TWM613552U - Micro lens module improvement for light sensor - Google Patents

Abstract

An improvement of the micro lens module of the light sensor, which is provided with a photodiode on the light sensor to convert the light incident from the outside into an electronic signal. The photodiode There is a micro lens module on the upper end surface; it is characterized in that: the micro lens module is composed of a plurality of micro lenses or a plurality of micro lens arrays, so as to achieve whether the light entering the photodiode (photodiode) is Both small-angle light and large-angle light can achieve uniformity of the incident light through the microlens module, thereby improving the precise sensing and judgment of the light sensor.

Description

Improved micro lens module of light sensor

This new model relates to a microlens module of a photo sensor, especially a photodiode (photodiode) of the photo sensor with a microlens model composed of a plurality of microlenses or a plurality of microlens arrays. group.

With the rapid development of electronic technology, Light Sensors, which use photosensitive elements to convert light signals into telecommunication signals, are increasingly used in a wide range of applications, such as smart phones, tablet computers, digital single-lens cameras, wearable sports devices, and Fitness devices, etc. are related products that are widely used.

As shown in Figures 1 and 2, in addition to forming the necessary circuit layout on the surface of the conventional light sensor 100, at least one photodiode 101 must be provided. When the photodiode 101 receives a light signal, the light The signal is transformed into the characteristics of a telecommunications signal to achieve the purpose of monitoring or control. As shown in the figure, in order to improve the accuracy of light received by the photodiode 101, a microlens 102 will be arranged on the upper end of the photodiode 101, so that the light will be focused by the microlens 102 before entering the photodiode. 101 to increase the amount of light received, thereby improving the accuracy of sensing. However, with the development of miniaturization of electronic products, and In response to the flatness requirements of the package, the incident light angle exceeding 60 degrees is already a trend in the future. For the existing process, the traditional method of reducing the structure and thickness of the coating layer can only solve some of the problems. For example, in Figure 3, the coating thickness is 5um and the incident light angles are 0 degrees, 5 degrees, 10 degrees, and 15 degrees. Spectral diagrams of degrees, 20 degrees, 25 degrees, 30 degrees, and 35 degrees; Figure 4 shows that the coating thickness is reduced to 0.6um, and the incident light angles from top to bottom are 0 degrees, 10 degrees, 20 degrees, 30 degrees, Spectral diagrams of 40 degrees, 50 degrees, and 60 degrees. Figure 5 shows the use of special pigment coatings. Blue, green and red light are used respectively. The incident light angles are 0 degrees, 10 degrees, 20 degrees, 30 degrees, Spectral diagrams of 40 degrees, 50 degrees and 60 degrees. These spectrum diagrams show that when light is incident at a large angle, the phenomenon of spectrum shift is often caused, and it is necessary to improve it.

In view of the aforementioned shortcomings of the prior art, the creators are engaged in various related manufacturing experience and technology accumulation, and carefully research various solutions to the above-mentioned shortcomings. After continuous research, experimentation and improvement, they finally developed and designed a new type of this new type. The improvement of the micro-lens module of the new light sensor is expected to eliminate the defects caused by the previous technology.

Therefore, the present invention aims to provide an improved micro-lens module of a photo sensor. The photodiode (photodiode) of the photo sensor is provided with a micro lens composed of a plurality of microlenses or a plurality of microlens arrays. Lens module.

According to the improvement of the micro lens module of the light sensor of this new type, by Many microlenses or many microlens arrays are formed on the upper end surface of the photodiode, which can guide the light source when the light is incident from the side, so as to achieve the requirement of receiving the correct spectrum when the light is incident at a large angle. Furthermore, the optical signal received by the photodiode is more accurate, which is the second purpose of this new type.

According to the improvement of the micro lens module of the photo sensor of the present invention, by arranging a micro lens module containing a large number of micro lenses or a large number of micro lens arrays on the upper end of the photodiode, it can be applied to the flying of 3D sensing. Time of Flight (ToF), Image sensor or Ambient light sensor are another purpose of the new model.

