CN111446311A - Optical sensing device - Google Patents

Abstract

The present invention provides an optical sensing device, comprising: at least one semiconductor with a photosensitive region, an optical structure; and a wavelength band pass layer, wherein light from outside the optical sensing device is stacked to the photosensitive region by stacking The optical structure and the wavelength band pass layer on the photosensitive region reach the photosensitive region, the wavelength band pass layer only allows light within a specific wavelength range to pass through, and the optical structure includes an angle limiting layer to block a large angle range The incident light passes through, improving the collimation of the incident light.

Description

Optical sensing device

technical field

The present invention relates to the technical field of semiconductors, and more particularly, to an optical sensing device.

Background technique

The principle of the light sensor is that the external light is incident on the photodiode (Photo Diode), and after it is received, the light energy is converted into an electrical signal, and the intensity of the external light is determined by the intensity of the electrical signal. The specific wavelength light sensor only receives light of a specific wavelength into the photodiode to determine the intensity of the light of a specific wavelength. The general method is to coat the photodiode to form a band pass film of a specific wavelength to achieve Purpose.

The band pass spectrum range of the Band pass film is defined as the measurement result of the forward light, but there are different angles of light in practical applications, the equivalent path length of the light of different angles traveling through the Band pass film and the path of the forward light With different lengths, the wavelength band that penetrates the spectrum will shift, thus causing incident light at non-design wavelengths. A general design solution is to open a hole in the package to limit the angle of the incident light, so as to avoid the phenomenon that the wavelength of light with different angles is shifted. However, the process capability of opening holes in the package shell is limited, and the holes cannot be opened too small. When the hole cannot be too small and the incident light is only collimated and concentrated, the height of the mouth must be set high to limit the angle of the incident light, which increases the thickness and cost of the light sensor.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide an optical sensing device, which can block the incidence of light with a large angle to the photosensitive region and reduce the incidence of light with non-design wavelengths.

According to an aspect of the present invention, an optical sensing device is provided, comprising: at least one semiconductor having a photosensitive region, an optical structure; and a wavelength band pass layer, wherein the light outside the optical sensing device is stacked to The optical structure and the wavelength band pass layer above the photosensitive region reach the photosensitive region, the wavelength band pass layer only allows light within a specific wavelength range to pass, and the optical structure includes an angle limiting layer to Blocks a wide angular range of incident light from passing through.

Preferably, the optical structure includes at least one light-transmitting layer.

Preferably, the optical structure includes alternately stacked filter layers and light-transmitting layers.

Preferably, the filter layer includes a light-transmitting area and an opaque area.

Preferably, the opaque area reflects the incident light so as to block the passage of incident light with a large angle.

Preferably, the opaque area blocks the passage of incident light with a large angle by absorbing the incident light.

Preferably, the light-transmitting regions have the same size.

Preferably, the thickness of the optical structure and the size of the light-transmitting area determine the maximum incident angle of the incident light passing through the optical structure.

Preferably, the maximum incident angle of the incident light passing through the optical structure is not greater than 60°.

Preferably, in the stacking direction, the light-transmitting regions of each filter layer are aligned.

Preferably, in the stacking direction, the light-transmitting regions of at least one layer of the filter layer are arranged in a staggered manner.

Preferably, the distance range in which the light-transmitting regions are displaced is sufficient to allow the incident light at the maximum incident angle to pass through.

Preferably, the light-transmitting area is configured as a circle or a polygon.

Preferably, the light-transmitting regions are arranged in a regular pattern in a preset order.

Preferably, the opaque area is provided as metal.

Preferably, the opaque area is configured as a black photoresist.

Preferably, the light-transmitting layer and the light-transmitting region are configured as a medium layer.

Preferably, the wavelength band pass layer is located above the optical structure.

Preferably, the optical structure is located above the wavelength band pass layer.

Preferably, an encapsulation body encapsulating the semiconductor, the optical structure and the wavelength bandpass layer is also included.

Preferably, the encapsulation body is provided as an encapsulation colloid comprising scattering particles.

Preferably, the encapsulation body is configured as a transparent encapsulation colloid.

Preferably, a diffusion membrane on the package body is also included.

Preferably, the semiconductor with the photosensitive region is configured as a photodiode.

