TWI545335B - Optical apparatus and light sensitive device with micro-lens - Google Patents

Description

Optical device and photosensitive element using microlens

The present invention relates to an optical device, and more particularly to an optical device having the advantages of small size, low cost, and ease of assembly.

1A is a schematic diagram of a conventional optical device sensing a gesture movement, and FIG. 1B is a schematic cross-sectional view of the optical device 100 of FIG. 1A. As shown in FIG. 1A and FIG. 1B , the optical device 100 includes a package housing 110 , a light emitting component 120 , a photosensitive element 130 , and a collecting lens 140 . The package housing 110 has a light exit opening 112 and a light receiving opening 114. The light beam L0 generated by the light emitting element 120 in the package housing 110 is emitted by the light exit opening 112, and the photosensitive element 130 located in the package housing 110 is disposed. It is adapted to receive the light beam L1 reflected by a moving object 101 through the light collection port 114 to form an image. In addition, the condensing lens 140 is disposed at the light collecting port 114 for collecting the light beam L1 reflected by the moving object 101 and condensing and imaging the light to the photosensitive element 130.

The conventional optical device 100 mainly performs image imaging using a single condensing lens 140, so that the thickness of the optical device 100 as a whole cannot be further reduced. In general, although the use of a Fresnel lens can achieve the purpose of reducing the overall thickness, the overall cost of the optical device 100 cannot be effectively reduced.

The present invention provides an optical device which has the advantages of small size, low cost, and easy assembly.

The present invention further provides a photosensitive member using a microlens and a method of fabricating the same, which are applicable to the aforementioned optical device and have the same advantages.

Other objects and advantages of the present invention can be derived from the technical features disclosed by the present invention. Learn more about it.

To achieve one or a portion or all of the above or other objects, the present invention provides an optical device comprising a substrate, a light-emitting element, a photosensitive element, and a plurality of microlenses. The light emitting element is disposed on the substrate and is adapted to provide a light beam. The photosensitive element comprises a plurality of photosensitive cells arranged in an array and disposed on the substrate to receive a reflected beam formed by an object reflecting the light beam. The microlenses are disposed above the photosensitive element and respectively correspond to the photosensitive unit.

The invention further provides a method for fabricating a photosensitive element using a microlens, comprising the steps of: providing a photosensitive element, wherein the photosensitive element comprises a plurality of photosensitive units arranged in an array; forming a protective layer on the photosensitive element; Forming at least two patterned metal layers thereon to form a plurality of optical channels, wherein the optical channels respectively correspond to the photosensitive cells; forming a plurality of microlenses corresponding to the optical channels.

The invention further provides a photosensitive element using a microlens, comprising a plurality of photosensitive cells, a light blocking stack layer and a plurality of microlenses. The photosensitive cells are arranged in an array. The light blocking stack layer is formed on the photosensitive cells and includes a plurality of light channels respectively corresponding to the photosensitive cells, wherein a portion of the light channels are inclined at an oblique angle toward a direction away from a center of the array. The microlenses are disposed on the light blocking stack layer and respectively correspond to the optical channels.

In an embodiment of the present invention, the optical device further includes a light blocking stack layer disposed on the photosensitive element; wherein the light blocking stack layer comprises a plurality of optical channels corresponding to the photosensitive cells facing away from a center of the photosensitive element The direction is inclined by an oblique angle for limiting an incident angle of one of the reflected beams incident on the photosensitive cells.

In various embodiments of the invention, the light blocking stack layer is located between the microlenses and the photosensitive element.

As described above, the optical device of the present invention can be configured to have a corresponding microlens disposed on the photosensitive member to effectively reduce the use of the conventional single lens, thereby making it easier for the optical device to be assembled and reducing the optical device. The overall size, in addition, can also effectively reduce the manufacturing cost of the optical device. In addition, the optical device of the present invention is configured to limit the incident angle of the reflected light beam incident on each photosensitive unit by stacking a light blocking stacked layer around the adjacent photosensitive cells, thereby achieving the function of determining the movement of the object and reducing The effect of stray light or light leakage; wherein each photosensitive unit may comprise one or a plurality of light diodes.

