Circuit board assembly, photosensitive component, camera module and method for manufacturing a photosensitive component

Abstract

The present invention provides a photosensitive component, comprising: a photosensitive chip, which has a photosensitive area and a non-photosensitive area surrounding the photosensitive area, wherein a plurality of chip electrodes are provided in the non-photosensitive area; a circuit board, which has through holes corresponding to the photosensitive area, the lower surface of the circuit board has a plurality of first electrodes, and the circuit board is a rigid board or a rigid-flexible board; and a redistribution layer, formed on the lower surface of the circuit board, the lower surface of the redistribution layer has a plurality of second electrodes, and each of the plurality of first electrodes is electrically connected to the corresponding second electrode through a redistribution trace; the photosensitive chip is attached to the lower surface of the redistribution layer, and the second electrodes are respectively in contact with and conduct with the chip electrodes one by one. The present invention also provides a corresponding circuit board assembly, a camera module and a method for manufacturing a photosensitive component. The present invention can achieve high-density packaging of the photosensitive chip of the camera module; it can achieve packaging with a high number of I / Os.

Description

Technical Field

[0001] The present invention relates to the field of optical technologies. Specifically, the present invention relates to a circuit board assembly, a photosensitive component, an imaging module, and a manufacturing method thereof. Background Art

[0002] With the rapid development of smart phones and other electronic devices, due to the increasing trend of mobile phone screens towards full-screen and thin-and-light designs, the demand for miniaturization of imaging modules is becoming increasingly strong.

[0003] An imaging module generally includes an optical lens assembly and a photosensitive component. The photosensitive component usually includes a circuit board and a photosensitive chip mounted on the circuit board. In existing imaging modules, the photosensitive chip is usually electrically connected to the circuit layer through a "wire bonding" (i.e., wirebond or wire bonding) process or a flip-chip process.

[0004] Conventional printed circuit boards are limited by factors such as current requirements, circuit board material-induced line heating, and printed circuit board manufacturing capabilities, resulting in common printed circuit board line widths and line spacings of about 70 μm. Correspondingly, limited by the line widths and line spacings of conventional circuit boards, when the chip is electrically connected, factors related to the circuit board also need to be considered, and the pad pitch cannot be further reduced, which is contrary to the development trend of continuous miniaturization of chips. In addition, due to the increasing density of the chip pads and the gradually approaching limit of the pitch, in the wire bond process, in the case of such a high density of gold wires, interference between the gold wires is likely to occur, resulting in circuit failures. On the other hand, in the entire manufacturing process, a series of steps such as molding and lens mounts will be carried out after the wire bond process, which will all affect the reliability of the gold wire connection. Moreover, the gold wire has a certain arc height, so an additional height is usually required in the module to avoid the gold wire. Therefore, the presence of the gold wire may hinder the miniaturization development of the module.

[0005] Nowadays, some manufacturers adopt the flip chip process to solve a series of problems brought by gold wires. For example, in the flip chip process, since the chip is directly attached to the bottom side of the circuit board, and then the conduction between the chip and the circuit board is achieved through gold balls. In this process, the conduction length between the circuit board and the photosensitive chip is greatly shortened, reducing the delay and effectively improving the electrical performance. On the other hand, the flip chip process has high requirements for conduction accuracy and flatness, and a ceramic substrate with high structural strength and not easy to bend needs to be used as the circuit board (i.e., the printed circuit board), and its price is very expensive. In addition, this process solution requires the pad size and pad density of the circuit board to be the same or basically the same as those of the photosensitive chip. Generally speaking, due to process limitations, the minimum size of the pads on the circuit board is limited, and at the same time, the line width of the gold ball bumps is relatively large, such as about 100 μm. In order to adapt to the flip chip process, it is difficult to further reduce the size of the pads on the photosensitive chip to match the pad size of the circuit board. In this way, the number of pads that can be arranged on the photosensitive chip is reduced, or increasing the number of pads will result in an increase in the size of the photosensitive chip, which is not conducive to reducing the size of the camera module. This is because the higher the pixel of the photosensitive chip, the larger the amount of image data to be output, and thus more I / O ports are required to output data. And fewer pad numbers result in fewer I / O ports for outputting data. Therefore, the existing flip chip process is not conducive to increasing the pixel number of the photosensitive chip. Summary of the Invention

[0006] The present invention aims to provide a solution that can overcome at least one defect of the prior art.

[0007] According to one aspect of the present invention, a photosensitive component is provided, including: a photosensitive chip having a photosensitive area and a non-photosensitive area surrounding the photosensitive area, wherein a plurality of chip electrodes are provided in the non-photosensitive area; a circuit board having through holes corresponding to the photosensitive area, the lower surface of the circuit board having a plurality of first electrodes, and the circuit board being a rigid board or a rigid-flexible board; and a redistribution layer formed on the lower surface of the circuit board, the lower surface of the redistribution layer having a plurality of second electrodes, each of the plurality of first electrodes being electrically connected to the corresponding second electrode through a redistribution trace; and the photosensitive chip is attached to the lower surface of the redistribution layer, and the plurality of second electrodes are respectively in contact with and conduct with the plurality of chip electrodes in a one-to-one correspondence.

[0008] Wherein, the second electrode is closer to the through hole than the first electrode.

[0009] Wherein, the area of the second electrode is smaller than the area of the first electrode.

[0010] Among them, the density of the plurality of second electrodes is higher than that of the plurality of first electrodes.

[0011] Among them, the circuit board is a rigid-flexible printed circuit board, which includes a rigid board area and a flexible board area. The through hole is located in the rigid board area, and the plurality of first electrodes are located on the lower surface of the rigid board area.

[0012] Among them, the width of the trace of the redistribution layer is smaller than the width of the trace of the circuit board.

[0013] Among them, the second electrode is a metal pillar.

[0014] Among them, the metal pillar is filled with insulating protective glue around it.

[0015] Among them, the second electrode and the chip electrode are attached together by a ball mounting process.

[0016] Among them, the position of the ball mounting is filled with insulating protective glue.

[0017] Among them, the photosensitive component further includes a metal sheet, which has a groove. The metal sheet is attached to the lower surface of the redistribution layer and houses the photosensitive chip in the groove.

[0018] Among them, the metal sheet does not contact the photosensitive chip.

[0019] Among them, the photosensitive component further includes a molding layer, which is formed on the surface of the redistribution layer and the back surface of the photosensitive chip, and the molding layer contacts the side surface of the photosensitive chip and the insulating protective glue.

[0020] Among them, the lower surface of the circuit board has a groove, the photosensitive chip is located in the groove, the photosensitive component further includes a metal sheet, the metal sheet is attached to the circuit board and covers the groove, and there is a gap between the metal sheet and the photosensitive chip.

[0021] Among them, the lower surface of the circuit board is a surface after planarization treatment.

[0022] According to another aspect of the present invention, there is also provided a circuit board assembly, comprising: a circuit board having through holes corresponding to the photosensitive regions, the lower surface of the circuit board having a plurality of first electrodes, and the circuit board being a rigid board or a rigid-flexible board; and a redistribution layer formed on the lower surface of the circuit board, the lower surface of the redistribution layer having a plurality of second electrodes, each of the plurality of first electrodes being electrically connected to the corresponding second electrode through redistribution; and the photosensitive chip is attached to the lower surface of the redistribution layer, and the size and layout of the plurality of second electrodes are adapted to attach the photosensitive chip based on the flip-chip process, so that the plurality of second electrodes are respectively in contact with and conduct with a plurality of chip electrodes of the photosensitive chip one by one.

