CN212694098U - Wafer level optical lens module - Google Patents

Abstract

The utility model relates to a wafer level optical lens module, including transparent substrate, transparent substrate include relative first surface and second surface, at least one in first surface and the second surface on have and form and be in transparent substrate on the optical part, optical part and/or transparent substrate have the gradual change refractive index. The utility model discloses an use the graded index material preparation wafer level optical lens module, can reduce optical system to the degree of dependence of complicated face type, can realize even using the plane to accomplish the function of present complicated face type.

Description

Wafer level optical lens module

Technical Field

The utility model belongs to optical part field, in particular to wafer level optical lens.

Background

The wafer-level optical lens is manufactured by adopting a wafer-level lens manufacturing process to copy and process lenses on a whole glass wafer in batches by a semiconductor process, and polymer glue is coated on the glass wafer, heated and pressed to form an optical part and form a whole with the glass wafer, and then the optical part and the glass wafer are cut into single lenses. The wafer-level optical lens has the characteristics of small size, low height, good consistency and the like.

However, in the prior art, the optical path is shaped by using a material with a fixed refractive index, as shown in fig. 1, due to the difference of the optical paths of the light rays with different incident angles, the material must be made into a spherical surface, an aspherical surface or even a free-form surface to complete the purpose of shaping the light rays with different incident angles, so that the surface shape of the lens becomes more complicated along with the improvement of the optical performance, and the requirement of the surface shape processing precision also becomes severe along with the improvement of the surface shape complexity.

Disclosure of Invention

In order to solve the above technical problem, the present invention provides a wafer level optical component with a simple surface shape.

In order to realize the purpose of the utility model, the utility model adopts the following technical scheme: a wafer-level optical lens module comprises a transparent substrate, wherein the transparent substrate comprises a first surface and a second surface which are opposite, at least one of the first surface and the second surface is provided with an optical part formed on the transparent substrate, and the optical part and/or the transparent substrate have a graded refractive index.

Optionally, the transparent substrate has a graded refractive index.

In the above technical solution, preferably, the transparent substrate has graded refractive indexes in an X coordinate direction and a Y coordinate direction, and the refractive index in a Z coordinate direction is kept unchanged.

In the above technical solution, preferably, the thickness of the transparent substrate is between 0.1mm and 4 mm.

In the above technical solution, preferably, the first surface and the second surface of the transparent substrate are both planar.

Preferably, the optical portion has a graded refractive index.

In the above technical solution, preferably, the optical portion has a graded refractive index in an X coordinate direction and a Y coordinate direction, and the refractive index in a Z coordinate direction is kept constant.

In the above technical solution, preferably, the rise of the optical portion is 0.05-0.5 mm.

In the above technical solution, preferably, the optical portion is a plane lens, a spherical lens or an aspherical lens.

Optionally, the optical portion and the transparent substrate are bonded by polymer adhesive.

Compared with the prior art, the utility model obtain following beneficial effect: the utility model discloses a graded index's lens preparation wafer level optical lens module can reduce optical system to the degree of dependence of complicated face type, can realize even using the plane to accomplish the function of present complicated face type.

Drawings

FIG. 1 is a schematic diagram of light propagating within a conventional convex lens;

FIG. 2 is a schematic illustration of light propagating within a graded index material;

fig. 3 is a schematic structural diagram of a first embodiment of the present invention;

fig. 4 is a light path diagram in the first embodiment of the present invention;

fig. 5 is a dot-sequence diagram of the lens module according to the first embodiment;

fig. 6 is a schematic diagram illustrating a change of a refractive index of a transparent substrate along with an X coordinate according to a first embodiment of the present invention;

fig. 7 is a schematic diagram illustrating a change of a refractive index of a transparent substrate along with a Y coordinate according to a first embodiment of the present invention;

fig. 8 is a light path diagram of a second embodiment of the present invention;

fig. 9 is a dot arrangement diagram of the lens module according to the second embodiment;

fig. 10 is a schematic diagram illustrating the change of the refractive index of the first optical portion with the X coordinate according to the second embodiment of the present invention;

fig. 11 is a schematic diagram illustrating the change of the refractive index of the first optical portion with the Y coordinate according to the second embodiment of the present invention;

wherein: 1 a transparent substrate; 2. a first optic portion; 3. a first surface; 4. a second surface; 5. a second optical portion; 6. a housing.

Detailed Description

To explain the technical content, structural features, achieved objects and functions of the present invention in detail, the following detailed description is made with reference to the accompanying drawings.

Fig. 3 and 8 show that, in order to implement the wafer level optical lens module of the present invention, the lens module is an integrated wafer level optical lens (WLO) having a smaller size of the imaging system. The lens module comprises a transparent substrate 1, a first optical part 2, an optional second optical part 5, a packaging shell 6 and the like which are sequentially arranged along the optical axis direction. The transparent substrate 1 comprises a first surface 3 and a second surface 4 which are opposite, the first surface 3 is provided with the first optical part 2, the second surface 4 is provided with the second optical part 5, and structures such as a diaphragm and the like can be arranged between the transparent substrate 1 and the first optical part 2 or the second optical part 5.

One or more of the transparent substrate 1, the first optical part 2 and the second optical part 6 are made of gradient refractive index materials and have gradient refractive indexes. The gradient refractive index material can be a cube, a sphere or an anisotropic structure with one plane and the other curved surface.

