CN211828785U

CN211828785U - Optical sensing device

Info

Publication number: CN211828785U
Application number: CN202020570539.1U
Authority: CN
Inventors: 钟炜竣; 林苏逸
Original assignee: Hangzhou Silergy Semiconductor Technology Ltd
Current assignee: Hangzhou Silergy Semiconductor Technology Ltd
Priority date: 2020-04-16
Filing date: 2020-04-16
Publication date: 2020-10-30
Anticipated expiration: 2030-04-16

Abstract

The utility model provides an optical sensing device, include: at least one semiconductor having a photosensitive region, an optical structure; and a wavelength band pass layer, wherein light outside the optical sensing device reaches the photosensitive region through the optical structure stacked on the photosensitive region and the wavelength band pass layer, the wavelength band pass layer passing only light within a specific wavelength range, the optical structure including an angle limiting layer to block incident light of a large angle range from passing, improving collimation of the incident light.

Description

Optical sensing device

Technical Field

The utility model relates to the field of semiconductor technology, more specifically relates to an optical sensing device.

Background

The principle of the Photo sensor is that external light is incident on a Photo Diode (Photo Diode), and after being received by the Photo Diode, the Photo Diode converts light energy into an electrical signal, and the intensity of the external light is determined according to the intensity of the electrical signal. The specific wavelength light sensor only receives light with a specific wavelength to enter the photodiode to determine the intensity of the light with the specific wavelength, and a commonly used method is to form a band pass (band pass) film with the specific wavelength on the photodiode by coating.

The Band-pass spectrum range of the Band pass film is defined as a forward light measurement result, but in practical application, light with different angles exists, the equivalent path length of the light with different angles in the Band pass film is different from the path length of the forward light, and the wave Band capable of penetrating the spectrum is subjected to displacement change, so that light with non-designed wavelength is incident. The conventional design solution is to form an opening in the package casing to limit the angle of incident light, so as to avoid the wavelength shift of light with different angles. However, the process capability of opening the package is limited, and the hole cannot be too small. When the holes cannot be too small, and the incident light is only collimated and concentrated, the height of the opening is required to be set high to limit the angle of the incident light, so that the thickness and the cost of the light sensor are increased.

SUMMERY OF THE UTILITY MODEL

In view of the above, an object of the present invention is to provide an optical sensing device, which blocks the incidence of large-angle light to a photosensitive region and reduces the incidence of light with off-design wavelength.

According to an aspect of the present invention, there is provided an optical sensing device, including: at least one semiconductor having a photosensitive region, an optical structure; and a wavelength band pass layer, wherein 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, the wavelength band pass layer passing only light within a specific wavelength range, the optical structure including an angle limiting layer to block a large angle range of incident light from passing therethrough.

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

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

Preferably, the filter layer comprises a light-transmitting area and a light-impermeable area.

Preferably, the opaque region blocks the passage of large-angle incident light by reflecting the incident light.

Preferably, the opaque region blocks the passage of large-angle incident light by absorbing the incident light.

Preferably, the size of the light-transmitting areas is the same.

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

Preferably, the maximum angle of incidence of the incident light through the optical structure is no greater than 60 °.

Preferably, in the laminating direction, the light-transmitting areas of each filter layer are aligned.

Preferably, in the lamination direction, the light-transmitting areas of at least one of the filter layers are arranged in a staggered manner.

Preferably, the light-transmitting regions are displaced by a distance in a range sufficient to allow incident light of the maximum incident angle to pass through.

Preferably, the light-transmitting region is provided in a circular shape or a polygonal shape.

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

Preferably, the opaque region is provided as a metal.

Preferably, the opaque region is provided as a black photoresist.

Preferably, the light-transmitting layer and the light-transmitting region are provided as a dielectric 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, a package is further included that encapsulates the semiconductor, the optical structure, and the wavelength bandpass layer.

Preferably, the encapsulant is provided as an encapsulant comprising scattering particles.

Preferably, the encapsulant is provided as a transparent encapsulant.

Preferably, the package further comprises a diffusion membrane located on the package body.

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

The utility model provides an optical sensing device includes an optical structure, optical structure restricts the incident light of wide angle through the filter layer and the euphotic layer of range upon range of setting and passes through, increases the collimation nature of incident light, and the displacement changes when preventing the light incidence of the specific wavelength of wide angle, reduces the light incidence of non-design wavelength, has improved the sensing accuracy of device. Further, the utility model discloses set up the light tight region of filter layer into the metal the same with the peripheral metal circuit of semiconductor that has the sensitization region, need not to increase extra design cost.

Drawings

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

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

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

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

Detailed Description

The invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by like reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale. In addition, certain well known components may not be shown. For simplicity, the semiconductor structure obtained after several steps can be described in one figure.

