TWI759153B - Fingerprint sensing module - Google Patents

Abstract

A fingerprint sensing module including a substrate, a plurality of photosensitive devices, a collimation structure layer, a light shielding layer, an interposer and a plurality of micro lenses is provided. The photosensitive devices are disposed on the substrate. The collimation structure layer is disposed on the photosensitive devices. The light shielding layer is disposed on the collimation structure layer and has a surface and a plurality of first openings recessed from the surface. The first openings respectively overlap the photosensitive devices. The interposer is disposed on the collimation structure layer and positioned in a part of the first openings of the light shielding layer. The micro lenses are disposed on the interposer and respectively overlap the first openings.

Description

Fingerprint sensor module

The present invention relates to an optical sensing module, and more particularly, to a fingerprint sensing module.

In order to increase the screen-to-body ratio of the display to achieve a narrow bezel design, under-screen fingerprint sensing technology has become a trend. To put it simply, the under-screen fingerprint sensing technology is to dispose the fingerprint sensing module below the display panel of the electronic device. After the electronic device detects that the user touches the display screen, the electronic device controls the display panel to emit light to illuminate the surface of the user's finger. The sensing light will be reflected by the user's finger (diffusely) into the fingerprint sensing module under the display panel, and the reflected light will be concentrated on the photosensitive element through a plurality of microlenses and collimating structures to convert into a digital image signal. The fingerprint image of the user can be obtained.

In order to prevent such fingerprint sensing module from easily receiving stray light incident from a large angle due to the large interval between these microlenses, the fingerprint image will be blurred. A light shielding layer can be arranged between these microlenses. However, the adhesion of these microlenses on the light shielding layer is easily reduced due to poor matching of materials, resulting in the easy peeling of these microlenses on the surface of the light shielding layer, which affects the overall production yield.

The present invention provides a fingerprint sensing module with anti-counterfeiting function, and the number of manufacturing process steps is small.

The present invention provides a fingerprint sensing module with high process yield.

A fingerprint sensing module according to an embodiment of the present invention includes a substrate, a plurality of photosensitive elements, a collimation structure layer, a light shielding layer, an intermediate layer, and a plurality of microlenses. These photosensitive elements are arranged on the substrate. The collimation structure layer is provided on these photosensitive elements. The light shielding layer is disposed on the collimating structure layer, and has a surface and a plurality of first openings recessed from the surface. The first openings are respectively overlapped with the photosensitive elements. The interposer is disposed on the collimation structure layer and located in a part of the first opening of the light shielding layer. The microlenses are disposed on the interposer and overlap the first openings respectively.

A fingerprint sensing module according to an embodiment of the present invention includes a substrate, a plurality of photosensitive elements, a collimation structure layer, a light shielding layer, an intermediate layer, and a plurality of microlenses. These photosensitive elements are arranged on the substrate. The collimation structure layer is provided on these photosensitive elements. The light shielding layer is disposed on the collimating structure layer, and has a surface and a plurality of first openings recessed from the surface. The first openings are respectively overlapped with the photosensitive elements. The interposer is disposed on the collimation structure layer and covers the surface of the light shielding layer. The microlenses are disposed on the interposer and overlap the first openings and part of the interposer.

Based on the above, in the fingerprint sensing module of an embodiment of the present invention, the light shielding layer has a plurality of first openings overlapping the plurality of photosensitive elements. By arranging an interposer in some of the first openings, the difference in optical characteristics (eg, spectral distribution) of the plurality of light rays after passing through the first openings and being transmitted to the corresponding photosensitive elements can be further increased. Accordingly, the fingerprint sensing module can have an anti-counterfeiting function, and the number of manufacturing steps is less than that of a general color-resistance anti-counterfeiting structure. In the fingerprint sensing module of another embodiment of the present invention, the light shielding layer is provided with an interposer on the surfaces of the plurality of first openings. By extending the microlenses overlapping the first openings to the surface of the light shielding layer and contacting the interposer, the risk of peeling off of the microlenses can be effectively reduced, thereby improving the production yield of the fingerprint sensing module . In addition, the degree of freedom in material selection of the light shielding layer and the microlens can also be increased.

As used herein, "about", "approximately", "substantially", or "substantially" includes the stated value and the average value within an acceptable deviation of the particular value as determined by one of ordinary skill in the art, taking into account all The measurement in question and the specific amount of error associated with the measurement (ie, the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within ±30%, ±20%, ±15%, ±10%, ±5%, for example. Furthermore, the terms "about", "approximately", "substantially", or "substantially" as used herein may depend on measurement properties, cutting properties, or other properties to select a more acceptable range or standard deviation, and may Not one standard deviation applies to all properties.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. It will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element, or Intermediate elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to a physical and/or electrical connection. Furthermore, the "electrical connection" may refer to the existence of other elements between the two elements.

