Photosensitive chip packaging structure and preparation method thereof

Abstract

The application discloses a photosensitive chip packaging structure and a preparation method thereof, and relates to the technical field of semiconductors. The method comprises the following steps: arranging a glass cover plate on a first temporary bonding layer of a first carrier plate, and opening a first groove on a first surface of the glass cover plate; unbonding the glass cover plate from the first carrier plate, and arranging the glass cover plate on a second temporary bonding layer of a second carrier plate through the first surface, so as to open a second groove on a second surface of the glass cover plate; arranging a cofferdam on a fixed area of the second surface; arranging a photosensitive chip on a substrate and electrically connecting the photosensitive chip with the substrate; unbonding the glass cover plate from the second carrier plate, and arranging the glass cover plate on the substrate through the cofferdam; and performing cutting treatment along the first groove by using a cutting process. The method not only solves the problem of glue overflow and cavity pollution during glass mounting, but also avoids the problem of fragments and vibration during cutting, which affects product quality, and simultaneously realizes whole-piece mounting of the glass cover plate and efficient cutting of the packaging structure.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more specifically, to a photosensitive chip packaging structure and its fabrication method. Background Technology

[0002] In traditional processes, the packaging process for photosensitive chips is as follows: First, a dam (DAM) is attached to the substrate to provide a positioning and support reference for subsequent structures; then, the chip is mounted to the designated position on the substrate to achieve mechanical fixation and electrical connection; finally, individual glass pieces are mounted one by one to the top of the dam to protect the photosensitive area of ​​the chip, and then the substrate is cut to obtain a single package.

[0003] The aforementioned traditional process has the following obvious drawbacks: First, the adhesive used when mounting the glass to the cofferdam is prone to overflow and may flow downwards due to gravity, thereby contaminating the cavity area between the chip and the glass and affecting the chip's photosensitivity. Second, the glass material is highly brittle and easily produces fragments during cutting. Furthermore, the cutting vibration is transmitted to the molding compound and the substrate, which may lead to quality problems such as cracking of the molding compound and loosening of the substrate solder joints. To avoid the above risks, the traditional process can only use a single glass piece to be mounted one by one, which cannot achieve batch operation and results in low production efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a photosensitive chip packaging structure and its preparation method. By pre-setting double grooves on the glass cover plate and fixing the cofferdam in the fixed area formed between two adjacent first grooves, and cutting the packaging structure along the second groove, the problem of glue overflow and contamination of the cavity during glass mounting in traditional processes is solved. It also avoids the problem of fragments and vibrations during cutting affecting product quality. At the same time, it realizes the whole-piece mounting of the glass cover plate and the efficient cutting of the packaging structure, effectively improving the production efficiency and product reliability in the photosensitive chip packaging process.

[0005] The embodiments of the present invention are implemented as follows:

[0006] A first aspect of the present invention provides a method for fabricating a photosensitive chip packaging structure, the method comprising:

[0007] A glass cover plate with a light filtering function is fixedly disposed on the first temporary bonding layer of the first carrier plate, and a plurality of first grooves are formed on the first surface of the glass cover plate away from the first carrier plate.

[0008] The glass cover plate is debonded from the first carrier plate, and the glass cover plate is fixedly disposed on the second temporary bonding layer of the second carrier plate through the first surface, so as to open a plurality of second grooves on the second surface of the glass cover plate that is opposite to the first surface, wherein a fixed area or a photosensitive area is formed between two adjacent second grooves, the fixed area is opposite to the first groove, and the photosensitive area is offset from the first groove;

[0009] The cofferdam is fixed to the fixed area of ​​the second surface using adhesive.

[0010] The photosensitive chip is fixedly mounted on the substrate and electrically connected to the substrate;

[0011] The glass cover plate is unbonded to the second carrier plate, and the glass cover plate is fixedly disposed on the substrate by the cofferdam to form an encapsulation structure, and the photosensitive chip and the photosensitive area are disposed opposite to each other;

[0012] The packaging structure is cut into individual products along the first groove using a cutting process.

