TWI771725B - Fingerprint sensing apparatus - Google Patents

Abstract

A fingerprint sensing apparatus is provided, which includes a substrate, a fingerprint sensor, a metal middle frame and a supporting component. The fingerprint sensor is disposed on the substrate, and the metal middle frame has an opening. The supporting component is assembled on the opening of the metal middle frame, and the supporting component is disposed on the substrate. The fingerprint sensor is below the opening. A metal layer is formed on a outer surface of the supporting component, and the metal layer is electrically conducted to the metal middle frame.

Description

Fingerprint Sensing Device

The present invention relates to a fingerprint sensing device, and more particularly, to an ESD protection structure for the fingerprint sensing device.

As the screens of mobile electronic devices become larger and larger, the space for fingerprint sensing elements under the non-display area is gradually limited. Under such circumstances, in order to bring a more convenient user experience to the user, the under-screen fingerprint sensing solution in which the optical fingerprint sensor is arranged at the bottom of the screen has been paid more and more attention. It can be known that electrostatic discharge (ESD) is one of the reasons why the fingerprint sensor is damaged under the display panel. Therefore, the fingerprint sensor module is generally designed with electrostatic protection to prevent damage from electrostatic discharge. For example, antistatic components (such as transient voltage suppressors (TVS)) can be disposed on the I/O pins of the fingerprint sensor. However, existing anti-static components may cause a latch-up effect, so that the fingerprint sensor needs to be reset to function properly. In addition, adding an anti-static element can only protect against electrostatic discharge entering from the I/O pins of the fingerprint sensor, and cannot protect against electrostatic discharge generated by fingers or other objects above the display panel.

In view of this, the present invention provides a fingerprint sensor device with a support structure that helps to improve the anti-static discharge capability, so as to prevent the fingerprint sensor from being damaged.

An embodiment of the present invention provides a fingerprint sensing device, which includes a substrate, a fingerprint sensor, a metal middle frame, and a support. The fingerprint sensor is arranged on the substrate, and the metal middle frame has an opening. The support piece is assembled at the opening of the metal middle frame and fixed on the base plate. The fingerprint sensor is located below the opening. The metal layer is formed on the outer surface of the support member, and the metal layer and the metal middle frame are electrically connected.

Based on the above, in the embodiment of the present invention, the fingerprint sensor is placed in the accommodating space of the support member with the metal layer on the outer surface. Since the metal layer on the outer surface of the support member is electrically connected to the metal middle frame, static electricity can be guided to the metal middle frame, thereby preventing electrostatic discharge from damaging the fingerprint sensor.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

100: Fingerprint Sensing Device

110: Fingerprint sensor

120: Metal middle frame

125: Opening

130: Supports

131: Lens fixing part

132: Abutment

140: Substrate

150: Display panel

L1: Lens

C1: Metal layer

21: Metal lock attachment

22: Adhesive layer

23: Solder Balls

31: electrostatic protective layer

32: Conductive pad

S1: first surface

S2: Bottom

S3: Second Surface

34, 35: Adhesive layer

61, 62: Adhesive layer

FIG. 1 is a schematic cross-sectional view of a fingerprint sensing device according to an embodiment of the present invention.

2A is a schematic diagram of a support member fixed to a metal middle frame through an adhesive layer according to an embodiment of the present invention.

FIG. 2B shows the support member fixed to the metal by soldering according to an embodiment of the present invention Schematic of the middle frame.

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

FIG. 4A and FIG. 4B are schematic diagrams of a support member fixed on a substrate through an adhesive layer according to an embodiment of the present invention.

5 is a schematic cross-sectional view of a fingerprint sensing device according to an embodiment of the present invention.

6A and 6B are schematic diagrams of a lens fixed on a support member through an adhesive layer according to an embodiment of the present invention.

In order to make the content of the present invention more comprehensible, the following specific embodiments are taken as examples by which the present invention can indeed be implemented. In addition, where possible, elements/components/steps using the same reference numerals in the drawings and embodiments represent the same or similar parts.