[0023] Wherein, the second electrodes are closer to the through holes than the first electrodes; the density of the plurality of second electrodes is higher than that of the plurality of first electrodes.

[0024] Wherein, the area of the second electrodes is smaller than the area of the first electrodes.

[0025] According to another aspect of the present invention, there is also provided an imaging module, comprising: any one of the foregoing photosensitive components; and an optical lens mounted on the photosensitive component.

[0026] According to another aspect of the present invention, there is also provided a method for manufacturing a photosensitive component, comprising: forming a redistribution layer on the lower surface of a circuit board to form a circuit board assembly, wherein the lower surface of the circuit board has a plurality of first electrodes, the lower surface of the redistribution layer has a plurality of second electrodes, and each of the plurality of first electrodes is electrically connected to the corresponding second electrode through redistribution; and attaching a photosensitive chip to the circuit board assembly, wherein the plurality of second electrodes are respectively in contact with and conduct with the plurality of chip electrodes one by one.

[0027] Wherein, the step of forming the redistribution layer on the lower surface of the circuit board comprises: planarizing the lower surface of the circuit board; and forming the redistribution layer on the planarized lower surface of the circuit board.

[0028] Wherein, the step of forming the redistribution layer on the lower surface of the circuit board comprises: directly fabricating redistribution traces on the lower surface of the circuit board, the redistribution traces connecting the first electrodes from a first end far from the light-transmitting hole of the circuit board to a second end close to the light-transmitting hole; and fabricating the second electrodes at positions of the second ends of the redistribution traces.

[0029] Wherein, the step of forming the redistribution layer on the lower surface of the circuit board further comprises: after attaching the photosensitive chip to the circuit board assembly, covering the first electrodes and the redistribution traces by a bottom filling process.

[0030] Among them, the step of forming a redistribution layer on the lower surface of the circuit board further includes: filling an insulating protective adhesive at the connection between the second electrode and the chip electrode through a bottom filling process after manufacturing the second electrode.

[0031] Among them, the step of directly manufacturing redistribution traces on the lower surface of the circuit board includes: spin-coating a photoresist on the lower surface of the circuit board; exposing the photoresist; developing the exposed photoresist; plating a conductive material in the trace grooves formed by the development; and removing the photoresist, leaving the traces formed by the conductive material.

[0032] Among them, the step of forming a redistribution layer on the lower surface of the circuit board includes: leading out the first electrode; filling an insulating material on the lower surface of the circuit board to form a first dielectric layer, wherein the first dielectric layer is flush with the surface of the led-out first electrode; manufacturing redistribution layer traces on the surface of the first dielectric layer and the led-out first electrode; filling an insulating material on the surface of the first dielectric layer to form a second dielectric layer, wherein the second dielectric layer is flush with the surface of the redistribution layer traces; leading out a second electrode on the surface of the redistribution layer traces; and filling an insulating material on the surface of the second dielectric layer and the surface of the redistribution layer traces to form a third dielectric layer.

[0033] Among them, in the step of forming a redistribution layer on the lower surface of the circuit board, the redistribution layer traces are made through a process flow of spin-coating a photoresist, exposing, developing, plating or implanting a conductive material, and removing the photoresist.

[0034] Among them, the step of leading out the first electrode is made through a process flow of spin-coating a photoresist, exposing, developing, plating or implanting a conductive material, and removing the photoresist.

[0035] Among them, the step of leading out a second electrode on the surface of the redistribution layer traces is made through a process flow of spin-coating a photoresist, exposing, developing, plating or implanting a conductive material, and removing the photoresist.

[0036] Among them, the circuit board has through holes corresponding to the photosensitive area; before performing the step of forming a redistribution layer on the lower surface of the circuit board, filling the through holes so that the lower surface of the circuit board and the lower surface of the filler form a complete plane; and before performing the step of attaching a photosensitive chip to the circuit board assembly, removing the filler to expose the through holes.

[0037] Among them, in the step of filling the through holes, the filler is a photoresist.

[0038] Compared with the prior art, the present invention has at least one of the following technical effects:

[0039] 1. The present invention can achieve the conduction of circuit board pads / traces with a larger line width to a photosensitive chip with smaller contacts, realizing the high-density packaging of the photosensitive chip of the camera module.

[0040] 2. The present invention can achieve the conduction of circuit board pads relatively close to the outside of the optical window to chip pads closer to the optical window.

[0041] 3. The present invention can enable the camera module to adopt a conventional printed circuit board to implement the flip-chip process to achieve high-I / O packaging.

[0042] 4. The present invention can avoid processes such as ACF that require high-temperature hot pressing to attach the connection tape of the camera module, contributing to the miniaturization of the camera module and improving the yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Exemplary embodiments are shown in the accompanying drawings. The embodiments and drawings disclosed herein should be regarded as illustrative and not restrictive.

[0044] Figure 1 A cross-sectional schematic diagram of a photosensitive component according to an embodiment of the present invention is shown;

[0045] Figure 2 Shown is Figure 1 the electrodes and redistribution layer traces of the photosensitive component from a top view angle;

[0046] Figure 3 A flexible-rigid printed circuit board with through holes is shown;

[0047] Figure 4 A schematic diagram of a circuit board after spin-coating photoresist is shown;

[0048] Figure 5 A schematic diagram of exposing the first photoresist layer is shown;

[0049] Figure 6 A schematic diagram of developing the exposed first photoresist layer is shown;

[0050] Figure 7 A schematic diagram of copper implantation or copper plating at the grooves of the first photoresist layer is shown;

[0051] Figure 8 A schematic diagram of removing the first photoresist layer is shown;

[0052] Figure 9 A schematic diagram of filling an insulating / protective medium on the surface of the circuit board is shown;

[0053] Figure 10 A schematic diagram of spin-coating photoresist on the top surface of the insulating dielectric layer and the copper implantation or copper plating is shown;

[0054] Figure 11 Shows a schematic diagram of exposing the second photoresist layer;

[0055] Figure 12 Shows a schematic diagram of developing the exposed second photoresist layer;

[0056] Figure 13 Shows a schematic diagram of forming a rerouting layer trace in the groove of the second photoresist layer;

[0057] Figure 14 Shows a schematic diagram of removing the second photoresist layer;

[0058] Figure 15 Shows a schematic diagram of filling an insulating / protective medium on the first dielectric layer to form a second dielectric layer;

[0059] Figure 16 Shows a schematic diagram of spin - coating photoresist on the surface of the second dielectric layer and the rerouting layer trace;

[0060] Figure 17 Shows a schematic diagram of exposing the third photoresist layer;

[0061] Figure 18 Shows a schematic diagram of developing the exposed third photoresist layer;

[0062] Figure 19 Shows a schematic diagram of copper implantation or copper plating at the groove of the third photoresist layer;

[0063] Figure 20 Shows a schematic diagram of removing the third photoresist layer;

[0064] Figure 21 Shows a schematic diagram of filling an insulating / protective medium on the second dielectric layer and the rerouting layer trace;

[0065] Figure 22 Shows a schematic diagram of implanting copper pillars on the top of the second electrode;

