that the electromagnetic shielding cover here is a non-sealed structure, and there is a gap at its edge, which can be used for heat dissipation, thereby improving the heat dissipation effect of the stacked chip structure. The present invention can achieve electromagnetic shielding between different chips inside the packaging structure by setting a heat dissipation shielding cover 130, thereby preventing the sensor chip 140 from receiving electromagnetic wave interference, and at the same time, it can play a heat dissipation role and improve the heat dissipation effect of the structural chip 120. In addition, by setting a protective light-shielding cover 150, it is possible to block external light, avoid refraction or diffraction of external light causing poor photosensitivity of the sensor chip 140, and further improve the photosensitivity effect of the sensor chip 140.

[0038] In some embodiments, a receiving groove 111 is provided on the substrate 110, and the structural chip 120 is mounted in the receiving groove 111, and the edge of the heat dissipation shielding cover 130 is connected to the opening periphery of the receiving groove 111. Specifically, the front side of the substrate 110 is provided with a receiving groove 111, and the back side is provided with a solder ball. The structural chip 120 can be a radio frequency chip, a logic chip or a storage chip (such as a flash memory chip and a DRAM chip), and the structural chip 120 is mounted in the receiving groove 111 using a flip chip process. The depth of the receiving groove 111 of the structural chip 120 is less than the height of the structural chip 120. On the one hand, by providing the receiving groove 111, the packaging height of the structural chip 120 can be reduced, thereby further reducing the overall packaging height, which is conducive to the miniaturization of the packaging structure. On the other hand, the receiving groove 111 can also be used as a mounting positioning groove to achieve rapid mounting when mounting the structural chip 120. Furthermore, the structural chip 120 protrudes from the receiving groove 111 , so that the heat dissipation shielding cover 130 can be attached to the back of the memory chip while the edge is bent downward to connect to the substrate 110 , so as to better support the upper sensor chip 140 .

[0039] In some embodiments, the heat dissipation shielding cover 130 includes a cover body 131 and a plurality of legs 132. The cover body 131 is attached to the surface of the side of the structural chip 120 away from the substrate 110. The plurality of legs 132 are arranged at intervals on the edge of the cover body 131 and connected to the opening periphery of the receiving groove 111. Specifically, the plurality of legs 132 are integrally arranged on the periphery of the cover body 131, and a heat dissipation gap is formed between adjacent legs 132, and the heat dissipation gap can effectively improve the heat dissipation effect of the structural chip 120. In addition, the plurality of legs 132 are all bent downward structures. By providing the plurality of legs 132, a stable support structure can be formed, and the structural strength of the heat dissipation shielding cover 130 can be improved to better support the upper sensor chip 140.

[0040] In some embodiments, a first connection pad 142 is provided on the side of the sensor chip 140 facing away from the substrate 110, the first connection pad 142 is provided around the photosensitive area 141, and a first connection wire 143 is provided on the first connection pad 142, and the first connection wire 143 is connected to the substrate 110, so that the sensor chip 140 is electrically connected to the substrate 110. Specifically, the sensor chip 140 is mounted on the top surface of the heat dissipation shielding cover 130, and the first connection wire 143 is formed on the first connection pad 142 by a wire bonding process, and a substrate 110 pad is correspondingly provided on the substrate 110, and the first connection wire 143 is connected to the substrate 110 pad, thereby realizing the electrical connection between the substrate 110 and the sensor chip 140. Among them, the first connection wire 143 extends outward from the first connection pad 142, so as not to block the normal light entering the photosensitive area 141.

[0041] Furthermore, an electromagnetic shielding adhesive layer 160 is also provided on the substrate 110, and the electromagnetic shielding adhesive layer 160 is provided in the protective light shielding cover 150, and covers the sensor chip 140, the heat dissipation shielding cover 130 and the structural chip 120, and the photosensitive area 141 is exposed to the electromagnetic shielding adhesive layer 160. Specifically, the electromagnetic shielding adhesive layer 160 can cover the first connecting pad 142, the first connecting wire 143 and the substrate 110 pad on the substrate 110, and can enter the receiving groove 111 through the gap between the legs 132, thereby filling the gap between the legs 132, and filling the receiving groove 111 together, and completing the covering of the structural chip 120. The electromagnetic shielding adhesive layer 160 may be composed of carbon fiber, tributyl citrate, antioxidant, epoxy resin, etc. It is a non-conductive adhesive, so that the external electromagnetic waves are refracted or reflected in the adhesive layer, thereby achieving an attenuation effect, and then the electromagnetic shielding layer can cooperate with the heat dissipation shielding cover 130 to further electromagnetically shield the structural chip 120, and can further prevent the electromagnetic waves from being refracted or diffracted into the photosensitive area 141. In addition, the combination of the electromagnetic shielding adhesive layer 160 and the support foot 132 can enhance their bonding strength, thereby enhancing the overall structural strength.