According to the improvement of the microlens module of the photo sensor of the present invention, the number of microlens arrays (Microlens array) arranged on the upper end of the photodiode can be 1 to 500, and the number of microlenses in each microlens array can be 1 to 100,000, which is another purpose of the new model.

According to the improvement of the micro-lens module of the photo sensor of the present invention, the micro-lens array arranged on the upper end of the photodiode is manufactured by a wafer level process and adopts positive photoresist (Positive PR) Or the negative photoresist (Negative PR) is patterned by the yellow light process, and then formed by thermal reflow or patterned dry etching (photo-etching), which is another purpose of the new model.

According to the improvement of the microlens module of the photo sensor of the present invention, most of the microlenses arranged on the upper end surface of the photodiode, the size of each microlens can be 0.3μm to 500μm, and the gap between the microlenses (gap ) Can be from no spacing (zero gap) to 300μm, the curvature radius of the microlens (microlens) can be from 0.1μm to 1000μm, which is another purpose of this new type.

In order to facilitate your reviewer to have a further understanding and understanding of the purpose, shape, features and effects of the structure and device of the present invention, a detailed description is given as follows:

100: light sensor

101: photodiode

102: Micro lens

200: light sensor

300: photodiode

400: Micro lens module

41, 42, 43: micro lens

510: silicon wafer

520: photoresist layer

530: Line pattern

540: Optical film

Figure 1 is a schematic plan view of a conventional light sensor.

Figure 2 is a schematic cross-sectional view of a conventional light sensor with a microlens.

Figure 3 is a schematic diagram of the first spectrum of a conventional light sensor.

Figure 4 is a schematic diagram of the second spectrum of the conventional light sensor.

Figure 5 is a schematic diagram of the third spectrum of the conventional light sensor.

Figure 6 is a schematic plan view of the improved microlens module of the new light sensor.

Figure 7 is a schematic diagram of the manufacturing process of the new light sensor.

Figure 8 is a schematic diagram of the spectrum of a single microlens used in the implementation of the new light sensor and the conventional one.

The improved micro-lens module of the photo sensor of the present invention, as shown in Figure 6, is provided with a photo sensor 200. In addition to the necessary circuit layout, the surface of the photo sensor 200 is provided with at least one photodiode (photodiode) 300, the upper end surface of the photodiode (photodiode) 300 is provided with a microlens module 400, the microlens module 400 is composed of a plurality of microlenses 41, 42, 43... or a plurality of microlens arrays By. With the arrangement of most microlenses 41, 42, 43... or most microlens arrays, the light source can be guided when the light is incident from the side, so as to achieve the requirement of receiving the correct spectrum even when the light is incident at a large angle. Moreover, whether the light comes from a small-angle light or a large-angle light, it can pass through the plurality of microlenses 41, 42, 43... or most of the microlens arrays to achieve uniformity, thereby improving the photodiode 300's sense of quality. Test efficiency.

The micro-lens module of the light sensor of the new type is improved. Since the light from the outside can pass through most of the micro-lens 41, 42, 43... or most of the micro-lens array, it can be used for high-level sensing. And the image sensor that mainly senses images, or the ambient light sensor that mainly senses changes in ambient light, or even the time-of-flight measurement that senses 3D changes Distance (Time of Flight, ToF).

The micro-lens module of the photo sensor of the present invention is improved. Most of the micro-lens or micro-lens array formed on the upper end surface of the photodiode 300 can be manufactured through a wafer level process. Positive PR or Negative PR is patterned by the yellow light process, and then formed by thermal reflow or photo-etching after patterning.

The formed on the upper end of the photodiode 300 For most of the microlenses 41, 42, 43... or microlens arrays, the microlens array (Microlens array) can be 1 to 500, and the number of microlenses in each microlens array can be 1 to 100,000. The size of each microlens can be 0.3μm to 500μm, the gap between each microlens can be from zero gap to 300μm, and the curvature radius of the microlens can be from 0.1 μm to 1000μm.

