WO2022141367A1

WO2022141367A1 - Cambered capacitive fingerprint packaging structure, module, electronic device and packaging method

Info

Publication number: WO2022141367A1
Application number: PCT/CN2020/142013
Authority: WO
Inventors: 段晓锋; 刘相英
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-07-07

Abstract

The present application relates to the field of packaging, and in particular relates to a cambered capacitive fingerprint packaging structure, a module, an electronic device, a packaging method, and a method for fabricating the cambered capacitive fingerprint module. The cambered capacitive fingerprint packaging structure comprises a packaging material layer, a capacitive fingerprint sensor, a ceramic sheet, and a first die attach film (DAF) adhesive layer; the first DAF adhesive layer is disposed between the capacitive fingerprint sensor and the ceramic sheet so as to fix the ceramic sheet above the capacitive fingerprint sensor; the first DAF adhesive layer is disposed on the upper surface of the capacitive fingerprint sensor; the ceramic sheet is disposed on the upper surface of the first DAF adhesive layer; the upper surface of the packaging material layer is cambered; and the packaging material layer covers the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet. By means of arranging the ceramic sheet above the capacitive fingerprint sensor, the problem of poor fingerprint image quality due to the cambered arrangement is ameliorated.

Description

A curved capacitive fingerprint packaging structure, module, electronic device and packaging method

technical field

The present application relates to the field of biometric identification, and in particular, to a curved capacitive fingerprint packaging structure, a module, an electronic device and a packaging method.

Background technique

At present, with the development of biometric sensors, especially the rapid development of fingerprint recognition sensors, fingerprint recognition sensors are widely used in mobile terminal equipment, smart home, automotive electronics and other fields. As the years go by, the requirements of users for products are not only the pursuit of high quality and high performance, but have expanded to the diversification of appearance requirements, and the aesthetic vision of different user groups is also diversified. At present, the capacitive fingerprints in the mainstream market are all flat structures, which are not enough to adapt to the curved parts of mobile terminal devices. The surface of the side fingerprint (such as the capacitive fingerprint set near the power button) can be made into a curved surface, but the quality of the collected fingerprint image is poor, so that even for the target user, the fingerprint recognition success rate is low, and the user experience is poor.

SUMMARY OF THE INVENTION

In view of the problem of poor fingerprint image quality of curved fingerprints in the prior art, the embodiments of the present application provide a curved capacitive fingerprint packaging structure, a module, an electronic device, a packaging method, and a method for manufacturing a curved capacitive fingerprint module .

A first aspect of the embodiments of the present application provides a curved capacitive fingerprint packaging structure, including a packaging material layer, a capacitive fingerprint sensor, a ceramic sheet, and a first die-bonding film DAF adhesive layer;

A first DAF glue layer is arranged between the capacitive fingerprint sensor and the ceramic sheet to fix the ceramic sheet above the capacitive fingerprint sensor;

The first DAF adhesive layer is arranged on the upper surface of the capacitive fingerprint sensor;

The ceramic sheet is arranged on the upper surface of the first DAF adhesive layer;

The upper surface of the packaging material layer is an arc surface;

The packaging material layer covers the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet.

According to the first aspect, in a possible implementation manner, the roughness of the ceramic sheet is 0.2um to 0.8um.

According to the first aspect, in a possible implementation manner, the roughness of the upper surface of the ceramic sheet is 0.2um to 0.8um.

According to the first aspect, in a possible implementation manner, the dielectric constant of the ceramic sheet is 25 to 35.

According to the first aspect, in a possible implementation manner, the dielectric constant of the first DAF adhesive layer is 25 to 35.

According to the first aspect, in a possible implementation manner, the dielectric constant of the first DAF adhesive layer is less than or equal to the dielectric constant of the ceramic sheet;

The dielectric constant of the first DAF adhesive layer is greater than or equal to ninety percent of the dielectric constant of the ceramic sheet.

According to the first aspect, in a possible implementation manner, the thickness of the ceramic sheet is 50um to 200um.

According to the first aspect, in a possible implementation manner, the thickness of the ceramic sheet is 100um.

According to the first aspect, in a possible implementation manner, the area of the upper surface of the ceramic sheet is equal to the area of the sensing area of the capacitive fingerprint sensor; the length of the ceramic sheet is smaller than that of the capacitive fingerprint sensor, and the width of the ceramic sheet is smaller than that of the capacitive fingerprint sensor width.

According to the first aspect, in a possible implementation manner, the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the packaging material layer is 150um to 480um.

According to the first aspect, in a possible implementation manner, a second DAF adhesive layer and a substrate are further included, and a second DAF adhesive layer is arranged between the capacitive fingerprint sensor and the substrate so that the capacitive fingerprint sensor is fixed above the substrate; The DAF adhesive layer is arranged on the upper surface of the substrate;

The capacitive fingerprint sensor is arranged on the upper surface of the second DAF adhesive layer;

It also includes a solder layer and an FPC, and a solder layer is arranged between the substrate and the FPC to electrically connect the substrate and the FPC;

It also includes a reinforcing plate, and the reinforcing plate is arranged on the lower surface of the FPC.