[0042] It should be noted that the electromagnetic shielding layer 160 here does not block the photosensitive area 141, but covers the first connecting pad 142 around the photosensitive area 141, thereby effectively preventing electromagnetic waves from being refracted or diffracted into the photosensitive area 141 without affecting the amount of light entering the photosensitive area 141.

[0043] In some embodiments, an adhesive layer 144 is further provided between the sensor chip 140 and the heat dissipation shielding cover 130. Specifically, the adhesive layer 144 can play a role in fixing the sensor chip 140. Furthermore, the heat dissipation shielding cover 130 and the back side of the structure chip 120 can be connected through an indium sheet or a thermally conductive adhesive layer, thereby improving the heat transfer efficiency between the heat dissipation shielding cover 130 and the structure chip 120.

[0044] In some embodiments, a positioning groove 152 is further provided on the side of the protective light shielding cover 150 away from the substrate 110, and the positioning groove 152 is provided on at least two sides of the photosensitive opening 151. Specifically, the positioning grooves 152 are located on both sides of the photosensitive port, and the positioning grooves 152 can be used for positioning and adsorption by an external suction nozzle, thereby achieving positioning and mounting. At the same time, the provision of the positioning grooves 152 also increases the heat dissipation area of ​​the protective light shielding cover 150, thereby improving the heat dissipation effect. Among them, the protective light shielding cover 150 can be a metal material or a non-metallic material, such as copper or ceramic, preferably a copper material, which can play a structural support effect, and can well block external electromagnetic waves, and prevent electromagnetic waves from entering except the photosensitive opening 151.

[0045] It should be noted that the protective light shielding cover 150 of this embodiment includes a top cover portion and a surrounding plate portion that are integrally arranged, the surrounding plate portion is arranged around the periphery of the top cover portion, the photosensitive opening 151 and the positioning groove 152 are both arranged on the top cover portion, and the top cover portion is spaced apart from the sensor chip 140 and the electromagnetic shielding adhesive layer 160. The surrounding plate portion is connected to the substrate 110, and the surrounding plate portion and the electromagnetic shielding adhesive layer 160 are also spaced apart.

[0046] See also Figure 3In some other preferred embodiments, a protective rubber layer 170 is further provided on the substrate 110, and the protective rubber layer 170 is provided outside the protective light-shielding cover 150 and coated on the protective light-shielding cover 150. Specifically, the protective rubber layer 170 is entirely coated on the outside of the protective light-shielding cover 150. Preferably, the protective rubber layer 170 is a transparent rubber layer, and the protective rubber layer 170 seals and covers the photosensitive opening 151. By providing a transparent protective rubber layer 170, on the one hand, the sensor chip 140 and the structural chip 120 can be completely enclosed therein to effectively protect the packaging structure, and on the other hand, the light transmission effect can be ensured, and the photosensitivity effect of the photosensitive area 141 can be ensured. In addition, the provision of the positioning groove 152 here can also enhance the binding force of the protective rubber layer 170, thereby enhancing the overall structural strength.

[0047] See also Figure 4 In some embodiments, a first grounding pad 112 and a second grounding pad 113 are provided on the substrate 110, the bottom end of the protective light shielding cover 150 is connected to the first grounding pad 112 through the first conductive adhesive layer 114, the second grounding pad 113 is located on the side of the first grounding pad 112 close to the heat dissipation shielding cover 130, a second connecting pad 145 is further provided on the side of the sensor chip 140 away from the substrate 110, a second connecting wire 146 is provided on the second connecting pad 145, the second connecting wire 146 is connected to the second grounding pad 113, and the first conductive adhesive layer 114 extends outside the second grounding pad 113, so that the protective light shielding cover 150 and the sensor chip 140 are grounded. Specifically, the first grounding pad 112 and the second grounding pad 113 can both be grounded, and the bottom end of the enclosure portion of the protective light shielding cover 150 is connected to the first grounding pad 112 through the first conductive adhesive layer 114, thereby achieving the grounding of the protective light shielding cover 150. At the same time, the first conductive adhesive layer 114 extends to the second ground pad 113, so that the first ground pad 112 and the second ground pad 113 can be equal in potential, and the second connecting wire 146 can connect the sensor chip 140 to the second ground pad 113, so that the sensor chip 140 can be grounded and connected to the protective light shielding cover 150. In this case, the static electricity in the protective light shielding cover 150 is dissipated through the second connecting wire 146, and the protective light shielding cover 150 and the sensor chip 140 are equal in potential to eliminate static electricity, avoiding the phenomenon of chip breakdown caused by inconsistent static electricity difference between the inside and outside of the protective light shielding cover 150, and ensuring the normal performance of the sensor chip 140.