Reference will now be made in detail to 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.

FIG. 1 is a schematic top view of a fingerprint sensing module according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the fingerprint sensing module of FIG. 1 . Fig. 2 corresponds to the section line A-A' of Fig. 1 . FIG. 3 is a graph of refractive index versus wavelength for the interposer and the auxiliary layer of FIG. 1 . In particular, for the sake of clarity and description, FIG. 1 only illustrates the substrate 100 , the auxiliary layer 130 , the opening 140 a of the light shielding layer 140 , the interposer 150 and the plurality of microlenses 160 in FIG. 2 .

1 and 2 , the fingerprint sensing module 10 includes a substrate 100 , a photosensitive element layer 110 , a collimation structure layer 120 , an auxiliary layer 130 , a light shielding layer 140 , an interposer 150 and a plurality of microlenses 160 . The photosensitive element layer 110 is provided on the substrate 100 . For example, the photosensitive element layer 110 may include a plurality of photosensitive elements 115 and a plurality of control elements (not shown), and the electrical connection relationship between the control elements and the photosensitive elements 115 may be one-to-one or one-to-many. The control elements here are, for example, thin film transistors (TFTs), and these control elements are suitable for sequentially transmitting the electrical signals from the photosensitive elements 115 to the photosensitive elements 115 through a plurality of signal lines (not shown). A signal processing circuit (not shown) is used for identifying the fingerprint image, but not limited thereto.

The alignment structure layer 120 is disposed on the photosensitive element layer 110 and includes at least one light-shielding pattern layer. In this embodiment, the alignment structure layer 120 can selectively include two light-shielding pattern layers, which are a first light-shielding pattern layer 121 and a second light-shielding pattern layer 123 respectively. The light-shielding pattern layers are all disposed between the plurality of microlenses 160 and the photosensitive element layer 110 , and the second light-shielding pattern layer 123 is disposed between the microlenses 160 and the first light-shielding pattern layer 121 . The first light-shielding pattern layer 121 has a plurality of first openings 121 a, and the first openings 121 a respectively overlap the microlenses 160 in the stacking direction (eg, the direction Z) of the two light-shielding pattern layers. The second light-shielding pattern layer 123 has a plurality of second openings 123a, and the second openings 123a overlap the first openings 121a (or the plurality of microlenses 160 ) in the direction Z, respectively.

In the present embodiment, a plurality of microlenses 160 are disposed on the collimation structure layer 120 , and each is associated with a corresponding first opening 121 a , a corresponding second opening 123 a , and a corresponding one of the photosensitive element layers 110 . Element 115 corresponds. However, the present invention is not limited to this. According to other embodiments, each microlens 160 may also correspond to at least two photosensitive elements 115 of the photosensitive element layer 110 . In order to achieve the effect of light collimation, a flat layer 122 is provided between the first light-shielding pattern layer 121 and the second light-shielding pattern layer 123 , and a second light-shielding pattern layer 123 and the microlenses 160 can optionally be provided with The flat layer 124, but not limited thereto. In this embodiment, the plurality of microlenses 160 may be arranged in an array, for example, the microlenses 160 may be arranged in multiple columns and rows in the directions X and Y, respectively, but not limited thereto. In other embodiments, the arrangement of the plurality of microlenses 160 may be adjusted according to the actual product design, for example, the arrangement may be honeycomb-like or unequally spaced.

In order to prevent the fingerprint sensing module 10 from easily receiving stray light incident from a large angle due to the large interval between the microlenses 160 , resulting in blurred fingerprint images, light shielding is provided between the microlenses 160 and the collimating structure layer 120 . Layer 140. The light shielding layer 140 has a surface 140s and a plurality of openings 140a recessed from the surface 140s , and the plurality of microlenses 160 (or the plurality of photosensitive elements 115 ) respectively overlap the openings 140a in the direction Z. In this embodiment, the material of the light shielding layer 140 is, for example, molybdenum metal, and the material of the flat layer 124 of the collimation structure layer 120 is, for example, an organic photoresist material. In order to stabilize the connection between the light shielding layer 140 and the collimation structure layer 120 , an auxiliary layer 130 is disposed between the light shielding layer 140 and the flat layer 124 , and the material of the auxiliary layer 130 is, for example, silicon nitride (SiN _x ).