A second aspect of the embodiments of the present application provides an arc-surface capacitive fingerprint module, including the arc-surface capacitive fingerprint package structure according to any one of the first aspects, further comprising an arc-shaped coating layer, and the arc-shaped coating layer It is arranged on the upper surface of the packaging material layer, and the upper surface of the arc-shaped coating layer is an arc surface.

According to the second aspect, in a possible implementation manner, the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the arc-shaped coating layer is 170um to 500um.

According to the second aspect, in a possible implementation manner, the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the arc-shaped coating layer is 200um to 500um.

According to the second aspect, in a possible implementation manner, the radius of the upper surface of the arc-shaped coating layer is 0.8 mm to 8 mm.

A third aspect of the embodiments of the present application provides an electronic device, comprising: a circuit board and the curved capacitive fingerprint module according to any one of the second aspects, wherein the curved capacitive fingerprint module and the circuit board are connected by a connector .

A fourth aspect of the embodiments of the present application provides an encapsulation method, which is applied to the fabrication of the arc-surface capacitive fingerprint encapsulation structure according to any one of the first aspects, and is characterized in that, it includes:

The capacitive fingerprint sensor is pasted above the substrate through the second DAF adhesive layer;

The ceramic sheet is pasted above the capacitive fingerprint sensor through the first DAF adhesive layer;

The pins of the capacitive fingerprint sensor are electrically connected to the pins of the substrate through metal wires;

The second DAF adhesive layer, the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet are covered with a plastic packaging material to form a packaging material layer above the substrate, and the upper surface of the packaging material layer is an arc surface.

According to the fourth aspect, in a possible implementation manner, before the ceramic sheet is pasted above the capacitive fingerprint sensor through the first DAF adhesive layer, the method further includes: processing the ceramic sheet so that the roughness of the upper surface of the ceramic sheet is 0.2um to 0.8 um;

The ceramic sheet is pasted above the capacitive fingerprint sensor through the first DAF adhesive layer, including:

The lower surface of the ceramic sheet is pasted on the upper surface of the capacitive fingerprint sensor through the first DAF adhesive layer.

A fifth aspect of the embodiments of the present application provides a method for manufacturing a curved capacitive fingerprint module, which is applied to the manufacturing of the curved capacitive fingerprint module as in any one of the second aspects, and is characterized in that, comprising:

The second DAF adhesive layer, the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet are covered with a plastic packaging material to form a packaging material layer above the substrate, and the upper surface of the packaging material layer is an arc surface;

The upper surface of the encapsulating material layer is coated to form an arc-shaped coating layer.

According to the fifth aspect, in a possible implementation manner, before the ceramic sheet is pasted on the capacitive fingerprint sensor through the first DAF adhesive layer, the method further includes: processing the ceramic sheet so that the roughness of the upper surface of the ceramic sheet is 0.2um to 0.8 um;

Pasting the ceramic sheet on the capacitive fingerprint sensor through the first DAF glue layer includes: pasting the lower surface of the ceramic sheet on the upper surface of the capacitive fingerprint sensor through the first DAF glue layer.

Compared with the prior art, the beneficial effects of the embodiments of the present application are: the embodiments of the present application provide a curved capacitive fingerprint packaging structure, a module, an electronic device, a packaging method, and a method for making a curved capacitive fingerprint module, By arranging the ceramic plate above the capacitive fingerprint sensor, the problem of poor fingerprint image quality caused by the curved surface arrangement is improved.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

1 is a cross-sectional view of a capacitive fingerprint module according to an embodiment of the present application;

FIG. 2 is a flowchart of an encapsulation method provided by an embodiment of the present application;

3 is a schematic diagram of a package sheet provided by an embodiment of the present application;

4 is a schematic diagram of another packaging sheet provided by an embodiment of the present application;

5 is a schematic diagram of an encapsulation sheet with another cross-sectional angle provided by an embodiment of the present application;

6 is a schematic diagram of yet another packaging sheet provided by an embodiment of the present application;

FIG. 7 is a flowchart of another packaging method provided by an embodiment of the present application;

8 is a flowchart of a method for manufacturing a curved capacitive fingerprint module according to an embodiment of the present application;

FIG. 9 is a schematic diagram of yet another packaging sheet provided by an embodiment of the present application;

FIG. 10 is a flowchart of another method for manufacturing a curved capacitive fingerprint module provided by an embodiment of the present application.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, some embodiments of the present application will be described in detail below by way of examples in conjunction with the accompanying drawings. However, one of ordinary skill in the art will appreciate that in each instance, numerous technical details are set forth in order to provide the reader with a better understanding of the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can be realized.

For a long time, the capacitive fingerprint module has always adopted the traditional structure, which is basically a square or circular plane contact structure. The user feels uncomfortable and unsightly in use, and in harsh environments such as windy sand and dust, the Dust will be easily adsorbed on the flat contact structure, resulting in misjudgment of fingerprint recognition when the capacitive fingerprint module is in use. The effective solution is to use a curved capacitive fingerprint scheme. This new structural design scheme improves the fingerprint recognition module. After it is installed on the whole machine, the whole machine is more aesthetically pleasing in appearance, and the user feels comfortable. , visually has a three-dimensional sense, on the other hand, the use of the curved three-dimensional design can avoid damage to the entire capacitive fingerprint recognition module when the mobile phone is dropped.