[0048] Furthermore, a grounding pin 153 is also provided at the bottom end of the protective light shielding cover 150, and the grounding pin 153 extends to the first conductive adhesive layer 114 and is electrically connected to the second grounding pad 113. Specifically, the grounding pin 153 is integrally provided at the bottom end of the enclosure portion of the protective light shielding cover 150 and extends toward the electromagnetic shielding adhesive layer 160, and the first conductive adhesive layer 114 can partially cover the grounding pin 153 at the same time, thereby ensuring that the protective light shielding cover 150 can be stably electrically connected to the second grounding pad 113.

[0049] See also Figure 5 In some embodiments, a third connecting wire 133 is further provided on the second grounding pad 113, and the third connecting wire 133 is connected to the heat shielding cover 130. Specifically, the third connecting wire 133 is connected to the leg 132 of the heat shielding cover 130, and the second grounding pad 113 is electrically connected to the protective light shielding cover 150, so that the heat shielding cover 130 is electrically connected to the protective light shielding cover 150 by wire bonding, which can further realize the electromagnetic shielding of the structural chip 120 at the bottom on the one hand, and on the other hand, since the receiving groove 111 will occupy a certain volume of the substrate 110, it is generally necessary to thicken the substrate 110 to realize the grounding wiring of the heat shielding cover 130, however, here the heat shielding cover 130 can be grounded by the third connecting wire 133, so that the heat shielding cover 130 is no longer designed with a grounding pad and grounding wiring, thereby reducing the wiring layer structure.

[0050] See also Figure 6 In some embodiments, the edge of the heat dissipation shielding cover 130 is further provided with a conductive column 180, and the conductive column 180 extends and connects to the protective light shielding cover 150. Specifically, the conductive column 180 is a metal column, which is embedded in the electromagnetic shielding adhesive layer 160, and connects the legs 132 of the heat dissipation shielding cover 130 to the protective light shielding cover 150, so as to further enhance the electromagnetic shielding effect of the underlying structure chip 120 through the conductive column 180. And similarly, since the conductive column 180 is connected to the protective light shielding cover 150, the grounding of the heat dissipation shielding cover 130 can be achieved, which can play a role in static dissipation on the one hand, and on the other hand, the heat dissipation shielding cover 130 no longer needs to design a grounding pad and grounding wiring, thereby reducing the wiring layer structure.

[0051] Furthermore, the edge of the heat dissipation shielding cover 130 is also provided with a second conductive adhesive layer 181, which is coated on the root of the conductive column 180 and extends to the substrate 110. Specifically, the second conductive adhesive layer 181 can cover the conductive column 180 and the support leg 132, thereby improving the electrical connection effect between the conductive column 180 and the support leg 132. And the conductive column 180 and the second conductive adhesive layer 181 are joined and can be pressed on the heat dissipation shielding cover 130, thereby reducing the warping phenomenon of the heat dissipation shielding cover 130. At the same time, the conductive column 180 can play a role in shielding the derived light, avoiding the diffraction and refraction of the optical fiber in the cavity of the protective light shielding cover 150, thereby further avoiding ghosting and double images. There can be multiple conductive columns 180, and multiple conductive columns 180 can separate the cavity of the protective light shielding cover 150, thereby improving the electromagnetic shielding performance. The conductive column 180 uses a metal column, which can conduct heat to the protective light shielding cover 150, thereby further improving the heat dissipation effect.

[0052] See also Figure 7a In some embodiments, the conductive column 180 is connected to the periphery of the photosensitive opening 151, and a supporting cross column 182 is also provided at one end of the conductive column 180 close to the protective light shielding cover 150, and the supporting cross column 182 extends toward the center of the photosensitive opening 151. A transparent cover plate 190 is also provided on the supporting cross column 182, and the transparent cover plate 190 blocks the photosensitive opening 151. Specifically, the conductive columns 180 are connected to both sides of the photosensitive opening 151, and the supporting cross column 182 is integrally arranged on the side opposite to the conductive column 180 and extends toward the center, and the supporting horizontal axis does not extend to the top of the photosensitive area 141, effectively avoiding interference. Here, the supporting cross column 182 can serve as a supporting platform, thereby facilitating the setting of the transparent cover plate 190. The transparent cover plate 190 can protect the photosensitive area 141 of the sensor chip 140 from external contamination.