[0013] As one possible implementation, the first temporary bonding layer is a pyrolytic temporary bonding layer, and the step of unbonding the glass cover from the first carrier plate includes:

[0014] The glass cover plate is debonded from the first carrier plate by heating.

[0015] Furthermore, the second temporary bonding layer is a pyrolytic temporary bonding layer, and the step of unbonding the glass cover plate from the second carrier plate includes:

[0016] The glass cover plate is debonded to the second carrier plate by heating.

[0017] As one possible implementation, the fixing adhesive is a UV adhesive, and the process of fixing the cofferdam to the fixing area of ​​the second surface using the fixing adhesive includes:

[0018] The cofferdam is fixed to the fixed area of ​​the second surface using UV adhesive;

[0019] The UV adhesive is cured using ultraviolet light.

[0020] As one possible implementation, fixing the photosensitive chip onto the substrate and electrically connecting the photosensitive chip to the substrate includes:

[0021] The photosensitive chip is fixed onto the substrate using conductive adhesive;

[0022] The photosensitive chip is electrically connected to the substrate using wire bonding.

[0023] As one possible implementation, fixing the glass cover plate onto the substrate via the dike to form an encapsulation structure includes:

[0024] The cofferdam is fixed to the substrate with UV adhesive, so that the glass cover is fixed to the substrate through the cofferdam to form an encapsulation structure;

[0025] The UV adhesive is cured using ultraviolet light.

[0026] As one possible implementation, a third groove is provided on the fixing area, the third groove being used to accommodate the fixing adhesive.

[0027] In one possible implementation, the depth of the first groove is 1 / 4 to 1 / 3 of the thickness of the glass cover plate, and the depth of the second groove is 1 / 9 to 1 / 6 of the thickness of the glass cover plate.

[0028] In one possible implementation, the width of the second groove is greater than the width of the first groove, and the difference between the width of the second groove and the width of the first groove is 0.1-0.3 mm.

[0029] As one possible implementation, the difference between the thermal expansion coefficient of the cofferdam and the thermal expansion coefficient of the substrate is less than or equal to ±5ppm / ℃.

[0030] In a second aspect, the present invention provides a photosensitive chip packaging structure, which is prepared by the above-described method for preparing a photosensitive chip packaging structure.

[0031] The beneficial effects of the embodiments of the present invention include:

[0032] The method includes fixing a glass cover plate with a light-filtering function onto a first temporary bonding layer of a first carrier plate, and forming a plurality of first grooves on a first surface of the glass cover plate away from the first carrier plate; debonding the glass cover plate from the first carrier plate, and fixing the glass cover plate onto a second temporary bonding layer of a second carrier plate via the first surface, so as to form a plurality of second grooves on a second surface of the glass cover plate opposite to the first surface; fixing a cofferdam onto a fixed area of ​​the second surface with adhesive; fixing a photosensitive chip onto a substrate and electrically connecting the photosensitive chip to the substrate; debonding the glass cover plate from the second carrier plate, and fixing the glass cover plate onto the substrate via the cofferdam to form an encapsulation structure, wherein the photosensitive chip and the photosensitive area are opposite to each other; and cutting the encapsulation structure into individual products along the first grooves using a cutting process. This method fixes the cofferdam within a fixed area between two adjacent second grooves. The second grooves can contain any overflowing adhesive, preventing adhesive from flowing into the photosensitive area. This eliminates the need for additional cleaning processes and improves product yield. Simultaneously, the first groove serves as a cutting path, reducing vibration and stress concentration during cutting, preventing glass fragments from contaminating the photosensitive chip, and reducing wear on the cutting tools. Furthermore, processing the glass cover plate with double grooves, sealing it as a single piece, and then cutting it into individual pieces reduces positioning errors and time costs associated with traditional individual glass processing, significantly increasing batch production capacity compared to traditional processes. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is one of the schematic diagrams illustrating the fabrication of the photosensitive chip packaging structure provided in the embodiments of the present invention;

[0035] Figure 2 This is a second schematic diagram illustrating the fabrication of the photosensitive chip packaging structure provided in an embodiment of the present invention;

[0036] Figure 3 This is the third schematic diagram illustrating the fabrication of the photosensitive chip packaging structure provided in this embodiment of the invention;

