CN105676953B

CN105676953B - Mobile terminal with fingerprint sensor packaging structure and preparation method thereof

Info

Publication number: CN105676953B
Application number: CN201510992328.0A
Authority: CN
Inventors: 吴磊; 黄昊; 徐启波
Original assignee: CHENGDU FEIENGEER MICROELECTRONICS TECHNOLOGY Co Ltd; Shanghai Figorn Microelectronics Technology Co Ltd
Current assignee: Shanghai Feigeen Microelectronics Technology Co ltd
Priority date: 2015-12-25
Filing date: 2015-12-25
Publication date: 2020-03-20
Anticipated expiration: 2035-12-25
Also published as: CN105676953A

Abstract

A mobile terminal with a fingerprint sensor packaging structure and a preparation method thereof are provided, wherein a fingerprint sensor assembly in the mobile terminal comprises two independent parts, the first part is a sensor injection molding part, and the mobile terminal comprises: the sensor comprises a semiconductor sensor die, a sensing pixel array on the surface, a substrate for bearing the sensor die and electrically connected with pins of the sensor die, bonding wires for electrically connecting the pins of the sensor die and the pins of the substrate, and an injection molding material for wrapping the sensor die (including the sensing pixel array on the surface), the bonding wires and the substrate; the second part includes: the sensor injection molding comprises a substrate used for bearing the sensor injection molding and electrically connected with the sensor injection molding, a connector connected with the substrate, and a metal frame embedded around the surface of the sensor injection molding. Therefore, the fingerprint sensor module can be greatly reduced in size according to the fingerprint sensor assembly of the invention, and is particularly suitable for being applied to mobile terminals or equipment with strict requirements on space dimensions.

Description

Mobile terminal with fingerprint sensor packaging structure and preparation method thereof

Technical Field

The present invention relates to the field of semiconductor packaging, and more particularly, to a packaging technique of a capacitive semiconductor fingerprint sensor and a related method thereof, and more particularly, to a mobile terminal having a fingerprint sensor packaging structure and a method for manufacturing the same.

Background

With the rise of Touch ID of apple iphone5S fingerprint identification device in recent years, a tide of fingerprint identification is blown in the field of smart phones.

However, the prior art fingerprint recognition scheme requires that a fingerprint recognition assembly be mounted in a groove formed in the front or rear surface of the mobile phone case such that the collection surface of the fingerprint recognition assembly is exposed to contact with a finger. The case slotting scheme, particularly the front panel, needs to open holes in the touch screen, which not only increases the process steps of the touch screen, but also affects the overall structure and appearance of the terminal device, so that the ID design becomes complicated.

In addition, the limit detection sensitivity of the capacitive fingerprint sensor in the prior art can only reach 100um due to the limitation of the design principle and the architecture. Although the detection sensitivity of the radio frequency fingerprint sensor is higher than that of a capacitive type fingerprint sensor, a radio frequency electrode is needed, and a conductive radio frequency electrode is difficult to manufacture on the surface of a touch screen cover plate by a touch screen processing technology, so that the support of the existing touch screen on the radio frequency fingerprint sensor is almost unrealizable.

Disclosure of Invention

In view of the above background, the present invention provides a Glass Cover Module (GCM) packaging technology for mobile terminals such as mobile phones and tablet computers, which enables a mobile phone manufacturer to place a fingerprint sensor under a touch panel without placing the fingerprint sensor in a slot on a front panel or a rear case of the mobile phone, that is, the GCM technology of the present invention does not change the ID style of the original design of the mobile phone, and does not change the usage habit of the android phone for the user.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a mobile terminal with a touch screen comprises a shell, a liquid crystal display screen and the touch screen, wherein the touch screen comprises a touch cover plate and a touch induction sensor film, and the touch screen further comprises a fingerprint sensor module, and the fingerprint sensor module is adhered below the touch cover plate through anisotropic conductive Adhesive (ACF).

Specifically, the touch cover may be made of Sapphire glass (Sapphire), which has a hardness of 9H, a dielectric constant: a to 13.2, C to 11.4; the Glass can also be strengthened Glass, the hardness of the Glass can reach 7H, and the dielectric constant of the Glass is 6.0-7.38, for example, third generation Corning Gorilla Glass (Gorilla Glass).

Furthermore, be equipped with the silk screen printing layer that is used as the sign below the touch cover plate for the suggestion user fingerprint sensor module is in touch cover plate below position, and the user of being convenient for presses the finger.