[0066] Figure 23 Shows a schematic diagram of attaching a photosensitive chip to the implanted copper pillars;

[0067] Figure 24 Shows a schematic diagram of applying an insulating protective glue at the copper pillars;

[0068] Figure 25 Shows a schematic diagram of ball implantation on the top of the second electrode;

[0069] Figure 26 Shows a schematic diagram of attaching a photosensitive chip to the second electrode through ball implantation;

[0070] Figure 27Shows a schematic diagram of applying an insulating protective adhesive at the ball mounting position;

[0071] Figure 28 Shows a photosensitive component with a steel sheet in an embodiment of the present invention;

[0072] Figure 29 Shows a photosensitive component with a molding layer in an embodiment of the present invention;

[0073] Figure 30 Shows a schematic diagram of the unevenness of the circuit board surface;

[0074] Figure 31 Shows a schematic diagram of grinding the circuit board;

[0075] Figure 32 Shows a schematic diagram of the circuit board after grinding;

[0076] Figure 33 Shows a schematic diagram of hot pressing or heavy pressing on the circuit board;

[0077] Figure 34 Shows a schematic diagram of self-leveling of the circuit board;

[0078] Figure 35 Shows a schematic diagram of the photoresist layer forming a slope at the edge near the through hole;

[0079] Figure 36 Shows a schematic diagram of the circuit board material layer in an embodiment of the present invention;

[0080] Figure 37 Shows the circuit board assembly obtained after manufacturing the redistribution layer on the complete surface;

[0081] Figure 38 Shows the manufacturing process of the circuit board assembly in another embodiment of the present invention;

[0082] Figure 39 Shows a cross-sectional view of a redistribution layer in the prior art;

[0083] Figure 40 Shows a schematic diagram of directly manufacturing the redistribution layer traces on the circuit board after planarization treatment and forming the circuit board assembly;

[0084] Figure 41 Shows in Figure 40 Schematic diagram of attaching a photosensitive chip to the circuit board assembly;

[0085] Figure 42 Shows a schematic diagram of applying an insulating protective adhesive at the attachment position;

[0086] Figure 43A schematic diagram showing an insulating material covering the traces in the redistribution layer is presented;

[0087] Figure 44 A schematic diagram showing the redistribution circuit and the circuit board circuit in an embodiment of the present invention is presented;

[0088] Figure 45 A cross-sectional schematic diagram of a photosensitive component in another embodiment of the present invention is presented. Detailed implementation manners

[0089] To better understand the present application, more detailed descriptions of various aspects of the present application will be made with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application and do not limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0090] It should be noted that in this specification, the expressions such as first, second, etc. are only used to distinguish one feature from another feature and do not represent any limitation on the feature. Therefore, without departing from the teachings of the present application, the first subject discussed below may also be referred to as the second subject.

[0091] In the drawings, for ease of illustration, the thickness, dimensions, and shape of the objects have been slightly exaggerated. The drawings are only examples and are not drawn strictly to scale.

[0092] It should also be understood that the terms "comprise", "comprising", "have", "including", and / or "containing", when used in this specification, indicate the presence of the stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or combinations thereof. In addition, when an expression such as "at least one of..." appears after the list of listed features, it modifies the entire list of listed features rather than individual elements in the list. In addition, when describing the embodiments of the present application, the use of "may" means "one or more embodiments of the present application". And the term "exemplary" is intended to refer to an example or illustration.

[0093] As used herein, the terms "substantially", "about", and similar terms are used as terms indicating approximation and not as terms indicating degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by a person of ordinary skill in the art.

[0094] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It should also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0095] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments may be combined with each other. The following will describe this application in detail with reference to the drawings and in combination with the embodiments.

[0096] Figure 1 The cross-sectional schematic diagram of a photosensitive component according to an embodiment of the present invention is shown. Refer to Figure 1, the photosensitive component includes: a photosensitive chip 103, a circuit board 101, and a redistribution layer 102. The photosensitive chip 103 has a photosensitive area 1031 and a non-photosensitive area 1032 surrounding the photosensitive area 1031. Multiple chip electrodes 1033 are provided in the non-photosensitive area 1032. These multiple chip electrodes 1033 (or can be called chip pads) can surround the photosensitive area 1031. The circuit board 101 in this embodiment can be a rigid-flexible printed circuit board. The rigid-flexible printed circuit board includes a rigid board area 1011 and a flexible board area 1012. A through hole 1013 is provided in the center of the rigid board area 1011. In this article, the rigid board area 1011 can be understood as the area that is overall rigid (not bendable at room temperature) in the rigid-flexible printed circuit board, and the flexible board area 1012 can be understood as the area that is overall flexible (bendable) in the rigid-flexible printed circuit board. It should be noted that the rigid board area 1011 can be an area that is overall rigid formed by laminating multiple rigid boards 1011a and flexible boards 1012a, and is not necessarily composed only of the rigid board 1011a. Further, multiple first electrodes 1014 (or can be called first pads) are provided on the lower surface of the rigid board area 1011. The redistribution layer 102 is formed on the lower surface of the rigid board 1011a. Multiple second electrodes 1022 (or can be called second pads) are provided on the lower surface of the redistribution layer 102. Each of the multiple first electrodes 1014 is electrically connected to the corresponding second electrode 1022 through a redistribution circuit 1021 (i.e., the redistribution layer trace); and, the photosensitive chip 103 is attached to the lower surface of the redistribution layer 102, and the multiple second electrodes 1022 are respectively in contact with and conduct with the multiple chip electrodes 1033 in a one-to-one correspondence. The through hole 1013 can be a light-passing hole, and the position and size of the light-passing hole are adapted to the photosensitive area 1031 of the photosensitive chip 103. The area of the first electrode 1014 can be larger than the area of the second electrode 1022. The area of the second electrode 1022 is adapted to the area of the chip electrode 1033 (such as equal or substantially equal). The circuit board 101 also has a circuit board trace 1015, which can form the functional circuit of the photosensitive component. Further, Figure 2 shows Figure 1 the electrodes and the redistribution layer traces 1021 of the photosensitive component from a top view angle. It can be seen that in this embodiment, the first electrode 1014 is located outside the second electrode 1022 (i.e., the second electrode 1022 is closer to the light-passing hole 1013 than the first electrode 1014). In this embodiment, the electrodes can all be metal electrodes.