[0037] Figure 4 This is the fourth schematic diagram illustrating the fabrication of the photosensitive chip packaging structure provided in this embodiment of the invention;

[0038] Figure 5 Fifth schematic diagram of the fabrication of the photosensitive chip packaging structure provided in the embodiments of the present invention;

[0039] Figure 6 This is the sixth schematic diagram illustrating the fabrication of the photosensitive chip packaging structure provided in this embodiment of the invention;

[0040] Figure 7 This is the seventh schematic diagram illustrating the fabrication of the photosensitive chip packaging structure provided in this embodiment of the invention.

[0041] Icons: 100 - Photosensitive chip packaging structure; 10 - Glass cover; 11 - First groove; 12 - Second groove; 13 - Third groove; 20 - First carrier; 21 - First temporary bonding layer; 30 - Second carrier; 31 - Second temporary bonding layer; 40 - Dike; 41 - Fixing adhesive; 50 - Photosensitive chip; 51 - Conductive adhesive; 60 - Substrate; 200 - Single product; S1 - Fixing area; S2 - Photosensitive area. Detailed Implementation

[0042] The embodiments described below represent the information necessary for those skilled in the art to practice the embodiments and illustrate the best mode for practicing the embodiments. After reading the following description with reference to the accompanying drawings, those skilled in the art will understand the concepts of this disclosure and will recognize the application of these concepts not specifically set forth herein. It should be understood that these concepts and applications fall within the scope of this disclosure and the appended claims.

[0043] It should be understood that when an element (such as a layer, region, or substrate) is referred to as "on another element" or "extending to another element," it may be directly on another element or directly extending to another element, or there may be an intermediate element. Similarly, it should be understood that when an element (such as a layer, region, or substrate) is referred to as "on another element" or "extending over another element," it may be directly on another element or directly extending to another element, or there may be an intermediate element.

[0044] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that, when used herein, the term “comprising” indicates the presence of the stated feature, integer, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups of the foregoing.

[0045] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that the terms used herein should be interpreted as having the same meaning as they would in the context of this specification and the relevant field, and not in an idealized or overly formal sense, unless expressly defined herein.

[0046] The traditional photosensitive chip packaging process involves first attaching a dike to the substrate to provide positioning support, then mounting the chip onto the substrate and establishing electrical connections between the two, and finally mounting individual glass chips one by one onto the top of the dike. After completion, the substrate is cut to obtain a single package. This traditional process has the following significant limitations: First, the adhesive is prone to overflowing during glass mounting and may flow downwards due to gravity, contaminating the cavity between the chip and the glass, affecting photosensitivity. Second, glass is brittle and easily breaks during cutting; the vibration during cutting can cause the molding compound to crack and the substrate solder joints to loosen. To avoid these risks, the traditional process requires mounting individual glass chips one by one, which is not feasible for batch processing and restricts production efficiency.

[0047] To solve the above problems, please refer to the following: Figures 1 to 7 This application provides a photosensitive chip packaging structure 100 and its preparation method. By pre-setting a first groove 11 and a second groove 12 on opposite sides of a glass cover plate 10, and fixing a dam 40 in a fixed area S1 formed between two adjacent first grooves 11, the first groove 11 can accommodate the fixing adhesive 41 that overflows when the dam 40 is fixed. After packaging, the packaging structure is cut along the second groove 12, with the second groove 12 serving as the cutting path. This solves the problem of adhesive overflow and contamination of the cavity during glass mounting in traditional processes, and avoids the problem of fragments and vibrations affecting product quality during cutting. At the same time, it achieves the whole-piece mounting of the glass cover plate 10 and efficient cutting of the packaging structure, effectively improving the production efficiency and product reliability in the photosensitive chip 50 packaging process.

[0048] Specifically, such as Figures 1 to 7 As shown, in a first aspect of this application, a method for fabricating a photosensitive chip packaging structure 100 is provided, the method comprising:

[0049] S110. A glass cover plate 10 with a light filtering function is fixedly disposed on the first temporary bonding layer 21 of the first carrier plate 20, and a plurality of first grooves 11 are formed on the first surface of the glass cover plate 10 away from the first carrier plate 20.