The present invention proposes that the optical sensing device includes an optical structure, and the optical structure restricts the passage of incident light with a large angle by stacking a filter layer and a light-transmitting layer, increases the collimation of the incident light, and prevents the specific wavelength of the large angle. The displacement changes when the light is incident, which reduces the incidence of light of non-design wavelengths and improves the sensing accuracy of the device. Further, in the present invention, the opaque area of the filter layer is set to the same metal as the metal circuit around the semiconductor having the photosensitive area, without adding additional design cost.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

1 shows a cross-sectional view of an optical sensing device according to an embodiment of the present invention;

Figures 2a and 2b show cross-sectional views of an optical structure according to a first embodiment of the invention;

Figure 3 shows a top view of an optical structure according to a first embodiment of the present invention.

Detailed ways

The present invention will be described in more detail below with reference to the accompanying drawings. In the various figures, like elements are designated by like reference numerals. For the sake of clarity, various parts in the figures have not been drawn to scale. Additionally, some well-known parts may not be shown. For the sake of simplicity, the semiconductor structure obtained after several steps can be depicted in one figure.

It will be understood that, in describing the structure of a device, when a layer or region is referred to as being "on" or "over" another layer or region, it can be directly on the other layer or region, or Other layers or regions are also included between it and another layer, another region. And, if the device is turned over, the layer, one region, will be "under" or "under" another layer, another region.

In order to describe the situation directly above another layer, another area, the expression "A is directly above B" or "A is above and adjacent to B" will be used herein. In this application, "A is located directly in B" means that A is located in B, and A is directly adjacent to B, rather than A located in a doped region formed in B.

In this application, the term "punch wire" refers to the phenomenon that after the chip is fixed on the lead frame and the wire bonding is performed, during the process of injecting the encapsulation compound, the leads adjacent to each other contact each other due to the impact of the encapsulation compound, resulting in a short circuit. .

Numerous specific details of the present invention are described below, such as device structures, materials, dimensions, processing techniques and techniques, in order to provide a clearer understanding of the present invention. However, as can be understood by one skilled in the art, the present invention may be practiced without these specific details.

The present invention provides an optical sensing device, comprising: at least one semiconductor with a photosensitive region, an optical structure; and a wavelength bandpass layer, wherein the optical structure and the wavelength bandpass layer are located in the photosensitive region Above, the light outside the optical sensing device reaches the photosensitive region through the optical structure and the wavelength band pass layer, the wavelength band pass layer only allows light in a specific wavelength range to pass, and the optical structure An angle limiting layer is included to block the passage of incident light in a wide angle range and improve the collimation of incident light.

FIG. 1 shows an optical sensing device provided by an embodiment of the present invention. The optical sensing device includes a semiconductor 501 having a photosensitive region, an optical structure 502 located above the photosensitive region, and an optical structure 502 located above the optical structure 502 . The wavelength band pass layer 503 . Wherein, the wavelength band pass layer 503 only allows light within a specific wavelength range to pass, and the optical structure 502 only allows incident light within a predetermined angle range to pass. Specifically, the optical structure 502 includes an angle limiting layer to block incident light with a large angle from passing through. In this embodiment, the optical structure 502 includes alternately stacked filter layers and light-transmitting layers. In other embodiments, the optical structure may also include only laminated filter layers. When external incident light passes through the optical structure 502 and the wavelength band pass layer 503 and reaches the photosensitive region, the semiconductor with the photosensitive region converts the incident light signal of the specific wavelength into an electrical signal to detect the incident light of the specific wavelength. The strength of light. In this embodiment, the wavelength band pass layer allows light to pass through the visible light range of 480 nm to 780 nm, but is not limited thereto, and the wavelength band pass layer may also be configured to allow light in other wavelength ranges to pass through. The optical structure blocks large-angle incident light from passing through, which prevents the large-angle light from entering the wavelength bandpass layer 503 and changes in displacement, causing light with non-design wavelengths to reach the photosensitive area and improving the collimation of incident light. .

In this embodiment, the semiconductor with the photosensitive region is configured as a photodiode, and in other embodiments, it can also be configured as other photoelectric structures. In another embodiment, the optical sensing device may also only include a semiconductor 501 having a photosensitive area, and an optical structure 502 located above the photosensitive area.