Optionally, the graded-index features vary in three dimensions, with the index of refraction varying between 1.45 and 1.75 along the X-coordinate direction; the refractive index along the Y coordinate direction varies between 1.45-1.75; the refractive index along the Z coordinate direction is a fixed refractive index and is between 1.45 and 1.75.

Alternatively, the graded index member may be a planar lens, a spherical lens or an aspherical lens, and may be required to meet a sagittal height range of 0.05-0.5 mm. The utility model discloses the key feature lies in adopting the gradual change refractive index material preparation optical lens, can strengthen the plastic effect of lens to light to reduce the face type complexity and the processing degree of difficulty of lens.

In the first embodiment of the present application, a wafer-level optical lens module for identifying fingerprints under a screen needs to be designed, and the main design parameters are as follows: the effective focal length is 0.09mm, the F/# is 6.5, the image plane sensor size is 6 x 6mm, and the pixel size is 3 x 3 um. In the optical lens module, the transparent substrate 1 is glass, and the first optical portion 2 is made of a graded-index material, as shown in fig. 3. Because the module can reach the design parameter requirement at this moment, and this application is comparatively harsh to the module volume requirement, the module overall structure is compacter. The first optical part 2 is adhered to the surface of the transparent substrate 1 through polymer adhesive, the thickness of the transparent substrate is 0.1mm, the transparent substrate is solidified and cut, and finally, a wafer-level optical lens with the diameter of about 8.5mm is formed, and about three hundred lens modules can be cut on each 8-inch wafer.

Fig. 4 is a schematic diagram of the optical path of a single pixel in the lens module. The whole fingerprint identification system is composed of a plurality of pixels, the light path of each pixel is the same, and the propagation path of light in the whole system can be seen in the figure.

Fig. 5 is a dot arrangement diagram obtained by software Zemax simulation, in which the object point is imaged on the image plane sensor after passing through the lens module, and it can be seen from the diagram that the lens module of this embodiment has an excellent focusing effect on the light, and the size of the image formed on the pixel after the fingerprint information passes through the whole optical system shows the good performance parameters of the lens module. In this embodiment, the transparent substrate 1 has a fixed refractive index, the refractive index is 1.456, the refractive index of the first optical unit is 1.45 to 1.51, and the refractive index gradually changes along the X axis and the Y coordinate direction, the horizontal axis in fig. 6 represents the distance of a certain point on the X axis of the first optical unit, and the vertical axis represents the refractive index, and this figure shows the change tendency of the refractive index of the first optical unit along the X axis. The horizontal axis in fig. 7 represents the distance of a certain point on the Y axis of the first optical portion, and the vertical axis represents the refractive index.

The second embodiment of the present application is a mini wide-angle lens, and the main design parameters are as follows: f number is 2, total length is 1mm, sensor diagonal is 1 mm. As shown in fig. 8, in the optical lens module, the transparent substrate 1 is made of glass, the first optical portion 2 is made of a graded index material, and the second optical portion 5 is a polymer lens. The first optical part 2 is adhered on the surface of the transparent substrate by polymer glue, and the second optical part 5 is adhered on the surface of the transparent substrate by polymer glue through hot pressing. The first optical portion 2 is made of a material having a gradually changing refractive index of 1.45 to 1.75, the trend of the change of the refractive index of the first optical portion in the X, Y axis direction is shown in fig. 10 and 11, and the refractive index of the first optical portion is kept constant in the Z axis direction. Fig. 8 is a diagram showing light paths of light rays with different incident angles passing through the optical lens module, and fig. 9 is a dot-column diagram of the second embodiment, which shows the focusing effect of light rays respectively incident at different angles of 0-45 degrees.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration only, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims, specification and equivalents thereof.

Claims (10)

1. A wafer level optical lens module comprises a transparent substrate, wherein the transparent substrate comprises a first surface and a second surface which are opposite, at least one of the first surface and the second surface is provided with an optical part formed on the transparent substrate, and the wafer level optical lens module is characterized in that: the optical part and/or the transparent substrate have graded refractive indexes.

2. The wafer-level optical lens module of claim 1, wherein: the transparent substrate has a graded refractive index.

3. The wafer-level optical lens module as recited in claim 2, wherein the transparent substrate has graded refractive indices in an X-coordinate direction and a Y-coordinate direction, and the refractive index in a Z-coordinate direction remains constant.

4. The wafer-level optical lens module of claim 2, wherein: the thickness of the transparent substrate is between 0.1 and 4 mm.

5. The wafer-level optical lens module of claim 2, wherein: the first surface and the second surface of the transparent substrate are both planes.

6. The wafer-level optical lens module of claim 1, wherein: the optical part has a graded refractive index.

7. The wafer-level optical lens module of claim 6, wherein: the optical part has graded refractive index in the X coordinate direction and the Y coordinate direction, and the refractive index in the Z coordinate direction is kept unchanged.

8. The wafer-level optical lens module of claim 6, wherein: the rise of the optical part is 0.05-0.5 mm.

9. The wafer-level optical lens module of claim 8, wherein: the optical part is a plane lens, a spherical lens or an aspheric lens.

10. The wafer-level optical lens module of claim 1, wherein: the optical part is combined with the transparent substrate through polymer glue.

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