Photosensitive device, preparation method thereof and electronic equipment

Abstract

The embodiment of the invention provides a photosensitive device, a preparation method thereof and electronic equipment. The photosensitive device comprises a substrate and a chip. Wherein the substrate is provided with a first surface and a second surface, the first surface of the substrate is provided with a first opening, the second surface of the substrate is provided with a second opening, the second opening is larger than the first opening, and the second opening is communicated with the first opening; the chip is located in the second opening, the chip is electrically connected with the substrate, the chip is provided with a first surface, the first surface of the chip is provided with a photosensitive area, and the photosensitive area is located in the range of the first opening. The photosensitive device provided by the embodiment of the invention not only can be light, thin and miniaturized, but also can improve the heat dissipation performance.

Description

[0001] This application claims the priority of Chinese Application No. 202311723339.X filed on December 14, 2023, and the above application is incorporated into this application in its entirety by reference. Technical Field

[0002] This application relates to the field of integrated circuits. More specifically, this application relates to a photosensitive device, a preparation method thereof, and an electronic device. Background Art

[0003] Optical sensors are widely used in Internet of Things (IoT) devices, consumer electronics, and wearable devices, such as complementary-metal-oxide-semiconductor image sensors (CIS), ambient light sensors (ALS), time-of-flight sensors (ToF), etc. Since consumers prefer thinner and better-performing electronic products, the miniaturized design of electronic products has become increasingly common. To meet the needs of users, the photosensitive devices used inside electronic products are also continuously evolving in the direction of being thinner and more power-efficient.

[0004] Specifically, currently, the photosensitive devices used under the screen mainly exist in the form of surface mounting, that is, a photosensitive chip is fixed on the surface of a substrate using glue, and the chip and the substrate are electrically connected through leads. At the same time, in order to protect the chip and the leads while achieving light transmission, a transparent resin is further used to encapsulate the chip and the leads. However, this technical solution will bring a series of problems. On the one hand, encapsulating the surface-mounted chip with a transparent resin will make the final photosensitive device large in size and relatively thick in thickness; on the other hand, in the surface-mounting solution, the physical path between the chip and the main board is relatively long, and the heat dissipation performance is not excellent. Summary of the Invention

[0005] Embodiments of this application provide a photosensitive device, a preparation method thereof, and an electronic device. This photosensitive device can not only take into account the characteristics of being thin and highly integrated, but also improve the heat dissipation problem of the photosensitive chip on the basis of the existing technical solutions.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a photosensitive device, which includes a substrate and a chip. The substrate has a first opening on its first surface and a second opening on its second surface. Among them, the second opening is larger than the first opening, and the first opening and the second opening communicate with each other. The chip is located in the second opening provided on the second surface of the substrate, and the chip is electrically connected to the substrate. The chip has a first surface, and among them, the first surface of the chip has a photosensitive area, and this photosensitive area is located within the range of the first opening provided on the first surface of the substrate.

[0008] In the photosensitive device provided by the embodiment of the present application, on the one hand, the chip is directly installed inside the substrate with an opening design and is electrically connected to the inside of the substrate. The photosensitive area of the chip is located within the range of the first opening provided on the first surface of the substrate and is used to receive incident light irradiation. Most of the other areas of the first surface of the chip except the photosensitive area are covered by the substrate. Therefore, the photosensitive device provided by the embodiment of the present application does not need to introduce a transparent plastic package on the surface of the chip. Compared with the technical solution of directly mounting the chip on the surface of the substrate, this solution is more miniaturized and thinner. On the other hand, compared with the prior art, the physical path from the photosensitive chip to the second surface of the substrate in the photosensitive device provided by the embodiment of the present application is shorter. Further, the heat dissipation performance of this photosensitive device is better.

[0009] In a possible design, in the photosensitive device provided by the embodiment of the present application, the substrate includes a first part and a second part located below the first part. The first part of the substrate has an upper surface, an inner surface, and a lower surface, and the second part of the substrate has an inner surface and a lower surface. Among them, the upper surface of the first part of the substrate is the first surface of the substrate, and the lower surface of the second part of the substrate is the second surface of the substrate. The inner surface of the first part of the substrate is exposed by the first opening provided on the first surface of the substrate. The lower surface of the first part of the substrate and the inner surface of the second part of the substrate are exposed by the second opening provided on the second surface of the substrate. In addition, the substrate further includes an upper pad located on the lower surface of the first part of the substrate and a lower pad located on the lower surface of the second part of the substrate.

[0010] In a possible design, the chip is located in the second opening, and the chip is electrically connected to the substrate, specifically including: The chip further includes a second surface, the plane where the second surface of the chip is located is not lower than the horizontal plane where the lower pad of the substrate is located, and the first surface of the chip is directly or indirectly connected to the upper pad of the substrate through metal bumps.

[0011] Specifically, in the photosensitive device provided in the embodiment of the present application, the thickness of the first part of the substrate and the thickness of the second part can be adjusted, but the adjustment range has certain limitations. All adjustment schemes should be guided by process effects and process costs. In order not to affect the soldering effect of the photosensitive device, the horizontal plane where the second surface of the chip is located is not lower than the horizontal plane where the substrate underlay is located. In addition, the lengths of the lower surfaces of the first part of the substrate and the second part of the substrate can also be adjusted in the horizontal direction.

[0012] Compared with wire bonding, the product using metal bump bonding does not need to reserve space for wires, thus reducing the requirement for the edge area of chip packaging, greatly reducing the packaging area, and improving the regional utilization rate of the substrate. In addition, the signal transmission path between the chip and the substrate is shorter, and the transmission loss between the chip and the substrate is lower.

[0013] In a possible design, the photosensitive device provided in the embodiment of the present application further includes a filling material, which is distributed in the gap between the chip and the substrate. Since the lower surface of the first part of the substrate and the inner surface of the second part of the substrate are exposed by the second opening formed in the second surface of the substrate, and the chip is located in the second opening formed in the second surface of the substrate, the gap between the chip and the substrate includes the area between the lower surface of the first part of the substrate and the chip and the area between the inner surface of the second part of the substrate and the chip. The filling material distributed in the gap between the chip and the substrate can control the stress caused by the difference in thermal expansion coefficient between the metal bumps and the substrate. After the filling material is cured, the filling material will absorb the stress, thereby reducing the strain of the metal bumps and reducing the reaction generated at the joint between the chip and the substrate. Finally, the purpose of protecting the chip, enhancing the product reliability, and extending the product service life is achieved.

[0014] In a possible design, the filling material of the photosensitive device provided in the embodiment of the present application is also distributed on the side wall of the first opening.

[0015] The filling material distributed on the side wall of the first opening of the substrate can not only further fix and protect the chip, but also adjust its height and specific structure in combination with a high-precision mold, so that the working distance from the optical path adjustment device installed above the photosensitive area to the photosensitive area is more flexible.

[0016] In a possible design, the thickness of the filling material distributed on the side wall of the first opening becomes thicker in the direction towards the chip. Specifically, the structure design with a narrower upper part and a thicker lower part makes the support of the filling material for the relevant device more stable.

[0017] In a possible design, the filling material on the side wall of the first opening adopts a stepped structure design, wherein the inner surface of the first part of the substrate is completely covered by the filling material.

[0018] In a possible design, the filling material on the sidewall of the first opening is designed with a stepped structure, where the inner surface of the first part of the substrate is partially covered by the filling material.

[0019] In a possible design, the filling material distributed on the sidewall of the first opening has a downward concave curve structure, thus achieving a better optical path effect.

[0020] In a possible design, the filling material is also distributed on the second surface of the chip, and the horizontal plane where the filling material on the second surface of the chip is located is not lower than the horizontal plane where the underpad of the substrate is located.

[0021] In a possible design, the substrate is a packaging substrate, the chip is a bare die, and the packaging substrate is connected to the printed circuit board through the underpad.

[0022] In a possible design, the connection gap between the packaging substrate and the printed circuit board further includes a heat conduction layer. The design of the heat conduction layer enables better heat dissipation performance of the photosensitive device.

[0023] In a possible design, the substrate is a printed circuit board and the chip is a packaged chip.

[0024] In a possible design, the filling material includes at least one of the following materials: underfill, molding compound, potting compound. Other materials with a relatively small coefficient of thermal expansion and a relatively small molding shrinkage rate can also be used. In the prior art, in order to achieve light transmission while protecting the chip, transparent resin is used for encapsulation. However, the coefficient of thermal expansion and the molding shrinkage rate of the transparent resin are both large, and long-term use is likely to cause the photosensitive device to fail and deform, and yellowing will also occur. Therefore, the filling material used in this technical solution is a non-transparent resin, and has a relatively small coefficient of thermal expansion and a relatively small molding shrinkage rate, so as to better protect the chip and further improve the electrical performance.

[0025] Optionally, the filling material can be realized by injection molding, dispensing (coating), potting or other methods.

[0026] In a possible design, the filling material distributed on the second surface of the chip, the filling material distributed on the sidewall of the first opening, and the filling material distributed in the gap between the chip and the substrate are of the same kind.

[0027] In a possible design, the filling material distributed on the second surface of the chip, the filling material distributed on the sidewall of the first opening, and the filling material distributed in the gap between the chip and the substrate are of different kinds.

[0028] In a possible design, in the three regions of the gap between the substrate and the chip, the sidewall of the first opening, and the second surface of the chip, the filling material in any one region can be of the same kind.

[0029] In a possible design, the filling materials in any one of the three regions, namely, the gap between the substrate and the chip, the sidewall of the first opening, and the second surface of the chip, can be different types.

