TWM645514U - Optical sensing device - Google Patents

Abstract

An optical sensing device is provided, which includes a substrate, a light-emitting element, a light-sensing die, and a transparent adhesive material. The light-emitting element is disposed on the substrate. The light-sensing die is disposed on the substrate and has a photosensitive area. The transparent adhesive material is disposed on the substrate and covers the light-emitting element and the light-sensing die. A light-absorbing material is disposed on a surface of the transparent adhesive material. The light emitted by the light-emitting element includes a first part emitted from the surface and a second part reflected from the surface back into the transparent adhesive material, and the light-absorbing material is located on the optical path of the second part of the light.

Description

Optical sensing device

The present invention relates to a sensing device, and in particular to an optical sensing device.

With the development of technology, various sensors can bring many applications. For example, optical sensing devices can be widely used in many consumer electronic devices, bringing various applications to users, such as distance measurement, proximity sensing or gesture sensing, etc. Optical sensing devices generally include light-emitting elements and optical sensors. The light emitted by the light-emitting element hits an external object, and the optical sensor is used to sense the reflected light reflected by the external object. Based on this, the distance information of external objects can be estimated based on the reflected light information.

Please refer to FIG. 1A , which is a schematic diagram of an optical sensing device with crosstalk noise. The encapsulant 110 of the optical sensing device 100 covers the light sensing chip 120 and the light emitting element 130 . It should be noted that the light emitted by the light-emitting element 130 will be reflected at the interface I1 between the packaging colloid 110 and other materials, causing the light to be reflected multiple times in the packaging colloid 110 and enter the photosensitive area of the light sensing chip 120 121. These interfering light rays that are not reflected by external objects will cause crosstalk noise, thereby causing ranging errors of the optical sensing device 100 . For now, please Refer to FIG. 1B , which is a schematic diagram of an existing optical sensing device. An existing improved packaging method is to provide an opaque blocking wall 140 between the light-sensing chip 120 and the light-emitting element 130 to block these interfering light rays from entering the photosensitive area 121 of the light-sensing chip 120 . However, during the construction process of the opaque blocking wall 140 , the encapsulant 110 may need to be significantly cut to create a space for the opaque blocking wall 140 , which may cause damage to the structure of the optical sensing device 100 . damage. In addition, the arrangement of the opaque blocking wall 140 also requires reserved space for accommodation, which is not conducive to miniaturization design.

This new creation proposes an optical sensing device, which includes a substrate, a light-emitting element, a light-sensing chip, and a transparent adhesive material. The light-emitting element is arranged on the substrate. The light sensing chip is arranged on the substrate and has a photosensitive area. The transparent adhesive material is arranged on the substrate and covers the light-emitting element and the light-sensing chip. The surface of the transparent adhesive material is provided with light absorbing material. The light emitted by the light-emitting element includes a first part emitted from the surface and a second part reflected from the surface back into the transparent plastic material. The light-absorbing material is located on the optical path of the second part of the light.

In an embodiment of the present invention, the above-mentioned light-absorbing material includes a main area, which extends from the edge of the surface of the transparent adhesive material between the light-emitting element and the photosensitive area.

In an embodiment of the present invention, the above-mentioned light absorbing material further includes a first auxiliary area. The first auxiliary area is connected to the main area, and the width of the first auxiliary area is the same as or different from the width of the surface of the transparent adhesive material.

In an embodiment of the present invention, the width of the above-mentioned first auxiliary area is the same as the width of the main area.

In an embodiment of the present invention, the above-mentioned light absorbing material further includes a second auxiliary area. The second auxiliary area connects the main area and the first auxiliary area, and the main area, the first auxiliary area and the second auxiliary area surround the photosensitive area.

In an embodiment of the present invention, the above-mentioned light absorbing material further includes a third auxiliary area, the third auxiliary area connects the main area and the first auxiliary area, and the main area, the first auxiliary area and the third auxiliary area surround and emit light. element.

In an embodiment of the present invention, the surface of the above-mentioned transparent adhesive material has a groove, and the light absorbing material is filled in the groove.

