Optical sensor packaging structure

Abstract

The invention 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] The present invention relates to the field of package manufacturing, and more particularly to an optical sensor package structure, and more specifically to an optical sensor package structure with a filter film and its protective layer. Background Art

[0002] Due to the rapid development of intelligentization, the rapid iteration of optical sensors has been driven. The difference between the package structure of an optical sensor and a normal integrated circuit lies in the need for transparent encapsulation to ensure that light can pass through the transparent encapsulation and irradiate on the chip. At the same time, to meet different application requirements, some optical sensors need to filter different lights, and the requirement of screening lights with different wavelengths can be met by plating a filter film on the chip surface.

[0003] The current package structure of an optical sensor with a plated filter film is relatively mature. The filter film needs to be plated on the chip surface before encapsulation, and its components will contain metals such as silver and CuTi, which are easily affected by the environment. Especially during subsequent transportation and encapsulation, it may be affected by temperature, humidity, dust, etc., resulting in effects such as oxidation or degradation of the elements in the filter film, causing irreversible damage. As one of the most important structures of an optical chip, the filter film will directly cause the chip to fail after being damaged.

[0004] If the prior art needs to achieve the premise of blocking the intrusion of water vapor while maintaining the stable performance of the chip, it needs to be operated in a vacuum environment, or replace the filter material with an inert material such as ceramics, etc. This will also have problems such as high sintering temperature and difficulty in analyzing after failure, which is very costly and difficult in operation and processing.

[0005] Due to the characteristics of the transparent encapsulant and the substrate, high-temperature curing is required during the production process. This process will cause the internal stress after curing to be unable to be released due to the mismatch of the thermal expansion coefficients between the encapsulant / substrate and the chip, easily resulting in failures such as cracks, delamination, misalignment, and deformation. At the same time, during the user's use process, due to the change of the environmental temperature, stress failure problems may also occur in the scenario of thermal expansion and contraction. Summary of the Invention

[0006] Aiming at the defects in the prior art, the purpose of the present invention is to provide an optical sensor package structure.

[0007] An optical sensor package structure provided by the present invention includes: a protective layer, a plastic package body, a filter film, a chip, and a substrate;

[0008] The chip is installed on the substrate, a filter film is provided on the side of the chip facing away from the substrate, and a protective layer is provided on the side of the filter film facing away from the chip;

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

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

[0011] Preferably, inner leads are provided between the substrate and the encapsulant, outer leads are provided outside the substrate, and the inner leads are connected to the outer leads.

[0012] Preferably, the wiring area of the chip is connected to the inner leads through wire bonding.

[0013] Preferably, the protective layer completely covers and extends beyond the filter film, and the part of the protective layer extending beyond the filter film fits on the chip.

[0014] Preferably, the protective layer avoids the wiring area on the chip, and the wiring area is distributed at the four corners of the chip.

[0015] Preferably, the protective layer and the encapsulant are light-transmissive.

[0016] Preferably, the material of the protective layer includes polyimide film, glass or glue.

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

[0018] 1. By pre-covering the protective layer on the filter film, the present application can form a good protection for the filter film, make the optical performance more stable, and at the same time solve the problems such as abrasion, contamination and water vapor intrusion of the filter film that may be caused in the subsequent transportation and production processes, and improve the yield.

[0019] 2. Through the protective layer, the water vapor intrusion during use is also blocked by the protective layer, ensuring the integrity of the filter film and improving the reliability and service life.

[0020] 3. The present application is easy to implement, the protective layer is easy to obtain, and the coverage of the protective layer can be realized through mature processes.

[0021] 4. Without changing the structure and processing technology of the filter film, the present application can remove the equipment cost of hundreds of thousands for each vacuum operation, reduce the processing difficulty, realize the same function of isolating water vapor / dust with a lower cost, ensure the stable performance of the chip, and have extremely high cost performance.

[0022] 5. Since the added protective layer is made of light-transmissive resin or polyimide and other materials, it can ensure that the optical performance of the chip is not affected at all, and even can achieve higher precision through the addition of Trim during the chip testing process.