[0030] In a possible design, in the photosensitive device provided in the embodiment of the present application, a glue injection hole is further formed on the first surface of the substrate, and the glue injection hole communicates with the gap between the chip and the substrate. The glue injection hole can be used to inject glue or exhaust air inside the photosensitive device when necessary, so as to improve the processability of the product. The specific number, position, and size of the glue injection hole will vary according to the product requirements.

[0031] In a possible design, in the photosensitive device provided in the embodiment of the present application, the shape of the first opening formed on the first surface of the substrate includes a circle, a rectangle, or a square, and the shape of the photosensitive area includes a circle, a rectangle, and a square, and the shapes of the two can be arbitrarily combined.

[0032] In a possible design, the photosensitive device further includes an optical path adjusting device, which is located above the photosensitive area of the chip and is used to filter and / or focus the incident light incident on the photosensitive area.

[0033] In a possible design, the optical path adjusting device includes at least one of the following devices: an optical lens, a filter, a cover glass, a prism, or a diaphragm.

[0034] The optical path adjusting device can be connected to both the filling material distributed on the sidewall of the first opening and the first surface of the substrate at the same time, or can be only connected to the filling material distributed on the sidewall of the first opening. The connection method can be gluing or welding.

[0035] In a possible design, the photosensitive device further includes components mounted on the first surface of the substrate. The components include at least one of the following devices: an active device, a passive device, or a gold wire structure, so as to achieve further integration.

[0036] In a possible design, the photosensitive device further includes a bracket mounted on the first surface of the substrate, and the bracket has a light-transmitting hole. Other areas of the bracket except the light-transmitting hole are not light-transmitting, so as to allow light to pass through at a certain angle.

[0037] In a possible design, the bracket is connected to the first surface of the substrate, and the connection method can be gluing or welding.

[0038] In a possible design, the photosensitive device further includes an encapsulating material. The encapsulating material is used to completely encapsulate the components, or can also partially encapsulate the components. The encapsulating material can also encapsulate other areas of the bracket except the light-transmitting hole.

[0039] Preferably, the encapsulation material is a resin, especially a dark-colored resin such as black, brown, blue, etc., so as to avoid light interference in a certain frequency band. The encapsulation material can be realized by injecting glue, dotting glue (coating glue) or potting glue.

[0040] In a second aspect, an embodiment of the present application provides a method for manufacturing a photosensitive device. It mainly includes:

[0041] Provide a substrate. The substrate has a first surface and a second surface. The first surface is provided with a first opening, and the second surface is provided with a second opening. The second opening is larger than the first opening, and the second opening communicates with the first opening;

[0042] Install a chip in the second opening of the substrate. The chip is electrically connected to the substrate. The chip includes a first surface, and the first surface of the chip has a photosensitive area, and the photosensitive area is within the range of the first opening.

[0043] In a possible design, install the chip in the second opening of the substrate, and the chip is electrically connected to the substrate, including: The chip also has a second surface opposite to the first surface, and the substrate also includes an underpad located on the second surface of the substrate. The horizontal plane where the second surface of the chip is located is not lower than the horizontal plane where the underpad is located.

[0044] In a possible design, the chip is electrically connected to the substrate, including: The substrate includes a first part, the first part of the substrate has a lower surface, and the substrate also includes an upper pad located on the lower surface of the first part of the substrate. The first surface of the chip is connected to the upper pad through metal bumps.

[0045] In a possible design, the method for manufacturing a photosensitive device further includes: injecting a filling material into the gap between the chip and the substrate.

[0046] In a possible design, before injecting the first filling material into the gap between the chip and the substrate, it further includes: providing a glue injection hole on the first surface of the substrate, and the glue injection hole communicates with the gap between the substrate and the chip;

[0047] Inject the first filling material through the glue injection hole.

[0048] In a possible design, the method for manufacturing a photosensitive device further includes: coating a second filling material on the side wall of the first opening of the substrate, and the coating thickness of the second filling material becomes thicker along the direction towards the chip.

[0049] In a possible design, the method for manufacturing a photosensitive device further includes: The chip has a second surface, and a third filling material is coated on the second surface of the chip, and the horizontal plane where the third filling material is located is not lower than the horizontal plane where the underpad is located.

[0050] In a possible design, the filling material includes at least one of the following materials: underfill, molding compound or potting compound.

[0051] A possible design, the method for manufacturing a photosensitive device further includes: installing an optical path adjusting device above the photosensitive area, where the optical path adjusting device includes an optical path filtering device and / or an optical path focusing device.

[0052] A possible design, the optical path adjusting device includes at least one of the following components: an optical lens, a filter, a cover glass, a prism, or a diaphragm.

[0053] In a third aspect, an embodiment of the present application provides a photosensitive device. The photosensitive device includes: a substrate, an opening is provided on the first surface of the substrate; a chip is embedded inside the substrate, the chip is electrically connected to the substrate, the chip has a first surface, and a photosensitive area is provided on the first surface of the chip, and the photosensitive area is within the range of the opening provided on the first surface of the substrate.

[0054] The substrate includes a first part and a second part and a third part located below the first part. The first part has an upper surface and an inner surface, the second part has an inner surface, and the third part has a lower surface. Among them, the upper surface of the first part is the first surface of the substrate, and the lower surface of the third part is the second surface of the substrate.

[0055] A possible design, the substrate further includes an upper pad located on the lower surface of the first part of the substrate, and the first surface of the chip is electrically connected to the upper pad through a via hole.

[0056] Compared with wire bonding, the packaged product using via hole connection does not need to reserve space for wires, reducing the edge area requirement of wafer packaging, greatly reducing the packaging area, and improving the utilization rate of the substrate area. At the same time, via hole connection also shortens the signal path between the chip and the substrate, reduces the transmission loss between the two, and improves the electrical performance.

[0057] A possible design, the photosensitive device further includes a filling material, and the filling material is distributed on the side wall of the opening provided on the first surface of the substrate. Further, a high-precision mold can be used to adjust the height and specific structure of the filling material distributed on the side wall of the opening, so that the working distance from the optical path adjusting device above the photosensitive area to the photosensitive area is more flexible.

[0058] A possible design, the thickness of the filling material distributed on the side wall of the substrate opening becomes thicker in the direction towards the chip, making the support for the optical path adjusting device more stable.

[0059] A possible design, the filling material includes at least one of the following materials: underfill, encapsulant, or potting compound.

[0060] A possible design, the substrate is a packaging substrate and the chip is a bare die. The packaging substrate is connected to the printed circuit board through a lower pad.

[0061] A possible design, the connection gap between the encapsulation substrate and the printed circuit board further includes a heat conduction layer.

[0062] A possible design, the substrate is a printed circuit board, and the chip is a packaged chip.

[0063] A possible design, the shape of the opening formed on the first surface of the substrate includes a circle, a rectangle or a square, the shape of the photosensitive area includes a circle, a rectangle and a square, and the shapes of the two can be arbitrarily combined.

[0064] A possible design, the photosensitive device provided by the embodiment of the present application further includes an optical path adjusting device, the optical path adjusting device is located above the photosensitive area, and the optical path adjusting device is used to filter and / or focus the incident light incident on the photosensitive area.

[0065] A possible design, the optical path adjusting device provided by the embodiment of the present application includes at least one of the following materials: an optical lens, a filter, a cover glass, a prism or a diaphragm.

[0066] A possible design, the optical path adjusting device is connected to the first surface of the substrate, or can be connected to the first surface of the substrate and the filling material on the side wall of the substrate opening at the same time, or can be only connected to the filling material on the side wall of the substrate opening. The connection method can be adhesion or welding.

[0067] A possible design, the photosensitive device further includes components mounted on the first surface of the substrate. The components include at least one of the following devices: an active device, a passive device or a gold wire structure. All kinds of components and the first surface of the substrate can be connected by adhesion or by welding.

[0068] A possible design, the photosensitive device further includes a bracket mounted on the first surface of the substrate. The bracket has a light-transmitting hole, and other areas of the bracket except the light-transmitting hole are not light-transmitting, so as to realize the transmission of light at a certain angle.

[0069] A possible design, the bracket is connected to the first surface of the substrate, and the connection method can be adhesion or welding.

[0070] A possible design, the photosensitive device provided by the embodiment of the present application further includes an encapsulating material, and the encapsulating material is used to encapsulate the components mounted on the first surface of the substrate, so as to protect the components and also realize the further integration of the packaged product. The encapsulating material can encapsulate all the components or can partially encapsulate the components. The encapsulating material can also encapsulate other areas of the bracket except the light-transmitting hole.

[0071] Preferably, the encapsulating material is a resin, especially a dark resin, such as black, brown, blue, etc., so as to avoid light interference in a certain frequency band. The encapsulating material can be realized by injection molding, dispensing (coating) or potting.

[0072] A possible design is that the bracket is connected to the encapsulation material, and the connection method can be gluing or welding.

[0073] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a photosensitive device. It mainly includes:

[0074] Manufacture a substrate such that the chip is embedded inside the substrate and electrically connected to the substrate. The chip has a first surface, and the first surface of the chip has a photosensitive area;

[0075] The substrate has a first surface, and an opening is formed on the first surface of the substrate such that the photosensitive area is within the range of the opening formed on the first surface of the substrate.

[0076] A possible design is that manufacturing the substrate specifically includes:

[0077] Coat a sacrificial glue on the upper layer of the photosensitive area of the chip;

[0078] Embed the chip inside the substrate through a lamination process;

[0079] During the lamination process, form a via through a via opening process such that the chip and the substrate are electrically connected through the via.

[0080] A possible design is that forming an opening on the first surface of the substrate specifically includes: forming an opening on the first surface of the substrate through a grooving process such that the photosensitive area coated with the sacrificial glue is within the range of the opening formed on the first surface of the substrate.

