Optical sensor packaging structure

Abstract

The utility model provides an optical sensor packaging structure. The optical sensor packaging structure comprises a protective layer, a plastic packaging body, a filtering diaphragm, a chip and a substrate, a chip is mounted on the substrate, a filtering diaphragm is arranged on one side, back to the substrate, of the chip, and a protective layer is arranged on one side, back to the chip, of the filtering diaphragm; the substrate is connected with the plastic package body, and the protection layer, the filtering diaphragm and the chip are located between the substrate and the plastic package body. According to the invention, the protective layer covers the filter membrane in advance, so that the filter membrane can be well protected, the optical performance is more stable, meanwhile, the problems of scratch, contamination, water vapor immersion and the like of the filter membrane possibly caused in the subsequent transportation and production process are solved, and the yield and reliability are improved.

Description

Technical Field

[0001] This utility model relates to the field of packaging manufacturing, specifically to an optical sensor packaging structure. More particularly, it relates to an optical sensor packaging structure with a filter film and its protective layer. Background Technology

[0002] The rapid development of intelligent technology has driven the rapid iteration of optical sensors. The difference between the packaging structure of optical sensors and normal integrated circuits is that they require transparent plastic encapsulation to ensure that light can pass through the transparent plastic encapsulation and shine onto the chip. At the same time, in order to meet different application requirements, some optical sensors need to filter different wavelengths of light, which can be achieved by depositing a filter film on the chip surface.

[0003] The current optical sensor packaging structure with coated filter films is relatively mature. The filter film needs to be coated on the chip surface before packaging. The composition of the film contains metals such as silver and CuTi, which are easily affected by the environment. In particular, during subsequent transportation and packaging, the film may be affected by temperature, humidity, dust, etc., which can cause oxidation or degradation of the elements in the filter film, resulting in irreversible damage. As one of the most important structures of optical chips, damage to the filter film will directly lead to chip failure.

[0004] To achieve both moisture intrusion prevention and chip performance stability, existing technologies require operation in a vacuum environment or replacement of the filter material with inert materials such as ceramics. However, this leads to problems such as high sintering temperatures and difficulties in post-failure analysis, resulting in significant costs and operational challenges.

[0005] Due to the characteristics of transparent molding compound and substrate, high-temperature curing is required during the production process. This process can lead to failures such as cracking, delamination, misalignment, and deformation because the thermal expansion coefficients of the molding compound / substrate and the chip are mismatched and the internal stress after curing cannot be released. Additionally, during user operation, changes in ambient temperature may also cause stress failure issues under thermal expansion and contraction scenarios. Utility Model Content

[0006] In view of the deficiencies in the prior art, the purpose of this utility model is to provide a light sensor packaging structure.

[0007] According to the present invention, a light sensor packaging structure includes: a protective layer, a molding compound, a filter film, a chip, and a substrate;

[0008] A chip is mounted on the substrate, and a filter film is disposed on the side of the chip facing away from the substrate. A protective layer is disposed on the side of the filter film facing away from the chip.

[0009] The substrate is connected to the molding compound, and the protective layer, the filter film, and the chip are located between the substrate and the molding compound.

[0010] Preferably, the chip is bonded to the substrate by an adhesive layer.

[0011] Preferably, an inner pin is provided between the substrate and the molding compound, and an outer pin is provided on the outside of the substrate, with the inner pin connected to the outer pin.

[0012] Preferably, the wiring area of ​​the chip is connected to the internal pins via bonding wires.

[0013] Preferably, the protective layer completely covers and extends beyond the filter film, and the portion of the protective layer extending beyond the filter film is attached to the chip.

[0014] Preferably, the protective layer avoids the wiring areas on the chip, which are distributed at the four corners of the chip.

[0015] Preferably, the protective layer and the encapsulation are light-transmitting.

[0016] Preferably, the protective layer is made of polyimide film, glass, or adhesive.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. This application provides a protective layer to the filter film in advance, which can provide good protection for the filter film, making the optical performance more stable. At the same time, it solves the problems of filter film scratches, contamination and moisture intrusion that may occur during subsequent transportation and production processes, thereby improving the yield.

[0019] 2. This application uses a protective layer to prevent moisture intrusion during use, thus ensuring the integrity of the filter membrane and improving its reliability and service life.

[0020] 3. This application is easy to implement, the protective layer is readily available, and the protective layer coverage can be achieved through mature processes.

[0021] 4. This application can eliminate the equipment cost of hundreds of thousands of dollars caused by vacuum operation without changing the structure and processing technology of the filter film, and reduce the processing difficulty. It can achieve the same function of isolating water vapor / dust at a lower cost, ensuring stable chip performance and extremely high cost performance.

[0022] 5. The added protective layer, being made of transparent resin or polyimide, ensures that the optical performance of the chip remains unaffected and can even achieve higher precision during chip testing through the addition of Trim.