1 is a cross-sectional view of a curved capacitive fingerprint module provided by an embodiment of the present application. The curved fingerprint module 100 includes a capacitive fingerprint sensor 101 and a ceramic sheet 111 , and a first capacitive fingerprint sensor 111 is disposed between the ceramic sheet 111 and the capacitive fingerprint sensor 101 . Die Attach Film (DAF) adhesive layer 112, the first DAF adhesive layer 112 is used to fix the ceramic sheet 111 above the capacitive fingerprint sensor 101. For convenience of description, the capacitive fingerprint sensor is represented by Die, the module It also includes a substrate 102 , the Die101 is electrically connected to the substrate 102 , the substrate 102 is located below the Die101 , a second DAF adhesive layer 104 is arranged between the Die101 and the substrate 102 , and the second DAF adhesive layer 104 is used to fix the Die101 above the substrate 102 . The Die 101 can be directly attached to the upper surface of the substrate 102 through the second DAF adhesive layer 104 , and then the electrical connection between the Die 101 and the substrate 102 can be realized by wire bonding (Wire Bonding, WB). The module 100 further includes a flexible circuit board (Flexible Printed Circuit, FPC) 103, the module further includes a solder layer 107, and the solder layer is disposed between the substrate 102 and the FPC 103. In this embodiment, solder is then filled with underfill (underfill). ) glue connects the substrate 102 and the FPC 103 , the solder layer 107 includes solder and glue, the solder is used to electrically connect the substrate 102 and the FPC 103 , and the glue is used to strengthen the physical connection between the substrate 102 and the FPC 103 . The template also includes a reinforcing steel plate (or referred to as a reinforcing plate, a steel reinforcement, or a reinforcing steel sheet) 108 . The reinforcing steel plate is arranged on the lower surface of the FPC 103 , and the reinforcing steel plate 108 is used to fix the FPC 103 . The module 100 may further include a packaging material layer 105, the packaging material layer 105 covers the Die101, and since the upper surface of the Die101 is the first DAF adhesive layer 112, and the upper surface of the first DAF adhesive layer 112 is the ceramic sheet 111, therefore, The packaging material layer 105 covers the packaging sheet composed of the Die 101 , the first DAF adhesive layer 112 and the ceramic sheet 111 . For the convenience of description, the packaging material layer is described by taking an epoxy resin molding compound or an epoxy molding compound (Epoxy Molding Compound, EMC) layer as an example. The upper surface of the EMC layer 105 is provided with an arc-shaped coating layer 106. The layers are, for example, ink layers. In this embodiment, the encapsulation material layer can be obtained by CNC surface machining and then polishing, or through a molding (Molding) process using an arc-surface Molding mold to obtain an encapsulation material layer with an arc surface on the upper surface.

In this embodiment, by arranging a ceramic sheet above the capacitive fingerprint sensor, since ceramic is a high-dielectric material, the dielectric constant of the ceramic sheet is higher than that of the EMC layer. Therefore, under the same physical environment of the finger and the surface of the finger, When the ceramic sheet is set above the Die, the signal volume of the capacitance obtained by the test is larger, which can be understood as improving the penetration ability of the capacitance signal, which is of great significance to the curved fingerprint. For a flat fingerprint module, the distance between the user's finger and the upper surface of the Die is small, so a better quality fingerprint image can be obtained. For curved fingerprints, when the user presses the finger on the curved fingerprint module, the distance between the upper surface of the capacitive fingerprint sensor and the finger is relatively large. Therefore, it is not easy to obtain high-quality fingerprint images. After the ceramic chip is arranged above the capacitive fingerprint sensor, the problem of poor fingerprint image quality can be improved. In addition, for the curved capacitive fingerprint package or module structure, there is enough space above the capacitive fingerprint sensor to accommodate the ceramic chip. Therefore, Placing a ceramic sheet above the capacitive fingerprint sensor in the package or module generally does not increase the thickness of the curved fingerprint package or module, and the user experience is better.

Based on the contents disclosed in the above embodiments, in this embodiment, since the ceramic sheet is disposed above the capacitive fingerprint sensor, the packaging material layer 105 covers the capacitive fingerprint sensor 101 and the packaging material layer also covers the ceramic sheet 111 and the first For a DAF adhesive layer 112, if the upper surface of the ceramic sheet 111 is smooth, delamination is likely to occur at the contact position between the EMC layer 105 and the ceramic sheet 111, that is, an air gap will be generated between the ceramic sheet and the EMC layer 105. The dielectric constant of the ceramic sheet is low, so the quality of the fingerprint image will be reduced. In order to solve this problem, the roughness of the ceramic sheet can be set to 0.2um to 0.8um. Specifically, the roughness of the upper surface of the ceramic sheet can be set as 0.2um to 0.8um, in addition, this setting can also enhance the bonding force between the packaging material layer and the ceramic sheet, which helps to improve the reliability of the packaging structure or the module. The evaluation parameters of the surface roughness stipulated in the national standard mainly include basic parameters and additional parameters, among which, the substrate parameter is also called the amplitude parameter, and the roughness in this embodiment can be understood as the amplitude parameter Ra (the arithmetic mean deviation of the contour). In this embodiment, the overall roughness of the ceramic sheet can also be set to be 0.2um to 0.8um, that is, the roughness of the lower surface or side surface of the ceramic sheet can also be set to 0.2um to 0.8um, which also helps to improve the first DAF. The bonding force between the adhesive layer and the ceramic sheet can avoid the generation of an air gap between the first DAF adhesive layer and the ceramic sheet, so that the quality of the fingerprint image is degraded, and the reliability can also be improved.