[0053] Furthermore, the side of the transparent cover plate 190 away from the substrate 110 is flush with the side of the protective light shielding cover 150 away from the substrate 110. Specifically, the flushness of the transparent cover plate 190 with the protective light shielding cover 150 can prevent the transparent cover plate 190 from being damaged.

[0054] In some embodiments, the support crossbar 182 is spaced apart from the protective light shielding cover 150 to form a heat dissipation gap. Specifically, the support crossbar 182 is spaced apart from the inner surface of the protective light shielding cover 150, and the support crossbar 182 is also spaced apart from the electromagnetic shielding adhesive layer 160 and the third connecting wire 133, which can effectively avoid structural interference. The heat dissipation gap can improve the heat dissipation effect of the support crossbar 182 and the conductive column 180.

[0055] It should be noted that the support cross column 182 here can be in a circular shape and blocked and supported on the bottom side of the transparent cover 190, so that the support cross column 182 can block the reflected light or refracted light of the side wall of the transparent cover 190, thereby solving the ghost or double image phenomenon.

[0056] In some embodiments, see Figure 7b , a plurality of heat dissipation fins 183 are also provided on the support crossbar 182, and the plurality of heat dissipation fins 183 are arranged at intervals and can extend horizontally or vertically, so that the heat dissipation effect of the heat dissipation gap is further improved, and the heat dissipation effect of the overall structure is improved. Optionally, when a protective adhesive layer 170 is added to the protective light shielding cover 150, the protective adhesive layer 170 can be filled into the heat dissipation gap and contact the heat dissipation fins 183, so that the heat dissipation fins 183 can be used to greatly improve the bonding force of the protective adhesive layer 170, thereby improving the overall structural strength.

[0057] In addition, in some embodiments, an auxiliary horizontal column 184 is further provided below the supporting horizontal column 182, and the auxiliary horizontal column 184 is parallel to the supporting horizontal column 182 and connected to the conductive column 180. Furthermore, the auxiliary horizontal column 184 extends toward the center of the transparent cover plate 190 relative to the supporting horizontal column 182, and the auxiliary horizontal column 184 does not block the photosensitive area 141 of the sensor chip 140. By providing the auxiliary horizontal column 184, the reflected or refracted light at the photosensitive area 141 can be reduced, and the ghost or double image phenomenon can also be reduced.

[0058] It should be noted that the protective adhesive layer 170 covers the light-transmitting cover plate 190 , and the protective adhesive layer 170 is made of transparent adhesive, which can effectively protect the light-transmitting cover plate 190 and prevent the intrusion of external moisture or impurities.

[0059] The embodiment of the present invention further provides a method for preparing the image sensor package structure 100, which is used to prepare the image sensor package structure 100 as described in the above embodiment. The method comprises the following steps: S1: mounting the structure chip 120 on the substrate 110 .

[0060] See also Figure 8 Specifically, a substrate 110 is first provided, and a receiving groove 111 is pre-prepared on the substrate 110. The receiving groove 111 can be used as a positioning groove for placing a structure chip 120. The structure chip 120 can be flip-chip arranged in the receiving groove 111, and the structure chip 120 can be a radio frequency chip, a logic chip or a memory chip, etc., preferably a radio frequency chip.

[0061] S2: Mounting the heat dissipation shielding cover 130 on the substrate 110 .

[0062] See also Fig. 9Specifically, the heat shielding cover 130 is disposed outside the structure chip 120, and the middle part of the heat shielding cover 130 is attached to the side of the structure chip 120 away from the substrate 110, and the edge of the heat shielding cover 130 is connected to the substrate 110. During actual mounting, the legs 132 of the heat shielding cover 130 are mounted on the substrate 110 around the receiving groove 111, and the cover body 131 of the heat shielding cover 130 is mounted on the back of the structure chip 120 through an indium sheet or a heat dissipation adhesive layer to achieve heat dissipation.

[0063] S3: mounting the sensor chip 140 on the middle portion of the side of the heat dissipation shielding cover 130 away from the substrate 110 .