The above described features and advantages of the present invention will be more apparent from the following description.

100, 200‧‧‧ optical devices

110, 260‧‧‧ package housing

120, 220‧‧‧Lighting elements

130, 230‧‧‧Photosensitive elements

140‧‧‧ Concentrating lens

112, 262‧‧‧ light exit

114, 264‧‧ ‧ light receiving port

101, 270‧‧ objects

L0‧‧‧beam

L1‧‧‧ reflected beam

210‧‧‧Substrate

232‧‧‧Photosensitive unit

240‧‧‧Microlens

250‧‧‧Light blocking stack

252‧‧‧Lighting material layer

254‧‧‧ opaque stack

S1‧‧‧First accommodation space

S2‧‧‧Second accommodating space

310‧‧‧Protective layer

320‧‧‧First patterned metal layer

330‧‧‧Second patterned metal layer

θ, θ1, θ2‧‧‧ incident angle

D1, D2‧‧‧ offset distance

C‧‧‧Light channel

S ₄₁ ~S ₄₄ ‧‧‧Steps

FIG. 1A is a schematic diagram of a conventional optical device sensing a gesture movement.

1B is a schematic cross-sectional view of the optical device of FIG. 1A.

2A is a schematic cross-sectional view of an optical device according to an embodiment of the present invention.

2B is a partial enlarged view of the optical device of FIG. 2A.

2C is another partial enlarged view of the optical device of FIG. 2A.

3A to 3D are schematic views showing a method of fabricating a photosensitive element using a microlens according to an embodiment of the present invention.

4A to 4E are another schematic views showing a method of fabricating a photosensitive element using a microlens according to an embodiment of the present invention.

FIG. 5 is a flow chart showing a method of fabricating a photosensitive element using a microlens according to an embodiment of the present invention.

FIG. 6 is another schematic cross-sectional view of an optical device according to an embodiment of the present invention.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only directions referring to the additional drawings. Therefore, the directional terminology used is for the purpose of illustration and not limitation.

2A is a schematic cross-sectional view of an optical device according to an embodiment of the present invention, and FIGS. 2B and 2C are partial enlarged views of the optical device of FIG. 2A. 2A, 2B, and 2C, the optical device 200 of the present embodiment includes a substrate 210, a light-emitting element 220, a light-receiving element 230, and a plurality of micro-lenses 240. The optical device 200 is used to detect an object 270. The light emitting element 220 and the light sensing element 230 can be disposed on the substrate 210 and electrically connected to the substrate 210, as shown in FIG. 2A is shown. In another embodiment, the light-emitting element 220 and the light-receiving element 230 are respectively disposed on different substrates. FIG. 2A is only for illustrating an embodiment, and is not intended to limit the present invention.

In this embodiment, the substrate 210 may be in the form of a rigid circuit board, a flexible circuit board or a lead frame. This part may have different designs according to different requirements. Therefore, FIG. 2A is not intended to limit the present invention. . In addition, the light-emitting element 220 is adapted to provide a light beam L0; wherein the light-emitting element 220 can be a light-emitting diode element, and the light beam L0 provided by the light-emitting element 220 can have a light wavelength of invisible light, such as infrared light or ultraviolet light. Here, infrared light is taken as an example, but is not limited thereto. In other embodiments, light-emitting element 220 can be other suitable active light sources. In this embodiment, the photosensitive element 230 may be a CCD image sensor or a CMOS image sensor, wherein a CMOS image sensor is used as an embodiment. The photosensitive element 230 is adapted to receive a reflected light beam L1 formed by the object 270 reflecting the light beam L0.