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, "electrically connected" or "coupled" may refer to the existence of other elements between the two elements.

Referring to FIG. 1 , the fingerprint sensing device 100 provides an off-screen fingerprint identification function. The user's finger can press the glass cover above the display panel 150 so that the fingerprint sensor 110 below the display panel 150 can obtain a fingerprint image. Display panel 150 A display panel with self-luminous display elements, such as an organic light-emitting diode (Organic Light-Emitting Diode, OLED) display panel, can be used, but the present invention is not limited thereto. During fingerprint sensing, the user places the finger on the display panel 150, and the display panel 150 emits an illumination beam to illuminate the finger, and the reflected beam reflected by the finger is transmitted to the fingerprint sensor 110 for fingerprint sensing. Measurement. The fingerprint sensing device 100 is, for example, a smart phone, a panel, a game console, or other electronic devices having an optical under-screen fingerprint identification function, which is not limited in the present invention. In one embodiment, the fingerprint sensing device 100 includes a substrate 140 , a fingerprint sensor 110 , a metal middle frame 120 , and a support member 130 .

The fingerprint sensor 110 may include a sensing pixel array composed of a plurality of sensing pixels, each of which includes at least one photodiode for photoelectric conversion. For example, the fingerprint sensor 110 may include a complementary metal oxide semiconductor (CMOS) sensor, a charge coupled device (CCD) sensor, or other suitable image sensors. In one embodiment, the fingerprint sensor 110 may further include other optical elements disposed above the sensing pixel array, such as lenses, collimators, filter layers, etc., which are not limited in the present invention. The fingerprint sensor 110 can be implemented as a chip, or a chip with optical elements disposed thereon, which is not limited in the present invention. In addition, the present embodiment takes one fingerprint sensor 110 as an example for description, but the present invention does not limit the number of fingerprint sensors.

The fingerprint sensor 110 is disposed on the substrate 140 . The substrate 140 is, for example, a printed circuit board (PCB), or a support base and disposed thereon flexible printed circuit (FPC). The fingerprint sensor 110 can be electrically connected to the circuit layer of the substrate 140 , so that the fingerprint sensor 110 can be electrically connected to external circuits through the substrate 140 . In this way, the fingerprint sensor 110 can provide the fingerprint sensing data to other processing units of the fingerprint sensing device 100 .

The metal middle frame 120 is a frame for supporting the display panel 150 in the fingerprint sensing device 100 . In addition, the metal middle frame 120 can also be used as a frame for carrying various internal device elements, and the above-mentioned device elements can be a motherboard, a camera device, a microphone, or various sensors, and so on. In order for the fingerprint sensor 110 to receive the light beam reflected by the finger, the metal middle frame 120 has an opening 125 and the fingerprint sensor 110 is located below the opening 125 . The light beam reflected by the finger can be transmitted to the fingerprint sensor 110 through the opening 125 .

The support member 130 is assembled on the metal middle frame 120 and aligned with the opening 125 . In addition, the supporting member 130 is fixed on the substrate 140 , so that the fingerprint sensor 110 on the substrate 140 is located in the accommodating space of the supporting member 130 . Based on this, the substrate 140 can be fixedly connected with the metal middle frame 120 by the support member 130 , so that the fingerprint sensor 110 is fixedly disposed under the display panel 150 . In one embodiment, at least a part of the support member 130 is located in the opening 125 , and the support member 130 assembled on the metal middle frame 120 can be used to support the display panel 150 at the same time. The support member 130 can be made of resin material or other opaque materials.