Based on the content disclosed in the above embodiments, in this embodiment, in order to further improve the quality of the fingerprint image, the dielectric constant of the ceramic sheet is set between 25 and 35. When the dielectric constant of the ceramic sheet is set between 25 and 35 , under the same physical environment of the finger and the surface of the finger, the signal quantity of the detected capacitance is larger, therefore, the quality of the obtained fingerprint image can be further improved. In this embodiment, the dielectric constant of the first DAF adhesive layer is not limited, for example, the dielectric constant of the first DAF adhesive layer can be set to be 3.5.

Based on the content disclosed in the above embodiments, in this embodiment, in order to further improve the quality of the fingerprint image, the dielectric constant of the first DAF adhesive layer is set to be between 25 and 35. When the dielectric constant of the first DAF adhesive layer is set to Between 25 and 35, under the same physical environment of the finger and the surface of the finger, the signal amount of the detected capacitance is larger, therefore, the quality of the obtained fingerprint image can be further improved. Further, if the dielectric constant of the ceramic sheet is between 25 and 35, and the dielectric constant of the first DAF adhesive layer is also between 25 and 35, when the dielectric constants of the ceramic sheet and the first DAF adhesive layer are similar, The quality of the acquired fingerprint image can be further improved.

Based on the contents disclosed in the above embodiments, in this embodiment, the dielectric constant of the first DAF adhesive layer is less than or equal to the dielectric constant of the ceramic sheet, and the dielectric constant of the first DAF adhesive layer is greater than or equal to the dielectric constant of the ceramic sheet ninety percent. In this embodiment, the dielectric constants of the ceramic sheet and the first DAF adhesive layer are similar. Specifically, the dielectric constant of the first DAF adhesive layer is less than or equal to the dielectric constant of the ceramic sheet and greater than or equal to the dielectric constant of the ceramic sheet. 90%, the relationship between the dielectric constant of the first DAF adhesive layer and the dielectric constant of the ceramic sheet is set in this way, which is easy to implement in terms of technology and saves costs.

Based on the content disclosed in the above embodiments, in this embodiment, the thickness of the ceramic sheet is 50um to 200um. If the ceramic sheet is too thin, the ceramic sheet is easily broken during the process of attaching to the fingerprint recognition sensor, which is not conducive to the realization of the process. , If the ceramic sheet is too thick, the distance between the finger and the fingerprint recognition sensor may be too far, so that the obtained fingerprint image quality is poor and the fingerprint recognition is affected. When the thickness of the ceramic sheet is set to 50 to 200um, the fingerprint image can be guaranteed. The quality of the package can also guarantee the yield of the package or module.

Based on the content disclosed in the above embodiments, in this embodiment, the thickness of the ceramic sheet can be set to 100um, when the thickness of the ceramic sheet is set to 100um, a better quality fingerprint image can be obtained, which is easy to identify, and the ceramic sheet is also easy to Attached to the fingerprint recognition sensor, it can be a good balance of fingerprint image quality and reliability.

Based on the contents disclosed in the above embodiments, in this embodiment, the area of the upper surface of the ceramic sheet is equal to the area of the sensing area of the capacitive fingerprint sensor. Generally, since the area of the upper surface of the ceramic sheet is equal to the area of the lower surface, it is also It can be understood that the area of the lower surface of the ceramic sheet is equal to the area of the sensing area of the capacitive fingerprint sensor. Since the sensing area of the capacitive fingerprint sensor is used to test the signal amount of the capacitance, when the ceramic sheet is placed directly above the sensing area and can completely cover the capacitance When the sensor is in the sensing area of the sensor, a better fingerprint image can be obtained. Generally, the area of the sensing area of the capacitive fingerprint sensor is smaller than the area of the upper surface of the capacitive fingerprint sensor. In this embodiment, the area of the upper surface of the ceramic sheet is equal to the area of the sensing area of the capacitive fingerprint sensor, and the length of the ceramic sheet is smaller than that of the capacitive fingerprint sensor. The length of the sensor and the width of the ceramic sheet are smaller than the width of the capacitive fingerprint sensor.

Based on the contents disclosed in the foregoing embodiments, in this embodiment, the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the packaging material layer is 150 um to 480 um. The packaging material layer covers the capacitive fingerprint sensor. When the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the packaging material layer is too far, the acquired fingerprint image quality is poor and the fingerprint recognition is affected. When the distance from the center of the upper surface of the capacit When the distance from the center of the upper surface is 150um to 480um, the quality of the fingerprint image can be guaranteed, and the yield can also be guaranteed.

In this embodiment, the center of the plane graphics can be understood as the intersection of the diagonals of the plane graphics. For example, if the upper surface of the Die is a rectangle, the center of the upper surface of the Die is the intersection of the diagonals of the rectangle. If the upper surface is a circle, the center of the upper surface of Die is the center of the circle.