[0023] 6. Due to the characteristics of the material, the protective layer added on the chip surface has a jelly-like property, which greatly releases the stress caused by thermal expansion and contraction during the curing process of the plastic package material and the stress imbalance during the subsequent use by users. Such stress effects will reduce the reliability of the chip. At the same time, for stress-sensitive products, such stress will also directly lead to fluctuations in product functions and very poor consistency. Description of the Drawings

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

[0025] Figure 1 It is a schematic diagram of the optical sensor packaging structure;

[0026] Figure 2 It is a schematic plan view of the protective layer;

[0027] As shown in the figure:

[0028] Detailed Embodiment

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

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

[0031] The substrate 9 and the adhesive layer 3 are a carrier and a welding agent for packaging. The outer lead 1 and the inner lead 2 are components of the substrate 9. The chip 8 plated with the filter film 7 with the protective layer 5 is bonded and fixed on the substrate 9 through the adhesive layer 3, and the adhesive layer 3 can use glue.

[0032] The chip 8 with the filter film 7 and its protective layer 5 is such that the filter film 7 is plated on the surface of the chip 8 and the protective layer 5 is added. Before encapsulation, in this embodiment, a protective layer 5 will be added on the filter film 7 first. In this embodiment, the protective layer 5 completely covers and extends beyond the filter film 7, and the part of the protective layer 5 that extends beyond the filter film 7 adheres to the chip 8. The wiring areas 10 are distributed at the four corners of the chip 8, and the protective layer 5 avoids the wiring areas 10 on the chip 8. The adopted protective layer 5 needs to consider: 1. It should have good light transmission performance. A material with light transmission property is used and a relatively thin thickness is selected according to the design requirements of the actual product; 2. The protective layer 5 is easy to pattern. The wiring areas 10 of the chip 8 do not need the protective layer 5, and the protective layer 5 needs to be added to the rest of the positions of the chip 8, so as to protect the filter film 7 from being invaded by water vapor over a larger area; 3. The performance of the filter film 7 will be affected by high temperature. In view of the above requirements, the protective layer 5 is preferably a polyimide film. For the production processes such as glue coating, baking, and patterning involved, the temperature needs to be controlled during the baking process, and the position accuracy needs to be controlled during the patterning production process. The secondary choice for the protective layer 5 is glass or glue because it is difficult to achieve the patterning or alignment requirements. Finally, the optical performance of the sensor after adding the protective layer 5 can meet the application requirements through testing and adjustment.

[0033] The plastic package 6 is a thermoplastic transparent material that can protect internal structures such as the chip 8 and the bonding wires 4 from the external environment and has the function of light transmission at the same time.

[0034] Specifically, the chip 8 is bonded to the substrate 9 through the adhesive layer 3. A filter film 7 is provided on the side of the chip 8 facing away from the substrate 9, and 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 plastic package 6, and the protective layer 5, the filter film 7, and the chip 8 are located between the substrate 9 and the plastic package 6. Inner leads 2 are provided between the substrate 9 and the plastic package 6, and outer leads 1 are provided outside the substrate 9. The inner leads 2 are connected to the outer leads 1, and the chip 8 is connected to the inner leads 2 through the bonding wires 4.

[0035] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0036] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A light sensor packaging structure, characterized in that, Including: A protective layer (5), a plastic package (6), a filter film (7), a chip (8), and a substrate (9); The 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), and 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 plastic package (6), and the protective layer (5), the filter film (7), and the chip (8) are located between the substrate (9) and the plastic package (6).

2. The optical sensor package structure according to claim 1, wherein: The chip (8) is bonded to the substrate (9) through an adhesive layer (3).

3. The optical sensor package structure according to claim 1, wherein: Inner leads (2) are provided between the substrate (9) and the plastic package (6), outer leads (1) are provided outside the substrate (9), and the inner leads (2) are connected to the outer leads (1).

4. The optical sensor packaging structure according to claim 3, wherein: The wiring area (10) on the chip (8) is connected to the inner lead (2) through a bonding wire (4).

5. The optical sensor package structure according to claim 1, wherein: The protective layer (5) completely covers and extends beyond the filter film (7), and the part of the protective layer (5) that extends beyond the filter film (7) is attached to the chip (8).

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

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

8. The optical sensor packaging structure according to claim 1, wherein: The protective layer (5) and the plastic package (6) have light transmissivity.

9. The optical sensor packaging structure according to claim 1, wherein: The material of the protective layer (5) includes a polyimide film, glass, or glue.

Images