[0023] 6. Due to the characteristics of the materials, the protective layer added to the chip surface has a jelly-like property, which greatly releases the stress caused by thermal expansion and contraction of the molding material during the curing process and the stress imbalance during subsequent user use. This stress effect will reduce the reliability of the chip. At the same time, for stress-sensitive products, this stress will also directly lead to fluctuations in product function and poor consistency. Attached Figure Description

[0024] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the optical sensor packaging structure.

[0026] Figure 2 This is a schematic diagram of the planar structure of the protective layer;

[0027] As shown in the figure:

[0028] Detailed Implementation

[0029] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0030] like Figure 1-2 As shown, this embodiment includes: outer pin 1, inner pin 2, adhesive layer 3, bonding wire 4, protective layer 5, encapsulation body 6, filter film 7, chip 8, and substrate 9.

[0031] The substrate 9 and the adhesive layer 3 are a carrier and soldering agent for encapsulation. The outer lead 1 and the inner lead 2 are components of the substrate 9. The chip 8 with a protective layer 5 and a filter film 7 is bonded to the substrate 9 and fixed through the adhesive layer 3. The adhesive layer 3 can be made of glue.

[0032] The chip 8 with a filter film 7 and its protective layer 5 consists of a filter film 7 deposited on the surface of the chip 8 and a protective layer 5 added. Before encapsulation, this embodiment first adds a protective layer 5 to the filter film 7. In this embodiment, the protective layer 5 completely covers and extends beyond the filter film 7. The portion of the protective layer 5 extending beyond the filter film 7 is attached to the chip 8. The wiring areas 10 are distributed at the four corners of the chip 8, and the protective layer 5 avoids obstructing the wiring areas 10 on the chip 8. The protective layer 5 should consider the following: 1. Good light transmittance, using a light-transmitting material and selecting a thinner thickness according to the actual product design requirements; 2. Easy patterning of the protective layer 5, as the wiring areas 10 of the chip 8 do not require the protective layer 5, but the remaining areas of the chip 8 require the addition of the protective layer 5 to protect the filter film 7 from moisture penetration over a larger area; 3. The performance of the filter film 7 is affected by high temperatures. Given the above requirements, protective layer 5 is preferably a polyimide film, involving production processes such as coating, baking, and patterning. Temperature control is required during baking, and positional accuracy must be controlled during patterning. Glass or adhesive is also considered for the second layer due to the difficulty in achieving the required patterning or alignment. Finally, the optical performance of the sensor after adding protective layer 5 can be tested and adjusted to meet application requirements.

[0033] The molding compound 6 is a thermoplastic transparent material that can protect the internal chip 8, bonding wires 4 and other structures from the influence of the external environment, while also allowing light to pass through.

[0034] Specifically, chip 8 is bonded to substrate 9 via adhesive layer 3. A filter film 7 is disposed on the side of chip 8 facing away from substrate 9, and a protective layer 5 is disposed on the side of filter film 7 facing away from chip 8. Substrate 9 is connected to molding compound 6, and the protective layer 5, filter film 7, and chip 8 are located between substrate 9 and molding compound 6. Inner pin 2 is disposed between substrate 9 and molding compound 6, and outer pin 1 is disposed on the outer side of substrate 9. Inner pin 2 is connected to outer pin 1, and chip 8 is connected to inner pin 2 via bonding wire 4.

[0035] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A light sensor packaging structure, characterized in that, include: Protective layer (5), molding compound (6), filter film (7), chip (8), and substrate (9); A chip (8) is mounted on the substrate (9). A filter film (7) is provided on the side of the chip (8) facing away from the substrate (9). A protective layer (5) is provided on the side of the filter film (7) facing away from the chip (8). The substrate (9) is connected to the encapsulation body (6), and the protective layer (5), the filter film (7) and the chip (8) are located between the substrate (9) and the encapsulation body (6).

2. The optical sensor packaging structure according to claim 1, characterized in that: The chip (8) is bonded to the substrate (9) by an adhesive layer (3).

3. The optical sensor packaging structure according to claim 1, characterized in that: An inner pin (2) is provided between the substrate (9) and the encapsulation body (6), and an outer pin (1) is provided on the outside of the substrate (9). The inner pin (2) is connected to the outer pin (1).

4. The optical sensor packaging structure according to claim 3, characterized in that: The wiring area (10) on the chip (8) is connected to the inner pin (2) via bonding wire (4).

5. The optical sensor packaging structure according to claim 1, characterized in that: The protective layer (5) completely covers and extends beyond the filter film (7), and the portion of the protective layer (5) extending beyond the filter film (7) is attached to the chip (8).

6. The optical sensor packaging structure according to claim 4, characterized in that: The protective layer (5) avoids the wiring area (10) on the chip (8).

7. The optical sensor packaging structure according to claim 4, characterized in that: The wiring areas (10) are distributed at the four corners of the chip (8).

8. The optical sensor packaging structure according to claim 1, characterized in that: The protective layer (5) and the encapsulation body (6) are transparent.

9. The optical sensor packaging structure according to claim 1, characterized in that: The protective layer (5) is made of materials including polyimide film, glass, or adhesive.

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