Based on the contents disclosed in the above embodiments, in this embodiment, please refer to FIG. 1 , the capacitive fingerprint packaging structure further includes a second DAF adhesive layer 104 and a substrate 102 , and the second DAF adhesive layer is disposed between the capacitive fingerprint sensor 101 and the substrate 102 So that the capacitive fingerprint sensor 101 is fixed on the upper surface of the substrate 102 through the second DAF adhesive layer. The capacitive fingerprint package structure may further include a solder layer 107 and an FPC 103 , the solder layer 107 is disposed between the substrate 102 and the FPC 103 , and the solder layer is used to electrically connect the substrate 102 and the FPC 103 .

Based on the contents disclosed in the above embodiments, in this embodiment, please refer to the curved capacitive fingerprint module shown in FIG. 1 . Different from the package structure of the curved capacitive fingerprint, the curved capacitive fingerprint module also includes an arc coating Layer 106, the arc-shaped coating layer 106 is disposed on the upper surface of the packaging material layer 105, and the upper surface of the arc-shaped coating layer 106 is an arc surface. In this embodiment, the arc-shaped coating layer can be formed by a coating process. Compared with the traditional cover plate process, the arc-shaped coating layer formed by the coating process is selected in terms of material, thickness, color and other characteristics. Higher degrees of freedom.

Based on the content disclosed in the above embodiments, in this embodiment, the distance D1 from the center of the upper surface of the fingerprint sensor to the center of the upper surface of the arc-shaped coating layer is 170um to 500um. When the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the arc-shaped coating layer is too far, the acquired fingerprint image quality is so poor that fingerprint recognition is affected. When the distance between the center of the upper surface of the arc-shaped coating layer is too close, it may cause reliability problems, so that the yield may be reduced, when the center of the upper surface of the capacitive fingerprint sensor is set to the upper surface of the arc-shaped coating layer. When the distance from the center is 170um to 500um, the quality of the fingerprint image can be guaranteed, and the yield can also be guaranteed. In addition, when the distance D1 from the center of the upper surface of the fingerprint sensor to the center of the upper surface of the arc-shaped coating layer is 200um to 500um, arranging the ceramic sheet 111 above the fingerprint sensor 101 can greatly improve the quality of the fingerprint image . Generally speaking, for the planar capacitive fingerprint module, the maximum distance from the capacitive fingerprint sensor to the planar coating layer is generally 200um. When the distance from the capacitive fingerprint sensor to the planar coating layer is greater than 200um, high-quality fingerprint images may not be obtained. However, the fingerprint recognition is affected. For the curved capacitive fingerprint module, setting a ceramic sheet above the capacitive fingerprint sensor can increase the distance from the capacitive fingerprint sensor to the curved coating layer to 500um, which can better satisfy consumers' expectations for the whole machine. Requirements for a wide curvature of the fingerprint identification face (the face that contacts the consumer's finger). In this embodiment, the ceramic sheet can be pasted on the surface of the fingerprint recognition sensor through the DAF adhesive layer, and then the whole is made into a package sheet, and finally a coating process is performed for surface treatment to form an arc-shaped coating layer, so as to make a curved capacitive fingerprint mold Group. In the present embodiment, the R angle of the upper surface of the arc-shaped coating layer 106 may be 0.8 mm˜8 mm, and the radius of the upper surface of the arc-shaped coating layer may be set at 0.8 mm˜8 mm, so as to satisfy consumers’ requirements for wide curvature. need. For the thickness design of the arc-shaped coating layer, if the arc-shaped coating layer is a matte layer, its thickness can be set to 25um, and if the arc-shaped coating layer is a high-gloss layer, its thickness can be set to 30um.

Based on the content disclosed in the foregoing embodiments, this embodiment discloses an electronic device, which may be a mobile phone, tablet, computer, or other electronic device including the fingerprint module disclosed in the foregoing embodiment, the capacitive fingerprint module and the electronic device. The circuit boards inside are connected by connectors.

Based on the contents disclosed in the above embodiments, the present embodiment discloses a packaging method, which is applied to the capacitive fingerprint packaging structure disclosed in the above embodiments. Specifically, as shown in FIG. 2 , the method includes the following steps:

S201: pasting the capacitive fingerprint sensor on the top of the substrate through the second DAF adhesive layer;

S202: pasting the ceramic sheet on the capacitive fingerprint sensor through the first DAF adhesive layer;

S203: electrically connect the pins of the capacitive fingerprint sensor to the pins of the substrate through metal wires;

S204 : encapsulating the second DAF adhesive layer, the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet with a plastic packaging material to form a packaging material layer above the substrate, and the upper surface of the packaging material layer is an arc surface.

In step S201 , referring to FIG. 3 , the capacitive fingerprint sensor 301 is pasted on the substrate 302 through the second DAF adhesive layer 304 through a die bonding (DB) process to form a package as shown in FIG. 3 . 300. The capacitive fingerprint sensor 301 , the second DAF adhesive layer 304 , and the substrate 302 in this embodiment are the same as or similar to the capacitive fingerprint sensor 101 , the second DAF adhesive layer 104 , and the substrate 102 disclosed in the previous embodiments, and will not be repeated here.