[0097] In the prior art, the pad size of the flexible-rigid printed circuit board ranges from 60 to 80 μm, while the pad size of the redistribution layer can be made to be 20 to 50 μm. Therefore, in the above embodiment, by forming the redistribution layer 102 on the flexible-rigid printed circuit board 101 and implementing the fan-in packaging, the flexible-rigid printed circuit board assembly formed by the flexible-rigid printed circuit board 101 and the redistribution layer 102 can have metal electrodes (i.e., pads) with a small area and dense arrangement, so that the electrodes (i.e., pads) of the flexible-rigid printed circuit board assembly can contact and conduct with the densely arranged chip electrodes 1033 one by one, which helps to increase the pixel number of the photosensitive component of the filpchip process solution and avoid various defects brought by the existing wire bond process. On the other hand, the flexible-rigid printed circuit board 101 is a flexible printed circuit board (also referred to as the flexible board 1012a, i.e., the FPC board) and a rigid printed circuit board (also referred to as the rigid board 1011a, i.e., the PCB board), which are combined together through processes such as lamination according to relevant process requirements to form a circuit board with FPC characteristics and PCB characteristics. At present, the manufacturing process of the flexible-rigid printed circuit board 101 has been relatively mature and has a greater cost advantage compared with circuit boards of other processes such as ceramic substrates. Moreover, the connection tape of the photosensitive component in the above embodiment is made using the manufacturing process of the flexible-rigid printed circuit board 101, which can avoid attaching the connection tape through processes such as ACF that require high-temperature hot pressing after attaching the photosensitive chip 103. The connection tape can electrically connect the rigid board area to the connector for electrical connection with the main board of a terminal device (such as a mobile phone). The flexible board 1012a of the flexible-rigid printed circuit board 101 can directly serve as the connection tape of the photosensitive component. In the flexible-rigid printed circuit board 101, the flexible board area 1012 extends from the side of the rigid board area 1011 to the rigid board area. Based on the ACF process, the connection tape is connected to the rigid board 1011a through the surface of the rigid board (usually the edge area of the surface of the rigid board).

[0098] It should be noted that Figure 1The flexible-rigid board 101 of the illustrated embodiment can be replaced with a rigid board (such as a PCB board). Fan-in packaging is achieved by forming a redistribution layer 102 on the PCB board, so that the circuit board assembly composed of the PCB board and the redistribution layer 102 can have metal electrodes with a small area and dense arrangement, so that the electrodes of the flexible-rigid board assembly can contact and conduct with the densely arranged chip electrodes 1033 one by one, thus avoiding various defects brought by the existing wire bond process. At the same time, it also helps to increase the pixel number of the photosensitive component of the filpchip process solution. Further, since the second pad 1022 of the circuit board assembly is closer to the light passing hole 1013 than the first pad 1014, in the reverse mounting process, the attachment point (which can be a welding point, a pressing point or other types of attachment points) of the photosensitive chip 103 and the circuit board assembly is closer to the photosensitive area 1031. In this way, the chip pads 1033 of the photosensitive chip 103 can be arranged at a position closer to the photosensitive area 1031, which helps to reduce the total area of the photosensitive chip 103 (here the total area refers to the total area including the photosensitive area 1031 and the non-photosensitive area 1032). Therefore, the circuit board assembly of this embodiment helps to reduce the total area of the photosensitive chip 103, and further helps the miniaturization development of the camera module.

[0099] Further, still referring to Figure 1 , in one embodiment, the second electrode 1022 can be implemented as a metal column, such as a copper column 1022a. By spin-coating a photoresist layer on the PCB board, and then through exposure, development, and copper plating, a plurality of copper columns 1022a corresponding to the chip electrodes 1033 are formed. Since the photoresist is spin-coated on the upper surface of the flexible-rigid board, by controlling the rotation speed, time, etc. of the spin-coating, it can be ensured that the upper surface of the photoresist layer has a high flatness, and then it is ensured that the upper end surfaces of the copper columns 1022a are flush, that is, the upper end surfaces of the copper columns are located on the same surface. Therefore, the chip electrodes 1033 of the photosensitive chip 103 can contact the upper end surfaces of the copper columns simultaneously, thus solving the problem that some chip electrodes 1033 cannot achieve electrical connection due to the easy warping of the PCB board. Further, the copper column 1022a and the chip electrode 1033 can be electrically connected by a suitable process such as ultrasonic welding, and the conduction method of the present invention is not limited.

[0100] Further, in one embodiment, a conductive attachment material such as nickel, palladium, gold, solder paste or conductive silver paste can be further attached to the upper surface of the copper column 1022a, and the chip electrode 1033 and the copper column are conducted through the attached conductive attachment material, and at the same time, it is also convenient for the attachment (such as welding or pressing) between the electrodes.

[0101] Further, according to an embodiment of the present invention, a method for manufacturing a photosensitive component is also provided, including the following steps.

[0102] Step S100: Prepare a circuit board 101 with through holes. Figure 3 A flexible-rigid printed circuit board 101 with through holes is shown. It should be noted that in another embodiment of the present invention, the circuit board 101 in this step can also be a circuit board without through holes, and the through holes can be made after the redistribution layer is fabricated. The circuit board 101 in this step can be fabricated by itself or purchased on the market.

[0103] Step S200: Spin-coat a photoresist on the surface of the circuit board. The surface of the circuit board in this step refers to the surface where the first electrode 1014 (i.e., the circuit board electrode) is disposed, that is, Figure 1 the lower surface in Figure 4 A circuit board 101 after spin-coating the photoresist is shown. It can be seen that a first photoresist layer 104 is formed on the surface of the circuit board 101. In Figure 4 , the circuit board 101 is inverted, so the surface where the first electrode 1014 is disposed is located above.

[0104] Step S300: Expose the first photoresist layer 104. Figure 5 A schematic diagram of exposing the first photoresist layer 104 is shown. It can be seen that the exposed position 104a corresponds to the position where the first electrode 1014 (i.e., the circuit board electrode) is located.

[0105] Step S400: Develop the exposed first photoresist layer 104, that is, transfer a specific pattern to the first photoresist layer 104 by lithography process, so as to form a groove 104b at the first electrode, so that the first electrode 1014 of the circuit board 101 is exposed by the photoresist layer. Figure 6 A schematic diagram of developing the exposed first photoresist layer 104 is shown.

[0106] Step S500: Perform a plating process (copper implantation or copper plating at the grooves of the first photoresist layer 1014) with the patterned first photoresist layer 1014 as a mask, so that a conductive material can be plated on the first electrode 1014 exposed by the photoresist layer, forming a plurality of copper pillars respectively electrically connected to the first electrode 1014, thereby leading out the first electrode 1014 for the redistribution layer to be electrically connected to the circuit board. Figure 7 A schematic diagram of copper implantation or copper plating at the grooves of the first photoresist layer 104 is shown. The conductive material can be copper or other suitable metals.

[0107] Step S600: Remove the first photoresist layer 104. Figure 8 A schematic diagram of removing the first photoresist layer is shown.

[0108] Step S700: Fill the surface of the circuit board (the surface where the first electrode is provided) with an insulating medium to form a first dielectric layer. Note that the top surface of the copper pillar is exposed outside the first dielectric layer. Figure 9 A schematic diagram showing the filling of an insulating medium on the surface of the circuit board is shown.

[0109] Step S800: Spin-coat a photoresist on the top surface of the first dielectric layer 106 and the copper pillar to form a second photoresist layer 105. Figure 10 A schematic diagram showing the spin-coating of a photoresist on the top surface of the first dielectric layer 106 and the copper pillar is shown.

[0110] Step S900: Expose the second photoresist layer 105. Figure 11 A schematic diagram showing the exposure of the second photoresist layer 105 is shown. It can be seen that the exposed area 105a corresponds to the trace of the redistribution layer.

[0111] Step S1000: Develop the exposed second photoresist layer 105, that is, transfer a specific pattern to the second photoresist layer 105 by photolithography, and display the pattern corresponding to the trace of the redistribution layer. This pattern forms a groove 105b in the second photoresist layer 105. Figure 12 A schematic diagram showing the development of the exposed second photoresist layer 105 is shown.