[0050] It should be noted that the glass cover plate 10 can be made of high-transmittance filter glass (such as borosilicate glass or sapphire glass), with a thickness of 450-600μm. Its filter band should be compatible with the photosensitive chip 50 (such as visible light 400-760nm or infrared band). The first carrier plate 20 can be a silicon-based or glass carrier plate. The first temporary bonding layer 21 on its surface can be made of pyrolytic polyimide (PI) or ultraviolet debonding adhesive. The bonding strength can be controlled at 0.5-1.0MPa, which can prevent processing displacement and facilitate subsequent debonding.

[0051] In actual fabrication, multiple first grooves 11 can be processed on the first surface of the glass cover plate 10 using dry etching (such as plasma etching) or laser etching processes. The width of each first groove 11 can be 0.2-0.5 mm, and the depth can be 1 / 4-1 / 3 of the thickness of the glass cover plate 10. For example, the depth of the first groove 11 is 150-200 μm. The first groove 11 does not penetrate the glass cover plate 10. Multiple first grooves 11 are arranged in an array or in parallel. The spacing between two adjacent first grooves 11 should match the size of the subsequent single product 200.

[0052] S210. The glass cover plate 10 is debonded from the first carrier plate 20, and the glass cover plate 10 is fixedly disposed on the second temporary bonding layer 31 of the second carrier plate 30 through the first surface, so that a plurality of second grooves 12 are formed on the second surface of the glass cover plate 10 which is opposite to the first surface. A fixed area S1 or a photosensitive area S2 is formed between two adjacent second grooves 12. The fixed area S1 is opposite to the first groove 11, and the photosensitive area S2 is misaligned with the first groove 11.

[0053] It should be noted that, firstly, the bond between the glass cover plate 10 and the first carrier plate 20 is released. If the first temporary bonding layer 21 is pyrolytic, the glass cover plate 10 and the first carrier plate 20 can be heated to 200-250°C. If the first temporary bonding layer 21 is ultraviolet, it can be covered with 365nm ultraviolet light for 30-60s. Then, the glass cover plate 10 is flipped over and bonded to the second temporary bonding layer 31 of the second carrier plate 30 through the first surface with the first groove 11, ensuring that the second surface of the glass cover plate 10 opposite to the first surface is exposed upwards for easy processing.

[0054] Multiple second grooves 12 can be processed using the same etching process as the first groove 11. The width of each second groove 12 can be 0.3-0.8 mm, and the depth can be 1 / 9-1 / 6 of the thickness of the glass cover plate 10, such as a depth of 50-100 μm. Two types of areas are formed between two adjacent second grooves 12. The first type is a fixed area S1 (the width can be 1-2 mm, used to fix the installation dam 40) and a photosensitive area S2 (the size can be larger than the effective area of ​​the photosensitive chip 50). The fixed area S1 should be precisely aligned with the first groove 11, while the photosensitive area S2 should be staggered with the first groove 11 to avoid blocking the photosensitive path of the photosensitive chip 50.

[0055] S310. The cofferdam 40 is fixedly installed on the fixed area S1 of the second surface using the fixing adhesive 41;

[0056] It should be noted that the difference between the thermal expansion coefficient of the cofferdam 40 and that of the substrate 60 can be less than or equal to ±5ppm / ℃. For example, the material of the cofferdam 40 can be the core support material of the substrate 60, and its cross-section can be rectangular. Its height should be compatible with the thickness of the photosensitive chip 50, and its width should be less than the width of the fixed area S1 (e.g., the difference between the two is 0.1-0.3mm). The fixing adhesive 41 can be epoxy adhesive, which supports dual curing of UV fixing and thermal curing, such as initial curing after 60 seconds of UV irradiation and final curing after 30 minutes of baking at 120℃.

[0057] In actual preparation, adhesive can be applied to the fixed area S1 using a dispensing process. 3-4 dispensing points are set in each fixed area S1. After the cofferdam 40 is attached, the overflowing adhesive will naturally flow into the first groove 11 (i.e., the adhesive space) on the side of the fixed area S1, without contaminating the adjacent photosensitive area S2, thus making the overflow phenomenon controllable.