[0081] A possible design is that after forming an opening on the first surface of the substrate through the grooving process, the manufacturing method further includes: removing the sacrificial glue coated on the upper layer of the photosensitive area such that the photosensitive area is within the opening range.

[0082] A possible design is that the manufacturing method further includes: installing an optical path adjustment device on the first surface of the substrate. The optical path adjustment device is located above the photosensitive area, and the optical path adjustment device includes an optical path filtering device and / or an optical path focusing device.

[0083] A possible design is that the optical path adjustment device includes at least one of the following components: an optical lens, a filter, a cover glass, a prism, or a diaphragm.

[0084] In a fifth aspect, an embodiment of the present application provides an electronic device. The electronic device includes the photosensitive device in the foregoing embodiment and a printed circuit board, and the photosensitive device is installed on the printed circuit board.

[0085] These and other aspects of the present application will be more concise and understandable in the description of the specific implementation manners. Description of the Drawings

[0086] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, only a part of the embodiments of the present application are reflected in the following drawings. For those of ordinary skill in the art, without creative efforts, other embodiments of the present application can be obtained based on these drawings. And all these embodiments or implementation manners are within the protection scope of the present application.

[0087] Figure 1 It is a schematic diagram of the principle of a photosensor;

[0088] Figure 2 It is a schematic diagram of the overall structure of a mobile terminal;

[0089] Figure 3 It is a sectional view of the overall structure of a mobile terminal along Figure 2 the A-A direction in

[0090] Figure 4 It is a longitudinal sectional view of a photosensitive device;

[0091] Figure 5 It is a schematic diagram of a substrate opening provided by an embodiment of the present application;

[0092] Figure 6 It is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0093] Figure 7 It is a top view of a photosensitive device provided by an embodiment of the present application;

[0094] Figure 8 It is a bottom view of a photosensitive device provided by an embodiment of the present application;

[0095] Figure 9 It is a sectional view of a photosensitive device provided by an embodiment of the present application along Figure 6 the B-B direction in

[0096] Figure 10 It is a top view of a photosensitive device provided by an embodiment of the present application;

[0097] Figure 11 It is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0098] Figure 12 It is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0099] Figure 13 It is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0100] Figure 14 It is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0101] Figure 15 A longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0102] Figure 16 A longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0103] Figure 17 A longitudinal sectional view of a photosensitive device provided by an embodiment of the present application along Figure 16 the sectional view in the D-D direction in the figure;

[0104] Figure 18 A longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0105] Figure 19 A longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0106] Figure 20 A longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0107] Figure 21 A longitudinal sectional view of a photosensitive device provided by an embodiment of the present application;

[0108] Figure 22 A main method flow chart for preparing a photosensitive device provided by an embodiment of the present application;

[0109] Figure 23a - Figure 23h A main method flow chart for preparing a photosensitive device provided by an embodiment of the present application.

[0110] Reference numerals:

[0111] 101: Infrared emission light source 102: Receiver sensor 103: Approaching object

[0112] 100: Outer frame 200: Rear cover 300: Front screen

[0113] 400: Middle plate 500: Main board 600: Battery

[0114] 700: Small board 40: Photosensitive device 41: Chip

[0115] 41a: First surface of the chip 41b: Second surface of the chip 43: Circuit layer

[0116] 44: Underlay 45: Lead 46: Transparent resin

[0117] 47: Passive device 48: Photosensitive area 49: Upper pad

[0118] 42: Substrate 420: First part of the substrate 421: Second part of the substrate

[0119] 800: First opening 900: Second opening

[0120] 420a: Upper surface of the first part of the substrate (first surface of the substrate) 420b: Inner surface of the first part of the substrate 420c: Lower surface of the first part of the substrate 421a: Inner surface of the second part of the substrate

[0121] 421b: Lower surface of the second part of the substrate (second surface of the substrate) 422: Third part of the substrate

[0122] 422a: Lower surface of the third part of the substrate (second surface of the substrate)

[0123] 50: Filling material 501: A type of filling material 502: B type of filling material 503: C type of filling material

[0124] 51: Metal bump 52: Glue injection hole 53: Via hole

[0125] 54: Active device 56: Bracket 57: Light-transmitting hole

[0126] 58: Optical lens 59: First adhesive 60: Second adhesive

[0127] 61: Filter 62: Encapsulation material 63: Sacrificial glue Detailed implementation manners

[0128] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0129] The specific structure or solution described in the embodiments of the present application is to more clearly illustrate the technical solutions of the embodiments of the present application, and does not constitute a limitation to the technical solutions provided by the embodiments of the present application. Those of ordinary skill in the art know that the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0130] It should be noted that in the embodiments of the present application, the same reference numerals are used to represent the same component or the same part. For the same parts in the embodiments of the present application, only one of the parts or components may be labeled with the reference numeral in the figure. It should be understood that for other identical parts or components, the reference numerals are equally applicable.

[0131] It should also be noted that in the description of the embodiments of the present application, "metal bump" can also be referred to as bump or convex block. "Wire bonding (WB)" can also be referred to as wire bonding or wire connection. "Optical path adjustment device" can also be referred to as optical component, and those skilled in the art can understand its meaning.

[0132] The "connection" involved in the embodiments of the present application should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral one. It can be directly connected or indirectly connected through an intermediate medium. It can be a mechanical connection or an electrical connection.

[0133] The "upper" and "lower" involved in the embodiments of the present application are not limited to being defined according to the orientation of the components shown in the relative drawings. It should be understood that these directional terms can be relative concepts, which are used for relative description and clarification, and they can change accordingly with the change of the orientation of the components shown in the drawings.

[0134] The " / " in the embodiments of the present application indicates that the objects associated before and after are in an "or" relationship. For example, A / B can represent A or B; the "and / or" in the present application is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural.

[0135] Those skilled in the art can understand that the words such as "first" and "second" do not limit the quantity and execution order, and the words such as "first" and "second" do not necessarily limit being different.

[0136] The "first surface of the chip" involved in the embodiments of the present application can be used to indicate the active surface of the chip. In the embodiments of the present application, the "first surface of the chip" faces upward and is connected to the substrate through metal bumps. Correspondingly, the "second surface of the chip" involved in the embodiments of the present application can be used to indicate the passive surface of the chip.

[0137] The "photosensitive area is located within the range of the first opening (opening)" in the embodiments of the present application can be interpreted in various situations. In the top view of the photosensitive device, the projected area of the first opening (opening) can be larger than the projected area of the chip photosensitive area, and the projected area of the first opening (opening) can also be equal to the projected area of the chip photosensitive area. In addition, the chip photosensitive area can be surface-mounted on the first surface of the chip or partially embedded in the first surface of the chip.

[0138] The "not lower than the horizontal plane where the underpad is located" in the embodiments of the present application means not lower than the horizontal plane where the lower surface of the underpad is located.

[0139] In the embodiments of the present application, the "horizontal direction" refers to the direction parallel to the first surface and the second surface of the chip.

[0140] The substrate involved in the embodiments of the present application includes a package substrate (Substrate, SUB) and a printed circuit board (Printed Circuit Board, PCB). Among them, the printed circuit board refers to a non-conductive material on which conductive leads are printed or etched. Electronic components are mounted on the printed circuit board, and each component is connected by leads to assemble or form a working circuit. The printed circuit board can have one or two layers of conductors, or multiple layers of conductors or multiple conductive interlayers, and each layer is separated by an insulating layer. The package substrate is composed of an electronic circuit carrier (substrate material) and a copper-based electrical interconnection structure (such as electronic circuits, vias, etc.). The quality of the electrical interconnection structure directly affects the stability and reliability of the integrated circuit signal transmission and determines the normal operation of the electronic product design function. The package substrate mainly plays a transitional role in the electrical interconnection between the chip and different circuits of the printed circuit board.

[0141] The wire bonding (WB) involved in the embodiments of the present application is an electrical connection method between the chip and the substrate, that is, a gold wire with good conductivity is used to connect the chip pins to the substrate. In the field of semiconductor packaging and processing, in order to achieve normal signal output, an electrical connection must be established between the chip and the substrate.

[0142] The "exposure" involved in the embodiments of the present application is used to indicate exposure to light, that is, it mainly indicates exposure to air. In special cases, it can also be used to indicate exposure to incident light irradiation. Based on the structure of the embodiments of the present application, it is not excluded to cover the photosensitive area involved in the embodiments of the present application with a medium. The medium here includes transparent media and non-transparent media that meet the product requirements. The types of light transmission of the non-transparent media vary according to specific product requirements, including red media, blue media, and so on. It should be understood that since the thermal expansion coefficient of the transparent resin is relatively large, 5 to 6 times that of the conventional resin, the thermal expansion coefficient of the medium used based on the embodiments of the present application should be less than the thermal expansion coefficient of the transparent resin. The specific resin types are well-known to those skilled in the art.

[0143] The "height" involved in the embodiments of the present application refers to the straight-line distance of an object from a certain horizontal reference line in the vertical direction, specifically used to indicate the straight-line distance of the corresponding object from the second surface of the substrate in the vertical direction.

[0144] The "first opening" and "second opening" involved in the embodiments of the present application are relative concepts. The "first opening" does not fixedly correspond to the opening formed on the first surface of the substrate, and the "second opening" does not fixedly correspond to the opening formed on the second surface of the substrate. For the convenience of description in the present application, the "first opening" is defined as the opening formed on the first surface of the substrate, and the "second opening" is defined as the opening formed on the second surface of the substrate.