[0112] Step S1100: Perform a plating process with the patterned second photoresist layer 105 as a mask (copper plating or copper deposition (or conductive materials such as nickel-palladium-gold, etc.) at the groove of the second photoresist layer 105) to form a redistribution layer trace 1021. Figure 13 A schematic diagram showing the formation of a redistribution layer trace 1021 in the groove of the second photoresist layer 105 is shown.

[0113] Step S1200: Remove the second photoresist layer. Figure 14 A schematic diagram showing the removal of the second photoresist layer is shown.

[0114] Step S1300: Fill the insulating / protective medium on the first dielectric layer 106 to form a second dielectric layer 107. Figure 15 A schematic diagram showing the filling of the insulating / protective medium on the first dielectric layer 106 to form a second dielectric layer 107 is shown. The second dielectric layer 107 can use the same material as the first dielectric layer 106, and at this time, the first and second dielectric layers can be integrated.

[0115] Step S1400: Spin-coat a photoresist on the surface of the second dielectric layer 107 and the redistribution layer trace to form a third photoresist layer 108. Figure 16 A schematic diagram showing the spin-coating of a photoresist on the surface of the second dielectric layer 107 and the redistribution layer trace is shown.

[0116] Step S1500: Expose the third photoresist layer 108, and the exposed area 108a corresponds to the position of the second electrode (i.e., the redistribution layer electrode). Figure 17 The schematic diagram shows the exposure of the third photoresist layer 108.

[0117] Step S1600: Develop the exposed third photoresist layer 108, so as to form a groove 108b at the exposed position of the third photoresist layer 108. Figure 18 The schematic diagram shows the development of the exposed third photoresist layer 108.

[0118] Step S1700: Plant copper or electroplate copper at the groove of the third photoresist layer 108 to form the second electrode (i.e., the redistribution layer electrode). Figure 19 The schematic diagram shows planting copper or electroplating copper at the groove 108b of the third photoresist layer.

[0119] Step S1800: Remove the third photoresist layer 108. At this time, the second electrode is exposed. Figure 20 The schematic diagram shows the removal of the third photoresist layer 108.

[0120] Step S1900: Fill the insulating / protective medium in the second dielectric layer and the redistribution layer traces to form the third dielectric layer. The top of the second electrode 1022 is exposed outside the third dielectric layer 109. Figure 21 The schematic diagram shows filling the insulating / protective medium in the second dielectric layer and the redistribution layer traces. The third dielectric layer can be made of the same material as the first and second dielectric layers. At this time, the first, second, and third dielectric layers can be integrated.

[0121] Step S2000: Plant copper pillars on the top of the second electrode. Figure 22 The schematic diagram shows planting copper pillars 1022a on the top of the second electrode 1022.

[0122] Step S2100: Attach the photosensitive chip to the planted copper pillars. The photosensitive chip is inverted, and the chip electrodes of the photosensitive chip correspond to the second electrodes (redistribution layer electrodes) one by one. The attachment process can be attachment and conduction through anisotropic conductive adhesive, attachment and conduction through ultrasonic welding process, attachment and conduction through thermocompression welding process, or attachment and conduction through reflow welding process, etc. Figure 23 The schematic diagram shows attaching the photosensitive chip 103 to the planted copper pillars 1022a.

[0123] After completing step S2100, the Figure 1 shown photosensitive component can be obtained.

[0124] Furthermore, in an embodiment of the present invention, step S2200 can further be included.

[0125] Step S2200: Apply insulating protective glue at the copper pillar. In one embodiment, the insulating protective glue can be applied around the copper pillar through the Underfill process. Figure 24 The schematic diagram shows the application of insulating protective glue 110 at the copper pillar 1022a.

[0126] Furthermore, in one embodiment of the present invention, steps S2000 - S2200 can be replaced by the following steps S2000' - S2200'.

[0127] Step S2000': Ball placement on the top of the second electrode. Figure 25 The schematic diagram shows the ball placement 1022b on the top of the second electrode 1022. The ball can be a gold ball.

[0128] Step S2100': Attach the photosensitive chip to the second electrode through ball placement (such as a gold ball). The photosensitive chip is inverted, and the chip electrodes of the photosensitive chip correspond to the second electrodes (redistribution layer electrodes) one by one. The attachment process can be attachment and conduction through anisotropic conductive glue, attachment and conduction through ultrasonic welding process, attachment and conduction through thermocompression welding process, or attachment and conduction through reflow welding process, etc. Figure 26 The schematic diagram shows the attachment of the photosensitive chip 103 to the second electrode 1022 through the ball placement 1022b.

[0129] Step S2200': Apply insulating protective glue at the ball placement. In one embodiment, the insulating protective glue can be applied around the ball placement through the Underfill process. Figure 27 The schematic diagram shows the application of insulating protective glue 110 at the ball placement 1022b.

[0130] Furthermore, in one embodiment of the present invention, the photosensitive component may further include a steel sheet 111. Figure 28 The schematic diagram shows the photosensitive component with the steel sheet 111 in one embodiment of the present invention. Figure 28 The photosensitive component in... is inverted. Refer to Figure 28, the steel sheet is attached to the surface of the circuit board assembly (the surface close to the photosensitive chip side). And the steel sheet 111 has a groove 111a, and the photosensitive chip is accommodated in the groove (that is, the steel sheet covers the photosensitive chip). There is a gap between the steel sheet 111 and the photosensitive chip (that is, the two do not contact directly). The step of attaching the steel sheet 111 can be performed after step S2200 or step S2200' (it should be noted that the present invention is not limited to this). The steel sheet can isolate the photosensitive chip from the external environment and prevent the photosensitive chip from being damaged due to external force impact. Keeping a gap between the steel sheet 111 and the photosensitive chip can prevent collision between the steel sheet 111 and the photosensitive chip. Further, in some embodiments, the gap can be filled with materials such as air, glue, molding, insulating layer, etc. to better protect the chip. In a modified embodiment, the steel sheet 111 can be replaced by other metal sheets.

[0131] Further, in an embodiment of the present invention, the photosensitive component may further include a molding layer. The molding layer covers the back surface of the circuit board assembly (the surface close to the photosensitive chip side) and the back surface of the photosensitive chip (the surface on the opposite side of the photosensitive area). Figure 29 Shows a photosensitive component with a molding layer 112 in an embodiment of the present invention. The molding layer 112 can be made after step S2200 or step S2200'. The molding layer 112 can be directly formed on the back surface of the circuit board assembly and the back surface of the photosensitive chip, and the molding layer 112 contacts the side surface of the photosensitive chip and the insulating protective glue wrapping the copper pillars or solder balls. When making the molding layer, a molding cavity can be jointly formed by the mold and the back surface of the circuit board assembly, the back surface of the photosensitive chip, the side surface of the photosensitive chip, and the insulating protective glue wrapping the copper pillars or solder balls, and the liquid molding material fills the molding cavity, and the molding layer 112 is obtained after demolding. The molding layer 112 can isolate the photosensitive chip from the external environment and prevent the photosensitive chip from being damaged due to external force impact.

[0132] Further, the inventors found through research that the circuit board is prone to warping, resulting in an uneven surface, which is not conducive to the subsequent redistribution process. For example, when the surface of the circuit board is uneven ( Figure 30 Shows a schematic diagram of the uneven surface 1019 of the circuit board), the photoresist layer coated on the surface of the circuit board will also be uneven, so that the upper surfaces of the copper pillars formed in the photoresist will not be flush, which will make it difficult to ensure effective conduction of each pad when the chip is attached to the copper pillars. Therefore, in an embodiment of the present invention, in step S100, the circuit board can be planarized.

