WO2022193585A1

WO2022193585A1 - Light sensing array module and light transceiver device

Info

Publication number: WO2022193585A1
Application number: PCT/CN2021/118655
Authority: WO
Inventors: 范辰玮
Original assignee: 神盾股份有限公司
Priority date: 2021-03-18
Filing date: 2021-09-16
Publication date: 2022-09-22
Also published as: CN215988762U; TWM621242U; TW202239012A; TWI798834B; CN113809109A

Abstract

Provided are a light sensing array module and a light transceiver device, the light sensing array module comprising a light sensing array substrate, a lens array and a light shielding layer. The light sensing array substrate comprises a plurality of pixels arranged in an array. The lens array is configured above the light sensing array substrate, and comprises a plurality of microlenses respectively configured above the pixels. The light shielding layer is disposed between the light sensing array substrate and the lens array, and comprises a plurality of light-passing openings. The light-passing openings are respectively configured between the microlenses and the pixels, and light that is incident into the lens array at an incident angle of at least 14 degrees or less will be transmitted to the pixels through the light-passing openings without being shielded by the light shielding layer.

Description

Optical sensing array module and optical transceiver

technical field

The present invention relates to an optical module and a device, and in particular, to a light sensing array module and an optical transceiver.

Background technique

With the advancement of optoelectronic technology, time-of-flight ranging device or LiDAR was developed, which can measure the time of flight of light to calculate the distance of objects.

A time-of-flight ranging device, or lidar, includes a laser transmitter and a light-sensing array. Laser emitters emit laser light to illuminate objects in the outside world. External objects reflect the laser light back to the light sensing array.

In the conventional time-of-flight ranging device or lidar, the position and size of the opening of the casing determine the field of view angle of the light detected by the light sensing array. However, when the assembly position of the light sensing array in the casing is deviated, it is easy to cause part of the field of view to be blocked by the casing, resulting in increased edge noise.

If an angular filter is used to filter out large-angle light outside the signal, although the signal-to-noise ratio is improved, quantum efficiency is sacrificed.

SUMMARY OF THE INVENTION

The present invention is directed to a light sensing array module, which has both high quantum efficiency and low stray light interference.

The present invention is directed to an optical transceiver, which has both high quantum efficiency and low stray light interference.

An embodiment of the present invention provides a light sensing array module including a light sensing array substrate, a lens array and a light shielding layer. The light sensing array substrate includes a plurality of pixels arranged in an array. The lens array is disposed above the light sensing array substrate, and includes a plurality of microlenses disposed above the pixels respectively. The light shielding layer is disposed between the light sensing array substrate and the lens array, and includes a plurality of light passing openings. The light-passing openings are respectively disposed between the microlenses and the pixels, wherein light with an incident angle of the lens array within at least 14 degrees will be transmitted to the pixels through the light-passing openings without being blocked by the light shielding layer.

An embodiment of the present invention provides an optical transceiver, including a light-emitting element and the above-mentioned optical sensing array module. The light-emitting element is used to emit light beams. The light sensing array module is used for sensing the light generated by the object after reflecting the light beam.

In the light-sensing array module and the light-transmitting device according to the embodiments of the present invention, since a light-shielding layer is used to shield the stray light, and the light whose incident angle of the incident lens array is at least within 14 degrees is transmitted through these light-transmitting openings Therefore, the light-sensing array module and the light-transmitting device of the embodiments of the present invention have both high quantum efficiency and low stray light interference.

Description of drawings

FIG. 1 is a schematic cross-sectional view of an optical transceiver according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of the light sensing array module in FIG. 1 .

FIG. 3 is a schematic top view of the light shielding layer and the light spot in FIG. 2 .

4 is a schematic top view of a light shielding layer and a light spot according to another embodiment of the present invention.

FIG. 5A is a schematic top view of a light spot formed by the light shielding layer in FIG. 3 and light incident obliquely in the x direction.

FIG. 5B is a schematic top view of a light spot formed by the light shielding layer in FIG. 3 and light incident obliquely in a diagonal direction.

Detailed ways

Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals are used in the drawings and description to refer to the same or like parts.