[0145] The "thermal expansion" involved in the embodiments of the present application refers to the expansion and contraction phenomenon of an object due to temperature change. The "thermal expansion coefficient" involved in the embodiments of the present application is a physical quantity that measures the degree of thermal expansion of solid materials. The larger the value, the more significant the thermal expansion. Specifically, the thermal expansion coefficient refers to the change in the length value or volume value caused by a unit temperature change under isobaric conditions (constant pressure). Generally speaking, when the external pressure remains unchanged, the volume of most substances increases when the temperature rises and decreases when the temperature drops.

[0146] The "molding shrinkage rate" involved in the embodiments of the present application reflects the degree of size reduction of a molded part after being taken out of the mold and cooled. Specifically, it is used to indicate the percentage of the difference between the size of the molded part at the molding temperature and the size after being taken out of the mold and cooled to room temperature. The molding shrinkage rates of different materials are different. The factors affecting the molding shrinkage rate include material variety, molding conditions, mold structure, etc. In addition, the molding shrinkage rate is also greatly related to the shape of the molded part, the complexity of the internal structure, and whether there are inserts. For transparent resin, its thermal expansion coefficient is very large, 5 to 6 times that of conventional resin. In addition, the molding shrinkage rate of transparent resin is also large when it is cooled. Therefore, introducing transparent resin into the photosensitive device brings greater stress and deformation, which is not friendly to the robustness of the chip.

[0147] The "stress" involved in the embodiments of the present application is used to indicate the internal force per unit area when an object is deformed by external factors (such as force, humidity, temperature field change, etc.). The internal force refers to the force that acts on each part of the object when the object is deformed due to external factors. The internal force is used to resist the action brought by the external factor and tries to make the object return from the deformed position to the undeformed position.

[0148] The photosensitive device provided by the embodiments of the present application can be mainly applied to the following three scenarios. It should be clear that with the development of the technology in this field, the application scenarios of the photosensitive device are not limited to this.

[0149] The photosensitive device provided by the embodiments of the present application can be applied to the body temperature monitoring of smart watches. The light sensor used in the watch receives the infrared rays emitted by the body, thereby realizing the extraction of human biometric features and further realizing body temperature monitoring.

[0150] The photosensitive device provided by the embodiments of the present application can be applied to near-infrared ranging or infrared light ranging. Taking a Time of Flight (ToF) sensor as an example, the ToF sensor emits modulated near-infrared light or infrared light. After the near-infrared light or infrared light is reflected by an object, the ToF sensor calculates the time difference or phase difference between the light emission and reflection to convert the distance of the captured scene, so as to generate depth information, thereby realizing the ranging of objects in the scene. Figure 1 It is a schematic diagram of the principle of the optical sensor, as Figure 1 shown. The infrared light or near-infrared light emitted by the infrared emission light source 101 is reflected by the approaching object 103 to the receiving end sensor 102. The receiving end sensor 102 judges the distance between the approaching object 103 and the receiving end sensor 102 according to the intensity of the received infrared light, and then realizes the purpose of sensing the approaching object 103 and further makes a response. Among them, the infrared emission light source 101 may include an infrared light-emitting diode (IR LED) and a vertical-cavity surface-emitting laser (VCSEL).

[0151] The photosensitive device provided by the embodiments of the present application can be widely applied to the liquid crystal display field. Specifically, the final product form of the photosensitive device provided by the embodiments of the present application is an optical sensor module. The optical sensor module is widely used in electronic devices with display screens, and is applicable to mobile terminal electronic products such as mobile phones, tablet computers, and wearable devices to automobiles.

[0152] For the convenience of description, taking the mobile terminal electronic product mobile phone as an example, the application scenario of the photosensitive device will be introduced in detail below. This cannot be regarded as a specific limitation on the structural form of the mobile terminal. In a mobile phone with a display screen, an optical sensor is installed under the screen. After using the optical sensor under the display screen of the mobile phone, the optical sensor will sense the light conditions of the surrounding environment, and then inform the processing chip to automatically adjust the backlight brightness of the display, realizing the adaptive adjustment of the screen brightness, and finally reducing the power consumption of the mobile phone. When the ambient brightness is high, the liquid crystal display using the optical sensor will automatically adjust to a high brightness. When the external environment is dark, the liquid crystal display screen will be adjusted to a low brightness, thereby protecting the eyes. In addition, in mobile terminal devices such as mobile phones, the power consumed by the display accounts for up to 30% of the total battery power. Using an optical sensor can maximize the working time of the battery.

[0153] Figure 2 It is a schematic diagram of the overall structure of a mobile terminal provided by the embodiments of the present application. As Figure 2As shown, the mobile terminals sold on the market generally adopt a sandwich structure, that is, the overall structure of the mobile terminal consists of three parts: the front screen 300, the rear cover 200, and the middle frame. Figure 3 is Figure 2 a cross-sectional view of the mobile terminal shown from the A-A perspective. As Figure 3 shown, the middle plate 400 and the outer frame 100 together form the middle frame, which is the middle part of the sandwich structure of the mobile terminal. A chamber formed between the middle plate 400 and the rear cover 200 houses various electronic components such as the main board 500, the battery 600, and the small board 700.

[0154] The main board 500 is an important component of various mobile terminals, and various devices that make up the circuit system of the mobile terminal are installed on it. In some embodiments, especially in mobile terminals with a display screen, various sensor modules are also fixedly connected to the main board 500. Among them, the optical sensor module is relatively common, that is, the photosensitive device mentioned in the embodiments of the present application. Specifically, the photosensitive device mainly includes: a substrate, a processing chip, capacitors, resistors, inductors, and diodes and other various components. The specific product form of the photosensitive device can also selectively adopt various packaging structures and forms according to the actual product requirements.

[0155] As Figure 4 shown, Figure 4 is a longitudinal sectional view of a photosensitive device. In this photosensitive device, the surface of the chip 41 is mounted on the surface of the substrate 42, and a photosensitive area 48 is provided on the first surface of the chip 41. Further, the chip 41 and the substrate 42 are connected by leads 45 to achieve signal output, that is, the aforementioned lead connection method. In order to ensure the stable connection between the chip 41 and the substrate 42 while not affecting the photosensitivity of the photosensitive area 48, the chip 41 and the leads 45 are usually encapsulated as a whole with a transparent resin 46 to enable incident light to be directly projected onto the photosensitive area 48. In addition to the chip 41, active devices and passive devices can be selectively added to the first surface of the substrate 42 for packaging according to the actual product requirements, such as Figure 4 the passive device 47 in Figure 3 to finally form the final form of the sensor module, and this sensor module is connected to the main board 500 (see

[0156] (1) The overall size of the photosensitive device is large and the thickness is thick, and the product cannot be miniaturized and thinned;

[0157] (2) The distance between the chip 41 and the main board 500 (see Figure 3 ) is far, and the heat dissipation performance is not excellent;

[0158] To solve the above problems, the photosensitive device provided in the embodiments of the present application no longer adopts the surface mounting technology, but installs the chip inside the substrate, and the two form an integrated structure. The following will clearly and completely describe the specific implementation manners of the present application with reference to the accompanying drawings.

[0159] Before describing the photosensitive device according to the embodiments of the present application, it is necessary to understand an important component of the embodiments of the present application - the substrate with an opening design. Figure 5 This is a schematic diagram of the substrate opening provided for the embodiments of the present application. As Figure 5 shown, the substrate 42 has a first surface 420a and a second surface 421b. The first surface 420a is provided with a first opening 800, and the second surface 421b is provided with a second opening 900. The second opening 900 provided on the second surface 421b is larger than the first opening 800 provided on the first surface 420a. Both the first opening 800 and the second opening 900 are three-dimensional spaces, and the second opening 900 communicates with the first opening 800. The substrate 42 includes a first portion 420 divided by the illustrated C-C cross-section and a second portion 421 located below the first portion 420. Among them, the C-C cross-section is the intersection line of the first opening 800 and the second opening 900. The first portion 420 has a first surface 420a, an inner surface 420b, and a lower surface 420c, and the second portion 421 has an inner surface 421a and a second surface 421b. Among them, the first surface 420a of the first portion 420 is the first surface of the substrate 42, and the second surface 421b of the second portion 421 is the lower surface of the substrate 42. The inner surface 420b of the first portion 420 is exposed by the first opening 800 provided on the first surface 420a, and the lower surface 420c of the first portion 420 and the inner surface 421a of the second portion 421 are exposed by the second opening 900 provided on the second surface 421b.

[0160] Figure 6 This is a longitudinal sectional view of a photosensitive device provided for the embodiments of the present application. The photosensitive device 40, as an important component of the internal circuit system of the mobile terminal, is correspondingly installed on the main board 500 (see Figure 3 ) of the mobile terminal. As Figure 6 shown, in one embodiment, the photosensitive device 40 includes a substrate 42 with an opening design, a chip 41, and a filling material 50. The opening design adopted by the substrate 42 is as Figure 5As shown. The chip 41 is installed in the second opening 900 formed on the second surface 421b. The chip 41 has a first surface 41a and a second surface 41b. The chip 41 further includes a photosensitive area 48 arranged on the first surface 41a. The photosensitive area 48 is located within the opening range of the first opening 800 formed on the first surface 420a to receive incident light irradiation. The second surface 41b of the chip 41 has a higher horizontal height than the second surface 421b of the substrate, that is, the horizontal plane where the second surface 41b of the chip is located is higher than the horizontal plane where the second surface 421b of the substrate is located. The chip 41 and the substrate 42 are connected by metal bumps 51. The metal bumps 51 respectively contact the lower surface 420c of the first part 420 of the substrate and the first surface 41a of the chip 41. The gap between the chip 41 and the substrate 42 is filled with a filling material 50, thereby reducing the reaction generated at the joint due to different coefficients of thermal expansion of the chip 41, the substrate 42, and the metal bumps 51, and further protecting the chip 41 and the metal bumps 51. The inner surface 420b of the first part 420 and the second surface 41b of the chip 41 are also coated with the filling material 50. The filling material 50 coated at the second surface 41b of the chip is flush with the second surface 421b of the substrate. The gap between the chip 41 and the substrate 42 refers to the area where the first surface 41a of the chip 41 contacts the lower surface 420c of the first part 420, and the area where the left and right side surfaces of the chip 41 contact the inner surface 421a of the second part 421. The inner surface 420b of the first part 420 also refers to the side wall of the first opening 800 formed on the first surface 420a of the substrate.

