A display device and a method for manufacturing the same

Abstract

The present application discloses a display device and a preparation method thereof, which belongs to the field of display technology. The display device includes a display screen, a sensor chip, a conductive connector and a circuit board. Among them, the sensor chip is arranged on the non-display side of the display screen, and the sensor chip has a front and a back side arranged relatively, and the front side faces the display screen, which is used to receive light penetrating the display screen, and a solder pad is arranged on the back side. The conductive connector is arranged on the back side of the sensor chip and is electrically connected to the solder pad. The circuit board is arranged on the side of the conductive connector away from the sensor chip, and the conductive connector is electrically connected to the electrical connection point on the circuit board, so that when the circuit board drives the sensor chip to work, the sensor chip can perform fingerprint recognition based on the light. In the display device provided by the present application, the front side of the sensor chip can be directly attached to the display screen without reserving wiring space, which can enhance the intensity of the light signal received by the sensor chip under the screen, thereby improving the efficiency of fingerprint recognition.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display device and a method for preparing the same. Background Art

[0002] With the development of display technology, the popularity of smart terminals such as mobile phones and tablets with OLED display panels is increasing, and consumers have higher and higher requirements for the screen-to-body ratio, thus developing under-screen fingerprint recognition technology. The mainstream under-screen fingerprint recognition technology is optical fingerprint recognition technology, which is to move the fingerprint recognition module under the OLED screen. When performing fingerprint recognition, some pixels emit light to illuminate the finger surface and are reflected to the fingerprint recognition module, thereby performing fingerprint recognition. However, in the prior art, it is usually necessary to connect the sensor chip and the circuit board in the fingerprint recognition module by wire bonding (WB). The WB will produce an arc height. In order to prevent the WB from lifting the screen, it is necessary to add support around the sensor chip to leave space for the arc height generated by the WB. However, this will cause a distance between the sensor chip and the OLED screen, thereby weakening the intensity of the light signal received by the under-screen sensor chip and reducing the efficiency of fingerprint recognition. Summary of the invention

[0003] The main technical problem solved by the present application is to provide a display device and a method for preparing the same, which can enhance the intensity of the light signal received by the under-screen sensor chip and improve the efficiency of fingerprint recognition.

[0004] In order to solve the above technical problems, a technical solution adopted by the present application is: to provide a display device, comprising:

[0005] Display screen;

[0006] A sensor chip is arranged on a non-display surface side of the display screen, the sensor chip has a front side and a back side which are arranged opposite to each other, and the front side faces the display screen and is used to receive light penetrating the display screen, and the back side is provided with a solder pad;

[0007] A conductive connector, disposed on the back side of the sensor chip and electrically connected to the pad;

[0008] The circuit board is arranged on the side of the conductive connecting member away from the sensor chip, and the conductive connecting member is electrically connected to the electrical connection point on the circuit board, so that when the circuit board drives the sensor chip to work, the sensor chip can perform fingerprint recognition according to the light.

[0009] Wherein, the conductive connecting member includes a solder ball or a conductive column, and the solder ball or the conductive column corresponds to the solder pad one by one.

[0010] Wherein, the display device further comprises: an underfill located between the sensor chip and the circuit board and wrapping the conductive connector.

[0011] Wherein, in the direction from the circuit board to the sensor chip, the vertical cross-section of the bottom filler is a trapezoid.

[0012] Wherein, the display device also includes: a support member, located on the side of the circuit board away from the display screen, the support member is provided with a protrusion corresponding to the edge of the display screen, and the protrusion is in contact with the display screen; wherein the height of the protrusion is greater than or equal to the distance between the front side and the surface of the circuit board away from the sensor chip.

[0013] In order to solve the above technical problems, another technical solution adopted by the present application is: to provide a method for preparing a display device, comprising:

[0014] A sensor chip is provided, wherein the sensor chip has a front side and a back side which are arranged opposite to each other, wherein the front side is used to receive light, and the back side is provided with a solder pad;

[0015] forming a conductive connection member on the back side of the sensor chip, wherein the conductive connection member is electrically connected to the pad;

[0016] The sensor chip is arranged opposite to the circuit board, and the conductive connecting member is electrically connected to the electrical connection point on the circuit board;

[0017] The display screen is covered on the front surface of the sensor chip, and the non-display surface of the display screen faces the front surface, so that the sensor chip can receive the light penetrating the display screen from the front surface.