1 is a schematic cross-sectional view of an optical transceiver according to an embodiment of the present invention, FIG. 2 is a cross-sectional schematic view of the light sensing array module in FIG. 1 , and FIG. 3 is a schematic top view of the light shielding layer and the light spot in FIG. Referring to FIG. 1 to FIG. 3 , the optical transceiver 100 of this embodiment includes a light emitting element 110 and a light sensing array module 200 . The light emitting element 110 is used for emitting a light beam 112 . The light sensing array module 200 is used for sensing the light 52 generated by the object 50 after reflecting the light beam 112 . In this embodiment, the light-emitting element 110 is a laser transmitter, such as a vertical cavity surface-emitting laser (VCSEL), and the light beam 112 is a laser beam. However, in other embodiments, the light emitting element 110 may also be other laser emitters or other kinds of light emitting elements. The light sensing array module 200 includes a light sensing array substrate 210 , a lens array 220 and a light shielding layer 230 . The light sensing array substrate 210 includes a plurality of pixels 211 arranged in an array (eg, a two-dimensional array). In this embodiment, the light sensing array substrate 210 is a single photon avalanche diode (SPAD) array substrate, and each pixel 211 may include a single photon avalanche diode 212 . That is, in this embodiment, the optical transceiver 100 may be a time-of-flight ranging device, a light radar, or a proximity sensor.

The lens array 220 is disposed above the light sensing array substrate 210 and includes a plurality of microlenses 222 disposed above the pixels 211 respectively. That is to say, the microlenses 222 are also arranged in an array, for example, a two-dimensional array. The light shielding layer 230 is disposed between the light sensing array substrate 210 and the lens array 220 and includes a plurality of light passing openings 232 . The light-transmitting openings 232 are respectively disposed between the microlenses 222 and the pixels 211 . That is to say, the light-transmitting openings 232 are arranged in an array, for example, a two-dimensional array. The light whose incident angle θ of the incident lens array 220 is at least within 14 degrees will be transmitted to the pixels 211 through the light-transmitting openings 232 without being blocked by the light shielding layer 230 . The incident angle θ is defined as the angle between the traveling direction of the light 52 and the normal line N of the lens array 220 , and the normal line N is, for example, parallel to the optical axis of the microlens 222 .

In the light-sensing array module 200 and the light-transmitting device 100 of the present embodiment, the light-shielding layer 230 is used to shield the stray light, and the light 52 whose incident angle θ of the incident lens array 220 is at least within 14 degrees will pass through the light-shielding layer 230 . The light-transmitting openings 232 are transmitted to the pixels 211 without being blocked by the light-shielding layer 230 . Therefore, the light-sensing array module 200 and the light-transmitting device 100 of this embodiment have both high quantum efficiency and low stray light interference.

In this embodiment, the light shielding layer 230 is a metal layer, which is, for example, a metal layer formed of the same material as the metal circuit layer used to electrically connect the pixels 211 in the semiconductor process of fabricating the photo-sensing array substrate 210 .

In this embodiment, the shape of each light-passing opening 232 matches the shape of the light spot 53 formed at the light-passing opening 232 after the light 52 passes through the corresponding microlens 222 . For example, in this embodiment, the microlens 222 is, for example, a convex lens, the cross-section of which is shown in FIG. 2 , however, the top view of the microlens 222 is, for example, a square, so the light spot 53 is in an X shape, and the light-passing opening is 232 also assumes a shape that matches the X-shape. In this way, the light shielding layer 230 can allow the effective light 52 to pass through without blocking it, and on the other hand, can also block other stray light, so that the light sensing array module 200 of the present embodiment and the optical transceiver 100 can be combined With high quantum efficiency and low stray light interference.

In this embodiment, the light spot 53 has at least one recess 55 , and the inner wall 234 of the light-passing opening 232 has at least one protrusion 235 protruding toward the at least one recess 55 . When the light spot 53 is X-shaped and has four depressions 55 , the inner wall 234 of the light-transmitting opening 232 has four protrusions 235 protruding toward the four depressions 55 .

In other embodiments, when the light spot exhibits other shapes or does not have a recess, the light-transmitting opening may also exhibit a shape that matches it. For example, referring to FIG. 4 , in another embodiment, when the light spot 53a is elliptical, the shape of the light-transmitting opening 232a can be matched with it to be elliptical. In other embodiments, the light spot can also be circular, and the shape of the light-passing opening can be matched with it to be circular. Alternatively, the light spot can have other shapes, and the shape of the light-pass opening can be matched with it.