In an embodiment of the present invention, the surface of the above-mentioned transparent adhesive material has a first prohibited area and a second prohibited area. The first forbidden area is aligned with the light-emitting element and is located above the light-emitting element, and the second forbidden area is aligned with the photosensitive area and is located above the photosensitive area. The light absorbing material is not disposed within the first forbidden area and the second forbidden area.

In an embodiment of the present invention, the area radius of the above-mentioned first forbidden area is determined based on the light-emitting angle of the light-emitting element and the distance between the surface and the light-emitting element.

In an embodiment of the present invention, the area radius of the above-mentioned first restricted area is the same as the area radius of the second restricted area.

In an embodiment of the present invention, the above-mentioned photosensitive area and the light-emitting element are separated by a first distance, and the width of the light-absorbing material is less than the first distance minus the area radius of the first forbidden area and the area radius of the second forbidden area.

In one embodiment of the present invention, the above-mentioned light-absorbing material is laminated on the surface of the transparent adhesive material by printing, spraying, lamination, lamination, coating, sputtering, electroplating or chemical plating.

In an embodiment of the present invention, the light absorption of the above-mentioned light-absorbing material is at least greater than or equal to 50%.

In an embodiment of the present invention, the above-mentioned light absorbing material is used to absorb light of a specific wavelength.

Based on the above, in the embodiment of the present invention, the light-absorbing material disposed on the surface of the transparent plastic material can absorb the interfering light inside the transparent plastic material to reduce crosstalk noise. In addition, the arrangement of the light-absorbing material does not require reserved space on the substrate, which is beneficial to micro-package design. Moreover, the arrangement of the light-absorbing material does not require complex or complex manufacturing processes, thereby improving the packaging yield.

100,200: Optical sensing device

110: Encapsulating colloid

I1:Interface

140: opaque retaining wall

210:Substrate

130,220:Light-emitting element

120,230: Light sensing chip

121,231: Photosensitive area

240:Transparent adhesive material

250:Light absorbing material

S1: Surface

H: distance

:發光角度

:Lighting angle

O1: Groove

Z1: The first restricted area

Z2: The second restricted area

R1, R2: area radius

W1, W2’, W2”: Width

L1: first distance

E1,E2,E3,E4: edge

251:Main area

252:First auxiliary area

253:Third auxiliary area

254:Second auxiliary area

FIG. 1A is a schematic diagram of an optical sensing device with crosstalk noise.

FIG. 1B is a schematic diagram of a conventional distance sensing device.

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

Figure 3 is a schematic cross-sectional view of an optical sensing device according to an embodiment of the present invention.

Figure 4 is a schematic top view of a restricted area without light absorbing material according to an embodiment of the present invention.

FIG. 5A is a schematic top view of an optical sensing device according to an embodiment of the present invention.

FIG. 5B is a schematic top view of an optical sensing device according to an embodiment of the present invention.

Figure 5C is a schematic top view of an optical sensing device according to an embodiment of the present invention.

Figure 5D is a schematic top view of an optical sensing device according to an embodiment of the present invention.

Some embodiments of the present invention will be described in detail with reference to the drawings. The component symbols cited in the following description will be regarded as the same or similar components when the same component symbols appear in different drawings. These embodiments are only part of the invention and do not disclose all possible implementation modes of the invention.

Figure 2 is a schematic diagram of an optical sensing device according to an embodiment of the present invention. Referring to FIG. 2 , the optical sensing device 200 includes a substrate 210 , a light-emitting element 220 , a light-sensing chip 230 , and a transparent plastic material 240 . In one embodiment, the substrate 210 may be a copper foil substrate, a ceramic substrate, a resin substrate or a printed circuit board, but is not limited thereto.

The light-emitting element 220 and the light-sensing chip 230 are disposed on the substrate 210 . In some embodiments, the light-emitting element 220 and the light-sensing chip 230 can be connected through wire bonding. Co-fabricated wires are connected to the substrate 210. Alternatively, in other embodiments, the light-emitting element 220 and the light-sensing chip 230 can be connected to the substrate 210 through other methods, and the invention is not limited thereto. The light-emitting element 220 is used to generate emitted light, and the light sensing chip 230 is used to receive the reflected light of the emitted light, so as to estimate the distance or determine whether an object is close to the optical sensing device 200 based on the emitted light and reflected light. In different embodiments, the light sensing chip 230 can perform distance estimation or determine whether an object is close to the optical sensing device 200 based on the intensity or reflection time information of the reflected light.