It will be understood that when a layer or region is referred to as being "on" or "over" another layer or region in describing the structure of the device, it can be directly on the other layer or region or intervening layers or regions may also be present. And, if the device is turned over, that layer, region, or regions would be "under" or "beneath" another layer, region, or regions.

If for the purpose of describing the situation directly above another layer, another region, the expression "a directly above B" or "a above and adjacent to B" will be used herein. In the present application, "a is directly in B" means that a is in B and a and B are directly adjacent, rather than a being in a doped region formed in B.

In the present application, the term "wire punching" refers to a phenomenon in which, after a die is fixed on a lead frame and wire bonding is performed, leads adjacent to each other contact each other due to impact of an encapsulant during injection of the encapsulant, resulting in short circuit.

Numerous specific details of the invention, such as structure, materials, dimensions, processing techniques and techniques of the devices are described below in order to provide a more thorough understanding of the invention. However, as will be understood by those skilled in the art, the present invention may be practiced without these specific details.

The utility model provides an optical sensing device, include: at least one semiconductor having a photosensitive region, an optical structure; and a wavelength band pass layer, wherein the optical structure and the wavelength band pass layer are located above the photosensitive region, light outside the optical sensing device passes through the optical structure and the wavelength band pass layer to reach the photosensitive region, the wavelength band pass layer only allows light in a specific wavelength range to pass through, the optical structure includes an angle limiting layer to block incident light in a large angle range from passing through, and collimation of the incident light is improved.

An optical sensing device according to an embodiment of the present invention is shown in fig. 1, and the optical sensing device includes a semiconductor 501 having a photosensitive region, an optical structure 502 located above the photosensitive region, and a wavelength band pass layer 503 located above the optical structure 502. Wherein the wavelength band pass layer 503 passes only light within a specific wavelength range, and the optical structure 502 passes only incident light within a predetermined angle range. In particular, the optical structure 502 includes an angle limiting layer to block large-angle incident light from passing through. In this embodiment, the optical structure 502 includes a filter layer and a light-transmitting layer that are alternately stacked. In other embodiments, the optical structure may also include only a laminated filter layer. When external incident light reaches the photosensitive region through the optical structure 502 and the wavelength band pass layer 503, the semiconductor having the photosensitive region converts an incident light signal of the specific wavelength into an electrical signal to detect the intensity of the incident light of the specific wavelength. In this embodiment, the wavelength band pass layer allows light passing through in the visible light range of 480nm to 780nm, but not limited thereto, the wavelength band pass layer may be set to allow light passing through in other wavelength ranges. The optical structure blocks the passing of the large-angle incident light, so that the large-angle light is prevented from being shifted and changed after entering the wavelength band pass layer 503, and the light with the non-designed wavelength reaches the photosensitive region, thereby improving the collimation of the incident light.

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

The optical sensing device further includes an encapsulant 504 encapsulating the semiconductor 501 with the photosensitive region, the optical structure 502, and the wavelength bandpass layer 503. Specifically, in the present embodiment, the encapsulating body 504 contains scattering particles for scattering incident light into components of various angles, so that the light incident on the photosensitive region contains components of various angles, thereby increasing the range of the viewing angle (FOV). In other embodiments, the enclosure 504 may be a transparent glue, and a diffusion film is adhered to the upper surface of the enclosure 504.

In this embodiment, the filter layer 503 is located above the optical structure 502, but in other embodiments, the optical structure 502 may also be located above the filter layer 503, which achieves the same technical effect, and is not limited herein.

Fig. 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 comprises a filter layer 11 and a light-transmitting layer 12 which are alternately laminated, wherein the filter layer 11 comprises a light-transmitting area 112 and a light-tight area 111, when light enters the optical structure, the incident light with a small angle can directly pass through the light-transmitting area 112 and the light-transmitting layer 12, and the light with a large angle is reflected by the light-tight area and then reflected out through the light-transmitting area. Wherein the light transmissive layer 12 and the light transmissive region 112 of the filter layer are provided as dielectric layers, such as silicon oxide or other oxide layers. The opaque areas 111 of the filter layer are provided as a metal, for example an aluminium alloy, a copper alloy or another alloy metal. The metal and the metal wiring around the photosensitive element which receives light are selected from the same material, and can be formed in synchronization with the metal wiring around the photosensitive element. In other embodiments, the opaque region 111 of the filter layer may also be configured as a black photoresist, which is used to absorb incident light with large angles. In this embodiment, the thickness of each filter layer is the same and is 0.4 to 0.6 micrometers, and the thickness of each light transmission layer is the same and is 0.6 to 0.7 micrometers, but the design is not limited thereto. In the present embodiment, the light-transmitting areas 112 have the same size, and the positions of the corresponding light-transmitting areas of each filter layer are aligned in the stacking direction, as shown in fig. 2 a. Of course, because of process errors or design errors, there may be deviation or misalignment between the positions of the light-transmitting areas corresponding to each filter layer, as shown in fig. 2 b. Of course, those skilled in the art will also appreciate that in actual processes, the size of the transparent region may have some small deviations due to process errors.