[0058] S410. The photosensitive chip 50 is fixedly disposed on the substrate 60, and the photosensitive chip 50 is electrically connected to the substrate 60.

[0059] It should be noted that the substrate 60 can be a resin substrate 60 or a ceramic substrate 60, which has the advantages of high temperature resistance and low dielectric loss. The photosensitive chip 50 can be fixed to the preset area of ​​the substrate 60 by conductive adhesive 51 or flip-chip bonding. After the fixing is completed, the electrical connection between the photosensitive chip 50 and the substrate 60 can be achieved by wire bonding or flip-chip bonding. After the electrical connection is completed, an insulating coating (such as silicone coating) is applied to prevent short circuits or contamination.

[0060] S510, the glass cover plate 10 is debonded from the second carrier plate 30, and the glass cover plate 10 is fixedly disposed on the substrate 60 through the cofferdam 40 to form an encapsulation structure, and the photosensitive chip 50 is disposed opposite to the photosensitive area S2.

[0061] It should be noted that the bonding between the glass cover plate 10 and the second carrier plate 30 should be released first, and then the glass cover plate 10 should be aligned with the substrate 60 through the cofferdam 40. At this time, a small amount of fixing adhesive 41 can be applied between the bottom of the cofferdam 40 and the surface of the substrate 60 to enhance the sealing. After the encapsulation is completed, the coaxiality error between the photosensitive chip 50 and the photosensitive area S2 of the glass cover plate 10 is small, and the gap of the formed sealing cavity is small. Note that direct contact between the photosensitive chip 50 and the glass cover plate 10 should be avoided.

[0062] S610, The packaging structure is cut into individual products 200 along the first groove 11 using a cutting process.

[0063] It should be noted that a cutting tool or laser cutting process can be used to cut along the first groove 11, using the first groove 11 as the cutting path. Furthermore, since the glass cover 10 is thinner at the first groove 11, the cutting stress can be dispersed, preventing the glass cover 10 from fragmenting or chipping. The encapsulation structure formed by the glass cover 10 as a single piece can be separated into multiple individual products 200 through a single cutting process, significantly improving production efficiency compared to encapsulating individual glass pieces one by one. Moreover, the precise positioning and auxiliary guidance provided by the first groove 11 ensure that the cutting path will not damage the photosensitive chip 50 or the electrical connection structure.

[0064] Compared to traditional technologies, the preparation method provided in this application fixes the cofferdam 40 within the fixed area S1 between two adjacent second grooves 12. The second grooves 12 can accommodate the overflowing adhesive 41, preventing adhesive from flowing into the photosensitive area S2 from the structural design. This eliminates the need for additional cleaning processes and improves product yield. At the same time, the first groove 11 serves as a cutting path, reducing vibration and stress concentration during cutting, preventing glass fragments from splashing and contaminating the photosensitive chip 50, and reducing wear on the cutting tools. Furthermore, the glass cover plate 10 is processed with double grooves as a whole, packaged and fixed, and then cut into individual pieces, reducing the positioning errors and time costs of traditional single-piece glass processing. The single-batch production capacity is significantly improved compared to traditional processes.

[0065] As one possible implementation, the first temporary bonding layer 21 is a pyrolytic temporary bonding layer. S210, debonding the glass cover plate 10 from the first carrier plate 20 includes:

[0066] S211. The glass cover plate 10 is debonded to the first carrier plate 20 by heating.

[0067] And, the second temporary bonding layer 31 is a pyrolytic temporary bonding layer, S510, unbonding the glass cover plate 10 from the second carrier plate 30 includes:

[0068] S511. The glass cover plate 10 is debonded to the second carrier plate 30 by heating.