In one embodiment, the fingerprint sensor module includes: the semiconductor fingerprint sensor comprises a semiconductor fingerprint sensor tube core, a sensing pixel array on the surface, a Through Silicon Via (TSV) structure for guiding pins on the front surface of the sensor tube core to the back surface, a substrate for bearing the sensor tube core, copper columns or copper balls for electrically connecting the pins on the back surface of the sensor tube core and the pins of the substrate, and an encapsulating material for wrapping the side surface of the sensor tube core exposed on the surface, the copper columns or the copper balls on the back surface of the tube core and the region between the substrate.

Furthermore, the substrate is of a rigid-flexible structure, one rigid side of the substrate is used for bearing the sensor tube core, the flexible side of the substrate is led out to form an FPC flexible board, one end of the FPC flexible board is attached with a connector, and the connector is used for being electrically connected with a mainboard of the mobile terminal.

The FPC flexible board is generally classified into a single-layer board, a double-layer board, a multi-layer board, a double-sided board, and the like.

The structure of FPC single-layer soft board: the flexible board of this structure is a flexible board of the simplest structure. Usually, the substrate + transparent adhesive + copper foil is a commercially available raw material, and the protective film + transparent adhesive is another commercially available raw material. First, the copper foil is subjected to etching or other processes to obtain a desired circuit, and the protective film is drilled to expose the corresponding pad. After washing, the two are combined by a rolling method. Then, the exposed pad portion is protected by plating gold, tin, or the like. Thus, a large panel is completed. It is also common to stamp small circuit boards of corresponding shapes. Also, a solder resist is directly printed on a copper foil without using a protective film, so that the cost is low, but the mechanical strength of the circuit board is deteriorated. Unless strength requirements are low but price needs to be as low as possible, it is preferable to apply a method of attaching a protective film. The structure of the FPC double-layer soft board: when the circuit is too complex, the single layer board can not be wired or the copper foil is needed for grounding shielding, the double layer board or even the multi-layer board is needed. The most typical difference between multi-layer boards and single-layer boards is the addition of via structures to connect the copper foils of the various layers. The first processing technology of the substrate, the transparent adhesive and the copper foil is to manufacture a through hole. The base material and the copper foil are drilled, and the copper with a certain thickness is plated after cleaning, so that the via hole is formed. The subsequent manufacturing process is almost the same as for single layer boards. In addition, both sides of the double-sided board are provided with bonding pads which are mainly used for connecting with other circuit boards. Although it is similar to a single-layer board structure, the manufacturing process is very different. The raw materials are copper foil, protective film and transparent adhesive. Drilling holes on the protective film according to the position requirement of the bonding pad, then pasting the copper foil, corroding the bonding pad and the lead, and then pasting another protective film with drilled holes.

In another embodiment, the fingerprint sensor module includes: the sensing pixel array comprises a semiconductor fingerprint sensor tube core and a sensing pixel array on the surface, a Through Silicon Via (TSV) structure used for guiding a pin on the front surface of the sensor tube core to the back surface is used for bearing a substrate of the sensor tube core, a back surface pin is arranged at a pin position on the back surface of the tube core corresponding to the front surface of the tube core, the TSV communicates the pin on the front surface with the pin on the back surface, a grid array pad (Land grid array) is arranged on the back surface of the tube core, the pin on the back surface of the tube core is connected with the grid array pad through a redistribution layer (RDL) technology, and the micro size of the grid array pad is dozens of times of the pin on the back surface of the tube core, so that the pad can be used for directly welding the tube. An encapsulant is included that encapsulates the exposed sides of the sensor die, the area between the die and the substrate.

More preferably, the structure that the grid array bonding pad is arranged on the back surface of the tube core is adopted, a ball mounting process of semiconductor packaging is not needed, the process steps are simplified, the packaging difficulty is reduced, the yield is improved, and the packaging cost is saved.

In another embodiment, the fingerprint sensor module includes: a semiconductor fingerprint sensor tube core and a sensing pixel array on the surface form a pit at the outer edge of a tube pin of the tube core by adopting a deep recess process (Trench), then the tube pin of the tube core is arranged in the pit by a rewiring layer technology to bear a base plate of the sensor tube core, a bonding wire for electrically connecting the tube core tube pin and the base plate tube pin is electrically connected with the tube pin in the pit and the base plate tube pin by a bonding wire (wire bond), and an encapsulating material of the exposed side surface of the sensor tube core, the bonding wire and the area between the base plate is encapsulated.