On the other hand, in this embodiment, the material of the microlens 160 is, for example, an organic photoresist material. In order to reduce the risk of peeling off of the plurality of microlenses 160 on the light shielding layer 140 and the auxiliary layer 130 , an interposer 150 is provided between the microlenses 160 and the light shielding layer 140 . That is to say, the disposition of the interposer 150 can stabilize the connection between the microlens 160 and the collimating structure layer 120 . In this embodiment, the material of the interposer 150 is, for example, indium tin oxide (ITO), but not limited thereto. In other embodiments, the material of the interposer 150 may also be indium zinc oxide (IZO), or other suitable transparent conductive materials.

In this embodiment, the interposer 150 can also selectively cover the surface 140s of the light shielding layer 140 . That is, the area between the plurality of openings 140 a (or the plurality of microlenses 160 ) of the light shielding layer 140 may also be provided with the interposer 150 . Through the plurality of microlenses 160 partially overlapping the surface 140s of the light shielding layer 140 in the direction Z, and directly contacting the part of the surface 140s of the light shielding layer 140 covered by the interposer 150, the risk of peeling off of the microlenses 160 can be further reduced, thereby improving fingerprints The production yield of the sensing module 10 is measured.

It is particularly noted that, in addition to the above-mentioned functions, the configuration of the interposer 150 can also enable the fingerprint sensing module 10 to have an anti-counterfeiting function. For example, the interposer 150 can be selectively disposed in a part of the openings 140a of the light shielding layer 140, and has a plurality of openings 150a overlapping another part of the openings 140a in the direction Z, so that light can pass through the interposer 150. The spectral distribution after the opening 140a is different from the spectral distribution of the light passing through the opening 140a without the interposer 150 .

In the present embodiment, the auxiliary layer 130 may selectively have a plurality of openings 130 a overlapping the partial openings 140 a in the direction Z, and part of the interposer 150 may also be located in the partial openings 130 a of the auxiliary layer 130 . Therefore, it is possible to further increase the spectral distribution difference when the light passes through the plurality of openings 140 a of the light shielding layer 140 and is transmitted to the photosensitive element layer 110 . In order to realize the above-mentioned difference in spectral distribution, the refractive indices of the interposer 150 and the auxiliary layer 130 in this embodiment must have a certain rate of change in the visible light band. For example, the curve C1 of FIG. 3 shows the change in the refractive index of the interposer 150 made of ITO material in the visible light band, the curve C2 of FIG. 3 shows the change of the refractive index of the interposer 150 made of IZO material in the visible light band, The curve C3 in FIG. 3 shows the change of the refractive index of the auxiliary layer 130 made of silicon nitride in the visible light band.

For example, the auxiliary layer 130 and the interposer 150 both have openings in the disposition area of the microlenses 160 on the left side of FIG. 2 , and neither have openings in the disposition area of the microlenses 160 in the middle of FIG. 2 . In the arrangement area of the microlenses 160 on the right side of FIG. 2 , only the auxiliary layer 130 has an opening 130 a , and an interposer 150 is arranged in the opening 130 a of the auxiliary layer 130 . Therefore, the light rays incident on the three microlenses 160 have different spectral distributions when incident on the collimation structure layer 120 . From another point of view, the manufacturing process of the fingerprint sensing module 10 with the anti-counterfeiting function can also be simplified through the above-mentioned opening design of the interposer layer 150 and the auxiliary layer 130 .

In detail, the opening 130a of the auxiliary layer 130 exposes the surface 124s of the flat layer 124 of the collimation structure layer 120 , and the microlenses 160 on the left side of FIG. 2 can directly contact the surface 124s of the flat layer 124 . Since the materials of the microlenses 160 and the flat layer 124 in this embodiment can be selectively the same, making the microlenses 160 directly contact the flattening layer 124 helps to increase the adhesion of the microlenses 160 , but is not limited thereto. On the other hand, the auxiliary layer 130 further has a surface 130s exposed by the opening 140a of the light shielding layer 140 , a part of the interposer 150 further covers the surface 130s of the auxiliary layer 130 , and the microlens 160 in the middle of FIG. This portion within the opening 140a of the light shielding layer 140 . Another part of the interposer 150 further covers the surface 124s of the flat layer 124 exposed by the opening 130a of the auxiliary layer 130 , and the microlens 160 on the right side of FIG. Although the structures of the film layers in the disposition areas of the microlenses 160 are different, the disposition of the interposer 150 can prevent the microlenses 160 from directly contacting the auxiliary layer 130 and the light shielding layer 140 and increasing the risk of peeling from the surfaces of these film layers. From another point of view, the disposition of the interposer 150 can also increase the degree of freedom in the selection of materials for the auxiliary layer 130 , the light shielding layer 140 and the microlens 160 .