[0069] It should be noted that in this embodiment, the first temporary bonding layer 21 is a pyrolytic temporary bonding layer, and its material can be pyrolytic polyimide (PI) or thermosetting resin. In the bonded state (room temperature to 150°C), the bonding strength is stable at 0.5-1.0 MPa, which can firmly fix the glass cover plate 10 and meet the anti-displacement requirements during etching. The pyrolysis temperature range is precisely controllable (200-280°C, adjusted according to the material). When heated to the pyrolysis temperature, the first temporary bonding layer 21 will undergo thermal decomposition or thermal degradation, and the bonding strength will rapidly drop to below 0.05 MPa, achieving non-destructive release. After pyrolysis, there is no residue or stickiness, and no adhesive residue will be left on the glass cover plate 10. No additional cleaning process is required, avoiding contamination of the first groove 11 or the photosensitive area S2.

[0070] In actual preparation, a hot air circulating oven or a vacuum heating table can be used, with a vacuum environment preferred to avoid impurities in the air adhering to the surface of the glass cover plate 10. The temperature can be controlled using a curve-like method, first gradually increasing the temperature, then holding it at the pyrolysis temperature for a certain time, and finally allowing it to cool naturally. This avoids excessively rapid heating that could cause thermal stress deformation of the glass cover plate 10, ensuring complete pyrolysis of the first temporary bonding layer 21, reducing the bond strength to the release threshold, and preventing cracks in the glass cover plate 10 due to sudden cooling. After debonding, the glass cover plate 10 can be transferred using a vacuum suction cup, flipped, and then bonded to the second temporary bonding layer 31 of the second carrier plate 30, avoiding prolonged exposure of the first surface with the first groove 11 to dust accumulation. The bonding and debonding principles between the glass cover plate 10 and the second carrier plate 30 are the same as described above, so they will not be repeated here.

[0071] As one possible implementation, the fixing adhesive 41 is a UV adhesive. S310, fixing the cofferdam 40 to the fixing area S1 of the second surface using the fixing adhesive 41 includes:

[0072] S311. The cofferdam 40 is fixed to the fixed area S1 on the second surface using UV adhesive;

[0073] S312. UV adhesive is cured using ultraviolet light.

[0074] It should be noted that in some embodiments, the fixing adhesive 41 is a UV adhesive, which facilitates dispensing and allows for rapid wetting of the fixing area S1. After curing, it exhibits low shrinkage to prevent the cofferdam 40 from shifting due to shrinkage, and it has high bonding strength, ensuring the long-term stability of the cofferdam 40 without detachment. It can also withstand the pyrolysis temperature during the subsequent debonding of the glass cover plate 10 and the second carrier plate 30. In actual preparation, a dispensing machine can be used to evenly dispense adhesive into the fixing area S1, with 3-4 dispensing points in each area S1, and the total amount of adhesive dispensed is controllable. After attaching the cofferdam 40, slight pressure can be applied to ensure the fixing adhesive 41 is evenly spread. At this time, any overflowing adhesive will naturally flow into the first groove 11 corresponding to the side of the fixing area S1 (i.e., the adhesive space), without contaminating the adjacent photosensitive area S2, thus controlling the overflow phenomenon. For fixation, an LED UV curing lamp can be used for irradiation.

[0075] As one possible implementation, S410, fixing the photosensitive chip 50 onto the substrate 60 and electrically connecting the photosensitive chip 50 to the substrate 60 includes:

[0076] S411. The photosensitive chip 50 is fixedly disposed on the substrate 60 using conductive adhesive 51.

[0077] S412. The photosensitive chip 50 is electrically connected to the substrate 60 by wire bonding.

[0078] It should be noted that the conductive adhesive 51 can be silver paste conductive adhesive 51 or copper-based conductive adhesive 51, which takes into account both high conductivity and bonding reliability, and is compatible with the electrical signal transmission requirements of the photosensitive chip 50. In actual preparation, the adhesive is applied first and then cured, which will not be elaborated here. After the fixation is completed, the pads of the photosensitive chip 50 can be connected to the pads of the substrate 60 by using leads to realize the electrical connection between the photosensitive chip 50 and the substrate 60.

[0079] As one possible implementation, S510, fixing the glass cover plate 10 onto the substrate 60 via the dike 40 to form an encapsulation structure includes:

[0080] S511. The cofferdam 40 is fixedly mounted on the substrate 60 with UV adhesive so that the glass cover plate 10 is fixedly mounted on the substrate 60 through the cofferdam 40 to form an encapsulation structure.