The optical sensing device further includes an encapsulation body 504 encapsulating the semiconductor 501 having a photosensitive region, the optical structure 502 , and the wavelength bandpass layer 503 . Specifically, in this embodiment, the encapsulation body 504 contains scattering particles to scatter the incident light into components of various angles, so that the incident light reaching the photosensitive region contains components of various angles, increasing the viewing angle (FOV )scope. In other embodiments, the encapsulation body 504 can also be configured as a transparent colloid, and a diffusion film is pasted on the upper surface of the encapsulation body 504 .

In this embodiment, the filter layer 503 is located above the optical structure 502, and in other embodiments, the optical structure 502 can also be located above the filter layer 503, and the same technology can be achieved The effect is not limited here.

2a and 2b are cross-sectional views of the optical structure according to the first embodiment of the present invention, and FIG. 3 is a top view of the optical structure according to the first embodiment of the present invention. The optical structure includes alternately stacked optical filter layers 11 and light-transmitting layers 12. The optical filter layer 11 includes a light-transmitting area 112 and a non-transmitting area 111. When light is incident on the optical structure, a small-angle incident The light can directly pass through the light-transmitting area 112 and the light-transmitting layer 12, and light with a large angle is reflected by the non-light-transmitting area, and then reflected out through the light-transmitting area. Wherein, the light-transmitting layer 12 and the light-transmitting region 112 of the filter layer are set as dielectric layers, such as silicon oxide or other oxide layers. The opaque area 111 of the filter layer is set to be metal, such as aluminum alloy, copper alloy or other alloy metals. The metal and the metal circuit around the light-receiving element are selected from the same material, and can also be formed synchronously with the metal circuit around the photosensitive element. In other embodiments, the opaque area 111 of the filter layer can also be configured as a black photoresist, which is used to absorb incident light with a large angle. In this embodiment, the thickness of each layer of the filter layer is the same, and the thickness is 0.4-0.6 μm, and the thickness of each layer of the light-transmitting layer is the same, and the thickness is 0.6-0.7 μm, but the design is not limited to this. . In this embodiment, the light-transmitting regions 112 have the same size, and in the stacking direction, the positions of the corresponding light-transmitting regions of each of the filter layers are aligned, as shown in FIG. 2 a . Of course, due to process errors or design errors, there may also be deviations or dislocations in the positions of the light-transmitting regions corresponding to each of the filter layers, as shown in FIG. 2b. Of course, those skilled in the art also know that in the actual process, the size of the light-transmitting region also has some small deviations due to process errors.

FIG. 3 is a top view of an optical filter layer of the present invention. The filter layer includes a plurality of transparent regions 112 and opaque regions 111 , wherein the filter layer 11 includes at least two of the transparent regions. The light-transmitting regions 112 are arranged in a circular shape, and the diameters of the circles are the same. The light-transmitting regions of the filter layer are arranged in a regular pattern in a preset order. Of course, the arrangement of the light-transmitting regions of the filter layer of the present invention is not limited to the arrangement of this embodiment, and those skilled in the art can change the arrangement according to actual application requirements.

In this embodiment, the stack thickness of the optical structure and the size of the light-transmitting area determine the maximum incident angle through which the incident light can pass. As shown in Figures 2a and 2b, the stack thickness of the optical structure is H, so The size of the light-transmitting area is D (in this embodiment, the size D of the light-transmitting area is the diameter of a circle), then the maximum incident angle θ=arctan(D/H) of the incident light that can pass through. Therefore, the range of the dislocation of each filter layer in FIG. 2b cannot be too large, and is sufficient to allow the incident light with the maximum incident angle to pass. According to the above formula, it can also be obtained that the greater the number of layers stacked, that is, the greater the thickness of the optical structure, the smaller the maximum incident angle of the incident light, the larger the size of the light-transmitting area, and the greater the size of the incident light. The larger the maximum angle of incidence. In this embodiment, the stacking thickness of the optical structure and the size of the light-transmitting area are set so that the maximum incident angle θ is not greater than 60°. Of course, those skilled in the art can also make corresponding adjustments according to actual needs. Increase or decrease the maximum angle of incidence.