In another embodiment, the fingerprint sensor module independently encapsulates into the injection molding with the technology of Moulding plastics (Moulding), the sensor module includes: the fingerprint sensor comprises a semiconductor fingerprint sensor tube core, a sensing pixel array on the surface, a substrate for bearing the sensor tube core, bonding wires for electrically connecting pins of the sensor tube core and pins of the substrate, wherein the pins of the tube core and the pins of the substrate are electrically connected through the bonding wires (wire), and an injection molding material for wrapping the sensor tube core (including the sensing pixel array on the surface), the bonding wires and the substrate is wrapped. And a grid array bonding pad (Land grid array) is arranged on the back surface of the substrate and used for electrically connecting the sensor injection molding piece and the lining plate.

Furthermore, the lining plate is of a steel-flexible combined structure, one rigid side of the lining plate is used for bearing the sensor tube core, one flexible side of the lining plate is led out to form an FPC (flexible printed circuit) flexible board, one end of the FPC flexible board is attached with a connector, and the connector is used for being electrically connected with a main board of the mobile terminal.

More preferably, the injection molding process (Moulding) is the most common semiconductor packaging process, and compared with the expensive TSV process and the Trench + RDL process, the manufacturing cost is very low, the process difficulty is greatly reduced, the yield is very high, the fingerprint sensor module can be packaged very cheaply, and the large-scale mass production of the fingerprint sensor module is facilitated.

Another objective of the present invention is to provide a method for manufacturing and assembling a mobile terminal having a fingerprint sensor module. The mobile terminal may be, but is not limited to, a portable electronic device such as a mobile phone, a tablet computer, a personal PDA device, and the like. The method comprises the following steps: a casing and electronic circuit, liquid crystal display, the touch-sensitive screen that contains wherein, the touch-sensitive screen includes touch-sensitive sensor membrane, touch cover, still includes the fingerprint sensor module. Touch-sensitive sensor film has the trompil of a fingerprint sensor subassembly size to pass above-mentioned touch-sensitive sensor film with the fingerprint sensor module, through anisotropic conducting resin with the fingerprint sensor module bonding under the touch cover plate at last. The fingerprint sensor module at least comprises a Flexible Printed Circuit (FPC) and a connector connected with the FPC, and the connector electrically connects the fingerprint sensor module and an electronic circuit inside the shell together.

Drawings

The above features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings, in which like reference numerals are used to designate like elements between the various figures. The figures are exemplary only and are not drawn to scale. In the drawings:

FIG. 1 is a top view of an embodiment of a mobile terminal according to the present invention

FIG. 2 is a cut-away front view of an embodiment of a mobile terminal according to the present invention, illustrating a fingerprint sensor module disposed under a touch cover

FIG. 3 is a side view, in section, taken along the line A- -A' of FIG. 2, further illustrating the construction of the various elements of the assembly

FIG. 4 is a top view of the backside of a die of the fingerprint sensor module of FIG. 2 using a TSV process according to another embodiment of the invention

FIG. 5 is a cut-away front view of a mobile terminal according to another embodiment of the present invention, illustrating a fingerprint sensor module disposed under a touch cover

FIG. 6 shows a fingerprint sensor module independently packaged by an injection molding process according to another embodiment of the present invention

FIG. 7 is a back view of the fingerprint sensor module of FIG. 6

Description of the symbols in the drawings

10/10 '/10'. fingerprint sensor injection module

20. Casing (CN)

21. Touch screen

22. Liquid crystal display screen

23. Touch sensitive sensor film

24. Perforation of touch sensitive sensor film

30. Finger(s)

100. Touch cover plate

200/200 '/200'. semiconductor fingerprint sensor die

201/201'/201 ". sense pixel array of fingerprint sensor die surface

202/202'/202 ". Pin on front side of fingerprint sensor die

203. Pin on back of fingerprint sensor tube core

204. Rewiring layer routing

205. Grid array bonding pad

206. Through silicon via

207. Reset pin

208. Pit of fingerprint sensor tube core

300/300 '/300'. substrate

301/301 '/301'. pins of a substrate

302 '/302'. bonding wire

303. Anisotropic conductive adhesive

304/304' encapsulating material

305. Injection molding material

306. FPC soft board

307. Connector assembly

308. Copper cylinder or copper ball

309. Lining plate

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

It is to be understood that the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout.

First, referring to fig. 1, fig. 1 is a top view of a mobile terminal according to an embodiment of the invention. As shown, the mobile terminal now described includes a housing 20, a touch screen 21, and a liquid crystal display 22, the touch screen 21 including a fingerprint sensor module 10/10'/10 "in addition to a touch sensitive sensor film 23 and a touch cover 100.