[0018] Wherein, the step of forming a conductive connection member on the back side of the sensor chip comprises:

[0019] Using a steel mesh to form solder balls on the back surface corresponding to the solder pads; or,

[0020] A conductive column is formed on the back surface corresponding to the pad by using a photolithography process, and solder is formed on an end of the conductive column away from the pad.

[0021] The step of arranging the sensor chip opposite to the circuit board and electrically connecting the conductive connecting member to the electrical connection point on the circuit board includes:

[0022] The solder ball or the solder at one end of the conductive column is placed in contact with an electrical connection point on the circuit board;

[0023] The solder ball or the solder is electrically connected to the electrical connection point by using a reflow process.

[0024] Wherein, after the step of arranging the sensor chip opposite to the circuit board and electrically connecting the conductive connecting member to the electrical connection point on the circuit board, the method further includes:

[0025] An underfill is formed between the sensor chip and the circuit board, and the underfill wraps the conductive connector.

[0026] Wherein, before the step of covering the display screen on the front surface of the sensor chip, the method further includes:

[0027] Laminating a surface of the circuit board facing away from the sensor chip onto a support member, wherein a protrusion is provided on an edge of the support member, and a height of the protrusion is greater than or equal to a distance between the front surface and the surface of the circuit board facing away from the sensor chip;

[0028] The step of covering the display screen on the front side of the sensor chip comprises:

[0029] The display screen is covered on the front surface of the sensor chip, and the protrusion is made to fit the display screen.

[0030] The beneficial effects of the present application are as follows: the display device provided by the present application includes a display screen, a sensor chip, a conductive connector and a circuit board. Among them, the sensor chip is arranged on the non-display side of the display screen, and the sensor chip has a front and a back side arranged relatively, and the front side faces the display screen, and is used to receive light penetrating the display screen, and a solder pad is arranged on the back side. The conductive connector is arranged on the back side of the sensor chip and is electrically connected to the solder pad. The circuit board is arranged on the side of the conductive connector away from the sensor chip, and the conductive connector is electrically connected to the electrical connection point on the circuit board, so that when the circuit board drives the sensor chip to work, the sensor chip can perform fingerprint recognition based on the light. It can be seen that in the display device provided by the present application, the front side of the sensor chip can be directly attached to the display screen without reserving wiring space, which can enhance the intensity of the light signal received by the sensor chip under the screen, thereby improving the efficiency of fingerprint recognition. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0032] Figure 1 This is a schematic structural diagram of an embodiment of a display device of the present application;

[0033] Figure 2 for Figure 1 Schematic diagram of the cross section along the AA direction;

[0034] Figure 3 for Figure 1 Another cross-sectional schematic diagram along the AA direction;

[0035] Figure 4 This is a schematic flow chart of an implementation method of a method for manufacturing a display device of the present application;

[0036] Figure 5a for Figure 4 A structural schematic diagram corresponding to an implementation method of step S11;

[0037] Figure 5b for Figure 4 A structural schematic diagram corresponding to an implementation method of step S12;

[0038] Figure 5c for Figure 4 A structural schematic diagram corresponding to another implementation method of step S12;

[0039] Figure 5d for Figure 4 A structural schematic diagram corresponding to an implementation method of step S13 in FIG. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0041] See also Figure 1 ,and Figure 2 , Figure 1 This is a schematic diagram of the structure of an embodiment of the display device of the present application. Figure 2 for Figure 1 The cross-sectional schematic diagram along the AA direction shows that the display device includes a display screen 11 , a sensor chip 12 , a conductive connecting member 13 and a circuit board 14 . Figure 1 The sensor chip 12, the conductive connector 13 and the circuit board 14 are all located under the display screen 11. Figure 1 Only the display screen 11 is drawn, and the fingerprint recognition area is schematically drawn with a dotted circle.

[0042] The sensor chip 12 is disposed on the non-display surface side of the display screen 11. Figure 2The upward side of the middle display screen 11 is the display surface, and the downward side is the non-display surface. The sensor chip 12 has a front side 121 and a back side 122 that are arranged opposite to each other, and the front side 121 faces the display screen 11, and is used to receive light penetrating the display screen 11, and the back side 122 is provided with a solder pad 123. The conductive connector 13 is arranged on the back side 122 of the sensor chip 12, and is electrically connected to the solder pad 123. The circuit board 14 is arranged on the side of the conductive connector 13 away from the sensor chip 12, and the conductive connector 13 is electrically connected to the electrical connection point (not shown) on the circuit board 14, so that when the circuit board 14 drives the sensor chip 12 to work, the sensor chip 12 can perform fingerprint recognition according to the light received by its front side 121.