[0081] S512. UV adhesive is cured using ultraviolet light.

[0082] It should be noted that the encapsulation method of fixing the cofferdam 40 to the substrate 60 with UV adhesive and then curing it with ultraviolet light not only quickly achieves a stable connection between the glass cover plate 10 and the substrate 60, but also ensures the sealing performance of the encapsulation chamber. This method is compatible with the photosensitive chip 50 encapsulation process provided in this application, further improving mass production efficiency and product reliability. The working principle of fixing the cofferdam 40 to the substrate 60 with UV adhesive is the same as the working principle of fixing the cofferdam 40 to the fixing area S1 on the second surface with UV adhesive, so it will not be described again here.

[0083] As one possible implementation method, such as Figures 2 to 7 As shown, a third groove 13 is provided on the fixed area S1, and the third groove 13 is used to accommodate the fixing adhesive 41.

[0084] It should be noted that a third groove 13 is provided on the fixed area S1. The third groove 13 can be opened at the center of the fixed area S1, and its width should be smaller than the width of the bottom of the cofferdam 40. The third groove 13 can be precisely aligned with the first groove 11. In this embodiment, the third groove 13 and the first groove 11 are not connected. The third groove 13 can be processed simultaneously with the second groove 12 without additional processing. During dispensing, the fixing adhesive 41 is directly injected into the third groove 13 and fills the third groove 13 completely (a small amount of overflow is allowed). Compared with the embodiment without the third groove 13, the amount of adhesive dispensed can be significantly increased. When bonding the cofferdam 40, the cofferdam 40 can be lightly pressed. At this time, the adhesive in the third groove 13 will overflow evenly into the second grooves 12 on both sides of the fixing area S1, forming an adhesive layer of uniform thickness, covering the contact surface between the cofferdam 40 and the fixing area S1. After curing, the adhesive in the third groove 13 forms an embedded bonding structure. Compared with planar adhesive application, the bonding contact area is significantly increased, and the shear bonding strength between the cofferdam 40 and the glass cover plate 10 is significantly improved, making it more resistant to the mechanical stress of subsequent temporary carrier plate switching and encapsulation bonding.

[0085] As one possible implementation, the depth of the first groove 11 is 1 / 4 to 1 / 3 of the thickness of the glass cover plate 10, and the depth of the second groove 12 is 1 / 9 to 1 / 6 of the thickness of the glass cover plate 10. For example, the thickness of the glass cover plate 10 is 450-600 μm. In this case, the depth of the first groove 11 can be 150-200 μm, and the depth of the second groove 12 can be 50-100 μm.

[0086] In one possible implementation, the width of the second groove 12 is greater than the width of the first groove 11, and the difference between the width of the second groove 12 and the width of the first groove 11 is 0.1-0.3 mm.

[0087] It should be noted that the core function of the second groove 12 is to accommodate the overflowing adhesive 41, requiring a wider space. The core function of the first groove 11 is to serve as a cutting channel; if it were too wide, it would waste the area of ​​the glass cover plate 10 and the substrate 60, while if it were too narrow, it would not be able to effectively distribute the cutting stress. Therefore, the difference between the two is designed to be 0.1-0.3mm, which perfectly balances the adhesive space and material utilization. For example, the width of the first groove 11 can be 0.2-0.5mm, and the width of the second groove 12 can be 0.3-0.8mm.

[0088] When a third groove 13 is provided on the fixed area S1, the shape and size of the third groove 13 can be the same as the second groove 12, so that the second groove 12 and the third groove 13 can be formed simultaneously in the same process.

[0089] In a second aspect, this application provides a photosensitive chip packaging structure 100, which is prepared using the above-described method for preparing a photosensitive chip packaging structure 100.

