阅读说明：本技术 屏下指纹识别用像素级彩色滤光膜芯片制作方法 (Method for manufacturing pixel-level color filter film chip for identifying finger print under screen ) 是由 任玉 宋晨智 蔡红星 石晶 全王昕瑞 陈晓东 姚治海 张鹏波 于 2020-06-01 设计创作，主要内容包括：本发明公开了屏下指纹识别用像素级彩色滤光膜芯片制作方法,包括以下步骤：负性光刻胶通过紫外光刻技术刻度上彩色滤光膜阵列,将彩色滤光膜阵列与带有像素单元的cmos传感器进行封装,所述彩色滤光膜阵列的单一像素滤光块对应cmos传感器上N个像素单元,多个彩色滤光膜阵列离散的分布在cmos传感器上。相较传统多通道滤光膜制备法,省略了除胶,镀膜两个环节,将以往制备过程中的过度产物光刻胶作用充分发挥,拓展其滤光作用,无需镀无机氧化物类的光阻剂,简化了环节,缩减了成本。(The invention discloses a method for manufacturing a pixel-level color filter film chip for identifying fingerprints under a screen, which comprises the following steps: the negative photoresist is provided with a color filter film array on a scale through an ultraviolet lithography technology, the color filter film array and the cmos sensor with pixel units are packaged, a single pixel filter block of the color filter film array corresponds to N pixel units on the cmos sensor, and a plurality of color filter film arrays are distributed on the cmos sensor in a discrete mode. Compared with the traditional preparation method of the multi-channel filter film, the preparation method omits two links of removing the photoresist and coating the film, fully exerts the photoresist function of the excessive product in the previous preparation process, expands the filtering function, does not need to plate inorganic oxide photoresist, simplifies the link and reduces the cost.)

1. The manufacturing method of the pixel-level color filter film chip for identifying the finger print under the screen is characterized by comprising the following steps of:

s1: preparing a plating-accompanied sheet as a substrate, wherein the transmittance T of the plating-accompanied sheet in a visible light wave band is more than or equal to 90%;

s2: uniformly spin-coating negative photoresist on the plating assistant sheet, wherein the thickness of the negative photoresist is 1-2 microns;

s3: covering a mask plate on the negative photoresist for ultraviolet exposure, wherein the hollow area of the mask plate can transmit light, and irradiating the negative photoresist to obtain an exposure area which can be solidified on a plating partner;

s4: removing the mask plate, cleaning with alkali liquor for development, washing the unexposed area away, and leaving the desired monochromatic pixel filter block;

s5: repeating the steps S2-S4, and adopting negative photoresist with different colors to manufacture a 3 x 3 pixel filter block with 9 periods, and finally obtaining a color filter film array;

s6: the method comprises the following steps of packaging a color filter film array and a cmos sensor with pixel units, wherein a single pixel filter block of the color filter film array corresponds to N pixel units on the cmos sensor, and a plurality of color filter film arrays are distributed on the cmos sensor in a discrete manner.

2. The method for manufacturing a pixel-level color filter chip for underscreen fingerprint identification according to claim 1, wherein the color filter matrix finally forms a visible light film system, a near ultraviolet light film system and a near infrared light film system.

Technical Field

The invention relates to the field of manufacturing of spectrum chips, in particular to a method for manufacturing a pixel-level color filter film chip for identifying fingerprints under a screen.

Background

Compared with the conventional spectrum detection device, the spectrum chip has the advantages of low load, high integration level, low energy consumption and the like, is widely concerned in recent years, and can be integrated in mobile electronic devices such as mobile phones and the like due to the advantage of high integration level. At present, the underscreen fingerprint technology mainly adopts an oled + cmos pinhole imaging technology, full-screen identification cannot be achieved, and the LTPS technology is only suitable for soft screens and has higher cost. The under-screen spectrum detection module manufactured by the a-si process can realize large-area identification capability at any position under the screen, and the maximum identification area can be the same as that of the screen. The pixel-level color filter film is a key component, and the current under-screen spectral detector only has three RGB color filter structures, so that the application requirements of more spectral channels with higher precision cannot be met.

In the existing method for manufacturing a multi-channel filter film in the patent, for example, the patent publication No. CN1027074878B, the patent name is a method for manufacturing a multi-channel integrated optical filter, which needs to perform a photoresist removing step after defining an area by using a photolithography technique, remove the photoresist, and then use a coating technique to prepare a band-pass filter film made of materials such as SiO2, TiO2, and the like. The process is complex, the yield is low, the manufacturing cost is in the order of hundred thousand, and the method is difficult to be used for civil application.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for manufacturing a pixel-level color filter film chip for identifying fingerprints under a screen.