It should be noted that the metal layer C1 is formed on the outer surface of the support member 130 , and the metal layer C1 is electrically connected to the metal middle frame 120 . The metal layer C1 may be a plated metal layer or a conductive tape. In other words, the metal layer C1 can penetrate through the outside of the support member 130 . It is formed by electroplating metal on the surface or bonding conductive tape. In addition, the present invention does not limit the covering shape of the metal layer C1 covering the outer surface of the support member 130 , which can be set according to practical applications and requirements. Since the metal layer C1 is electrically connected to the metal middle frame 120 , static electricity can be guided to the metal middle frame 120 to discharge the static electricity, which can achieve the function of electrostatic discharge protection for the fingerprint sensor 110 . Thereby, the fingerprint sensor 110 is not easily damaged by electrostatic discharge and loses its function. It is worth mentioning that, in one embodiment, the resistance value of the metal layer C1 may be higher than the resistance value of the metal middle frame 120 . Based on this, it is more beneficial to guide static electricity from the metal layer C1 to the metal middle frame 120 .

In one embodiment, when the support member 130 is assembled on the metal middle frame 120 , the metal layer C1 can be in direct contact with the metal middle frame 120 to be electrically connected. Alternatively, in one embodiment, the support member 130 can be fixed on the metal middle frame 120 through a conductive fixing member, and the conductive fixing member is electrically connected to the metal layer C1, that is, the metal layer C1 can be connected to the middle frame through the conductive fixing member. 120 is electrically conductive. The conductive fasteners may include metal lock attachments, conductive glue or solder balls.

As shown in FIG. 1 , the support member 130 can be fixed on the metal middle frame 120 through the metal lock accessories 21 (eg, screws), so that the metal layer C1 in contact with the metal lock accessories 21 is electrically connected to the metal middle frame 120 . Correspondingly, the metal middle frame 120 and the support member 130 are respectively provided with positioning holes suitable for allowing the metal lock attachment 21 to pass through. Alternatively, FIG. 2A is a schematic diagram of a support member fixed to a metal middle frame through an adhesive layer according to an embodiment of the present invention. As shown in FIG. 2A , the support member 130 can be adhered to the metal middle frame 120 through the conductive adhesive 22 , so that the metal layer C1 in contact with the conductive adhesive 22 is electrically connected to the metal middle frame 120 . Alternatively, FIG. 2B is a through welding of a support member according to an embodiment of the present invention Schematic diagram of tin fixing to metal middle frame. As shown in FIG. 2B , the support member 130 can be attached to the metal middle frame 120 through the solder balls 23 , so that the metal layer C1 in contact with the solder balls 23 is electrically connected to the metal middle frame 120 .

Referring to FIG. 1 again, in the present embodiment, the support member 130 may include a lens fixing portion 131 and an abutting portion 132 , and the lens fixing portion 131 is connected to the abutting portion 132 . The lens L1 for collecting light beams is installed in the lens fixing part 131 , and the lens fixing part 131 is located in the opening 125 of the metal middle frame 120 . The lens L1 can be fixed on the lens fixing portion 131 through an adhesive layer. The outer surface of the support portion 130 includes the first surface S1 of the lens fixing portion 131 . In this embodiment, a local metal layer C1 is formed on the first surface S1 of the lens fixing portion 131 and located between the lens fixing portion 131 and the display panel 150 . between the bottoms. Thereby, part of the metal layer C1 covering the first surface S1 can be used to protect the electrostatic discharge caused by fingers or other objects above the display panel 150 .

3 is a schematic cross-sectional view of a fingerprint sensing device according to an embodiment of the present invention. Referring to FIG. 3 , the configuration of the substrate 140 , the fingerprint sensor 110 , the metal middle frame 120 , and the support member 130 of this embodiment is similar to that of the embodiment of FIG. 1 , and the main differences are as follows. In the embodiment of FIG. 2 , the substrate 140 may further include an electrostatic protection layer 31 and a conductive pad 32 .