Hereinafter, other embodiments will be listed to describe the present disclosure in detail, wherein the same components will be marked with the same symbols, and the description of the same technical content will be omitted.

FIG. 4 is a schematic top view of a fingerprint sensing module according to another embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of the fingerprint sensing module of FIG. 4 . Fig. 5 corresponds to the section line B-B' of Fig. 4 . It is particularly noted that, for the sake of clarity and description, FIG. 4 only illustrates the substrate 100 , the opening 140 a of the light shielding layer 140 , the interposer 150A and the plurality of microlenses 160 in FIG. 5 .

Referring to FIGS. 4 and 5 , the difference between the fingerprint sensing module 20 of this embodiment and the fingerprint sensing module 10 of FIG. 1 is that the configuration of the intermediate layer and the auxiliary layer is different. In this embodiment, the interposer 150A of the fingerprint sensing module 20 does not overlap the openings 140a of the light shielding layer 140 in the direction Z. As shown in FIG. More specifically, the interposer 150A has a plurality of openings 150a, and the openings 150a overlap the openings 140a of the light shielding layer 140 in the direction Z, respectively. Similarly, the auxiliary layer 130A has a plurality of openings 130a, and the openings 130a overlap the openings 140a of the light shielding layer 140 in the direction Z, respectively. That is, the auxiliary layer 130A does not overlap the openings 140a of the light shielding layer 140 in the direction Z either. In other words, the fingerprint sensing module 20 of this embodiment does not have the anti-counterfeiting function of the fingerprint sensing module 10 of FIG. 2 .

It should be noted that all the microlenses 160 in this embodiment penetrate through the openings 150a of the interposer 150A, the openings 140a of the light shielding layer 140 , the openings 130a of the auxiliary layer 130A and the surface of the flat layer 124 of the collimation structure layer 120 , respectively. 124s direct contact. For example, in the present embodiment, the openings 150a of the interposer 150A, the openings 140a of the light shielding layer 140 and the openings 130a of the auxiliary layer 130A can be selectively aligned with each other in the direction Z. More specifically, the openings of the interposer 150A, the light shielding layer 140 and the auxiliary layer 130A may be formed in the same etching process.

Since the material of the microlens 160 and the flat layer 124 in this embodiment can be selectively the same (for example, both are organic photoresist materials), the microlens 160 avoids the auxiliary layer 130A and the light shielding layer 140 as much as possible and directly contacts the flat layer 124, which can effectively reduce the risk of peeling off of the microlenses 160.

On the other hand, through the plurality of microlenses 160 partially overlapping the surface 140s of the light shielding layer 140 in the direction Z, and directly contacting the part of the interposer 150 covering the surface 140s of the light shielding layer 140 , the risk of peeling off of the microlenses 160 can be further reduced , thereby improving the production yield of the fingerprint sensing module 20 .

To sum up, in the fingerprint sensing module of an embodiment of the present invention, the light shielding layer has a plurality of first openings overlapping the plurality of photosensitive elements. By arranging an interposer in some of the first openings, the difference in optical characteristics (eg, spectral distribution) of the plurality of light rays after passing through the first openings and being transmitted to the corresponding photosensitive elements can be further increased. Accordingly, the fingerprint sensing module can have an anti-counterfeiting function, and the number of manufacturing steps is less than that of a general color-resistance anti-counterfeiting structure. In the fingerprint sensing module of another embodiment of the present invention, the light shielding layer is provided with an interposer on the surfaces of the plurality of first openings. By extending the microlenses overlapping the first openings to the surface of the light shielding layer and contacting the interposer, the risk of peeling off of the microlenses can be effectively reduced, thereby improving the production yield of the fingerprint sensing module . In addition, the degree of freedom in material selection of the light shielding layer and the microlens can also be increased.

10, 20: Fingerprint sensor module 100: Substrate 110: Photosensitive element layer 115: Photosensitive element 120: Collimation structure layer 121, 123: shading pattern layer 121a, 123a: Opening 122, 124: flat layer 124s, 130s, 140s: Surface 130, 130A: auxiliary layer 130a, 140a, 150a: openings 140: shading layer 150, 150A: Interposer 160: Micro lens X, Y, Z: direction A-A', B-B': section line

FIG. 1 is a schematic top view of a fingerprint sensing module according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the fingerprint sensing module of FIG. 1 . FIG. 3 is a graph of refractive index versus wavelength for the interposer and the auxiliary layer of FIG. 1 . FIG. 4 is a schematic top view of a fingerprint sensing module according to another embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of the fingerprint sensing module of FIG. 4 .