[0043] It can be seen that the sensor chip 12 is a flip chip, and its front side 121 is its functional side, and the pad 123 for electrically connecting to the circuit board 14 is arranged on its back side 122. The sensor chip 12 can directly electrically connect the pad 123 to the circuit board 14 providing the driving signal through the conductive connector 13. The front side 121 of the sensor chip 12 can be directly attached to the display screen 11 without reserving a wiring space, which can enhance the intensity of the optical signal received by the sensor chip 12 under the screen, thereby improving the efficiency of fingerprint recognition.

[0044] For further information, please refer to Figure 2 The conductive connecting member 13 includes solder balls, which correspond one to one with the pads 123. Usually, the back surface 122 of the sensor chip 12 is provided with a plurality of pads 123, so it is necessary to provide corresponding solder balls to electrically connect them with the circuit board 14.

[0045] For further information, please refer to Figure 2 , the present application also includes a support member 15, the support member 15 is located on the side of the circuit board 14 away from the display screen 11, and the support member 15 is provided with a protrusion (not shown) corresponding to the edge of the display screen 11, and the protrusion is in contact with the display screen 11. The height of the protrusion is greater than or equal to the distance H between the front surface 121 of the sensor chip 12 and the side surface of the circuit board 14 away from the sensor chip 12.

[0046] Preferably, the height of the protrusion is equal to the distance H between the front side 121 of the sensor chip 12 and the surface of the circuit board 14 facing away from the sensor chip 12, so that the front side 121 of the sensor chip 12 can just fit with the non-display surface of the display screen 11, thereby minimizing the distance between the sensor chip 12 and the display screen 11, making the intensity of the light signal received by the sensor chip 12 stronger, thereby improving the fingerprint recognition efficiency.

[0047] In another embodiment, see Figure 3 , Figure 3 for Figure 1Another cross-sectional schematic diagram along the AA direction in the embodiment, the display device also includes a display screen 11, a sensor chip 12, a conductive connecting member 13, a circuit board 14 and a supporting member 15, and the structural relationship between them is similar to Figure 2 The difference is that the conductive connector 13 includes a conductive column 131 and a solder 132 located at one end of the conductive column 131, and the conductive column 131 corresponds to the pad 123 one by one, and the solder 132 is used to make the conductive column 131 and the circuit board 14 form an electrical connection. Usually, the back side 122 of the sensor chip 12 is provided with a plurality of pads 123, so it is necessary to set a one-to-one corresponding conductive column 131 and use the solder 132 to electrically connect it to the circuit board 14. When the circuit board 14 drives the sensor chip 12 to work, the sensor chip 12 can perform fingerprint recognition according to the light received by its front side 121.

[0048] For further information, please refer to Figure 3 The display device of the present application further includes an underfill 16, which is located between the sensor chip 12 and the circuit board 14 and wraps the conductive connector 13, that is, wraps the conductive column 131 and the solder 132. In addition, in the direction from the circuit board 14 to the sensor chip 12, the vertical cross-section of the underfill 16 is a trapezoid, so that the overall structure of the display device in this embodiment is more stable, and the underfill 16 can also protect the conductive connector 13, so that the fingerprint recognition function of the display device is more stable.

[0049] It can be understood that the dimensional relationship between the various structures shown in the above drawings is only schematic. For the sake of clarity, some structures are enlarged and some structures are reduced. The dimensional relationship of the actual product is not limited to the dimensional relationship in the drawings.

[0050] Based on the same inventive concept, the present application also provides a method for preparing a display device, see Figure 4 , Figure 4 1 is a flow chart of an implementation method of a method for manufacturing a display device of the present application, and the manufacturing method includes the following steps.

[0051] Step S11, providing a sensor chip, wherein the sensor chip has a front side and a back side that are arranged opposite to each other, wherein the front side is used to receive light, and a solder pad is arranged on the back side.

[0052] See also Figure 5a , Figure 5a for Figure 4In the structural schematic diagram corresponding to the first embodiment of step S11, the sensor chip 12 has a front side 121 and a back side 122 which are arranged opposite to each other, and the front side 121 is used to receive light, and the back side 122 is provided with a pad 123. That is, the sensor chip 12 is a flip chip, the front side 121 is its functional side, and the pad 123 for electrical connection with other components is arranged on the back side 122. Among them, the sensor chip 12 has a fingerprint recognition function when driven by the circuit board.