In this embodiment, the electrostatic protection layer 31 may be a metal layer formed on the upper surface of the substrate 140 , such as metal wiring or a metal layer with other patterns. In addition, in other embodiments, the electrostatic protection layer 31 further includes a circuit layer in the substrate 140 or a metal layer formed on the lower surface of the substrate 140 . The electrostatic protection layer 31 is electrically connected to the metal layer C1. The electrostatic protection layer 31 on the substrate 140 can directly contact the metal layer C1 to be electrically conductive Alternatively, the electrostatic protection layer 31 on the substrate 140 can be electrically connected to the metal layer C1 through a conductive adhesive material. The static electricity protection layer 31 on the substrate 140 can guide the static electricity to the metal layer C1 , and the metal layer C1 can guide the static electricity to the metal middle frame 120 to release the static electricity. Therefore, the electrostatic protection layer 31 on the substrate 140 can effectively prevent the fingerprint sensor 110 from being damaged by electrostatic discharge. It is worth mentioning that, in one embodiment, the resistance value of the electrostatic protection layer 31 is higher than the resistance value of the metal layer C1 . Based on this, it is more advantageous to guide static electricity from the static electricity protection layer 31 to the metal layer C1 .

In this embodiment, the support member 130 can be fixed on the substrate 140 through the adhesive layer, that is, the abutting portion 132 of the support member 130 can be fixed on the substrate 140 through the adhesive layer. The contact portion 132 includes a bottom surface and a top surface, and the bottom surface of the contact portion 132 is opposite to the top surface of the contact portion 132 . The bottom surface of the abutting portion 132 faces the substrate 140 , and the top surface of the abutting portion 132 faces the metal middle frame 120 . It should be noted that, the adhesive layer for bonding the abutting portion 132 and the substrate 140 may be a conductive material or a non-conductive material. In detail, FIG. 4A and FIG. 4B are schematic diagrams of a support member fixed on a substrate through an adhesive layer according to an embodiment of the present invention. In the embodiment shown in FIG. 4A , the local metal layer C1 is formed on the bottom surface S2 of the abutting portion 132 and is located between the abutting portion 132 and the substrate 140 . The partial metal layer C1 can directly contact the electrostatic protection layer 31 on the substrate 140 , and the abutting portion 132 is fixed on the substrate 140 through the adhesive layer 34 made of conductive material or non-conductive material. In addition, in the embodiment shown in FIG. 4B , the metal layer C1 is not extended and formed on the bottom surface S2 of the abutting portion 132 . The contact portion 132 is fixed on the substrate 140 through the adhesive layer 35 of conductive material, and the metal layer C1 can be electrically connected to the electrostatic protection layer 31 on the substrate 140 through the adhesive layer 35 of conductive material.

On the other hand, in this embodiment, the conductive pads 32 on the substrate 140 are disposed below the fingerprint sensor 110 and are electrically connected to the fingerprint sensor 110 . The fingerprint sensor 110 can be connected to the lines on the substrate 140 via the conductive pads 32 . It is worth mentioning that, in one embodiment, the resistance value of the conductive pad 32 is higher than the resistance value of the electrostatic protection layer 31 . Based on this, static electricity is more easily guided to the metal layer C1 by the static electricity protection layer 31 , so as to prevent static electricity from entering the fingerprint sensor 110 through the conductive pad 32 and damaging the fingerprint sensor 110 .

5 is a schematic cross-sectional view of a fingerprint sensing device according to an embodiment of the present invention. Referring to FIG. 5 , the configuration of the substrate 140 , the fingerprint sensor 110 , the metal middle frame 120 , and the supporting member 130 of this embodiment is similar to that of the embodiment of FIG. 1 , and the main differences are as follows. In the embodiment of FIG. 5 , the local metal layer C1 may be formed on the second surface S3 of the lens fixing portion 121 . The second surface S3 is opposite to the lens L1, and the lens L1 can be attached to the local metal layer C1 on the second surface S3 through an adhesive layer. The local metal layer C1 formed on the second surface S3 can enhance the resistance to electrostatic discharge. As shown in FIG. 6A , FIG. 6A is a schematic diagram of a lens fixed on a support member through an adhesive layer according to an embodiment of the present invention. The adhesive layer 61 is a conductive material, the adhesive layer 61 is coated on the second surface S3 of the lens fixing portion 131 , and the adhesive layer 61 is electrically connected to the metal layer C1 . The adhesive layer 61 of conductive material can induce static electricity to the metal layer C1 , and the metal layer C1 can induce static electricity to release the metal middle frame 120 . Thereby, the adhesive layer 61 made of conductive material can also enhance the ability of resisting electrostatic discharge.