10: Fingerprint sensor module 100: Substrate 110: Photosensitive element layer 115: Photosensitive element 120: Collimation structure layer 121, 123: shading pattern layer 121a, 123a: Opening 122, 124: flat layer 124s, 130s, 140s: Surface 130: Auxiliary Layer 130a, 140a, 150a: openings 140: shading layer 150:Intermediary Layer 160: Micro lens X, Y, Z: direction A-A': section line

Claims (17)

A fingerprint sensing module comprises: a substrate; a plurality of photosensitive elements arranged on the substrate; an alignment structure layer arranged on the photosensitive elements; a light shielding layer arranged on the alignment structure layer, The light shielding layer has a surface and a plurality of first openings recessed from the surface, the first openings are respectively overlapped with the photosensitive elements; an interposer is disposed on the alignment structure layer, and a part of the interposer layer Covering the surface of the light shielding layer, another part of the interposer is located in a part of the first openings of the light shielding layer; and a plurality of microlenses are disposed on the interposer and overlap the first openings respectively. The fingerprint sensing module of claim 1, further comprising: an auxiliary layer disposed between the light shielding layer and the alignment structure layer, the auxiliary layer having a plurality of first openings overlapping a portion of the first openings Two open. The fingerprint sensing module of claim 2, wherein the alignment structure layer comprises a flat layer connected to the auxiliary layer, a surface of the flat layer is partially exposed by the second openings in the auxiliary layer, and part of the second openings expose a surface of the flat layer. The microlenses directly contact the surface of the flat layer. The fingerprint sensing module of claim 3, wherein the microlenses are made of the same material as the flat layer. The fingerprint sensing module of claim 2, wherein the intermediary layer is further disposed in part of the second openings of the auxiliary layer. The fingerprint sensing module of claim 2, wherein the auxiliary layer further has a surface exposed by part of the first openings, and the intermediate layer covers the surface of the auxiliary layer. The fingerprint sensing module of claim 1, wherein the microlenses partially overlap the surface of the light shielding layer, and directly contact the interposer and cover a portion of the surface of the light shielding layer. The fingerprint sensing module of claim 1, wherein the material of the light shielding layer comprises molybdenum metal. A fingerprint sensing module comprises: a substrate; a plurality of photosensitive elements arranged on the substrate; an alignment structure layer arranged on the photosensitive elements; a light shielding layer arranged on the alignment structure layer, The light-shielding layer has a surface and a plurality of first openings recessed from the surface, the first openings are respectively overlapped with the photosensitive elements; an intermediate layer is disposed on the alignment structure layer and covers the light-shielding layer. the surface; and a plurality of microlenses disposed on the interposer and overlapping the first openings and part of the interposer, the microlenses directly contacting the interposer. The fingerprint sensing module of claim 9, wherein the interposer is not located in the first openings of the light shielding layer. The fingerprint sensing module of claim 9, further comprising: an auxiliary layer disposed between the light shielding layer and the alignment structure layer, the auxiliary layer having a plurality of second openings overlapping the first openings Open your mouth. The fingerprint sensing module of claim 11, wherein the alignment structure layer comprises a flat layer connected to the auxiliary layer, the second openings of the auxiliary layer expose a surface of the flat layer, and the slightly The lens directly contacts the surface of the flat layer. The fingerprint sensing module of claim 12, wherein the microlenses are made of the same material as the flat layer. The fingerprint sensing module of claim 11, wherein the interposer has a plurality of third openings overlapping the first openings, and the first openings of the light shielding layer and the third openings of the auxiliary layer The two openings and the third openings of the interposer are aligned with each other. The fingerprint sensing module of claim 11, wherein the material of the auxiliary layer comprises silicon nitride, and the material of the microlenses comprises an organic photoresist material. The fingerprint sensing module of claim 9, wherein the material of the light shielding layer comprises molybdenum metal. A fingerprint sensing module, comprising: a substrate; a plurality of photosensitive elements arranged on the substrate; A collimation structure layer is disposed on the photosensitive elements; a light shielding layer is disposed on the collimation structure layer, the light shielding layer has a surface and a plurality of first openings recessed from the surface, the first openings are respectively overlapped on the photosensitive elements; an intermediary layer is arranged on the collimating structure layer and covers the surface of the light shielding layer; a plurality of microlenses are arranged on the interposer layer and overlap the first openings and part of the interposer; and an auxiliary layer disposed between the light shielding layer and the alignment structure layer, the auxiliary layer having a plurality of second openings overlapping the first openings.

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