Please refer to Figure 7, the improved micro-lens module of the photo sensor of the present invention, its manufacturing process includes: (a) Wafer cleaning process: cleaning silicon wafer 510 with photodiode 300 inside Surface; (b) Photoresist coating process: Use a photoresist coater (Spin coater) to suck the silicon wafer with a vacuum suction seat, drop the photoresist liquid from above and make the silicon wafer rotate at a high speed to make the light The resist liquid is thrown away by centrifugal force to form a photoresist layer 520 on the surface of the silicon wafer 510; (c) Exposure and development process: Use an optical exposure system to irradiate the mask with ultraviolet light and then project it onto the resist layer 520, and be irradiated by ultraviolet light The photoresist chemical bond in the passing area is destroyed, making the photoresist easy to be dissolved by chemicals. The lens group in the optical exposure system shrinks and projects the pattern on the photomask onto the silicon wafer 510, so that the light on the silicon wafer is reduced. The resist layer forms a circuit pattern 530; (d) Optical coating process: After an evaporation process, an optical film 540 is coated on the exposed photoresist layer and the photodiode 300; (e) Photoresist removal process: Use photoresist removal The liquid dissolves and removes the remaining photoresist on the silicon wafer, so that only the optical film 540 covering the photodiode 300 remains on the silicon wafer 510. (f) Microlens array formation process: forming a plurality of microlenses 41, 42, 43 or a plurality of microlenses on the optical film 540 and its peripheral surface The micro lens module 400 of the lens array.

Please refer to Figure 8, the micro lens module of the photo sensor of the present invention is improved by forming a large number of micro lenses 41, 42, 43... or Most of the microlens module 400 of the microlens array is implemented with BP940nm BW20nm AOI at 0 degrees, 10 degrees, and 20 degrees, respectively, and the comparative example using most microlens added (Microlens added), it can be clearly seen that when the incident light The angles are 0 degrees, 10 degrees, and 20 degrees, especially when the incident light is at a large angle (as shown by the dashed line relative to AOI-20 in the figure), the spectrum will shift significantly to the left. In contrast, the present invention uses a large number of microlenses 41, 42, 43... or a large number of microlens arrays of the microlens module 400 (as shown in the figure on the line of the Microlens added), which is significantly improved. When it is applied to Time of Flight (ToF), the sensing performance of Time of Flight (ToF) can be improved.

In summary, the improved micro-lens module of the light sensor of the present invention has an unprecedented innovative structure. It has not been seen in any publications, and there is no similar product on the market. Therefore, it has Novelty should undoubtedly be considered. In addition, the unique features and functions of this new model are far from comparable to those of conventional ones, so it is indeed more progressive than conventional ones, and it meets the requirements of the patent law of my country regarding the requirements for applying for a new type of patent. A patent application is filed in accordance with the law.

The above are only the preferred specific embodiments of the present invention, but the structural features of the present invention are not limited to this. In the new field, changes or modifications that can be easily thought of can be covered by the following patent scope in this case.

200: light sensor

300: photodiode

400: Micro lens module

41, 42, 43: micro lens

Claims (4)

An improvement of the micro lens module of the light sensor, which is provided with a photodiode on the light sensor to convert the light incident from the outside into an electronic signal. The photodiode And is provided with a microlens module; the feature is that the microlens module is composed of a plurality of microlenses or a plurality of microlens arrays, so as to reach the photodiode (photodiode) regardless of whether the light is Small-angle light or large-angle light can be homogenized through the microlens module to provide accurate interpretation of the light sensor, thereby improving the accuracy of control. The improvement of the micro-lens module of the photo sensor as described in item 1 of the scope of patent application, wherein the micro-lens array can be 1 to 500, and the number of micro-lens in each micro-lens array can be 1 to 100,000. . The improvement of the microlens module of the light sensor as described in the second item of the scope of patent application, wherein the size of the microlens can be 0.3μm to 500μm, and the gap between the microlenses can be changed from no gap ( Zero gap) to 300 μm, the curvature radius of the microlens (Microlens) can be from 0.1 μm to 1000 μm. The improvement of the microlens module of the photo sensor as described in item 2 of the scope of patent application, wherein a microlens array containing a large number of microlenses is arranged on the upper end surface of the photodiode, which can be applied to 3D sensing Time of flight (ToF), image sensor (Image sensor) or ambient light sensor (Ambient light sensor).

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