[0133] Further, in an embodiment of the present invention, the planarization treatment of the circuit board can be grinding the circuit board to make the surface of the circuit board corresponding to the redistribution layer have a high flatness. Figure 31A schematic diagram of grinding a circuit board is shown. Figure 32 A schematic diagram of the circuit board after grinding is shown. The grinding process in this embodiment can be completed in step S100.

[0134] In another embodiment of the present invention, the planarization treatment of the circuit board can be hot pressing, heavy pressing, or baking the circuit board, so that the surface of the circuit board corresponding to the redistribution layer has a high flatness. Figure 33 A schematic diagram of hot pressing or heavy pressing the circuit board is shown. The hot pressing or heavy pressing process in this embodiment is completed in step S100.

[0135] In another embodiment of the present invention, the planarization treatment of the circuit board can be achieved by a self-leveling process. Figure 34 A schematic diagram of self-leveling the circuit board is shown. Referring to Figure 34 , after the photoresist 119 is coated and left standing for a relatively long time, it can be self-leveled. The self-leveling process in this embodiment can be completed in step S200.

[0136] Furthermore, since the circuit board in the present invention has through holes (light through holes), after the photoresist is spin-coated, the photoresist layer may form a slope as shown in the figure at the through holes. And since the chip pads of the photosensitive chip are usually arranged on the periphery of the photosensitive area and are very close to the photosensitive area to reduce the chip size, correspondingly, the copper pillars formed on the redistribution layer will also be located at positions close to the through holes to correspond to the chip electrodes. Therefore, the copper pillars will be formed at the slope position of the photoresist layer. Since the copper pillars are formed by electroplating copper into the photoresist layer, the copper material may overflow along the inclined surface, resulting in uneven upper surfaces of the copper pillars. If the upper surfaces of the copper pillars are not flush, it may cause problems such as poor contact or short circuit due to electrical connection between the copper pillars. To further solve the above problems, in one embodiment of the present invention, the circuit board with through holes is improved, and fillers, such as photoresist, are applied at the through holes of each layer of the circuit board.

[0137] Furthermore, Figure 35 A schematic diagram of the photoresist layer forming a slope at the edge near the through hole is shown. Since the circuit board 101 in the present invention has through holes 1013, after the photoresist is spin-coated, the photoresist layer 1021a may form a slope 1021b as shown in Figure 11 at the through holes 1013. And since the chip electrodes 1033 of the photosensitive chip 103 are usually arranged on the periphery of the photosensitive area 1031 and are very close to the photosensitive area 1031 to reduce the chip size, correspondingly, the copper pillars 1022a formed on the redistribution layer 102 will also be located at positions close to the through holes 1013 to correspond to the chip electrodes 1033. Therefore, the copper pillars 1022a will possibly be formed at the slope 1021b position of the photoresist layer 1021a. As Figure 35As shown, since the copper pillar 1022a is formed by electroplating copper into the through hole 1013 of the photoresist layer 1021a, copper materials may overflow from the inclined surface, resulting in problems such as an uneven upper surface of the copper pillar 1022a or electrical connection with other copper pillars 1022a.

[0138] To solve this problem, an embodiment of the present invention proposes a manufacturing process for a photosensitive component, which can avoid the problems caused by the unevenness of the aforementioned photoresist layer 1021a. In this embodiment, Figure 36 shows a schematic diagram of a circuit board material layer according to an embodiment of the present invention. As Figure 36 shown, during the manufacturing process of the circuit board, a filling material 101b, such as photoresist, is pre-applied at the position of the through hole 1013 in each layer of its material 101a, and then each layer is laminated together to form the circuit board 101 (the circuit board 101 in this embodiment is a rigid-flexible board). At this time, the through hole 1013 of the formed circuit board 101 is filled with multiple layers of photoresist 101b, making the surface of the circuit board 101 a complete surface. Figure 37 shows a circuit board assembly obtained after manufacturing a redistribution layer on the complete surface. Spin-coating photoresist on this complete surface will no longer result in Figure 35 the slope 1021b in, thus ensuring the flatness of the upper surface of the copper pillar 1022a and the alignment of the upper surfaces of each copper pillar 1022a. It should be noted that in this embodiment, when manufacturing a rigid-flexible board, the flexible board 1012a and the rigid board 1011a can be combined together through a lamination process. The overall rigid regions formed by laminating multiple rigid boards and flexible boards constitute the rigid board area, and the area composed only of the flexible board forms the flexible board area. Further, after the redistribution layer 102 and the copper pillar 1022a on the redistribution layer 102 are formed, all the photoresist at the through hole 1013 (including the photoresist in the through hole and the photoresist layer corresponding to the through hole in the redistribution layer 102) is removed to form a through hole corresponding to the photosensitive chip, and the required circuit board assembly can be obtained. This circuit board assembly can attach the photosensitive chip based on an upside-down bonding process. For example, referring to Figure 1 , the photosensitive chip 103 can be attached to the lower surface of the circuit board 101, that is, the surface with the redistribution layer 102, to make the photosensitive chip 103 conduct with the copper pillar 1022a, thereby forming a photosensitive component.

[0139] Furthermore, Figure 38 shows the manufacturing process of a circuit board assembly in another embodiment of the present invention. As Figure 38As shown, in another embodiment of the present invention, after the circuit board 101 is laminated and formed, the circuit board 101 having through-holes 1013 can be filled. For example, a photoresist material 101c is filled into the through-holes 1013 to make the circuit board 101 have a flat surface. Then, a redistribution process and a copper plating process are performed on the circuit board with a flat surface, which can also prevent the occurrence of a slope 1021b in the photoresist layer. After the redistribution layer 102 and the copper pillars 1022a are formed, the photoresist material 101c at the through-holes 1013 is removed to re-expose the through-holes 1013, providing a light passing aperture for the photosensitive chip 103. Further, the photosensitive chip 103 is electrically connected to the copper pillars 1022a to form the photosensitive component.

[0140] Further, Figure 39 FIG. shows a cross-sectional view of a redistribution layer 102 in the prior art. The redistribution layer 102 includes a circuit layer and an insulating layer 1023 covering the circuit layer. In the prior art, polymide is usually used as the insulating layer material, and the insulating layer 1023 is cured after being baked at high temperature. However, in the present application, the redistribution layer 102 is formed on the lower surface of the circuit board 101, and the circuit board 101 is usually fabricated based on a lamination process and is prone to deformation (such as warping) under high-temperature baking. This may cause the redistribution layer 102 attached to the circuit board 101 to also warp. Performing a wiring process on a warped surface will result in a decrease in the reliability of the redistribution layer 102 and is not conducive to improving the yield.

[0141] Based on the foregoing analysis, according to an embodiment of the present invention, there is further provided a circuit board assembly having a redistribution layer 102 that omits a polymide layer (dielectric layer). Figures 40 - 43 FIG. shows a manufacturing process of a photosensitive component that omits a polymide layer, and the process includes the following steps.