[0053] Step S12: forming a conductive connector on the back side of the sensor chip, wherein the conductive connector is electrically connected to the pad.

[0054] See also Figure 5b , Figure 5b for Figure 4 The schematic structural diagram of step S12 corresponding to an embodiment of the present invention is as follows: a conductive connecting member 13 is formed on the back side 122 of the sensor chip 12 , and the conductive connecting member 13 is electrically connected to the pad 123 .

[0055] In this embodiment, the conductive connector 13 is a solder ball, which can be formed on the back side 122 of the sensor chip 12 corresponding to the pad 123 by using a steel mesh ball planting process. That is, the solder ball corresponds to the pad 123 one by one, so that the sensor chip 12 can be electrically connected to other components by means of the solder ball.

[0056] In another embodiment, see Figure 5c , Figure 5c for Figure 4 1 is a schematic structural diagram corresponding to another embodiment of step S12, firstly, a photolithography process is used to form a conductive column 131 on the back side 122 of the sensor chip 12 corresponding to the pad 123, and a solder 132 is formed at one end of the conductive column 131 away from the pad 123. That is, the conductive column 131 corresponds to the pad 123 one by one, so that the sensor chip 12 can be electrically connected to other components by means of the conductive column 131 and the solder 132.

[0057] Step S13, placing the sensor chip opposite to the circuit board, and electrically connecting the conductive connecting member to the electrical connection point on the circuit board.

[0058] See also Figure 5d , Figure 5d for Figure 4 The schematic structural diagram of step S13 corresponding to an embodiment of the present invention is as follows: the sensor chip 12 and the circuit board 14 are arranged opposite to each other, and the conductive connecting member 13 is electrically connected to an electrical connection point (not shown) on the circuit board 14 .

[0059] Specifically, when the conductive connection member 13 is a solder ball, the solder ball is first placed in contact with the electrical connection point on the circuit board 14, and then the solder ball and the electrical connection point are electrically connected by a reflow process. When the conductive connection member 13 is a conductive column 131 and a solder 132, the solder 132 at one end of the conductive column 131 is first placed in contact with the electrical connection point on the circuit board 14, and then the solder 132 and the electrical connection point are electrically connected by a reflow process. Figure 5d The conductive pillar 131 and the solder 132 are schematically shown.

[0060] For further information, please refer to Figure 5d After the sensor chip 12 is electrically connected to the circuit board 14 by using the conductive connector 13, an underfill 16 can be further formed between the sensor chip 12 and the circuit board 14. The underfill 16 wraps the conductive connector 13 to protect the conductive connector 13 and make the overall structure of the device more stable.

[0061] Step S14, the display screen is covered on the front side of the sensor chip, with the non-display side of the display screen facing the front side, so that the sensor chip can receive the light penetrating the display screen from the front side.

[0062] Please combine Figure 5d Continue reading Figure 3 , the display screen 11 is covered on the front side 121 of the sensor chip 12, Figure 3 The upward side of the display screen 11 is the display surface, and the downward side is the non-display surface. The non-display surface of the display screen 11 faces the front side 121, so that the sensor chip 12 can receive light penetrating the display screen 11 from the front side 121. That is, the display device prepared in this application has an under-screen fingerprint recognition function. When the sensor chip 12 is driven by the circuit board 14 and the user's finger covers the fingerprint recognition area on the display surface of the display screen 11, the pixels in the fingerprint recognition area light up, the light irradiates the finger surface and is reflected, and the reflected light penetrates the display screen 11 and enters the sensor chip 12, thereby performing fingerprint recognition.

[0063] Among them, continue to refer to Figure 5d Before the display screen 11 is placed on the front side 121 of the sensor chip 12, the surface of the circuit board 14 facing away from the sensor chip 12 can be attached to the support member 15, wherein a protrusion (not marked) is provided on the edge of the support member 15, and the height of the protrusion is greater than or equal to the distance H between the front side 121 of the sensor chip 12 and the surface of the circuit board 14 facing away from the sensor chip 12.