[0064] See also Fig.10 Specifically, the sensor chip 140 is electrically connected to the substrate 110, and a photosensitive area 141 is also provided on the side of the sensor chip 140 facing away from the substrate 110. The sensor chip 140 is a positive chip, which is designed with a photosensitive area 141 for image processing, and is fixed to the heat dissipation shielding cover 130 by an adhesive layer 144. Then, the electromagnetic shielding adhesive layer 160 can be applied on the first connecting pad 142 on the front of the sensor chip 140 through a wire bonding process, and then through a glue dispensing process to cover the gap between the wire bonding and the legs 132 of the heat dissipation shielding cover 130, thereby enclosing the structural chip 120, the sensor chip 140 and the heat dissipation shielding cover 130 to achieve electromagnetic shielding.

[0065] S4 : Mounting the protective light shielding cover 150 on the substrate 110 .

[0066] See also Fig.11 Specifically, the protective light shielding cover 150 is arranged outside the sensor chip 140 and the structure chip 120, and the protective light shielding cover 150 is provided with a photosensitive opening 151, and the photosensitive opening 151 corresponds to the photosensitive area 141; wherein the heat dissipation shielding cover 130 is configured to dissipate heat and electromagnetically shield the structure chip 120, and the protective light shielding cover 150 is configured to shield external light. In actual preparation, the protective light shielding cover 150 can be fixed by the first conductive adhesive layer 114, and a positioning groove 152 is designed on the protective light shielding cover 150, and the positioning groove 152 is used to realize positioning and mounting.

[0067] After the protective light shielding cover 150 is mounted, solder balls can be formed at the solder pad positions on the back side of the substrate 110 and a cutting process can be performed to form a single product.

[0068] In summary, the image sensor packaging structure 100 provided by the embodiment of the present invention mounts the structure chip 120 on the substrate 110, then sets the heat dissipation shielding cover 130 outside the structure chip 120, and mounts the sensor chip 140 on the heat dissipation shielding cover 130, while the photosensitive area 141 of the sensor chip 140 is away from the substrate 110, the protective light shielding plate is set on the substrate 110, and is set outside the sensor chip 140 and the structure chip 120, and the protective light shielding cover 150 is provided with a photosensitive opening 151 corresponding to the photosensitive area 141. Among them, the heat dissipation shielding cover 130 is configured to dissipate heat and electromagnetically shield the structure chip 120, and the protective light shielding cover 150 is configured to block external light. Compared with the prior art, the present invention can achieve electromagnetic shielding between different chips inside the packaging structure by setting the heat dissipation shielding cover 130, prevent the sensor chip 140 from being interfered by electromagnetic waves, and at the same time can play a heat dissipation role, thereby improving the heat dissipation effect of the structure chip 120. In addition, by providing the protective light shielding cover 150 , external light can be shielded to prevent the refraction or diffraction of external light from causing poor photosensitivity of the sensor chip 140 , thereby further improving the photosensitivity effect of the sensor chip 140 .

[0069] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An image sensor packaging structure, characterized in that: include: substrate; A structural chip, wherein the structural chip is mounted on the substrate; A heat dissipation shielding cover, wherein the heat dissipation shielding cover is arranged outside the structural chip, and the middle part of the heat dissipation shielding cover is attached to a side of the structural chip away from the substrate, and the edge of the heat dissipation shielding cover is connected to the substrate; A sensor chip, the sensor chip is mounted on the middle part of the side of the heat dissipation shielding cover away from the substrate and is electrically connected to the substrate, and a photosensitive area is also provided on the side of the sensor chip away from the substrate; A protective light shielding cover, which is arranged on the substrate and covers the sensor chip and the structure chip, and the protective light shielding cover is provided with a photosensitive opening, and the photosensitive opening corresponds to the photosensitive area; The heat dissipation shielding cover is configured to dissipate heat and provide electromagnetic shielding for the structural chip, and the protective light shielding cover is configured to block external light.

2. The image sensor packaging structure according to claim 1, characterized in that: The substrate is provided with a receiving groove, the structural chip is mounted in the receiving groove, and the edge of the heat dissipation shielding cover is connected to the opening periphery of the receiving groove.

3. The image sensor packaging structure according to claim 2, characterized in that: The heat dissipation shielding cover comprises a cover body and a plurality of legs. The cover body is attached to a surface of the structure chip on a side away from the substrate. The plurality of legs are arranged at intervals on the edge of the cover body and connected to the opening periphery of the accommodating groove.