[0142] Step S10: Directly fabricate redistribution layer traces on the flattened circuit board to form a circuit board assembly. The redistribution layer traces can be obtained based on a process flow of spin-coating photoresist, exposure, development, copper plating (or filling other conductive materials in the photoresist grooves obtained by development), and removing the photoresist.

[0143] Figure 40 FIG. shows a schematic diagram of directly fabricating redistribution layer traces on the flattened circuit board to form a circuit board assembly. As Figure 40 shown, after the circuit layer of the redistribution layer 102 is formed on the hard board area 1011, the first end of the redistribution circuit (i.e., the redistribution trace) is connected to the first electrode 1014 (i.e., the first pad) of the hard board area 1011, so that the circuit 1016 of the hard board area 1011 and the circuit of the redistribution layer are electrically connected.

[0144] It should be noted that the width of the trace 1022 of the rewiring circuit of the rewiring layer 102 is significantly smaller than the width of the trace of the circuit board 101. Under the process conditions of the prior art, the circuit accuracy on the circuit board 101 makes the minimum value of the width of the trace of the circuit board 101 be 60 - 80 μm (that is, the highest-precision trace width is 60 - 80 μm). For example, the highest-precision trace width of a PCB board can reach 60 μm, while the trace accuracy of a rigid-flex board may be lower than that of a PCB board, and its highest-precision trace width is about 75 μm. The trace width formed by adopting the rewiring technology can be controlled within 20 μm, such as 10 to 20 μm.

[0145] Figure 44 The schematic diagram of the rewiring circuit 1021 and the circuit board circuit 1016 in an embodiment of the present invention is shown. Refer to Figure 40 and Figure 44 , a plurality of second pads 1022 are further formed on the rewiring circuit 1021, and each second pad 1022 is correspondingly distributed with respect to the chip pad 1033 in the non-photosensitive area 1032 of the photosensitive chip 103, so that the two can be fixed and conduct through the flip-chip method. It is worth mentioning that the size of the first pad 1014 in the rigid board area 101 is larger than the size of the second pad 1022 formed by the rewiring circuit 1021 of the rewiring layer 102, and the second pad 1022 is exposed outside the rewiring layer 102 for attaching to the chip pad (such as welding or pressing). The second pad can be obtained through processes such as copper plating, copper implantation, or ball implantation. It should be noted that in the present invention, the second pad includes but is not limited to copper pillars, gold balls, etc. In this embodiment, when the planarization treatment of the circuit board is a grinding treatment, the topmost trace of the circuit board after grinding may be exposed on the surface of the circuit board. Therefore, in this case, the trace on the topmost layer of the circuit board needs to avoid the trace of the rewiring layer to prevent accidental connection between the two traces. In addition, in this embodiment, since the trace of the circuit board has been exposed, the circuit board can cancel the pad, and the trace of the rewiring layer is directly connected to the trace of the circuit board without conducting through the circuit board pad. At this time, the contact portion between the trace of the circuit board and the trace of the rewiring layer can be regarded as the circuit board electrode (that is, the first electrode).

[0146] Step S20: Attach a photosensitive chip to the circuit board assembly in step S10. Figure 41 The schematic diagram of attaching the photosensitive chip 103 to the circuit board assembly in Figure 40 is shown.

[0147] Step S30: Apply an insulating protective adhesive at the attachment position between the photosensitive chip and the circuit board assembly. In one embodiment, the insulating protective adhesive can be applied around the attachment position (such as the position of the copper pillar or the ball implantation) through the Underfill process.Figure 42 The schematic diagram shows the application of the insulating protective adhesive 1028 at the attachment position.

[0148] Step S40: Cover the insulating material on the redistribution layer traces. This step can also be achieved by the Underfill process. Figure 43 The schematic diagram shows the covering of the insulating material on the redistribution layer traces. Steps S30 and S40 can be combined into one step, that is, the positions of the copper pillars or the ball grid array and the trace part of the redistribution layer are uniformly filled (for example, filled by the Underfill process). The insulating protective adhesive can form a protective layer 1029, and the protective layer 1029 can protect the redistribution circuit 1021, and the protective layer 1029 can prevent the various circuits in the redistribution circuit 1021 from interfering with each other and causing a short circuit; it should be noted that in this embodiment, the protective layer 1029 is supported by a material that can be cured by processes such as low temperature or ultraviolet irradiation to prevent the warping problem caused by high-temperature curing.

[0149] Figure 45 The schematic cross-sectional view of the photosensitive component in another embodiment of the present invention is shown. The hard board area has a groove 1015 suitable for accommodating the redistribution layer 102 and the photosensitive chip 103, which is beneficial to reducing the height dimension of the photosensitive component and protecting the photosensitive chip 103. The size of the groove 1015 can be slightly larger than the size of the photosensitive chip 103. On the one hand, it is convenient for the installation of the photosensitive chip 103, and on the other hand, it provides space for the traces of the redistribution layer 102. In this embodiment, since the groove 1015 is formed in the hard board area, correspondingly, the trace space of the hard board area will be reduced. Therefore, some of the original lines formed on the hard board area can be transferred to be formed in the redistribution layer 102, thus alleviating the problem of tight traces after the groove 1015 is formed in the hard board area.

[0150] In a variant embodiment of the present invention, the size of the pad of the circuit board can be reduced to the size consistent with the traces of the circuit of the circuit board, that is, the first end of the redistribution circuit is directly bonded and conducted with the circuit of the circuit board (that is to say, the pad of the hard board can degenerate into a part of the hard board circuit trace). It can be understood that in the prior art, the pad size of the hard board is relatively large, resulting in the inability to reduce the size of the hard board. In this embodiment, the pad is cancelled, and the first end of the redistribution circuit can be directly connected to the circuit of the hard board. While ensuring the conduction of the redistribution circuit and the circuit of the hard board, the size of the circuit board can also be reduced.

[0151] It is worth mentioning that in another embodiment of the present invention, the performance of the rigid board or the rigid board area can be further improved so that it can withstand baking at a higher temperature without warping, thereby preventing the redistribution layer attached thereto from warping. In another embodiment of the present invention, the baking temperature of the insulating layer can also be reduced. For example, the insulating layer material can be replaced with a material that can be cured at a lower temperature instead of the traditional polymide. In this way, the rigid board will not warp during the curing process.

[0152] Furthermore, according to an embodiment of the present invention, there is also provided an imaging module, which includes a photosensitive component and an optical lens mounted on the photosensitive component. The photosensitive component can be the photosensitive component provided in any of the foregoing embodiments. The light collected by the optical lens can reach the photosensitive component along the light passing hole and perform an imaging reaction on the photosensitive component. The type of the optical lens can be adjusted accordingly according to the requirements of the imaging module. For example, the optical lens can be implemented as an integrated optical lens, a split optical lens, a bare lens, or an optical lens including a lens barrel, etc.

[0153] It should be noted that in this article, the photoresist refers to a material that does not require high-temperature processing, and the photoresist curing process includes, but is not limited to, processes with relatively low thermal effects such as light exposure, moisture, pressure, radiation, crystallization, etc.

[0154] The above description is only the preferred embodiment of the present application and the explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by the specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, a technical solution formed by mutually replacing the above features with (but not limited to) technical features having similar functions disclosed in the present application.