[0064] Preferably, the height of the protrusion can be set equal to the distance H between the front surface 121 of the sensor chip 12 and the surface of the circuit board 14 facing away from the sensor chip 12, so that the space formed by the protrusion can just accommodate the circuit board 14 facing away from the sensor chip 12. On the one hand, it can protect the circuit board 14 from facing away from the sensor chip 12, and on the other hand, it can minimize the distance between the sensor chip 12 and the display screen 11, so that the intensity of the light signal received by the sensor chip 12 is stronger.

[0065] Furthermore, when the display screen 11 is placed on the front surface 121 of the sensor chip 12, the protrusions on the edge of the circuit board 14 can fit with the display screen 11, thereby supporting and protecting the display device. Figure 3 Of course, in Figure 5b Further performing the above subsequent steps based on the structure shown in FIG. Figure 2 The display devices shown are not illustrated one by one here.

[0066] In the display device prepared in this embodiment, the sensor chip 12 can directly electrically connect the pad 123 to the circuit board 14 providing the driving signal through the conductive connector 13. The front surface 121 of the sensor chip 12 can be directly attached to the display screen 11 without reserving a wiring space, which can enhance the intensity of the optical signal received by the sensor chip 12 under the screen, thereby improving the fingerprint recognition efficiency.

[0067] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A display device, characterized in that: include: Display screen; A sensor chip is arranged on a non-display surface side of the display screen, the sensor chip has a front side and a back side which are arranged opposite to each other, and the front side faces the display screen and is used to receive light penetrating the display screen, and the back side is provided with a solder pad; A conductive connector, disposed on the back side of the sensor chip and electrically connected to the pad; A circuit board is arranged on a side of the conductive connecting member away from the sensor chip, the conductive connecting member is electrically connected to an electrical connection point on the circuit board, so that when the circuit board drives the sensor chip to work, the sensor chip can perform fingerprint recognition according to the light; An underfill is located between the sensor chip and the circuit board, wrapping the conductive connector, and the vertical section of the underfill is a trapezoid in the direction from the circuit board to the sensor chip; A support member is located on a side of the circuit board facing away from the display screen, and a protrusion is provided on the support member corresponding to an edge of the display screen, and the protrusion is in contact with the display screen; wherein the height of the protrusion is greater than or equal to the distance from the front side to a surface of the circuit board facing away from the sensor chip.

2. The display device according to claim 1, characterized in that The conductive connecting member includes a solder ball or a conductive column, and the solder ball or the conductive column corresponds to the pad one by one.

3. A method for preparing a display device, characterized in that: include: Providing a sensor chip, wherein the sensor chip has a front side and a back side that are arranged opposite to each other, wherein the front side is used to receive light, and the back side is provided with a solder pad; forming a conductive connection member on the back side of the sensor chip, wherein the conductive connection member is electrically connected to the pad; The sensor chip is arranged opposite to the circuit board, and the conductive connecting member is electrically connected to the electrical connection point on the circuit board; Covering the front surface of the sensor chip with a display screen, with the non-display surface of the display screen facing the front surface, so that the sensor chip can receive light penetrating the display screen from the front surface; Wherein, after the step of arranging the sensor chip opposite to the circuit board and electrically connecting the conductive connecting member to the electrical connection point on the circuit board, the method further includes: forming an underfill between the sensor chip and the circuit board, wherein the underfill wraps the conductive connector; Before the step of covering the display screen on the front surface of the sensor chip, the method further includes: Laminating a surface of the circuit board facing away from the sensor chip onto a support member, wherein a protrusion is provided on an edge of the support member, and a height of the protrusion is greater than or equal to a distance between the front surface and the surface of the circuit board facing away from the sensor chip; The step of covering the display screen on the front side of the sensor chip comprises: The display screen is covered on the front surface of the sensor chip, and the protrusion is made to fit the display screen.

4. The preparation method according to claim 3, characterized in that: The step of forming a conductive connection member on the back side of the sensor chip comprises: Using a steel mesh to form solder balls on the back surface corresponding to the solder pads; or, A conductive column is formed on the back surface corresponding to the pad by using a photolithography process, and solder is formed on an end of the conductive column away from the pad.

5. The preparation method according to claim 4, characterized in that: The step of arranging the sensor chip opposite to the circuit board and electrically connecting the conductive connecting member to the electrical connection point on the circuit board comprises: The solder ball or the solder at one end of the conductive column is placed in contact with an electrical connection point on the circuit board; The solder ball or the solder is electrically connected to the electrical connection point by using a reflow process.

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