In order to realize the purpose, the following technical scheme is provided:

the manufacturing method of the pixel-level color filter film chip for identifying the finger print under the screen comprises the following steps:

s1: preparing a plating-accompanied sheet as a substrate, wherein the transmittance T of the plating-accompanied sheet in a visible light wave band is more than or equal to 90%;

s2: uniformly spin-coating negative photoresist on the plating assistant sheet, wherein the thickness of the negative photoresist is 1-2 microns;

s3: covering a mask plate on the negative photoresist for ultraviolet exposure, wherein the hollow area of the mask plate can transmit light, and irradiating the negative photoresist to obtain an exposure area which can be solidified on a plating partner;

s4: removing the mask plate, cleaning with alkali liquor for development, washing the unexposed area away, and leaving the desired monochromatic pixel filter block;

s5: repeating the steps S2-S4, and adopting negative photoresist with different colors to manufacture a 3 x 3 pixel filter block with 9 periods, and finally obtaining a color filter film array;

s6: the method comprises the following steps of packaging a color filter film array and a cmos sensor with pixel units, wherein a single pixel filter block of the color filter film array corresponds to N pixel units on the cmos sensor, and a plurality of color filter film arrays are distributed on the cmos sensor in a discrete manner.

Preferably, the color filter film matrix finally forms a visible light film system, a near ultraviolet light film system and a near infrared light film system.

The invention has the beneficial effects that:

1. the corresponding relation between the pixel filtering block and the pixel unit is 1: n, the processing degree of difficulty of filter membrane has been reduced like this, has improved the fault-tolerant rate for it changes the cost step-down to produce the line upgrading.

2. Compared with the traditional preparation method of the multi-channel filter film, the preparation method omits two links of removing the photoresist and coating the film, fully exerts the photoresist function of the excessive product in the previous preparation process, expands the filtering function, does not need to plate inorganic oxide photoresist, simplifies the link and reduces the cost.

3. By utilizing the high-precision filter film of the 9-pixel period module, more spectral information can be realized compared with the existing RGB 3-pixel period module, the identification precision is obviously improved, more spectral information can be obtained, and besides the existing fingerprint identification function, the applications of heat source detection and identification, human skin detection, blood sugar spectrum detection and the like can be realized.

4. The color filter film arrays can completely cover detector pixels according to specific use scenes, and can also be distributed on the cmos sensor in a discrete mode, so that the fingerprint identification can be realized at multiple angles, blanks are left, the cost is saved, the existing algorithm can be compatible, and the conflict with other functions is avoided.

5. Compared with the traditional fingerprint identification technology, the fingerprint identification technology relies on the principle of fingerprint image identification, the detector has the function of spectrum detection after the light filtering film system is added, and the real and false fingerprints can be accurately distinguished through analyzing the obtained spectrum data by utilizing the principle that the scattering spectra of the finger and the false fingerprint model are different, so that the safety of fingerprint identification is improved.

Drawings

FIG. 1 is a schematic diagram of a process for manufacturing a pixel-level color filter chip for underscreen fingerprint identification;

FIG. 2 is a schematic view of a color filter array;

FIG. 3 is a diagram of a filter block and a pixel unit;

FIG. 4 is a diagram illustrating a discrete distribution of color filter arrays.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that in the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In addition, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In this embodiment, a discrete distribution is adopted, and the corresponding relationship between the pixel filter block and the pixel unit is 1: 4.

the method for manufacturing the pixel-level color filter film chip for identifying the finger print under the screen as shown in fig. 1 comprises the following steps:

s1: preparing a plating assistant sheet 10 as a substrate, wherein the transmissivity T of the plating assistant sheet 10 in a visible light wave band is more than or equal to 90%;

s2: uniformly spin-coating negative photoresist 11 on the plating assistant sheet 10;

s3: covering a mask plate 12 on the negative photoresist 11 for ultraviolet exposure, wherein a hollow area of the mask plate 12 can transmit light, and an exposure area obtained by irradiating the negative photoresist 11 can be solidified on the plating assistant sheet 10;

s4: removing the mask plate 12, cleaning with alkali liquor for development, washing the unexposed area away, and leaving the desired monochromatic pixel filter block 13;

s5: repeating the steps S2-S4 to fabricate a 3 × 3 9-cycle pixel filter block by using the negative photoresist 11 of different colors, so as to obtain the color filter array 14 as shown in fig. 2;

s6: the color filter array 14 is packaged with the cmos sensor 16 having the pixel units 15, a single pixel filter block 13 of the color filter array 14 corresponds to 4 pixel units 15 on the cmos sensor as shown in fig. 3, and a plurality of color filter arrays 14 are discretely distributed on the cmos sensor 16 as shown in fig. 4.

The color filter film matrix finally forms a visible light film system, a near ultraviolet light film system and a near infrared light film system.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.