Claims

1. A photosensitive component, characterized in that: include: A photosensitive chip having a photosensitive area and a non-photosensitive area surrounding the photosensitive area, wherein the non-photosensitive area is provided with a plurality of chip electrodes; A circuit board having through holes corresponding to the photosensitive areas, a lower surface of the circuit board having a plurality of first electrodes, and the circuit board is a rigid board or a rigid-flex board; as well as A rewiring layer is formed on the lower surface of the circuit board, and the lower surface of the rewiring layer has a plurality of second electrodes, each of the plurality of first electrodes is electrically connected to the corresponding second electrode through a rewiring trace, wherein the second electrode is closer to the through hole than the first electrode, and the area of the second electrode is smaller than the area of the first electrode; and the photosensitive chip is attached to the lower surface of the rewiring layer, and the plurality of second electrodes are in contact and conduction with the plurality of chip electrodes one by one.

2. The photosensitive component according to claim 1, characterized in that The density of the second electrodes is higher than that of the first electrodes.

3. The photosensitive component according to claim 1, characterized in that The circuit board is a rigid-flex board, which includes a rigid board area and a flexible board area. The through hole is located in the rigid board area, and the plurality of first electrodes are located on the lower surface of the rigid board area.

4. The photosensitive component according to claim 1, wherein: The width of the wiring of the redistribution layer is smaller than the width of the wiring of the circuit board.

5. The photosensitive component according to claim 1, characterized in that The second electrode is a metal column.

6. The photosensitive component according to claim 5, characterized in that The metal column is filled with insulating protective glue.

7. The photosensitive component according to claim 1, characterized in that The second electrode and the chip electrode are attached together through a ball planting process.

8. The photosensitive component according to claim 7, characterized in that The ball planting position is filled with insulating protective glue.

9. The photosensitive component according to claim 1, wherein: The invention also includes a metal sheet having a groove. The metal sheet is attached to the lower surface of the redistribution layer and the photosensitive chip is accommodated in the groove.

10. The photosensitive component according to claim 9, characterized in that The metal sheet does not contact the photosensitive chip.

11. The photosensitive component according to claim 6 or 8, characterized in that: It also includes a molding layer, which is formed on the surface of the rewiring layer and the back of the photosensitive chip, and the molding layer contacts the side of the photosensitive chip and the insulating protective glue.

12. The photosensitive component according to claim 1, wherein The lower surface of the circuit board has a groove, and the photosensitive chip is located in the groove. The photosensitive component also includes a metal sheet, which is attached to the circuit board and covers the groove. A gap is left between the metal sheet and the photosensitive chip.

13. The photosensitive component according to claim 1, wherein: The lower surface of the circuit board is a planarized surface.

14. A circuit board assembly, characterized in that: include: A circuit board having through holes corresponding to the photosensitive areas of the photosensitive chip, a lower surface of the circuit board having a plurality of first electrodes, and the circuit board is a rigid board or a rigid-flex board; as well as A rewiring layer is formed on the lower surface of the circuit board, the lower surface of the rewiring layer has a plurality of second electrodes, each of the plurality of first electrodes is electrically connected to the corresponding second electrode through rewiring, wherein the second electrode is closer to the through hole than the first electrode, and the area of the second electrode is smaller than the area of the first electrode; and the photosensitive chip is attached to the lower surface of the rewiring layer, and the size and layout of the plurality of second electrodes are suitable for attaching the photosensitive chip based on the flip-stick process, so that the plurality of second electrodes are respectively in contact and conductive with the plurality of chip electrodes of the photosensitive chip one by one.

15. The circuit board assembly according to claim 14, wherein: The density of the second electrodes is higher than that of the first electrodes.

16. A camera module, characterized in that: include: The photosensitive component according to any one of claims 1 to 13; as well as An optical lens is installed on the photosensitive component.

17. A method for manufacturing a photosensitive component, characterized in that: include: forming a rewiring layer on the lower surface of a circuit board to form a circuit board assembly, wherein the lower surface of the circuit board has a plurality of first electrodes, and the lower surface of the rewiring layer has a plurality of second electrodes, each of the plurality of first electrodes is electrically connected to a corresponding second electrode via rewiring, and an area of the second electrode is smaller than an area of the first electrode; and The photosensitive chip is attached to the circuit board assembly, wherein the plurality of second electrodes are in contact and conduction with the plurality of chip electrodes one by one, and the second electrodes are closer to the light holes on the circuit board corresponding to the photosensitive area of the photosensitive chip than the first electrodes.

18. The method for manufacturing a photosensitive component according to claim 17, wherein: The steps of forming a redistribution layer on the lower surface of the circuit board include: Planarizing the lower surface of the circuit board; and The rewiring layer is formed on the lower surface of the circuit board after the planarization process.

19. The method for manufacturing a photosensitive component according to claim 17 or 18, wherein: The steps of forming a redistribution layer on the lower surface of the circuit board include: directly fabricating a rewiring trace on the lower surface of the circuit board, wherein the rewiring trace connects the first electrode from a first end away from the light through hole of the circuit board to a second end close to the light through hole; and The second electrode is formed at the location of the second end of the rewiring trace.

20. The method for manufacturing a photosensitive component according to claim 19, wherein: The step of forming a rewiring layer on the lower surface of the circuit board also includes: after attaching the photosensitive chip to the circuit board assembly, covering the first electrode and the rewiring trace through a bottom filling process.

21. The method for manufacturing a photosensitive component according to claim 19, wherein: The step of forming a rewiring layer on the lower surface of the circuit board further includes: filling an insulating protective glue at a connection between the second electrode and the chip electrode through a bottom filling process after forming the second electrode.

22. The method for manufacturing a photosensitive component according to claim 17, wherein: The steps for making rerouting traces directly on the bottom surface of the circuit board include: Spin-coating photoresist on the lower surface of the circuit board; exposing the photoresist; developing the exposed photoresist; Plating a conductive material in the wiring groove formed by the development; and The photoresist is removed, leaving traces formed by the conductive material.

23. The method for manufacturing a photosensitive component according to claim 17, wherein: The steps of forming a redistribution layer on the lower surface of the circuit board include: Leading out the first electrode; Filling the lower surface of the circuit board with an insulating material to form a first dielectric layer, wherein the first dielectric layer is flush with the surface of the first electrode; Fabricate redistribution layer wiring on the surface of the first dielectric layer and the first electrode; Filling the surface of the first dielectric layer with an insulating material to form a second dielectric layer, wherein the second dielectric layer is flush with the surface of the redistribution layer wiring; Leading out a second electrode on the surface of the redistribution layer wiring; and An insulating material is filled on the surface of the second dielectric layer and the surface of the redistribution layer wiring to form a third dielectric layer.

24. The method for manufacturing a photosensitive component according to claim 23, wherein: In the step of forming a rewiring layer on the lower surface of the circuit board, the wiring of the rewiring layer is made through a process of spin coating photoresist, exposure, development, plating or implanting conductive material, and removing the photoresist.

25. The method for manufacturing a photosensitive component according to claim 23, wherein: The step of leading out the first electrode is completed through a process of spin coating photoresist, exposure, development, plating or implanting conductive material, and removing the photoresist.

26. The method for manufacturing a photosensitive component according to claim 23, wherein: The step of leading out the second electrode on the surface of the redistribution layer wiring is completed by a process of spin coating photoresist, exposure, development, plating or implanting conductive material, and removing the photoresist.

Images