[0161] As Figure 6 shown, the substrate 42 further includes an upper pad 49, a lower pad 44, and a circuit layer 43. Among them, the upper pad 49 is arranged at the lower surface 420c of the first part 420. The upper pad 49 and the chip 41 are electrically connected through the metal bumps 51. The lower pad 44 is arranged at the second surface 421b of the second part 421. The lower pad 44 is connected to the main board 500 (see Figure 3 ).

[0162] In an embodiment, the lengths of the lower surface 420c of the first part 420 and the second surface 421b of the second part 421 in the horizontal direction can be appropriately extended. That is, the projected area of the first opening 800 in the top view and the projected area of the second opening 900 (see Figure 5 ) in the bottom view can be adjusted. However, the projected area of the first opening 800 in the top view is smaller than the projected area of the second opening 900 (see Figure 5 ) in the bottom view.

[0163] In one embodiment, the thickness of the first part 420 and the second part 421 of the substrate can be moderately adjusted. For example, the first part 420 of the substrate is thinner than the second part 421 of the substrate, and the volume of the first opening 800 is smaller than the volume of the second opening 900. For example, the first part 420 of the substrate is thicker than the second part 421 of the substrate, and the volume of the first opening 800 is larger than the volume of the second opening 900. For another example, the first part 420 of the substrate is thicker than the second part 421 of the substrate, and the volume of the first opening 800 is smaller than the volume of the second opening 900. For still another example, the thickness of the first part 420 of the substrate is the same as that of the second part 421 of the substrate, and at this time, the volume of the first opening 800 is smaller than the volume of the second opening 900.

[0164] For the sake of convenience of description, the filling material filled in the gap between the chip and the substrate is called the first filling material, the filling material coated on the side wall of the first opening of the substrate is called the second filling material, and the filling material coated on the second surface of the chip is called the third filling material. There are various combination possibilities for the filling materials included in the photosensitive device.

[0165] In one embodiment, the photosensitive device does not include the third filling material and only includes the first filling material and the second filling material. At this time, in order not to affect soldering, the horizontal plane where the second surface 41b of the chip is located is not lower than the horizontal plane where the underlay 44 is located.

[0166] In one embodiment, the photosensitive device does not include the second filling material and only includes the first filling material and the third filling material. At this time, in order not to affect soldering, the horizontal plane where the third filling material is located is not lower than the horizontal plane where the underlay 44 is located.

[0167] In one embodiment, the photosensitive device only includes the first filling material. At this time, in order not to affect soldering, the horizontal plane where the second surface 41b of the chip is located is not lower than the horizontal plane where the underlay 44 is located.

[0168] In one embodiment, there may be other conductive metals between the first surface 41a of the chip, the lower surface 420c of the first part of the substrate, and the metal bump 51, that is, the metal bump 51 can be indirectly in contact with the first surface 41a of the chip and the lower surface 420c of the first part of the substrate.

[0169] The filling material 50 is different from the transparent resin 46, and its selection criteria need to take into account the dual characteristics of a relatively small coefficient of thermal expansion and low stress. Optionally, the filling material 50 can be an underfill, or a potting compound, a casting compound, or other materials that meet the requirements. The embodiments of the present application do not limit this.

[0170] Since the transparent resin 46 has relatively large coefficients of thermal expansion and molding shrinkage, long-term use can easily lead to the failure and deformation of the photosensitive device, and yellowing can also occur. Therefore, the filling material used in this technical solution is an opaque resin, which has a relatively small coefficient of thermal expansion and a relatively small molding shrinkage, so as to better protect the chip and further improve the electrical performance.

[0171] Optionally, the filling method or coating method of the filling material 50 can be injection molding, or it can be achieved by dispensing or other processes.

[0172] Optionally, the metal bumps 51 used to connect the chip 41 and the substrate 42 can be made of gold, tin or other conductive metals.

[0173] Optionally, the underpad 44 used to connect the substrate 42 and the main board 500 (see Figure 3 ) can be a solder pad or a solder ball.

[0174] Optionally, the photosensitive area 48 can be a photosensitive device, a photodiode, a filter film or other passive devices with photosensitive functions. The photosensitive area 48 is installed on the first surface 41a of the chip, and the installation method can be embedded installation or surface mounting.

[0175] Optionally, the substrate 42 can be a package substrate (Substrate, SUB) or a printed circuit board (Printed Circuit Board, PCB).

[0176] In one embodiment, the substrate 42 is a package substrate, and the substrate 42 is connected to the printed circuit board through the underpad 44. The installation gap between the package substrate and the printed circuit board further includes a heat conduction layer, so as to further improve the heat dissipation performance of the photosensitive device.

[0177] In the embodiment of the present application, the chip 41 is installed inside the substrate 42, which further improves the integration of the product. The photosensitive device installs the chip 41 inside the substrate 42 with an opening design, which greatly reduces the overall package thickness of the product and is beneficial to the miniaturization and thinness of the product. In addition, the distance between the chip 41 and the main board 500 (see Figure 3 ) becomes shorter, and the heat dissipation performance is better. The photosensitive device provided by the embodiment of the present application also does not need to introduce a transparent resin to protect the chip, further reducing the product thickness.

[0178] In this photosensitive device, the substrate and the chip no longer use the lead connection method, but are connected through the metal bumps 51, eliminating the interconnection leads, improving the area utilization rate of the substrate 42. In addition, the signal transmission path between the substrate 42 and the chip 41 becomes shorter, and the transmission loss is reduced, so the electrical performance is improved.

[0179] Optionally, the metal bumps 51 may be made of metal conductive materials such as gold, tin, etc., and are usually in the shape of spheres, columns, or blocks.

[0180] Figure 7 This is a top view of a photosensitive device provided in an embodiment of the present application. Figure 7 As shown, the outermost shaded area is the other area of ​​the first surface 420a of the substrate 42 except the first opening 800. From the outside to the inside, the second layer is the filling material 50, which is the part coated by the inner surface 420b of the first part 420. The third layer is a partial area of ​​the chip 41, that is, the area of ​​the chip 41 exposed by the first opening 800 opened on the first surface 420a and excluding the photosensitive area 48. The innermost layer is the photosensitive area 48, which is exposed by the first opening 800 opened on the first surface 420a. It can be seen that the third layer and the innermost layer are both part of the chip 41.

[0181] Figure 8 This is a bottom view of a photosensitive device provided in an embodiment of the present application. Figure 8 As shown, the background shaded area corresponds to the second surface 421b of the substrate 42. The rectangular area in the middle of the figure corresponds to the filling material 50 coated on the second surface 41b of the chip 41, which is used to fix and protect the chip 41. The two rows of rectangular areas symmetrically arranged at both ends of the figure are the lower pads 44, and the lower pads 44 and the main board 500 (see Figure 3 ) are connected.

[0182] Depend on Figure 7 and Figure 8 It can be concluded that the projection area of ​​the second opening 900 in the bottom view is larger than the projection area of ​​the first opening 800 in the top view. Figure 6 , Figure 7 and Figure 8 It can be concluded that the first opening 800 and the second opening 900 are both three-dimensional spaces.

[0183] Figure 9 A photosensitive device provided in an embodiment of the present application Figure 6 BB direction profile. Figure 9 As shown, the outermost shaded area corresponds to the substrate 42, the second rectangular loop from the outside to the inside is the filling material 50, and the illustrated area is the portion filled between the chip 41 and the inner surface 421a. The area surrounded by the filling material 50 is the chip 41, wherein the circular area surrounding the photosensitive area 48 is the metal bump 51, and the innermost rectangular area is the photosensitive area 48.

[0184] Furthermore, the shape of the photosensitive region 48 and the shape of the first opening 800 can be arbitrarily combined, including circular, rectangular, square or other irregular geometric shapes. For example, in one embodiment, when viewed from above, the photosensitive region 48 is circular and the shape of the first opening 800 is circular; for another example, in one embodiment, when viewed from above, the photosensitive region 48 is rectangular and the shape of the first opening 800 is rectangular. The embodiments of the present application are not necessarily limited thereto.

[0185] Figure 10 It is a top view of a photosensitive device provided by an embodiment of the present application. Figure 10 It is one of the combination forms of the shape of the first opening 800 formed on the first surface 420a of the substrate and the shape of the photosensitive region 48. In the figure, the shape of the first opening 800 is circular and the shape of the photosensitive region 48 is circular.

[0186] Furthermore, the first filling material, the second filling material, and the third filling material can be one or more. The sizes and areas coated by each filling material can be adjusted accordingly according to the actual needs of the product to improve the processability and reliability of the product.

[0187] For example, in one embodiment, the photosensitive device does not include the third filling material, and the first filling material and the second filling material are the same kind.

[0188] For example, in one embodiment, the photosensitive device does not include the second filling material and the third filling material, and the first filling material fills two or more different filling materials.

[0189] For example, in one embodiment, the photosensitive device does not include the second filling material, and the first filling material and the third filling material are the same kind.

[0190] For example, in one embodiment, the photosensitive device includes the first filling material, the second filling material, and the third filling material, and the first filling material, the second filling material, and the third filling material are the same kind.