The emitted light generated by the light-emitting element 220 may be, for example, infrared light or other light with a specific wavelength, and the invention is not limited thereto. The light-emitting element 220 may be, for example, a light-emitting diode (LED), an infrared LED, an organic LED (OLED), an infrared laser, or other types of light sources. In some embodiments, the light-sensing chip 230 may be an Application Specific Integrated Circuit (ASIC), which is manufactured through an integrated circuit process and may include a light-sensing area 231 and a computing circuit. The light sensing chip 230 has a photosensitive area 231 composed of photosensitive elements. Alternatively, in other embodiments, the photosensitive area 231 composed of photosensitive elements and the computing circuit can be implemented by different chips. For example, the light sensing chip 230 may include a photosensitive area 231 composed of photosensitive elements and be connected to another computing chip including a computing circuit.

The transparent adhesive 240 is disposed on the substrate 210 and covers the light-emitting element 220 and the light-sensing chip 230 . In other words, the transparent glue 240 can be a packaging glue, and the light-emitting element 220 and the light sensing chip 230 are sealed in the transparent glue 240 . The transparent glue material 240 may be formed by hardening or curing a liquid polymeric material or epoxy resin, for example. example For example, the transparent adhesive material 240 can be epoxy resin or silicone, and can cover the light-emitting element 220, the light-sensing chip 230 and other components through molding.

It should be noted that the surface S1 of the transparent adhesive material 240 is provided with a light absorbing material 250 . The orthographic projection of the light absorbing material 250 on the substrate 210 is located between the orthographic projection of the light-emitting element on the substrate 210 and the orthographic projection of the photosensitive area 231 on the substrate 210 . In some embodiments, the light absorbing material 250 can be laminated on the surface S1 of the transparent adhesive 240 by printing, spraying, laminating, coating, sputtering, electroplating or chemical plating. In some embodiments, the light absorbing material 250 may be a resin containing light absorbing particles or a resin containing light absorbing pigments, but is not limited thereto. For example, the light absorbing material 250 may be black ink, resin mixed with black toner, or other suitable materials. Alternatively, in some embodiments, the light absorbing material 250 may be implemented as glue or tape, but is not limited thereto. Alternatively, in some embodiments, the light absorbing material 250 may be metal or photoresist material.

In addition, in some embodiments, other packaging materials may be stacked on top of the light absorbing material 250 . For example, other transparent encapsulating materials or opaque encapsulating materials can be stacked on top of the light absorbing material 250 . In some embodiments, for a specific wavelength of light emitted by the light-emitting element 220, the light absorption of the light-absorbing material 250 is at least greater than or equal to 50% to ensure that the crosstalk between the light-sensing chip 230 and the light-emitting element 220 can effectively be lowered. In some embodiments, the light-absorbing material 250 can be used to absorb light of a specific wavelength, wherein the light emitted by the light-emitting element 220 has the above-mentioned specific wavelength. For example, when the light-emitting element 220 emits infrared light, the light absorbing material 250 can be an infrared light absorbing material, but is not limited thereto. In addition, it should be noted that in some embodiments, if As the thickness of the light absorbing material 250 increases, the light absorption can be increased accordingly. Therefore, it can be seen that this embodiment is set according to the luminous wavelength of the light-emitting element 220 and the selection of the material and thickness of the light-absorbing material 250, as well as the visible light absorbance requirements.

The light emitted by the light-emitting element 220 includes a first part emitted from the surface S1 and a second part reflected back from the surface S1 into the transparent plastic material 240. The light absorbing material 250 is located on the optical path of the second part of the light. The second portion of the light is reflected between surface S1 and substrate 210. The light absorbing material 250 can absorb the light reflected from the surface S1 back into the transparent adhesive material 240 . Thereby, by disposing the light absorbing material 250 through the surface S1 of the transparent plastic material 240 , the light absorbing material 250 can reduce the intensity of the interference light that is reflected multiple times in the transparent plastic material 240 and enters the photosensitive area 231 . It can be seen from this that the light absorbing material 250 provided on the surface S1 of the transparent adhesive material 240 can absorb the light reflected multiple times inside the transparent adhesive material 240 , thus effectively improving the problem of optical crosstalk.