Step S202 can be understood as attaching a ceramic sheet, please refer to FIG. 4 , that is, the ceramic sheet 411 is pasted above the capacitive fingerprint sensor 401 through the first DAF adhesive layer 412 , for example, the ceramic sheet 411 is pasted above the sensing area of the capacitive fingerprint sensor 401 . to form the encapsulation sheet shown in FIG. 4 . The ceramic sheet 411 , the first DAF adhesive layer 412 , the capacitive fingerprint sensor 401 , the second DAF adhesive layer 404 , and the substrate 402 in this embodiment are the same as the ceramic sheet 111 , the first DAF adhesive layer 112 , and the capacitive fingerprint sensor disclosed in the foregoing embodiments. 101 , the second DAF adhesive layer 104 and the substrate 102 are the same or similar, and will not be repeated here.

In step S203, please refer to the cross-sectional view of the curved capacitive fingerprint module shown in FIG. 5 from another angle, using the WB process, the pins (IO or Pad) of the capacitive fingerprint sensor 501 can be connected to the substrate through the metal wire 509. The pins of 502 are electrically connected to form the package sheet 500 shown in FIG. 5 , and the metal wire 509 is, for example, a gold wire. In this embodiment, the ceramic sheet 511 , the first DAF adhesive layer 512 , the capacitive fingerprint sensor 501 , the second DAF adhesive layer 504 , the substrate 502 , the solder layer 507 , the FPC 503 , the reinforcing steel plate 508 , the arc-shaped coating layer 506 , the package The material layer 505 and the ceramic sheet 111, the first DAF adhesive layer 112, the capacitive fingerprint sensor 101, the second DAF adhesive layer 104, the substrate 102, the solder layer 107, the FPC 103, the reinforcing steel plate 108, and the arc coating disclosed in the foregoing embodiments The layer 106 and the packaging material layer 105 are the same or similar, and are not repeated here. In this embodiment, the package structure may further include a reinforcing plate 508 , and the reinforcing plate 508 is disposed on the lower surface of the FPC 503 . The reinforcing steel plate 508 can also be used to fix the connector 510, and the connector 510 is used for connecting the capacitive fingerprint sensor with other circuits in the electronic device to realize the fingerprint identification function, such as the motherboard. It can be understood that the cross-section of the cross-sectional view shown in FIG. 5 in this embodiment is perpendicular to the cross-section of the cross-sectional view shown in FIG. 1 , and the cross-sectional view shown in FIG. 5 in this embodiment can conveniently show the gold wires 509 and connector 510.

In step S204 , please refer to the packaging sheet 600 shown in FIG. 6 , use the Molding process to make the EMC layer 605 with the plastic packaging material through the mold to cover the capacitive fingerprint sensor 601 , the first DAF adhesive layer 612 and the ceramic sheet 611 to protect the capacitor The fingerprint sensor 601 , the ceramic sheet 611 and the gold wire, that is, the packaging material layer can be molded according to the designed external dimensions to form the EMC layer 605 shown in FIG. 6 . As shown in FIG. 6, the distance D2 from the center of the upper surface of the capacitive fingerprint sensor 601 to the center of the upper surface of the encapsulation material layer 605 is 150 um to 480 um. The ceramic sheet 611 , the first DAF adhesive layer 612 , the capacitive fingerprint sensor 601 , the second DAF adhesive layer 604 , and the substrate 602 in this embodiment are the same as the ceramic sheet 111 , the first DAF adhesive layer 112 , and the capacitive fingerprint sensor disclosed in the foregoing embodiments. 101 , the second DAF adhesive layer 104 and the substrate 102 are the same or similar, and will not be repeated here. After molding so that the upper surface of the EMC is curved, a surface mount technology (Surface Mounted Technology, SMT) process can be used to form a solder layer 107 on the lower surface of the substrate as shown in FIG. 1 by soldering, so that the substrate and the The FPC is electrically connected, and then Coating is performed to form an arc-shaped coating layer on the upper surface of the EMC layer.

Based on the contents disclosed in the above embodiments, the embodiments of the present application provide a packaging method. Please refer to FIG. 7 . Unlike the packaging method shown in FIG. 2 , step S702 may also be included before attaching the ceramic sheet: processing the ceramic sheet to make The roughness of the upper surface thereof is 0.2um to 0.8um; after step S702, step S703 may be performed: pasting the lower surface of the ceramic sheet on the upper surface of the capacitive fingerprint sensor through the first DAF adhesive layer. In step S702, in this embodiment, processing the ceramic sheet may be understood as making a ceramic sheet with a roughness of the upper surface of 0.2um to 0.8um, or manufacturing a ceramic sheet with a roughness of the outer surface of 0.2um to 0.8um. In order to meet the roughness requirements of ceramics, it is possible to check whether the ceramic sheets meet the roughness requirements of 0.2um to 0.8um in the incoming quality control (Incoming Quality Control, IQA). In this embodiment, steps S701 , S704 , and S705 are the same as or similar to steps S201 , S203 , and S204 in the foregoing embodiments, and will not be repeated here.