[0191] For another example, in another embodiment, as Figure 11 shown, the filling material coated on the second surface 41b of the chip 41 and the resin filled between the chip 41 and the inner surface 421a are of the same kind, that is, the second type of filling material 502; the resin filled between the chip 41 and the lower surface 420c and the filling material coated on the inner surface 420b are of another kind, that is, the first type of filling material 501.

[0192] For another example, in another embodiment, as Figure 12As shown, the filling material coated on the second surface 41b of the chip 41 is the same as the filling material filled in the area between the chip 41 and the inner surface 421a, that is, the second-class filling material 502. The filling material coated on the inner surface 420b is the first-class filling material 501, and the third-class filling material 503 is used in the remaining areas.

[0193] Specifically, the specific material of the filling material 50 can be underfill, encapsulant, potting compound or other materials that meet the requirements. For example, the filling material 50 coated on the inner surface 420b and the second surface 41b of the chip is selected as underfill, and the filling material filled in the gap between the chip 41 and the substrate 42 is also selected as underfill. For another example, the filling material 50 coated on the inner surface 420b can be selected as potting compound, the filling material 50 filled in the gap between the chip 41 and the substrate 42 can be selected as underfill, and the filling material coated on the second surface 41b of the chip is selected as encapsulant. For another example, the filling material 50 filled in the gap between the chip 41 and the substrate 42 and the filling material 50 coated on the second surface 41b of the chip are both selected as potting compound, and the filling material 50 coated on the inner surface 420b is selected as underfill. The embodiments of the present application are not limited thereto.

[0194] In one implementation manner, any one of the above three regions can be filled or coated with two different types of filling materials. Taking the filling material coated on the inner surface 420b as an example, the filling material 50 coated on the inner surface 420b can be selected from two different materials, underfill and encapsulant. For another example, the filling material 50 coated on the inner surface 420b is selected from two different materials, underfill and encapsulant. For another example, the filling material 50 coated on the inner surface 420b is selected from two different materials, underfill and potting compound. For another example, the filling material 50 coated on the inner surface 420b is selected from two different materials, encapsulant and potting compound. For another example, the filling material 50 coated on the inner surface 420b is selected from three different materials, underfill, encapsulant and potting compound. The embodiments of the present application are not limited thereto.

[0195] Furthermore, the structure and shape of the filling material coated on the inner surface 420b can be adjusted accordingly according to the product requirements. On the premise of coating the filling material on the inner surface 420b, the structure or height of the filling material coated on the inner surface 420b can be adjusted by using a high-precision mold, so as to facilitate ensuring the optical precision requirements of the optical path adjusting device located above the photosensitive area 48, and also more conducive to improving the product reliability.

[0196] In one implementation manner, the thickness of the filling material distributed on the inner surface 420b becomes thicker in the direction towards the chip 41 in the horizontal direction, so that the support of the filling material 50 for the optical path adjusting device is more stable.

[0197] In one embodiment, the filling material 50 coated on the inner surface 420b of the first part 420 adopts a concave curve structure design, as Figure 13 shown, Figure 13 is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application. The filling material structure coated at the inner surface 420b adopts a concave curve structure design to achieve a better light path effect.

[0198] In one embodiment, the filling material 50 coated on the inner surface 420b of the first part 420 adopts a stepped structure design, wherein the inner surface 420b is partially exposed, as Figure 14 shown, Figure 14 is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application.

[0199] In one embodiment, the filling material 50 coated on the inner surface 420b of the first part 420 adopts a stepped structure design, wherein the inner surface 420b is completely covered by the filling material 50, as Figure 15 shown, Figure 15 is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application.

[0200] In view of the design of the filling material 50, in one embodiment, one or more glue injection holes may be opened on the first surface 420a of the substrate 42 for injecting glue or exhausting air inside the photosensitive device 40 to improve the product processability. The number, position and size of the holes can be adjusted according to the actual product requirements. As Figure 16 shown, Figure 16 is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application. Figure 16 and Figure 6 have a similar structure. The difference is that three glue injection holes 52 are added on the first surface 420a. The glue injection holes 52 communicate with the gaps between the chip 42 and the substrate 42 to facilitate the injection of the filling material 50.

[0201] Figure 17 is a sectional view of a photosensitive device provided by an embodiment of the present application along the Figure 15 D-D direction in Figure 17 shown. Three glue injection holes 52 are added on the first surface 420a of the substrate 42. In this embodiment, the cross-section of the glue injection hole 52 is rectangular.

[0202] Optionally, the cross-section of the glue injection hole 52 can be designed as circular, square or other geometric shapes.

[0203] In addition, embedding is another implementation form to achieve the beneficial effects of this application. Embedding belongs to a new process, namely embedded component package (ECP). Embedded component package is a packaging form in which electronic components such as capacitors, resistors, and chips are embedded inside the substrate. It can shorten the signal transmission path between components, reduce transmission loss, improve product integration, reduce the module form factor, and at the same time improve the reliability and electrothermal performance of the product. It is an important means to realize the multi-functionality and high performance of portable electronic devices. The embedded component photosensitive device creates three functional layers, that is, not limited to the top layer and the bottom layer, and there is also valuable space in the inner layer of the substrate. Such a substrate can achieve more functions than a traditional substrate of the same size. On the one hand, it can better protect the inner layer components and improve the reliability of the product. On the other hand, it can release the outer space and make the photosensitive device more compact.

[0204] Figure 18 A longitudinal sectional view of a photosensitive device provided by an embodiment of this application is as Figure 18 shown. A photosensitive device 40 includes a substrate 42 and a chip 41. The substrate 42 is divided into a first part 420, a second part 421 located below the first part 420, and a third part 422 by the illustrated C-C cross-section and E-E cross-section. Among them, the first part 420 has a first surface 420a, an inner surface 420b, and a lower surface 420c. The second part 421 has an inner surface 421a. The third part 422 has a lower surface 422a. It should be understood that the first surface 420a of the first part 420 is the first surface of the substrate 42, and the first surface 420a has an opening, and the inner surface 420b is exposed by the opening. The chip 41 is embedded and installed inside the substrate 42. The chip 41 has a first surface 41a and a second surface 41b. A photosensitive area 48 is provided on the first surface 41a of the chip. The photosensitive area 48 is located within the opening provided on the first surface 420a to receive incident light irradiation. The first surface 41a of the chip 41 is electrically connected to the upper pad 49 through a via 53. Compared with the foregoing embodiment, the lower surface 422a of the substrate 42 of the photosensitive device 40 does not contain an opening. Therefore, the photosensitive device 40 includes a third part 422 in addition to the first part 420 and the second part 422. The chip 41 is embedded and installed in the substrate 42, and the chip 41 contacts the lower surface 420c of the first part 420, the inner surface 421a of the second part 421, and the third part 422.

[0205] In one embodiment, the photosensitive device adopting the embedding process does not include the design of filling materials. In another embodiment, the inner surface 420b of the photosensitive device adopting the embedding process is coated with a filling material 50. The structure and height of the filling material 50 can be adjusted by a high-precision mold to achieve a better light path effect.

[0206] Optionally, the substrate in the photosensitive device adopting the embedding process may be a packaging substrate or a printed circuit board.

[0207] It should be noted that the embedding process in this embodiment is different from the process of the foregoing embodiment. The chip 41 in the photosensitive device 40 is directly embedded during the manufacturing process of the substrate 42, and after the embedding process is completed, subsequent processing procedures are used to expose the photosensitive area 48, such as the laser grooving process. In the foregoing embodiment, an opening is made after the substrate is manufactured, and the chip is installed inside the substrate opening.

[0208] The shape of the photosensitive area 48 and the shape of the opening formed on the first surface 420a of the substrate 42 can be arbitrarily combined, including circular, rectangular, square or other geometric shapes. For example, in one embodiment, when viewed from above, the shape of the photosensitive area 48 is circular, and the shape of the opening formed on the first surface 420a of the substrate 42 is circular; for another example, in one embodiment, when viewed from above, the shape of the photosensitive area 48 is rectangular, and the shape of the opening formed on the first surface 420a of the substrate 42 is rectangular. The embodiments of the present application are not necessarily limited thereto.

[0209] Optionally, the substrate 42 may be a packaging substrate or a printed circuit board.

[0210] In one embodiment, the substrate 42 is a packaging substrate, and the packaging substrate and the printed circuit board are connected by an underpad 44. The photosensitive device 40 further includes a heat conduction layer, and the heat conduction layer is distributed in the installation gap between the substrate 42 and the printed circuit board, thereby further improving the heat dissipation performance of the photosensitive device.

[0211] In one embodiment, one or more optical path adjustment devices may be added above the chip 41 to achieve focusing or filtering of the incident light incident on the photosensitive area, and the incident light is projected onto the photosensitive area 48 after being focused or filtered.

[0212] Optionally, the optical path adjustment device is at least one of the following devices: cover glass, optical lens, filter, prism, diaphragm. The optical path adjustment device may also be other optical devices with focusing or filtering functions, and the embodiments of the present application do not limit this.

[0213] For example, the optical path adjustment device may be a group of optical lenses or multiple groups of optical lenses. For another example, the optical path adjustment device may be a group of filters or multiple groups of filters. For another example, the optical path adjustment device may be a combination of an optical lens and a filter. For another example, the optical path adjustment device may be a combination of a filter and a prism. For another example, the optical path adjustment device may be a combination of an optical lens and a diaphragm. The embodiments of the present application are not necessarily limited thereto.

[0214] In one embodiment, the photosensitive device 40 includes a chip 41, a substrate 42, a filling material 50, and an optical path adjusting device. The optical path adjusting device is fixedly connected to the filling material 50 coated on the first surface 420a of the substrate and the inner surface 420b of the first part.