In addition, in some embodiments, the transparent glue material 240 may be disposed in the groove of the surface S1. Please refer to FIG. 3 , which is a schematic cross-sectional view of an optical sensing device according to an embodiment of the present invention. The surface S1 of the transparent adhesive material 240 may have a groove O1, and the light absorbing material 250 is filled in the groove O1. The groove O1 on the surface S1 can be produced by cutting or grinding the transparent adhesive material 240 or by molding. In addition, in some embodiments, other packaging materials may be stacked on top of the light absorbing material 250 in the groove O1. For example, other transparent encapsulating materials or opaque encapsulating materials may be stacked on top of the light absorbing material 250 .

It should be noted that in an embodiment of the present invention, in order to prevent the light-absorbing material 250 from reducing the light intensity of the light-emitting element 220 or reducing the reflection of external objects, Depending on the intensity of the reflected light that enters the photosensitive area 231, the surface of the transparent adhesive material 240 may have a prohibited area that prohibits the installation of the light absorbing material 250. That is, the arrangement of the light absorbing material 250 is based on the principle of not affecting the irradiation field of view (Field of View, FOV) of the light emitting element 220 .

Figure 4 is a schematic top view of a restricted area without light absorbing material according to an embodiment of the present invention. Referring to FIGS. 2 and 4 , the surface S1 of the transparent adhesive material 240 has a first prohibited area Z1 and a second prohibited area Z2. The first forbidden area Z1 is aligned with the light-emitting element 220 and is located above the light-emitting element 220 . The second forbidden area Z2 is aligned with the photosensitive area 231 and is located above the photosensitive area 231 . The light absorbing material 250 is not disposed within the first forbidden area Z1 and the second forbidden area Z2.

以及表面S1與發光元件220之間的距離H而決定。第一禁制Z1區的區域半徑R1與發光元件220的發光角度

與距離H都呈正相關。於一實施例中，第一禁制Z1區的區域半徑R1可根據下列公式(1)決定。 In this embodiment, the first prohibited area Z1 and the second prohibited area Z2 are circular areas. The area radius R1 of the first forbidden zone Z1 is based on the light-emitting angle of the light-emitting element 220

And the distance H between the surface S1 and the light-emitting element 220 is determined. The area radius R1 of the first forbidden zone Z1 and the light-emitting angle of the light-emitting element 220

There is a positive correlation with distance H. In one embodiment, the area radius R1 of the first forbidden zone Z1 can be determined according to the following formula (1).

其中，發光元件220的發光角度

為發光元件220的規格參數，亦可稱為發光元件220的視場(FOV)角。

Wherein, the light-emitting angle of the light-emitting element 220

is the specification parameter of the light-emitting element 220, which can also be called the field of view (FOV) angle of the light-emitting element 220.

In some embodiments, the area radius R1 of the first restricted area Z1 is the same as the area radius R2 of the second restricted area Z2. Based on the principle that the light-absorbing material 250 is prohibited to be installed in the first forbidden area Z1 and the second forbidden area Z2, the photosensitive area 231 and the light-emitting element are The width W1 of the light absorbing material 250 between the parts 220 is less than the first distance L1 minus the area radius R1 of the first forbidden area Z1 and the area radius R2 of the second forbidden area Z2, that is, W1<(L1-R1-R2). The photosensitive area 231 is separated from the light-emitting element 220 by a first distance L1. That is to say, the coverage area of the light absorbing material 250 on the surface S1 of the transparent adhesive material 240 is outside the first forbidden area Z1 and the second forbidden area Z2. Under this premise, the pattern formed by the light absorbing material 250 on the surface S1 of the transparent adhesive material 240 can be implemented in a variety of ways, some of which are listed below.