Specifically, the photosensitive element 230 has a plurality of photosensitive units 232 arranged in an array; wherein each photosensitive unit 232 can include at least one photodiode (PD) for converting light energy into an electrical signal, and the photosensitive unit 232 A light blocking stack layer 250 is stacked on the periphery. The light blocking layer 250 is disposed on the photosensitive element 230. The light blocking layer 250 includes a plurality of light channels C corresponding to the photosensitive unit 232 (FIG. 2C), which are inclined at a direction away from a center of the photosensitive element 230. The angle θ is used to limit an incident angle of the reflected light beam L1 incident to the photosensitive unit 232 (ie, the incident angle is equal to the tilt angle). Thereby, the photosensitive element 230 can achieve the function of judging the movement of the object and reduce the influence of stray light or light leakage, as shown in FIGS. 2B and 2C. In detail, the light blocking layer 250 may include a light transmissive material layer 252 and an opaque stack layer 254, wherein the light transmissive material layer 252 covers the photocell 232 as a light path of the reflected light beam L1 incident on the photosensitive unit 232. C, and the opaque stack layer 254 located in the light blocking stack layer 250 is used to limit the incident angle θ of the reflected light beam L1 incident on the photosensitive unit 232, and the light blocking stacked layer 250 can be fabricated using a conventional semiconductor. The etching process is carried out and will not be described here. The opaque stack layer 254 may be a metal material or a non-metal material (the metal is exemplified in the present invention). In addition, in order to prevent the reflected light beam L1 from being reflected by the opaque stack layer 254 when incident on the photosensitive unit 232, the opaque stack layer 254 is preferably formed of a light absorbing material. In addition, in order to enable the photosensitive unit 232 to receive the reflected light beam L1 of a specific angle to increase the sensing effect, the tilt angle θ of the optical channel is preferably light and light. The distance from the center of the photosensitive member 230 is positively correlated such that the incident angle of the reflected light beam L1 received by the photosensitive unit 232 is positively correlated with the distance from the light passage to the center of the photosensitive member 230; that is, closer to the edge of the photosensitive member 230 The light passage has a large camber inclination angle θ such that the corresponding photosensitive unit 232 receives the reflected light beam L1 having a larger incident angle.

In addition, the microlenses 240 are disposed on the photosensitive element 230 and respectively correspond to the photosensitive unit 232, as shown in FIG. 2A; that is, if the light guiding effect of the microlens 240 is good, the light blocking stacked layer 250 may not be implemented. When the optical device 200 of the present embodiment includes the light blocking stacked layer 250, the microlenses 240 respectively correspond to the optical channel C and are disposed on the light blocking stack layer 250 such that the light blocking stacked layer 250 is located at the microlens 240 and the photosensitive element 230. between. Specifically, each of the photosensitive cells 232 of the embodiment may be respectively matched with at least one micro-lens of different angles, so that different photosensitive cells 232 have different light-collecting angles, as shown in FIG. 2B. Therefore, the conventional single large lens is not required, and the photosensitive element 230 can effectively sense the movement of the object, and the overall thickness or size of the optical device 200 can be effectively reduced, and the manufacturing cost can be reduced. Assembly is easier (due to reduced assembly of a single lens). In other words, the optical device 200 can be configured with corresponding microlenses 240 on the photosensitive element 230 to effectively reduce the use of the conventional single lens, thereby making assembly easier, reducing overall size, and effectively reducing manufacturing costs.