Fig. 3 is a top view of a filter layer according to the present invention. The filter layer comprises a plurality of light transmissive areas 112 and non-light transmissive areas 111, wherein the filter layer 11 comprises at least two of the light transmissive areas. The light-transmitting regions 112 are arranged in a circle having the same diameter. The light transmitting areas of the filter layer are arranged into regular patterns according to a preset sequence. Of course, the arrangement of the light-transmitting regions of the filter layer of the present invention is not limited to the arrangement of the embodiment, and those skilled in the art can change the arrangement according to the actual application requirement.

In the present embodiment, the lamination thickness of the optical structure and the size of the light-transmitting area determine the maximum incident angle at which incident light can pass, and as shown in fig. 2a and 2b, the lamination thickness of the optical structure is H, the size of the light-transmitting area is D (in the present embodiment, the size D of the light-transmitting area is the diameter of a circle), and the maximum incident angle θ at which incident light can pass is arctan (D/H). Therefore, the range of misalignment of each filter layer in fig. 2b cannot be too large enough to allow the incident light of the maximum incident angle to pass through. As can also be seen from the above formula, the larger the number of layers stacked, i.e., the larger the thickness of the optical structure, the smaller the maximum incident angle of the incident light, and the larger the size of the light-transmitting region, the larger the maximum incident angle of the incident light. In the present embodiment, the maximum incident angle θ is not greater than 60 ° by setting the lamination thickness of the optical structure and the size of the light-transmitting area, and of course, the maximum incident angle may be increased or decreased according to actual needs by those skilled in the art.

In this embodiment, the shape of the light-transmitting area of each filter layer is set to be a circle, and in other embodiments, the shape of the light-transmitting area may also be set to be other shapes such as a polygon, a square, a triangle, and the like, which should not be limited herein.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

In accordance with the present invention, as described above, these embodiments do not set forth all of the details nor limit the invention to the specific embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and its various embodiments with various modifications as are suited to the particular use contemplated. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An optical sensing device, comprising:

at least one semiconductor having a photosensitive region,

an optical structure; and

a wavelength band pass layer,

wherein 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, the wavelength band pass layer passing only light within a specific wavelength range, the optical structure including an angle limiting layer to block a large angle range of incident light from passing.

2. The optical sensing device of claim 1, wherein the optical structure comprises at least one light transmissive layer.

3. The optical sensing device of claim 1, the optical structure comprising alternating layers of optical filters and optical transmission.

4. The optical sensing device of claim 3, wherein the filter layer comprises light transmissive areas and light opaque areas.

5. The optical sensing device of claim 4, wherein the opaque region blocks the passage of large-angle incident light by reflecting the incident light.

6. The optical sensing device of claim 4, wherein the opaque region blocks the passage of large-angle incident light by absorbing the incident light.

7. The optical sensing device of claim 4, wherein the light transmissive regions are the same size.

8. The optical sensing device of claim 4, wherein a thickness of the optical structure and a size of the light transmissive region determine a maximum incident angle of the incident light through the optical structure.

9. The optical sensing device of claim 8, wherein a maximum angle of incidence of the incident light through the optical structure is no greater than 60 °.

10. The optical sensing device of claim 3, wherein the light transmissive areas of each of the filter layers are aligned in the stacking direction.

11. The optical sensing device of claim 8, wherein the light transmissive regions of at least one of the filter layers are offset in the stacking direction.

12. The optical sensing device of claim 11, wherein the light transmissive regions are misaligned a distance in a range sufficient to allow incident light of the maximum incident angle to pass through.

13. The optical sensing device of claim 4, wherein the light transmissive region is provided in a circular or polygonal shape.

14. The optical sensing device of claim 4, wherein the light-transmissive regions are arranged in a regular pattern in a predetermined order.

15. The optical sensing device of claim 4, wherein the opaque region is provided as a metal.

16. The optical sensing device of claim 4, wherein the opaque region is provided as a black photoresist.

17. The optical sensing device according to claim 4, wherein the light transmissive layer and the light transmissive region are provided 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 band pass layer.

20. The optical sensing device of claim 1, further comprising a package that encapsulates the semiconductor, the optical structure, and the wavelength bandpass layer.

21. The optical sensing device of claim 20, wherein the encapsulant is provided as an encapsulant comprising scattering particles.

22. The optical sensing device of claim 20, wherein the encapsulant is provided as a transparent encapsulant.

23. The optical sensing device of claim 22, further comprising a diffusion membrane on the package.

24. The optical sensing device of claim 1, the semiconductor with photosensitive regions configured as a photodiode.