FIG. 5A is a schematic top view of an optical sensing device according to an embodiment of the present invention. Please refer to FIG. 5A. In this embodiment, the light absorbing material 250 includes a main area 251. The main area 251 extends from the edge E1 of the surface S1 of the transparent adhesive material 240 between the light-emitting element 220 and the photosensitive area 231. Based on the description of FIG. 4 , it can be seen that based on the principle of maintaining that the light absorbing material 250 is not disposed within the forbidden area, the width W1 of the main area 251 between the photosensitive area 231 and the light-emitting element 220 is less than the first distance L1 minus the first forbidden area Z1 The area radius R1 of the second restricted area Z2 and the area radius R2 of the second restricted area Z2. However, in other embodiments, the main area 251 of the light absorbing material 250 may not contact the edge E1 of the surface S1 of the transparent adhesive material 240 .

FIG. 5B is a schematic top view of an optical sensing device according to an embodiment of the present invention. Please refer to FIG. 5B . In this embodiment, the light absorbing material 250 includes a main area 251 . The main area 251 extends from the edge E1 of the surface S1 of the transparent adhesive 240 between the light-emitting element 220 and the photosensitive area 231 . In addition, the light absorbing material 250 also includes a first auxiliary region 252 . The first auxiliary area 252 is connected to the main area 251, and the width W2′ of the first auxiliary area 252 is different from the width of the surface S1 of the transparent adhesive material 240. Yu Ben In this embodiment, the width W2' of the first auxiliary area 252 is the same as the width W1 of the main area 251. In this embodiment, the first auxiliary area 252 may extend from the edge E2 of the surface S1 of the transparent adhesive 240 to the connection main area 251 . As shown in FIG. 5B , the light absorbing material 250 may be formed as a rectangular light absorbing area spanning between two edges of the surface S1 of the transparent adhesive material 240 .

Figure 5C is a schematic top view of an optical sensing device according to an embodiment of the present invention. Please refer to FIG. 5C . In this embodiment, the light absorbing material 250 includes a main area 251 extending from the edge E1 of the surface S1 of the transparent adhesive 240 between the light-emitting element 220 and the photosensitive area 231 . In addition, the light absorbing material 250 also includes a first auxiliary region 252 . The first auxiliary area 252 connects the main area 251 between the light-emitting element 220 and the photosensitive area 231. The width W2″ of the first auxiliary area 252 is the same as the width of the surface S1 of the transparent adhesive material 240. In this embodiment, the first auxiliary area 252 The area 252 extends from the edge E3 to the edge E4 of the surface S1 of the transparent adhesive material 240 , and its width W2″ is the same as the width of the surface S1 of the transparent adhesive material 240 . As shown in FIG. 5C , the light absorbing material 250 can form convex light absorbing areas on the surface S1 of the transparent adhesive material 240 .

Figure 5D is a schematic top view of an optical sensing device according to an embodiment of the present invention. Please refer to FIG. 5D . In this embodiment, the light absorbing material 250 includes a main area 251 . The main area 251 extends from the edge E1 of the surface S1 of the transparent adhesive 240 between the light-emitting element 220 and the photosensitive area 231 . In addition, the light absorbing material 250 also includes a first auxiliary region 252 . The first auxiliary area 252 connects the main area 251 between the light-emitting element 220 and the photosensitive area 231. The width W2″ of the first auxiliary area 252 is the same as the width of the surface S1 of the transparent adhesive material 240. In this embodiment, the first auxiliary area 252 District 252 It extends from the edge E3 of the surface S1 of the transparent adhesive material 240 to the edge E4, so that its width W2″ is the same as the width of the surface S1 of the transparent adhesive material 240. In addition, the light absorbing material 250 also includes a second auxiliary area 254 and a third Auxiliary area 253.

The second auxiliary area 254 connects the main area 251 and the first auxiliary area 252 , and the main area 251 , the first auxiliary area 252 and the second auxiliary area 254 surround the photosensitive area 231 on the surface S1 of the transparent adhesive material 240 . The second auxiliary area 254 is L-shaped. The second auxiliary area 254 is provided along the edge E3 and the edge E1 of the surface S1 of the transparent adhesive material 240 . The third auxiliary area 253 connects the main area 251 and the first auxiliary area 252 , and the main area 251 , the first auxiliary area 252 and the third auxiliary area 253 surround the light emitting element 220 on the surface S1 of the transparent adhesive material 240 . The third auxiliary area 253 has an L shape. The third auxiliary area 253 is provided along the edge E4 and the edge E1 of the surface S1 of the transparent adhesive material 240 . In other words, in this embodiment, the light absorbing material 250 has two openings on the surface S1 of the transparent adhesive material 240 .