Based on the content disclosed in the foregoing embodiments, the present embodiment discloses a method for manufacturing a capacitive fingerprint module. As shown in FIG. 8 , the method includes the following steps:

S801: pasting the capacitive fingerprint sensor on the top of the substrate through the second DAF adhesive layer;

S802: pasting the ceramic sheet on the capacitive fingerprint sensor through the first DAF adhesive layer;

S803: electrically connect the pins of the capacitive fingerprint sensor to the pins of the substrate through metal wires;

S804: Use a plastic packaging material to coat the second DAF adhesive layer, the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet to form a packaging material layer above the substrate, and the upper surface of the packaging material layer is an arc surface;

S805: Coating the upper surface of the packaging material layer to form an arc-shaped coating layer

In this embodiment, steps S801-S804 are the same as or similar to steps S201-S204 in the foregoing embodiment, and are not repeated here. In step S805 , the upper surface of the packaging material layer shown in FIG. 6 may be coated to form the arc-shaped coating layer 106 shown in FIG. 1 to form the capacitive fingerprint module structure 100 .

For step S804, encapsulating the capacitive fingerprint sensor with encapsulation material can also form the encapsulating sheet 900 shown in FIG. 9, wherein the top surface of the encapsulating material layer 905 is flat, and the encapsulating material layer can be processed by CNC surface machining and polishing process to As shown in FIG. 6 , an encapsulation sheet 600 having an arc surface on the top surface of the encapsulation material layer is formed, and then step S805 is performed to form the arc surface coating layer disclosed in the foregoing embodiments on the top surface of the encapsulation sheet 600 . The ceramic sheet 911 , the first DAF adhesive layer 912 , the capacitive fingerprint sensor 901 , the second DAF adhesive layer 904 , and the substrate 902 in this embodiment are the same as the ceramic sheet 111 , the first DAF adhesive layer 112 , and the capacitive fingerprint sensor disclosed in the previous embodiments. 101 , the second DAF adhesive layer 104 and the substrate 102 are the same or similar, and will not be repeated here. In this embodiment, between steps S804 and S805 , the steps may further include: attaching the substrate to the FPC through a solder layer through an SMT process, that is, setting a solder layer between the FPC and the substrate to realize electrical connection between the FPC and the substrate.

For step S804, the encapsulation material layer 605 with the upper surface of the encapsulation material layer being an arc surface can also be directly fabricated by the arc-surface molding mold. If the angle is preset, the chamfering and blanking process can be processed by CNC to form the chamfering angle of the preset angle, and then the coating surface treatment is performed to form the arc coating layer. In this embodiment, the CNC surface processing and polishing process.

Based on the contents disclosed in the above embodiments, the embodiments of the present application provide a method for manufacturing a capacitive fingerprint module. Please refer to FIG. 10 . Different from the method shown in FIG. 8 , step S1002 may also be included before attaching the ceramic sheet: The ceramic sheet is processed so that the upper surface has a roughness of 0.2um to 0.8um; after step S1002, step S1003 can be performed: pasting the lower surface of the ceramic sheet on the upper surface of the capacitive fingerprint sensor through the first DAF adhesive layer. In step S1002, a ceramic sheet with a roughness of the upper surface of 0.2um to 0.8um can be fabricated. In this embodiment, steps S1001, S1004, S1005, and S1006 are the same as or similar to steps S801, S803, S804, and S805 in the foregoing embodiments, and are not repeated here.

It should be noted that, compared with the capacitive fingerprint module structure in the foregoing embodiment, the capacitive fingerprint package structure provided in this embodiment omits the arc-shaped coating layer. For the specific implementation of the above, please refer to the above-mentioned embodiment, which is not repeated here. Repeat.

This embodiment also provides an electronic device, the electronic device is provided with a circuit board, and a specific circuit board may include a memory and a processor, and the capacitive fingerprint module is connected to the circuit board. Specifically, the capacitive fingerprint module is connected to the circuit board through a connection. The electronic device can be a mobile phone or a tablet, a computer and other electronic devices. For the specific implementation of the above, refer to the above-mentioned embodiments, and details are not repeated here.

It should be understood that, in this embodiment of the present application, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean that B is only determined according to A, and B may also be determined according to A and/or other information.

In addition, the term "and/or" in this article is only an association relationship to describe the associated objects, indicating that there can be three kinds of relationships, for example, A and/or B, it can mean that A exists alone, A and B exist at the same time, There are three cases of B alone. In addition, the character "/" in this document generally indicates that the related objects are an "or" relationship.

Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described systems, devices and units may refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. should be covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

A curved capacitive fingerprint packaging structure, characterized in that it comprises a packaging material layer, a capacitive fingerprint sensor, a ceramic sheet, and a first wafer bonding film DAF adhesive layer;

The first DAF adhesive layer is arranged between the capacitive fingerprint sensor and the ceramic sheet to fix the ceramic sheet above the capacitive fingerprint sensor;

the first DAF adhesive layer is disposed on the upper surface of the capacitive fingerprint sensor;

The ceramic sheet is arranged on the upper surface of the first DAF adhesive layer;

The upper surface of the packaging material layer is an arc surface;

The packaging material layer covers the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet.
The arc-surface capacitive fingerprint package structure according to claim 1, wherein the ceramic sheet has a roughness of 0.2um to 0.8um.
The arc-surface capacitive fingerprint package structure according to claim 2, wherein the roughness of the upper surface of the ceramic sheet is 0.2um to 0.8um.
The arc-surface capacitive fingerprint package structure according to any one of claims 1 to 3, wherein the dielectric constant of the ceramic sheet is 25 to 35.
The arc-surface capacitive fingerprint package structure according to any one of claims 1 to 4, wherein the dielectric constant of the first DAF adhesive layer is 25 to 35.
The arc-surface capacitive fingerprint package structure according to any one of claims 1 to 4, wherein the dielectric constant of the first DAF adhesive layer is less than or equal to the dielectric constant of the ceramic sheet;