In the embodiment of FIG. 2B, each photosensitive unit 232 is shown as corresponding to a single microlens 240 and a single optical channel. In another embodiment, as shown in FIG. 2C, when the size of the photosensitive unit 232 is large, each photosensitive unit 232 can correspond to a plurality of the same or different microlenses 240 and a plurality of optical channels C, for example, FIG. 2C shows each The photosensitive unit 232 corresponds to the two microlenses 240 and the two optical channels C to solve the difficulty of making a larger microlens 240 on the larger photosensitive unit 232 and increase the intensity of the signal. In detail, the manufacturing size of the microlens 240 itself is generally small, so that if the volume of the photosensitive unit 232 itself is large, a plurality of microlenses 240 can be formed on the single photosensitive unit 232 so that the light can be efficiently collected. . In other words, the number of the microlenses 240 and the optical path C formed above the photosensitive unit 232 can be determined according to the size of the photosensitive unit 232, and can be determined by the process precision of the microlens 240 itself being easily formed above the photosensitive unit 232. It is used for illustration and is not limited to this. For example, in an embodiment, when each photosensitive unit 232 corresponds to the plurality of optical channels C and the plurality of microlenses 240, corresponding to the same photosensitive sheet The light path C of the element 232 has the same tilt angle θ and the condensing angle of the microlens 240 is the same, so as to limit the incident angle of the reflected light beam L1 to be the same, as shown in Fig. 2C.

In addition, the optical device 200 can further include a package housing 260. The package housing 260 is disposed on the substrate 210 and has a light exit opening 262 and a light entrance opening 264. In this embodiment, when the package housing 260 is disposed on the substrate 210, a first accommodating space S1 and a second accommodating space S2 are formed. The first accommodating space S1 can accommodate the foregoing illuminating component. 220, and the second accommodating space S2 can accommodate the aforementioned photosensitive element 230, as shown in FIG. 2A. The light beam L0 provided by the light-emitting element 220 located in the first accommodating space S1 can be transmitted through the light-emitting port 262, and the photosensitive element 230 located in the second accommodating space S2 can be received by the light-incident port 264 by an object 270. Reflected reflected light beam L1. It should be noted that the package housing 260 and the substrate 210 may be integrally formed or formed separately. The parts may be different according to different processes. The drawings provided in this embodiment are for illustrative purposes only, and are not limited thereto. .

3A to 3D are schematic views showing a method of fabricating the photosensitive element using the microlens of Fig. 2B. Referring to FIG. 3A, firstly, a photosensitive element 230 is provided. The photosensitive element 230 can be a CMOS image sensor and includes a plurality of photosensitive cells 232 arranged in an array, for example, a rectangular array arranged in a rectangle or a square. . Thereafter, a protective layer 310 is formed on the photosensitive element 230; wherein the protective layer 310 may be a dielectric material as shown in FIG. 3B. Then, at least two patterned metal layers are formed on the protective layer 310 to form a plurality of light channels, and the light channels respectively correspond to the photosensitive cells 232. As described above, a part of the optical channels C (for example, optical channels not located at the central position of the photosensitive element 230) are inclined at an oblique angle toward the center away from the photosensitive element 230, and the oblique angles and the optical paths are photosensitive. The distance between one of the centers of the elements 230 is positively correlated; in addition, the optical path C located at the central position of the photosensitive element 230 (for example, the array center of one of the arrays formed by the photosensitive unit 232) may have no inclination angle for receiving the normal from the photosensitive element 230. The reflected light beam L1 in the direction is as shown in Figs. 2B and 2C.

The patterned metal layer is formed by, for example, forming a first patterned metal layer 320, as shown in FIG. 3B; wherein the first patterned metal layer 320 can be formed by using a conventional semiconductor lithography technique. Then, a second patterned metal layer 330 is formed on the first patterned metal layer 320, as shown in FIG. 3C; wherein the second patterned metal layer 330 can be formed by using a conventional semiconductor lithography technique. . Then, repeating the stacking in sequence A step of patterning the metal layer 320 and the second patterned metal layer 330 may form an embodiment as shown in FIG. 3D. Finally, the aforementioned microlenses 240 are formed above the photosensitive elements 230 and respectively correspond to the optical channels, thus completing the step of fabricating the microlenses 240 on the photosensitive elements 230 of FIG. 2B. It is worth mentioning that the stacked first patterned metal layer 320 and the second patterned metal layer 330 are the aforementioned opaque stacked layer 254 and the light transmissive material layer 252 is used as the optical channel C.