In this embodiment, the shape of the light-transmitting area of each filter layer is set to be a circle. In other embodiments, the shape of the light-transmitting area can also be set to a polygon, a square, a triangle, etc. shape, we do not make any restrictions here.

The present invention proposes that the optical sensing device includes an optical structure, and the optical structure restricts the passage of incident light with a large angle by stacking a filter layer and a light-transmitting layer, increases the collimation of the incident light, and prevents the specific wavelength of the large angle. The displacement changes when the light is incident, which reduces the incidence of light of non-design wavelengths and improves the sensing accuracy of the device. Further, in the present invention, the opaque area of the filter layer is set to the same metal as the metal circuit around the semiconductor having the photosensitive area, without adding additional design cost.

It should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

In accordance with the embodiments of the present invention as described above, these embodiments do not describe all the details and do not limit the invention to only the specific embodiments described. Obviously, many modifications and variations are possible in light of the above description. This specification selects and specifically describes these embodiments in order to better explain the principle and practical application of the present invention, so that those skilled in the art can make good use of the present invention and modifications based on the present invention. The present invention is to be limited only by the claims and their full scope and equivalents.

Claims (24)

1. An optical sensing device, comprising: at least one semiconductor having a photosensitive region, an optical structure; and wavelength bandpass layer, Wherein, the light outside the optical sensing device reaches the photosensitive region through the optical structure and the wavelength band pass layer stacked above the photosensitive region, and the wavelength band pass layer only makes the light in a specific wavelength range The optical structure includes an angle-limiting layer to block the passage of incident light in a wide angular range. 2. The optical sensing device of claim 1, wherein the optical structure comprises at least one light-transmitting layer. 3 . The optical sensing device according to claim 1 , wherein the optical structure comprises filter layers and light-transmitting layers alternately stacked. 4 . 4. The optical sensing device of claim 3, wherein the filter layer comprises a light-transmitting area and a light-opaque area. 5 . The optical sensing device of claim 3 , wherein the opaque area blocks the passage of incident light with a large angle by reflecting the incident light. 6 . 6 . The optical sensing device of claim 3 , wherein the light-tight region blocks the passage of incident light at large angles by absorbing the incident light. 7 . 7. The optical sensing device of claim 3, wherein the light-transmitting regions have the same size. 8 . The optical sensing device of claim 3 , wherein the thickness of the optical structure and the size of the light-transmitting area determine the maximum incident angle of the incident light through the optical structure. 9 . 9 . The optical sensing device of claim 8 , wherein a maximum incident angle of the incident light passing through the optical structure is not greater than 60°. 10 . 10 . The optical sensing device according to claim 3 , wherein, in the stacking direction, the light-transmitting regions of each of the filter layers are arranged in alignment. 11 . 11 . The optical sensing device according to claim 3 , wherein, in the stacking direction, the light-transmitting regions of at least one of the filter layers are dislocated. 12 . 12 . The optical sensing device of claim 11 , wherein the light-transmitting regions are displaced by a distance range sufficient to allow the incident light of the maximum incident angle to pass through. 13 . 13 . The optical sensing device of claim 3 , wherein the light-transmitting area is configured as a circle or a polygon. 14 . 14. The optical sensing device of claim 3, wherein the light-transmitting regions are arranged in a regular pattern in a preset order. 15. The optical sensing device of claim 3, wherein the opaque area is provided as metal. 16. The optical sensing device of claim 3, wherein the opaque area is configured as a black photoresist. 17. The optical sensing device of claim 3, wherein the light-transmitting layer and the light-transmitting region are configured as a dielectric layer. 18. The optical sensing device of claim 1, wherein the wavelength bandpass layer is located above the optical structure. 19. The optical sensing device of claim 1, wherein the optical structure is located above the wavelength bandpass layer. 20. The optical sensing device of claim 1, further comprising an encapsulation body encapsulating the semiconductor, the optical structure and the wavelength bandpass layer. 21. The optical sensing device of claim 20, wherein the encapsulant is configured as an encapsulant comprising scattering particles. 22. The optical sensing device of claim 20, wherein the encapsulation body is provided as a transparent encapsulant. 23. The optical sensing device of claim 22, further comprising a diffuser film on the package body. 24. The optical sensing device of claim 1, the semiconductor having a photosensitive region configured as a photodiode.

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