To sum up, in the embodiment of the present invention, the light-absorbing material disposed on the surface of the transparent plastic material can absorb the interfering light inside the transparent plastic material to reduce crosstalk noise. In addition, the arrangement of the light-absorbing material does not require reserved space on the substrate, which is beneficial to micro-package design. Moreover, the arrangement of the light-absorbing material does not require complex or complex manufacturing processes, thereby improving the packaging yield.

Although the embodiments of the present invention have been disclosed above, they are not intended to limit the invention. Anyone with ordinary knowledge in the technical field can make some modifications and changes without departing from the spirit and scope of the invention. Therefore, the scope of protection of this new creation shall be determined by the scope of the patent application attached.

200: Optical sensing device

210:Substrate

220:Light-emitting component

230:Light sensing chip

231: Photosensitive area

240:Transparent adhesive material

250:Light absorbing material

S1: Surface

H: distance

θ: luminous angle

Claims (14)

An optical sensing device including: a substrate; A light-emitting element is provided on the substrate; A light sensing chip is disposed on the substrate and has a photosensitive area; and A transparent adhesive material is disposed on the substrate and covers the light-emitting element and the light-sensing chip, Wherein a surface of the transparent adhesive material is provided with a light absorbing material, The light emitted by the light-emitting element includes a first part emitted from the surface and a second part reflected back from the surface into the transparent plastic material. The light-absorbing material is located on the optical path of the second part of the light. The optical sensing device of claim 1, wherein the light absorbing material includes a main area extending from an edge of the surface of the transparent adhesive material between the light-emitting element and the photosensitive area. The optical sensing device of claim 2, wherein the light absorbing material further includes a first auxiliary area connected to the main area, and the width of the first auxiliary area is the same as or different from that of the transparent glue The width of the surface of the material. The optical sensing device of claim 3, wherein the width of the first auxiliary area is the same as the width of the main area. The optical sensing device according to claim 3, wherein the light absorbing material further includes a second auxiliary area, the second auxiliary area connects the main area and the first auxiliary area, the main area and the first auxiliary area and the second auxiliary area surrounding the photosensitive area. The optical sensing device according to claim 3, wherein the light absorbing material further includes a third auxiliary area, the third auxiliary area connects the main area and the first auxiliary area, the main area and the first auxiliary area and the third auxiliary area surrounding the light-emitting element. The optical sensing device of claim 1, wherein the surface of the transparent plastic material has a groove, and the light absorbing material is filled in the groove. The optical sensing device according to claim 1, wherein the surface of the transparent plastic material has a first forbidden area and a second forbidden area, the first forbidden area is aligned with the light-emitting element and is located above the light-emitting element, The second forbidden area is aligned with the photosensitive area and is located above the photosensitive area, and the light absorbing material is not disposed within the first forbidden area and the second forbidden area. The optical sensing device of claim 8, wherein the area radius of the first forbidden area is determined based on the light-emitting angle of the light-emitting element and the distance between the surface and the light-emitting element. The optical sensing device according to claim 9, wherein the area radius of the first forbidden area is the same as the area radius of the second forbidden area. The optical sensing device of claim 9, wherein the photosensitive area is separated from the light-emitting element by a first distance, and the width of the light-absorbing material between the light-emitting element and the photosensitive area is less than the first distance minus the The area radius of the first restricted area and the area radius of the second restricted area. The optical sensing device of claim 1, wherein the light-absorbing material is laminated on the surface of the transparent adhesive material by printing, spraying, lamination, lamination, coating, sputtering, electroplating or chemical plating. The optical sensing device as claimed in claim 1, wherein the light absorption of the light absorbing material is at least greater than or equal to 50%. The optical sensing device as claimed in claim 1, wherein the light absorbing material is used to absorb light of a specific wavelength.

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