However, in other embodiments, the metal layer C1 may not extend between the lens fixing portion 131 and the lens L1. As shown in FIG. 6B , FIG. 6B is a schematic diagram of a lens fixed on a support member through an adhesive layer according to an embodiment of the present invention. Conductive material The quality adhesive layer 62 is located between the second surface S3 of the lens fixing portion 131 and the lens L1 . Although the metal layer C1 is not formed on the lens fixing portion 131 and the lens L1 , the adhesive layer 62 made of conductive material is in contact with the metal layer C1 and is electrically connected to the metal layer C1 . Similarly, the adhesive layer 62 made of conductive material can also induce static electricity to the metal layer C1 , and the metal layer C1 can induce static electricity to release the metal middle frame 120 . Thereby, the adhesive layer 62 made of conductive material can also enhance the anti-static discharge capability.

To sum up, in the embodiment of the present invention, the fingerprint sensor can be assembled on the metal middle frame by the support member, so that the fingerprint sensor can be stably disposed under the display panel, so that the fingerprint sensor device can be It can provide under-screen fingerprint recognition function. The fingerprint sensor is placed in the accommodating space of the support member whose outer surface has a metal layer. The metal layer on the outer surface of the support is electrically connected with the metal middle frame, so static electricity can be guided to the metal middle frame, thereby preventing electrostatic discharge events from damaging the fingerprint sensor. In addition, the metal layer can be formed between the display panel and the support, so that the local metal layer can be located above the fingerprint sensor, so as to avoid the fingerprint sensor from being damaged by ESD from above the display panel.

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.

100: Fingerprint Sensing Device

110: Fingerprint sensor

120: Metal middle frame

125: Opening

130: Supports

131: Lens fixing part

132: Abutment

140: Substrate

150: Display panel

L1: Lens

C1: Metal layer

21: Metal lock attachment

Claims (9)

A fingerprint sensing device, comprising: a substrate; a fingerprint sensor disposed on the substrate; a metal middle frame with an opening; and a support member assembled at the opening of the metal middle frame and fixed On the substrate, wherein the fingerprint sensor is located under the opening, a metal layer is formed on the outer surface of the support member, and the metal layer is electrically connected to the metal middle frame, wherein the resistance value of the metal layer is higher than the resistance value of the metal midframe. The fingerprint sensing device of claim 1, wherein the metal layer is an electroplated metal layer or a conductive tape. The fingerprint sensing device of claim 1, wherein the support member is fixed on the metal middle frame through a conductive fixing member, and the conductive fixing member is electrically connected to the metal layer. The fingerprint sensing device of claim 1, wherein the substrate comprises an electrostatic protection layer, and the electrostatic protection layer is electrically connected to the metal layer. The fingerprint sensing device of claim 4, wherein the resistance value of the electrostatic protection layer is higher than the resistance value of the metal layer. The fingerprint sensing device of claim 5, wherein the substrate comprises a conductive pad, the conductive pad is disposed below the fingerprint sensor to be electrically connected to the fingerprint sensor, and the resistance value of the conductive pad is higher than The resistance value of the electrostatic protection layer. The fingerprint sensing device of claim 1, wherein the support member comprises a lens fixing portion, the lens fixing portion is located in the opening of the metal middle frame, and a lens is fixed to the lens fixing portion through an adhesive layer the metal layer is formed on the first surface of the lens fixing part and located between the lens fixing part and the bottom surface of a display panel. The fingerprint sensing device of claim 7, wherein the adhesive layer is a conductive material, the adhesive layer is coated on the second surface of the lens fixing portion, and the adhesive layer is electrically connected to the metal layer. The fingerprint sensing device as claimed in claim 7, wherein the supporting member further comprises an abutting portion, the lens fixing portion is connected to the abutting portion, and the abutting portion is fixed on the substrate via another adhesive layer , the metal layer is formed on the bottom surface of the abutting portion and located between the abutting portion and the substrate.

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