[0090] It should be noted that the specific structure of the photosensitive chip packaging structure 100 provided in this embodiment is the same as the fabrication method of the photosensitive chip packaging structure 100 described above. Those skilled in the art can deduce the specific structure of the photosensitive chip packaging structure 100 based on the description of the fabrication method of the photosensitive chip packaging structure 100 described above, and this application will not repeat the description. Since the photosensitive chip packaging structure 100 provided in this embodiment is fabricated using the above-described fabrication method of the photosensitive chip packaging structure 100, it has the same beneficial effects as the above-described fabrication method of the photosensitive chip packaging structure 100, and will not be described again here.

[0091] The above description is merely an optional embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0092] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A method for fabricating a photosensitive chip packaging structure, characterized in that, The method includes: A glass cover plate with a light filtering function is fixedly disposed on the first temporary bonding layer of the first carrier plate, and a plurality of first grooves are formed on the first surface of the glass cover plate away from the first carrier plate. The glass cover plate is debonded from the first carrier plate, and the glass cover plate is fixedly disposed on the second temporary bonding layer of the second carrier plate through the first surface, so as to open a plurality of second grooves on the second surface of the glass cover plate that is opposite to the first surface, wherein a fixed area or a photosensitive area is formed between two adjacent second grooves, the fixed area is opposite to the first groove, and the photosensitive area is offset from the first groove; The cofferdam is fixed to the fixed area of ​​the second surface using adhesive. The photosensitive chip is fixedly mounted on the substrate and electrically connected to the substrate; The glass cover plate is unbonded to the second carrier plate, and the glass cover plate is fixedly disposed on the substrate by the cofferdam to form an encapsulation structure, and the photosensitive chip and the photosensitive area are disposed opposite to each other; The packaging structure is cut into individual products along the first groove using a cutting process.

2. The method for fabricating the photosensitive chip packaging structure according to claim 1, characterized in that, The first temporary bonding layer is a pyrolytic temporary bonding layer, and the step of debonding the glass cover from the first carrier plate includes: The glass cover plate is debonded from the first carrier plate by heating. Furthermore, the second temporary bonding layer is a pyrolytic temporary bonding layer, and the step of unbonding the glass cover plate from the second carrier plate includes: The glass cover plate is debonded to the second carrier plate by heating.

3. The method for fabricating the photosensitive chip packaging structure according to claim 1, characterized in that, The fixing adhesive is a UV adhesive, and the process of fixing the cofferdam to the fixing area of ​​the second surface using the fixing adhesive includes: The cofferdam is fixed to the fixed area of ​​the second surface using UV adhesive; The UV adhesive is cured using ultraviolet light.

4. The method for fabricating the photosensitive chip packaging structure according to claim 1, characterized in that, The step of fixing the photosensitive chip onto the substrate and electrically connecting the photosensitive chip to the substrate includes: The photosensitive chip is fixed onto the substrate using conductive adhesive; The photosensitive chip is electrically connected to the substrate using wire bonding.

5. The method for fabricating the photosensitive chip packaging structure according to claim 1, characterized in that, The step of fixing the glass cover plate onto the substrate via the dike to form an encapsulation structure includes: The cofferdam is fixed to the substrate with UV adhesive, so that the glass cover is fixed to the substrate through the cofferdam to form an encapsulation structure; The UV adhesive is cured using ultraviolet light.

6. The method for fabricating the photosensitive chip packaging structure according to claim 1, characterized in that, A third groove is provided on the fixing area, and the third groove is used to accommodate the fixing adhesive.

7. The method for fabricating the photosensitive chip packaging structure according to claim 1, characterized in that, The depth of the first groove is 1 / 4 to 1 / 3 of the thickness of the glass cover plate, and the depth of the second groove is 1 / 9 to 1 / 6 of the thickness of the glass cover plate.

8. The method for fabricating the photosensitive chip packaging structure according to claim 1, characterized in that, The width of the second groove is greater than the width of the first groove, and the difference between the width of the second groove and the width of the first groove is 0.1-0.3 mm.

9. The method for fabricating the photosensitive chip packaging structure according to claim 1, characterized in that, The difference between the thermal expansion coefficient of the cofferdam and the thermal expansion coefficient of the substrate is less than or equal to ±5ppm / ℃.

10. A photosensitive chip packaging structure, characterized in that, It is prepared by the method of any one of claims 1-9 for preparing the photosensitive chip packaging structure.

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