[0215] In one embodiment, the optical path adjusting device is installed at the filling material 50 coated on the inner surface 420b, and the optical path adjusting device is fixedly connected only to the filling material 50 coated on the inner surface 420b of the first part.

[0216] Optionally, the connection method of the optical path adjusting device can be adhesion or welding.

[0217] Optionally, the structure of the filling material 50 at the inner surface 420b includes Figure 6 the bevel design of Figure 13 the curved concave design of Figure 14 and Figure 15 the step design in

[0218] In one embodiment, the photosensitive device 40 includes a chip 41, a substrate 42, and an optical path adjusting device, without involving the filling material structure. The optical path adjusting device is only connected to the first surface 420a of the substrate.

[0219] Optionally, the connection method between the optical path adjusting device and the first surface 420a of the substrate can be adhesion or welding.

[0220] In one embodiment, various components can be added to the first surface 420a of the substrate, including active devices, passive devices, and devices such as gold wires, etc., to improve the integration level.

[0221] Optionally, the active devices and passive devices include components such as resistors, capacitors, inductors, or chips.

[0222] In one embodiment, a bracket can be added to the first surface 420a of the substrate, and the bracket has a light-transmitting hole. The remaining areas of the bracket except the light-transmitting hole are all light-impermeable to achieve light transmission at a certain angle, and the side wall of the light-transmitting hole is also light-impermeable.

[0223] Furthermore, the bracket can be fixed to the first surface 420a of the substrate by means such as welding or adhesion.

[0224] Figure 19 This is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application. Figure 19 and Figure 6 The structure of the embodiment is similar, the difference is that an optical path adjusting device is added above the chip 41, and active devices 54, passive devices 47, and a bracket 56 are respectively added to the first surface 420a of the substrate. In one embodiment, as Figure 19As shown, the optical path adjusting device above the chip 41 selects an optical lens 58. The optical lens 58 is connected to the filling material 50 coated at the inner surface 420b and the first surface 420a of the substrate through a first adhesive 59 respectively. Passive devices 47 and active devices 54 are added to the first surface 420a respectively. In addition, a bracket 56 with a light-transmitting hole 57 is added to the first surface 420a. The bracket 56 is connected to the first surface 420a of the substrate 42 through a second adhesive 60. In this embodiment, the path of the incident light is as follows: first, the light passing through a certain angle passes through the light-transmitting hole 57 of the bracket, then is focused by the optical lens 58, and finally is projected onto the photosensitive area 48.

[0225] Figure 20 It is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application. Figure 20 Similar to Figure 19 the structure, the difference is that the optical path adjusting device added above the chip 41 is changed from the lens 58 to a filter 61. In one embodiment, as Figure 20 shown, the optical path adjusting device above the chip 41 selects a filter 61. The filter 61 is connected to the first surface 420a and the filling material 50 coated at the inner surface 420b through a first adhesive 59 respectively. Passive devices 47 and active devices 54 are added to the first surface 420a of the substrate respectively; in addition, a bracket 56 with a light-transmitting hole 57 is added to the first surface 420a. The bracket 56 is connected to the first surface 420a of the substrate 42 through a second adhesive 60. In this embodiment, the path of the incident light is as follows: first, the light passing through a certain angle passes through the light-transmitting hole 57 of the bracket, then is filtered by the filter 61, and finally is projected onto the photosensitive area 48.

[0226] In one embodiment, an encapsulating material is used to encapsulate the newly added components on the first surface 420a of the substrate 42 to protect the chip, thereby reducing the product size and further integrating.

[0227] Optionally, the encapsulating material can encapsulate all the components or partially encapsulate the components.

[0228] Optionally, the newly added encapsulating material 62 can be realized by methods such as injection molding, dispensing (coating), potting, etc.

[0229] Figure 21 It is a longitudinal sectional view of a photosensitive device provided by an embodiment of the present application. As Figure 21As shown in the figure, the encapsulation material 62 is selected to encapsulate all the active devices 54 and passive devices 47 mounted on the first surface 420a of the substrate. The optical path adjustment device above the chip 41 selects the optical lens 58, and the optical lens 58 is fixedly connected to the photosensitive device 40 through the first adhesive 59. Except for the optical lens 59, the first adhesive 59 contacts the encapsulation material 62, the first surface 420a of the substrate 42, and the filling material 50 coated on the inner surface 420b respectively. A bracket 56 with a light-transmitting hole 57 is newly added on the upper surface of the encapsulation material 62, and the bracket 56 is connected to the upper surface of the encapsulation material 62 through the second adhesive 60.

[0230] Preferably, the encapsulation material 62 is selected as a dark resin to shield the light interference of other frequency bands, such as black, brown, and blue. The embodiments of the present application do not limit this. In addition, in order to avoid excessive deformation of the overall photosensitive device 40, the encapsulation material 62 also needs to take into account the characteristics of a small coefficient of thermal expansion and small stress. The encapsulation material 62 can be selectively selected as the same resin as the filling material 50. That is, it can be the first filling material 501, the second filling material 502, or the third filling material 503, or a material different from the foregoing filling materials but meeting the requirements. The embodiments of the present application do not limit this.

[0231] In one embodiment, the photosensitive device 40 includes a chip 41, a substrate 42, a filling material 50, and a lens 58, and the design without using the encapsulation material 62 is adopted. The lens 58 is fixedly welded to the filling materials at the first surface 420a and the inner surface 420b of the substrate respectively.

[0232] In one embodiment, the photosensitive device 40 includes a chip 41, a substrate 42, a filling material 50, a lens 58, and an encapsulation material 62. The encapsulation material 62 is selected to encapsulate all the newly added components on the first surface 420a of the substrate, and the lens 58 is adhesively fixed to the encapsulation material 62, the filling materials at the first surface 420a and the inner surface 420b of the substrate respectively.

[0233] In one embodiment, the photosensitive device 40 includes a chip 41, a substrate 42, components, and a bracket, and the encapsulation material 62 is selected to encapsulate all the components on the first surface 420a of the substrate, and the bracket 56 is fixedly welded to the upper surface of the encapsulation material 62.

[0234] In one embodiment, the photosensitive device 40 includes a chip 41, a substrate 42, components, and a bracket, and the design without using the encapsulation material 62 is adopted. The bracket 56 is fixedly connected to the first surface 420a of the substrate by gluing.

[0235] The embodiments of the present application provide a method for preparing a photosensitive device, as Figure 22 shown, Figure 22The main method flowchart for preparing a photosensitive device provided by an embodiment of the present application. The preparation method mainly includes:

[0236] S01: Provide a substrate 42 with an opening design and a chip 41

[0237] The first surface 420a of the substrate 42 has a first opening 800, and the second surface 421b of the substrate has a second opening 900. The first opening 800 and the second opening 900 are communicated with each other.

[0238] Connect the metal bumps 51 directly or indirectly to the pads of the chip 41. Among them, the manufacturing of the metal bumps 51 is generally based on a customized photomask and is formed through processes such as vacuum sputtering, yellow light, electroplating, and etching.

[0239] S02: Chip installation

[0240] Install the chip 41 with the metal bumps 51 inside the substrate 42 with an opening design.

[0241] S03: Open a glue injection hole

[0242] Open a glue injection hole 52 on the first surface 420a of the substrate with an opening design. The glue injection hole 52 is communicated with the gap between the chip 41 and the substrate 42 and is used to inject a filling material into the gap between the chip 41 and the substrate 42.

[0243] S04: Inject (coat) a filling material

[0244] Inject a first filling material into the gap between the chip 41 and the substrate 42. The first filling material is injected through the glue injection hole 53.

[0245] Optionally, coat a second filling material on the sidewall 420b of the first opening, and adjust the specific structure and height of the second filling material in combination with the precision mold to achieve a better light path effect. Further, an optical path adjusting device can be installed above the second filling material or above the first surface 420a of the substrate.

[0246] Optionally, coat a third filling material on the second surface 41b of the chip. The horizontal plane where the third filling material is located is not lower than the horizontal plane where the underlay 44 is located.

[0247] Further, various active devices 54 and passive devices 47 can be selectively added to the first surface 420a of the substrate to improve the integration of the photosensitive device 40.

[0248] Another method for preparing a photosensitive device is provided by an embodiment of the present application. Figure 23a - 23h The main method flowchart for preparing a photosensitive device provided by an embodiment of the present application. As Figure 23a - Figure 23h shown, the preparation process mainly includes:

[0249] S01: Chip Installation

[0250] As Figure 23a , the chip 41 with a photosensitive area 48 is installed above the metal layer. The metal layer is composed of a metal material, generally copper, or other materials that can achieve the corresponding functions.

[0251] S02: Overlay Coating

[0252] As Figure 23b , a sacrificial glue 63 is overlaid on the upper layer of the photosensitive area 48 of the chip. In the embodiments of the present application, the sacrificial glue can be a hydrogel or other materials that can play a protective role. The embodiments of the present application do not limit this.

[0253] S03: Lamination

[0254] As Figure 23c , lamination refers to a forming and processing method of combining one or more layers of the same or different materials into a whole under heating and pressurization conditions. In the embodiments of the present application, it refers to a processing method of combining multiple layers of resin (substrate material) into a complete substrate under heating and pressurization conditions. Further, during the lamination process, the stacked multiple layers of resin need to be pressed as Figure 23d shown.

[0255] S04: Opening via holes

[0256] As Figure 23e , use an opening or an opening process to open via holes 53 to lead out the circuit structure of the chip 41 to the outside of the substrate 42. This opening process can be a mechanical opening or a laser opening. The embodiments of the present application do not limit this.