The dielectric constant of the first DAF adhesive layer is greater than or equal to 90% of the dielectric constant of the ceramic sheet.
The arc-surface capacitive fingerprint package structure according to any one of claims 1 to 6, wherein the thickness of the ceramic sheet is 50um to 200um.
The arc-surface capacitive fingerprint package structure according to claim 7, wherein the thickness of the ceramic sheet is 100um.
The arc-surface capacitive fingerprint package structure according to any one of claims 1 to 8, wherein the area of the upper surface of the ceramic sheet is equal to the area of the sensing area of the capacitive fingerprint sensor; The length is smaller than the length of the capacitive fingerprint sensor, and the width of the ceramic sheet is smaller than the width of the capacitive fingerprint sensor.
The arc-surface capacitive fingerprint packaging structure according to any one of claims 1 to 9, wherein the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the packaging material layer is 150um to 150um 480um.
The arc-surface capacitive fingerprint package structure according to any one of claims 1 to 10, further comprising a second DAF adhesive layer and a substrate, and the second DAF adhesive layer is disposed between the capacitive fingerprint sensor and the substrate A DAF adhesive layer is used to fix the capacitive fingerprint sensor on the substrate; the second DAF adhesive layer is arranged on the upper surface of the substrate;

The capacitive fingerprint sensor is arranged on the upper surface of the second DAF adhesive layer;

It also includes a solder layer and an FPC, and the solder layer is arranged between the substrate and the FPC so that the substrate and the FPC are electrically connected;

It also includes a reinforcing plate, and the reinforcing plate is arranged on the lower surface of the FPC.
A curved capacitive fingerprint module, characterized in that it comprises the curved capacitive fingerprint encapsulation structure according to any one of claims 1 to 11, and further comprises an arc-shaped coating layer, wherein the arc-shaped coating layer is provided with On the upper surface of the packaging material layer, the upper surface of the arc-shaped coating layer is an arc surface.
The curved capacitive fingerprint module according to claim 12, wherein the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the arc-shaped coating layer is 170um to 500um.
The arc capacitive fingerprint module according to claim 12, wherein the distance from the center of the upper surface of the capacitive fingerprint sensor to the center of the upper surface of the arc-shaped coating layer is 200um to 500um.
The curved capacitive fingerprint module according to any one of claims 12 to 14, wherein the radius of the upper surface of the curved coating layer is 0.8 mm to 8 mm.
An electronic device, characterized in that it comprises: a circuit board and a curved capacitive fingerprint module according to any one of claims 12 to 15, wherein the curved capacitive fingerprint module and the circuit board pass through a connector connect.
An encapsulation method, which is applied to make the arc-surface capacitive fingerprint encapsulation structure according to any one of claims 1 to 11, characterized in that, comprising:

The capacitive fingerprint sensor is pasted above the substrate through the second DAF adhesive layer;

The ceramic sheet is pasted above the capacitive fingerprint sensor through the first DAF adhesive layer;

The pins of the capacitive fingerprint sensor are electrically connected to the pins of the substrate through metal wires;

The second DAF adhesive layer, the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet are covered with a plastic encapsulation material to form an encapsulation material layer over the substrate.
The packaging method according to claim 17, wherein before the first DAF adhesive layer is used to paste the ceramic sheet over the capacitive fingerprint sensor, the method further comprises: processing the ceramic sheet to make its upper surface rough Degree is 0.2um to 0.8um;

The step of pasting the ceramic sheet on the capacitive fingerprint sensor through the first DAF adhesive layer includes:

The lower surface of the ceramic sheet is pasted on the upper surface of the capacitive fingerprint sensor through the first DAF adhesive layer.
A method for making a curved capacitive fingerprint module, which is applied to the manufacturing of the curved capacitive fingerprint module according to any one of claims 12 to 15, wherein the method comprises:

The capacitive fingerprint sensor is pasted above the substrate through the second DAF adhesive layer;

The ceramic sheet is pasted above the capacitive fingerprint sensor through the first DAF adhesive layer;

The pins of the capacitive fingerprint sensor are electrically connected to the pins of the substrate through metal wires;

encapsulating the second DAF adhesive layer, the capacitive fingerprint sensor, the first DAF adhesive layer and the ceramic sheet with a plastic encapsulation material to form an encapsulation material layer over the substrate;

The upper surface of the encapsulating material layer is coated to form an arc-shaped coating layer.
The method for manufacturing a curved capacitive fingerprint module according to claim 19, wherein before the ceramic sheet is pasted on the capacitive fingerprint sensor through the first DAF adhesive layer, the method further comprises: processing the ceramic The roughness of the upper surface of the sheet is 0.2um to 0.8um;

The step of pasting the ceramic sheet over the capacitive fingerprint sensor through the first DAF adhesive layer includes: pasting the lower surface of the ceramic sheet on the upper surface of the capacitive fingerprint sensor through the first DAF adhesive layer.