4. The image sensor packaging structure according to claim 1, characterized in that: A first connecting pad is arranged on the side of the sensor chip facing away from the substrate. The first connecting pad is arranged around the photosensitive area. The first connecting pad is provided with a first connecting wire, which is connected to the substrate to electrically connect the sensor chip to the substrate.

5. The image sensor packaging structure according to claim 4, characterized in that: An electromagnetic shielding adhesive layer is also arranged on the substrate. The electromagnetic shielding adhesive layer is arranged in the protective light-shielding cover and covers the sensor chip, the heat dissipation shielding cover and the structural chip, and the photosensitive area is exposed to the electromagnetic shielding adhesive layer.

6. The image sensor packaging structure according to claim 4, characterized in that: An adhesive layer is also provided between the sensor chip and the heat dissipation shielding cover.

7. The image sensor packaging structure according to claim 1, characterized in that: A positioning groove is also arranged on a side of the protective light shielding cover away from the substrate, and the positioning groove is arranged on at least two sides of the photosensitive opening.

8. The image sensor packaging structure according to claim 7, characterized in that: A protective adhesive layer is also arranged on the substrate, and the protective adhesive layer is arranged outside the protective light-shielding cover and covers the protective light-shielding cover.

9. The image sensor packaging structure according to claim 8, characterized in that: The protective adhesive layer is a transparent adhesive layer, and the protective adhesive layer seals and covers the photosensitive opening.

10. The image sensor packaging structure according to any one of claims 1 to 8, characterized in that: A first grounding pad and a second grounding pad are provided on the substrate, the bottom end of the protective light shielding cover is connected to the first grounding pad through a first conductive adhesive layer, the second grounding pad is located on a side of the first grounding pad close to the heat dissipation shielding cover, a second connecting wire is also provided on a side of the sensor chip away from the substrate, the second connecting wire is connected to the second grounding pad, and the first conductive adhesive layer extends beyond the second grounding pad to ground the protective light shielding cover and the sensor chip.

11. The image sensor packaging structure according to claim 10, characterized in that: A grounding pin is also disposed at the bottom end of the protective light shielding cover. The grounding pin extends to the first conductive adhesive layer and is electrically connected to the second grounding pad.

12. The image sensor packaging structure according to claim 10, characterized in that: A third connecting wire is also disposed on the second grounding pad, and the third connecting wire is connected to the heat dissipation shielding cover.

13. The image sensor packaging structure according to claim 10, characterized in that: The edge of the heat dissipation shielding cover is also provided with a conductive column, and the conductive column is extended and connected to the protective light shielding cover.

14. The image sensor packaging structure according to claim 13, characterized in that: A second conductive adhesive layer is also disposed on the edge of the heat dissipation shielding cover. The second conductive adhesive layer covers the root of the conductive column and extends to the substrate.

15. The image sensor packaging structure according to claim 13, characterized in that: The conductive column is connected to the periphery of the photosensitive opening, and a supporting cross column is provided at one end of the conductive column close to the protective light shielding cover, the supporting cross column extends toward the center of the photosensitive opening, and a light-transmitting cover plate is also provided on the supporting cross column, the light-transmitting cover plate blocks the photosensitive opening.

16. The image sensor packaging structure according to claim 15, characterized in that: A side of the light-transmitting cover plate away from the substrate is flush with a side of the protective light-shielding cover away from the substrate.

17. The image sensor packaging structure according to claim 15, characterized in that: The supporting cross column and the protective light shielding cover are arranged at intervals to form a heat dissipation gap.

18. A method for preparing an image sensor packaging structure, used for preparing the image sensor packaging structure as claimed in claim 1, characterized in that: The preparation method comprises: Mounting the structural chip on the substrate; A heat dissipation shielding cover is mounted on the substrate, wherein the heat dissipation shielding cover is arranged outside the structural chip, and the middle part of the heat dissipation shielding cover is mounted on a side of the structural chip away from the substrate, and the edge of the heat dissipation shielding cover is connected to the substrate; A sensor chip is mounted on the middle of the side of the heat dissipation shielding cover away from the substrate, the sensor chip is electrically connected to the substrate, and a photosensitive area is also arranged on the side of the sensor chip away from the substrate; Mounting a protective light shielding cover on the substrate, wherein the protective light shielding cover is arranged outside the sensor chip and the structural chip, and the protective light shielding cover is provided with a photosensitive opening, and the photosensitive opening corresponds to the photosensitive area; The heat dissipation shielding cover is configured to dissipate heat and provide electromagnetic shielding for the structural chip, and the protective light shielding cover is configured to block external light.

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