In addition, please refer to FIG. 4A to FIG. 4E , which are another schematic diagram of the manufacturing method of the photosensitive element using the microlens of FIG. 2B , which is similarly provided with a photosensitive element 230 ( FIG. 4A ); then, the photosensitive element 230 Forming a protective layer 310 thereon; then, sequentially forming a light transmissive material layer 252 (FIG. 4B), an opaque stack layer 254 (ie, the first patterned metal layer 320) (FIG. 4C), and another light transmissive material. Layer 252 (Fig. 4D), another opaque stacked layer 254 (i.e., second patterned metal layer 330) (Fig. 4E), and stacked to form a structure as shown in Fig. 3D. Finally, a plurality of microlenses 240 are formed on the light blocking stack layer 250 to complete the photosensitive member using the microlens of the present invention. This embodiment can also form the light transmissive material layer 252, the opaque stack layer 254 (ie, the first patterned metal layer 320), the light transmissive material layer 252, and the impervious layer by conventional semiconductor lithography techniques. The light stacking layer 254 (ie, the first patterned metal layer 330) is not described herein.

In summary, the manufacturing method of the photosensitive element using the microlens of the embodiment includes the following steps: providing a photosensitive element (step _S41 ); forming a protective layer on the photosensitive element (step _S42 ); Forming at least two patterned metal layers on the layer to form a plurality of optical channels (step _S43 ); and forming a plurality of microlenses corresponding to the optical channels (step _S44 ), as shown in FIG. 5; wherein, the details of the embodiment The embodiments are shown in FIGS. 3A to 3D, FIGS. 4A to 4E, and related descriptions, and thus are not described herein again. It should be noted that although the first patterned metal layer 320 and the second patterned metal layer 330 are shown as having different shapes and sizes in FIGS. 3A-3D and FIGS. 4A-4E, they are not intended to limit the present invention; In one embodiment, the first patterned metal layer 320 and the second patterned metal layer 330 may also be substantially the same.

It should be noted that although five opaque stacked layers 254 are shown in FIGS. 2B and 2C, the present invention is not limited thereto, and may be, for example, two to five layers. The number of layers of the opaque stacked layer 254 can be determined, for example, according to system parameters such as a sensing range, a photosensitive unit size, and a microlens shape.

In FIG. 2B and FIG. 2C, the microlens 240 is formed to be aspherical and one part One of the centroids of the microlens 240 (i.e., the microlens not located at the center of the photosensitive element 230) is preferably offset from the corresponding photosensitive unit 232 by a distance away from the center of the photosensitive member 230 to effectively guide the reflected beam L1. The light-receiving unit 232 is matched with the tilt angle θ of the optical channel C, and the offset distance is also positively correlated with the distance between the microlens 240 and the center of the photosensitive element 230.

In another embodiment, referring to FIG. 6 , the microlens 240 may be formed to be spherically symmetric, and one of the centers of the microlenses 240 (ie, the center of the sphere) is preferably exposed from the corresponding photosensitive unit 232 toward the remote sensing. The direction of the center of element 230 is offset by an offset distance; for example, offset distances D1 and D2 in FIG. Similarly, with the tilt angle θ of the optical channel C, the offset distance is positively correlated with the distance from the center of the microlens 240 to the photosensitive element 230, for example, the distance D1 > the distance D2 to limit the reflected light beam L1 incident on the photosensitive unit 232. The incident angle, for example, the incident angle θ1>the incident angle θ2.

Based on the above, the optical device (such as FIG. 2A) of the embodiment of the present invention can be configured with corresponding microlenses on the photosensitive element, which can effectively reduce the use of the conventional single lens, thereby enabling the optical device to be assembled. It is easier to reduce the overall size of the optical device and can effectively reduce the manufacturing cost of the optical device. In addition, the optical device can be used to limit the incident angle of the reflected light beam incident on each photosensitive unit by stacking a light blocking stacked layer (as shown in FIGS. 2B, 2C and 6) around the adjacent photosensitive cells. Move functions and reduce the effects of stray light or light leakage.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention.