[0257] S05: Laying metal material

[0258] As Figure 23f , lay a metal material above the opened via holes. The metal material is generally copper, or other conductive materials that can achieve the corresponding functions.

[0259] S06: As Figure 23g , adopt a grooving process to open an opening above the first surface 420a of the substrate, such as laser grooving, etc., to expose the sacrificial glue.

[0260] S07: As Figure 23h , remove the sacrificial glue 63 to expose the photosensitive area 48 above the chip 41, so that the photosensitive area 48 is located inside the opening opened on the first surface 420a of the substrate to receive incident light irradiation.

[0261] Optionally, coat the filling material on the sidewall 420b of the opening, and adjust the height or structure of the filling material in combination with a high-precision mold to achieve a better light path effect.

[0262] Optionally, various active devices 54 and passive devices 47 can be selectively added to the first surface 420a of the substrate to improve the integration of the photosensitive device 40.

[0263] Furthermore, an embodiment of the present application provides an electronic device. The electronic device can be a mobile phone, a desktop computer, a tablet computer, a laptop computer, a handheld computer, etc. The electronic device can also be an automobile, a virtual reality device, an augmented reality device, etc. The specific form of the electronic device in the present application is not limited. Taking the mobile terminal mobile phone as an example, as Figure 2 and Figure 3 shown, the electronic device includes a front screen 300, a middle frame, and a rear cover 200. Among them, the middle frame further includes an outer frame 100 and a middle plate 400. A main board 500, a battery 600, and a small board 700 are distributed at intervals between the middle plate 400 and the rear cover 200. The photosensitive device provided by the embodiment of the present application is installed on the main board 500.

[0264] The above specific implementation manners further elaborate on the purpose, technical solution, and beneficial effects of the present application. It should be understood that the above are only specific implementation manners of the present application and are not used to limit the protection scope of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solution of the present application should be included within the protection scope of the present application.

Claims

1. A photosensitive device, characterized in that: The photosensitive device comprises: A substrate, the substrate having a first surface and a second surface, the first surface of the substrate having a first opening, the second surface of the substrate having a second opening, the second opening being larger than the first opening, and the second opening being communicated with the first opening; A chip is located in the second opening, the chip is electrically connected to the substrate, the chip has a first surface, the first surface of the chip has a photosensitive area, and the photosensitive area is located within the range of the first opening.

2. The photosensitive device according to claim 1, characterized in that: The chip further has a second surface opposite to the first surface, the substrate further includes a lower pad located on the second surface of the substrate, and the horizontal plane where the second surface of the chip is located is not lower than the horizontal plane where the lower pad is located.

3. The photosensitive device according to claim 1 or 2, characterized in that: The substrate comprises an upper pad, which is arranged in the second opening of the substrate and on an inner wall corresponding to the first surface of the chip, and the first surface of the chip is connected to the upper pad via a metal bump.

4. The photosensitive device according to any one of claims 1 to 3, characterized in that: The photosensitive device further includes a first filling material, and the first filling material is distributed in the gap between the chip and the substrate.

5. The photosensitive device according to claim 4, characterized in that: The photosensitive device further includes a second filling material, and the second filling material is distributed on the opening side wall of the first opening.

6. The photosensitive device according to claim 5, characterized in that: The thickness of the second filling material in the horizontal direction becomes thicker in a direction toward the chip.

7. The photosensitive device according to any one of claims 4 to 6, characterized in that: The photosensitive device further includes a third filling material, which is distributed on the second surface of the chip, and the level of the third filling material is not lower than the level of the lower pad.

8. The photosensitive device according to any one of claims 4 to 7, characterized in that: The first filling material, the second filling material and the third filling material include at least one of the following materials: bottom filling glue, plastic sealing material or potting material.

9. The photosensitive device according to any one of claims 1 to 8, characterized in that: The photosensitive device further comprises an optical path adjusting device, wherein the optical path adjusting device is located above the photosensitive area, and the optical path adjusting device comprises an optical path filtering device and / or an optical path focusing device.

10. The photosensitive device according to any one of claims 1 to 9, characterized in that: The substrate is a printed circuit board, and the chip is a packaged chip.

11. The photosensitive device according to any one of claims 1 to 9, characterized in that: The substrate is a packaging substrate, and the chip is a bare chip.

12. The photosensitive device according to claim 11, characterized in that: The photosensitive device also includes: A heat-conducting layer is disposed below the second surface of the chip.

13. A method for preparing a photosensitive device, characterized in that: The method comprises: Providing a substrate, the substrate having a first surface and a second surface, the first surface having a first opening, the second surface having a second opening, the second opening being larger than the first opening, and the second opening being in communication with the first opening; A chip is mounted in the second opening of the substrate. The chip is electrically connected to the substrate. The chip has a first surface. The first surface of the chip has a photosensitive area. The photosensitive area is located within the range of the first opening.

14. The method according to claim 13, characterized in that The chip further has a second surface opposite to the first surface, the substrate further includes a lower pad located on the second surface of the substrate, and the horizontal plane where the second surface of the chip is located is not lower than the horizontal plane where the lower pad is located.

15. The method according to claim 13 or 14, characterized in that The substrate includes a first part, the first part of the substrate has a lower surface, and the substrate also includes an upper pad located on the lower surface of the first part of the substrate, wherein the chip is installed in the second opening of the substrate, specifically including: the first surface of the chip is connected to the upper pad through a metal bump.

16. The method according to claim 13, characterized in that The method further includes injecting a first filling material into a gap between the chip and the substrate.

17. The method according to claim 16, characterized in that Before injecting a first filling material into the gap between the chip and the substrate, the method further includes: A glue injection hole is provided on the first surface of the substrate, wherein the glue injection hole is communicated with the gap between the substrate and the chip; The first filling material is injected through the glue injection hole.

18. The method according to claim 17, characterized in that The method further includes: coating a second filling material on the sidewall of the first opening of the substrate, wherein the thickness of the second filling material in a horizontal direction becomes thicker in a direction toward the chip.

19. The method according to any one of claims 16 to 18, characterized in that: The method further includes: the chip has a second surface, and a third filling material is applied to the second surface of the chip, wherein the level of the third filling material is not lower than the level of the lower pad.

20. The method of claim 19, wherein: The filling material includes at least one of the following materials: bottom filling glue, plastic sealing material or potting material.

21. The method of claim 20, wherein: The method further comprises: installing an optical path adjustment device above the photosensitive area, wherein the optical path adjustment device comprises an optical path filtering device and / or an optical path focusing device.

22. A photosensitive device, characterized in that: include: A substrate, wherein the substrate has a first surface, and an opening is formed on the first surface of the substrate; A chip is embedded in the substrate and electrically connected to the substrate. The chip has a first surface. The first surface of the chip has a photosensitive area. The photosensitive area is located within an opening range opened on the first surface of the substrate.

23. The photosensitive device according to claim 22, characterized in that: The substrate includes a first part and a second part located below the first part. The substrate also includes an upper pad located on the first part of the substrate. The first surface of the chip is electrically connected to the upper pad through a via.

24. The photosensitive device according to claim 22 or 23, characterized in that: The photosensitive device further includes a filling material, and the filling material is distributed on the sidewall of the opening.

25. The photosensitive device according to claim 24, characterized in that: The thickness of the filling material in the horizontal direction becomes thicker in a direction toward the chip.

26. The photosensitive device according to claim 24 or 25, characterized in that: The filling material includes at least one of the following materials: bottom filling glue, plastic sealing material or potting material.

27. The photosensitive device according to any one of claims 22 to 26, characterized in that: The photosensitive device further comprises an optical path adjusting device, wherein the optical path adjusting device is located above the photosensitive area, and the optical path adjusting device comprises an optical path filtering device and / or an optical path focusing device.

28. The photosensitive device according to any one of claims 22 to 27, characterized in that: The substrate is a packaging substrate, and the chip is a bare chip.

29. The photosensitive device according to claim 28, characterized in that The photosensitive device further includes: a heat-conducting layer. The substrate further has a second surface. The heat-conducting layer is located below the second surface of the substrate.

30. The photosensitive device according to any one of claims 22 to 27, characterized in that: The substrate is a printed circuit board, and the chip is a packaged chip.

31. A method for preparing a photosensitive device, characterized in that: The method comprises: Prepare a substrate so that a chip is embedded in the substrate and electrically connected to the substrate, wherein the chip has a first surface and the first surface of the chip has a photosensitive area; The substrate has a first surface, and an opening is opened on the first surface of the substrate, so that the photosensitive area is located within the range of the opening opened on the first surface of the substrate.

32. The method of claim 31, wherein: The preparing of the substrate specifically comprises: Coating a sacrificial glue on the upper layer of the photosensitive area of ​​the chip; Embedding the chip inside the substrate through a lamination process; During the lamination process, via holes are opened by a hole-opening process, so that the chip and the substrate are electrically connected through the via holes.

33. The method according to claim 31 or 32, characterized in that An opening is formed on the first surface of the substrate through a grooving process, so that the photosensitive area coated with the sacrificial glue is located within the range of the opening formed on the first surface of the substrate.

34. The method of claim 33, wherein: After an opening is formed on the first surface of the substrate by a grooving process, the method further comprises: removing the sacrificial glue coated on the upper layer of the photosensitive area so that the photosensitive area is located within the opening range.

35. The method according to any one of claims 31 to 34, characterized in that: The method further includes: installing an optical path adjustment device on the first surface of the substrate, the optical path adjustment device is located above the photosensitive area, and the optical path adjustment device includes an optical path filtering device and / or an optical path focusing device.

36. An electronic device, characterized in that: It comprises the photosensitive device and a printed circuit board as described in any one of claims 1-12 or 22-30, wherein the photosensitive device is mounted on the printed circuit board.

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