In this embodiment, the optical transceiver 100 further includes a controller 120 that is electrically connected to the light emitting element 110 and the light sensing array substrate 210 and used to calculate the object 50 according to the flight time or phase of the light beam 112 and the light 52 . The distance, that is, the optical transceiver device 100 is a time-of-flight ranging device or a light radar.

In one embodiment, the controller 120 is, for example, a central processing unit (CPU), a microprocessor (microprocessor), a digital signal processor (DSP), a programmable controller, a programmable controller, or a programmable controller. A logic device (programmable logic device, PLD) or other similar devices or a combination of these devices is not limited by the present invention. Furthermore, in one embodiment, each function of the controller 120 may be implemented as a plurality of program codes. These program codes will be stored in a memory and executed by the controller 120 . Alternatively, in one embodiment, the functions of controller 120 may be implemented as one or more circuits. The present invention does not limit the implementation of the functions of the controller 120 by means of software or hardware.

5A is a schematic top view of a light spot formed by the light shielding layer in FIG. 3 and light incident obliquely in the x direction, and FIG. 5B is a schematic diagram of the light shielding layer in FIG. 3 and light incident obliquely in the diagonal direction. Schematic top view of the formed light spot. Referring to FIGS. 1 , 2 , 5A and 5B, when the light 52 is incident on a position off-center of the light sensing array module 200 , the light 52 may be incident obliquely, so that the light 52 formed at the light-transmitting opening 232 is obliquely incident. The light spot 53b (as shown in FIG. 5A ) or the light spot 53c (as shown in FIG. 5B ) may be distorted, for example, skewed to one side or a corner. The light spot 53b in FIG. 5A is formed by the light 52 with an incident angle θ of 14 degrees in the x direction, while the light spot 53c in FIG. direction, where the x-direction is perpendicular to the y-direction) formed by light 52 with an incident angle θ of 14 degrees.

In this embodiment, the light 52 with the incident angle θ exceeding 14 degrees will be blocked by the light shielding layer 230 , especially in the diagonal direction as shown in FIG. 5B . However, in other embodiments, the light 52 with the incident angle θ of the incident lens array 220 within at least 20 degrees will be transmitted to the pixels 211 through the light-transmitting openings 232 without being blocked by the light shielding layer 230 . In one embodiment, the light 52 with the incident angle θ of the incident lens array 220 within 20 degrees will be transmitted to the pixels 211 through the light-transmitting openings 232 without being blocked by the light shielding layer 230 , and the incident angle θ exceeds 20 degrees. The light 52 is blocked by the light shielding layer 230 . Alternatively, in another embodiment, the light 52 with the incident angle θ of the incident lens array 220 within at least 40 degrees will be transmitted to the pixels 211 through the light passage openings 232 without being blocked by the light shielding layer 230 . In one embodiment, the light 52 with the incident angle θ of the incident lens array 220 within 40 degrees will be transmitted to the pixels 211 through the light passage openings 232 without being blocked by the light shielding layer 230 , and the incident angle θ exceeds 40 degrees. The light 52 is blocked by the light shielding layer 230 .

Referring to FIG. 2 , the light sensing array module 200 of this embodiment may include another light shielding layer 240 , and the light shielding layer 240 may have light-passing openings 242 respectively disposed between the microlenses 222 and the pixels 211 . The design of the light-passing opening 242 can be the same as that of the light-passing opening 232 , that is, the shape of the light-passing opening 242 can match the shape of the light spot formed by the light 52 passing through the light-passing opening 242 . Since the light shielding layer 240 is disposed between the light shielding layer 230 and the light sensing array substrate 210 , the size of the light passing opening 242 can be smaller than that of the light passing opening 232 .

Like the light-shielding layer 230 , the light-shielding layer 240 may also be a metal layer, which is, for example, a metal layer formed of the same material as the metal circuit layer used to electrically connect the pixels 211 in the semiconductor process of fabricating the light sensing array substrate 210 . . Since the metal circuit layer may have multiple layers, several layers of the metal circuit layer (eg, N layers, N is greater than or equal to 1) can be selected as the light shielding layer with the above characteristics (ie, the same design concept as the light shielding layer 230 ). In other embodiments, the light-shielding layer with the above-mentioned properties may also have only one layer (ie, the light-shielding layer 230 ). Alternatively, the light sensing array module 200 may only have the light shielding layer 230 without the light shielding layer 240 .