200‧‧‧Optical device

210‧‧‧Substrate

220‧‧‧Lighting elements

230‧‧‧Photosensitive elements

240‧‧‧Microlens

260‧‧‧Package housing

262‧‧‧ light exit

264‧‧‧Into the light port

270‧‧‧ objects

L0‧‧‧beam

L1‧‧‧ reflected beam

S1‧‧‧First accommodation space

S2‧‧‧Second accommodating space

Claims (19)

An optical device for detecting an object, the optical device comprising: a substrate; a light emitting element disposed on the substrate and adapted to provide a light beam; and a photosensitive element disposed on the substrate to be adapted to receive the light The object reflects a reflected beam formed by the light beam, the photosensitive element comprises: a plurality of photosensitive cells arranged on the photosensitive element; at least two patterned stacked layers stacked on the photosensitive element to form a plurality of photosensitive cells corresponding to each other a light channel, wherein the light channels are inclined toward a direction away from a center of the photosensitive element to limit an incident angle of the reflected light beam incident on the photosensitive cells; and a plurality of microlenses disposed above the photosensitive element Corresponding to the optical channel. The optical device of claim 1, wherein the incident angle is positively correlated with a distance from the optical channel to the center of the photosensitive element. The optical device of claim 1, wherein each of the photosensitive cells corresponds to the plurality of optical channels, and the optical channels corresponding to the same photosensitive cells limit the incident angles of the reflected beams to be the same. The optical device of claim 1, wherein the at least two patterned stacked layers are located between the microlenses and the photosensitive element. The optical device of claim 1, wherein the photosensitive element further comprises a light transmissive material layer as the optical channels. The optical device of claim 1, wherein the at least two patterned stacked layers are formed of a light absorbing material. The optical device of claim 1, wherein each of the photosensitive cells corresponds to at least one of the optical channels. The optical device of claim 1, wherein the microlenses are aspherical. The optical device of claim 1, wherein the microlenses are spherically symmetric and a center of gravity of the microlenses is offset from a corresponding one of the photosensitive cells toward a center away from a center of the photosensitive element. Move the distance. The optical device of claim 9, wherein the offset distance is positively related to a distance from the microlenses to the center of the photosensitive element. The optical device of claim 1, wherein the at least two patterned stacked layers are patterned metal layers. The optical device of claim 1, wherein a protective layer is formed on the photosensitive member. The optical device of any one of claims 1 to 12, wherein each of the photosensitive cells comprises at least one photodiode. A photosensitive element using a microlens, comprising: a plurality of photosensitive cells arranged in an array and having an array center; at least two patterned stacked layers stacked on the photosensitive cells to form a plurality of optical channels corresponding to the photosensitive cells, wherein A portion of the optical channels are inclined at an oblique angle toward a direction away from a center of the array; and a plurality of microlenses are disposed on the at least two patterned stacked layers and respectively correspond to the optical channels. The photosensitive member of claim 14, wherein the tilt angle is positively correlated with a distance from the optical channel to a center of the array. The photosensitive member according to claim 14, wherein a center of gravity of one of the microlenses is offset by an offset distance from the corresponding photosensitive unit toward a direction away from the center of the array. The photosensitive member of claim 14, wherein the two patterned stacked layers are patterned metal layers. The photosensitive member according to claim 14, wherein a protective layer is formed on the photosensitive member. A photosensitive element using a microlens, comprising: a plurality of photosensitive cells arranged in an array and having an array center; a protective layer formed on the photosensitive cells; a light blocking stacked layer formed on the protective layer and comprising a plurality of The light channel pair should wait for the photosensitive unit, wherein a part of the light channels are inclined at an oblique angle away from the center of the array; and a plurality of microlenses are disposed on the light blocking stack layer and respectively correspond to the light channels, wherein One of the centroids of the microlenses is offset from the corresponding optical channel by a distance away from the center of the array such that an optical axis of one of the microlenses is away from the corresponding optical channel toward the array. The direction of the center is inclined by an offset angle.