To sum up, in the light sensing array module and the light transceiver device according to the embodiments of the present invention, the light shielding layer is used to shield the stray light, and the light with the incident angle of the incident lens array within at least 14 degrees can pass through. The light-passing openings are transmitted to the pixels without being blocked by the light-shielding layer, so the light-sensing array module and the light-transmitting device of the embodiments of the present invention have both high quantum efficiency and low stray light interference.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims

A light sensing array module, characterized in that it includes:

a light sensing array substrate, including a plurality of pixels arranged in an array;

a lens array, disposed above the light sensing array substrate, and comprising a plurality of microlenses disposed above the plurality of pixels respectively; and

The light shielding layer is disposed between the light sensing array substrate and the lens array, and includes a plurality of light-passing openings, and the plurality of light-passing openings are respectively disposed on the plurality of microlenses and the plurality of pixels In between, the light incident on the lens array with an incident angle within at least 14 degrees will be transmitted to the plurality of pixels through the plurality of light-passing openings, and will not be blocked by the light shielding layer.
The light-sensing array module according to claim 1, wherein the shape of each light-passing opening matches the shape of a light spot formed at the light-passing opening after light passes through the corresponding microlens.
The light sensing array module according to claim 2, wherein the light spot has at least one recess, and the inner wall of the light-passing opening has at least one protrusion protruding toward the at least one recess. .
The light-sensing array module according to claim 3, wherein the light spot is X-shaped and has four recesses, and the inner wall of the light-passing opening has protrusions toward the four recesses. Four protrusions.
The light sensing array module according to claim 1, wherein light with an incident angle of at least 20 degrees incident on the lens array is transmitted to the plurality of pixels through the plurality of light-passing openings, and will not be blocked by the light shielding layer.
The light sensing array module according to claim 5, wherein light with an incident angle of at least 40 degrees incident on the lens array is transmitted to the plurality of pixels through the plurality of light-transmitting openings, and will not be blocked by the light shielding layer.
The light sensing array module according to claim 1, wherein the light shielding layer is a metal layer.
The light sensing array module according to claim 1, wherein the light sensing array substrate is a single photon avalanche diode array substrate.
An optical transceiver, characterized in that it includes:

a light-emitting element for emitting a light beam; and

A light-sensing array module for sensing light generated by an object after reflecting the light beam, the light-sensing array module comprising:

a light sensing array substrate, including a plurality of pixels arranged in an array;

a lens array, disposed above the light sensing array substrate, and comprising a plurality of microlenses disposed above the plurality of pixels respectively; and

The light shielding layer is disposed between the light sensing array substrate and the lens array, and includes a plurality of light-passing openings, and the plurality of light-passing openings are respectively disposed on the plurality of microlenses and the plurality of pixels In between, the light incident on the lens array with an incident angle within at least 14 degrees will be transmitted to the plurality of pixels through the plurality of light-passing openings, and will not be blocked by the light shielding layer.
The optical transceiver device according to claim 9, wherein the shape of each light-passing opening matches the shape of the light spot formed at the light-passing opening after the light passes through the corresponding microlens.
The optical transceiver according to claim 10, wherein the light spot has at least one recess, and the inner wall of the light-passing opening has at least one protrusion protruding toward the at least one recess.
The optical transceiver according to claim 11, wherein the light spot is X-shaped and has four recesses, and the inner wall of the light-passing opening has four protruding points toward the four recesses. bulge.
The optical transceiver according to claim 9, wherein the light with an incident angle of at least 20 degrees incident on the lens array will be transmitted to the plurality of pixels through the plurality of light-transmitting openings, and will not be transmitted to the plurality of pixels. blocked by the light shielding layer.
14. The optical transceiver according to claim 13, wherein light with an incident angle of at least 40 degrees incident on the lens array will be transmitted to the plurality of pixels through the plurality of light-passing openings, and will not be transmitted to the plurality of pixels. blocked by the light shielding layer.
The optical transceiver according to claim 9, wherein the light shielding layer is a metal layer.
The optical transceiver according to claim 9, wherein the light-emitting element is a laser transmitter, and the light-sensing array substrate is a single-photon avalanche diode array substrate.
The optical transceiver device according to claim 9, wherein the optical transceiver device is a time-of-flight ranging device or a light radar, and the optical transceiver device further comprises a controller electrically connected to the light-emitting element and the light-emitting element. The light sensing array substrate is used to calculate the distance of the object according to the flight time or phase of the light beam and the reflected light.