The liquid crystal display 22 covers the touch screen 21 and occupies most of the space to form a display area, the fingerprint sensor module 10/10 '/10' needs to be adhered to the non-display area at the bottom of the touch cover plate 100 by using an anisotropic conductive adhesive 303 to be close to the position of the physical Home key, or the fingerprint sensor module 10/10 '/10' replaces the function of the physical Home key to form a virtual Home key.

A silk-screen layer (not shown) is disposed under the touch cover 100 for indicating the location of the virtual Home key of the fingerprint sensor module 10/10'/10 ", so that the user can press the finger 30.

Referring to fig. 2 to 3, fig. 2 is a cross-sectional front view of a mobile terminal according to an embodiment of the present invention, illustrating a fingerprint sensor module disposed under a touch cover; FIG. 3 is a side view in cross-section taken along the direction indicated by the dashed line A- -A' in FIG. 2, further illustrating the structure of the various components of the assembly. In an embodiment of the present invention, the fingerprint sensor module 10 includes: the semiconductor fingerprint sensor die 200 and the sensing pixel array 201 on the surface guide pins 202 on the front surface of the die 200 to the back surface through silicon through holes 206 to form pins 203 corresponding to the positions of the pins 202 on the front surface of the die 200 on the back surface of the die 200, implant copper columns or copper balls 308 on the pins 203 on the back surface through a ball implantation process, electrically connect the pins 203 on the back surface of the die with pins 301 of the substrate 300 through a reflow soldering mode, and finally wrap the side surfaces (the surface needs to be exposed so as to be bonded with the touch cover plate 100) of the sensor die 200, the copper columns or copper balls 308 on the back surface of the die and the region between the substrate 300 with an encapsulating material 304 through a glue dropping process.

Referring to fig. 4, fig. 4 is a top view of a backside of a die of fig. 2 using a TSV process according to another embodiment of the fingerprint sensor module of the present invention. In an embodiment of the present invention, the fingerprint sensor module 10 includes: the semiconductor fingerprint sensor die 200 and the sensing pixel array 201 on the surface guide pins 202 on the front surface of the die 200 to the back surface through silicon vias 206 to form pins 203 corresponding to the positions of the pins 202 on the front surface of the die 200 on the back surface of the die 200, the back surface of the die 200 is provided with a grid array of pads 205, the pins 203 on the back surface of the die 200 and the grid array of pads 205 are connected through rewiring layer routing wires 204, the microscopic size of the grid array of pads 205 is dozens of times of that of the pins 203 on the back surface of the die, so that the pads 205 can easily adopt a reflow soldering technology to directly solder the die 200 and the substrate 300 of the fingerprint sensor, and finally, an encapsulating material 304 is wrapped on the side surface of the sensor die 200 (the surface needs to be exposed so as to be bonded with the touch cover plate 100) and the area between.

It should be noted that, by using the TSV process, it is avoided that the touch cover 100 cannot be smoothly adhered to the surface of the fingerprint sensor die 200 due to the arc height formed by front routing of the fingerprint sensor pin. The difficult problem of fingerprint sensor module assembly on mobile terminal equipment has effectively been solved.

More preferably, by adopting the structure that the grid array bonding pads 205 are arranged on the back surface of the die 200, a ball-planting process of semiconductor packaging can be omitted, so that the process steps are simplified, the packaging difficulty is reduced, the yield is improved, and the packaging cost is saved.

Referring to fig. 5, fig. 5 is a cut-away front view of another embodiment of a mobile terminal according to the present invention, showing a fingerprint sensor module disposed under a touch cover. In an embodiment of the present invention, the fingerprint sensor module 10' includes: a semiconductor fingerprint sensor die 200 'and a sensing pixel array 201' on the surface, forming a deep pit 203 'at the outer edge of a front pin 202' of the die 200 'by a deep recess process and forming a reset pin 207 in the pit, connecting the front pin 202' with the reset pin 207 in the pit by a rewiring layer wire (not shown), electrically connecting the reset pin 207 in the pit 203 'with a pin 301' of a substrate 300 'by a bonding wire 302', and finally wrapping the pit 203 'of the sensor die 200' and the reset pin 207 in the pit and the substrate 300 'with an encapsulating material 304' by a glue dropping process.

More preferably, the technique of Trench + RDL is used to wire the pins 202 'of the fingerprint sensor die 200' in the deep pits, and the bonding wires 302 'are wire bonded in the deep pits 203' through the reset pins 207, and the height of the bonding wires is not higher than the horizontal surface of the die 200', so that the touch cover plate 100 can be flatly adhered to the surface of the fingerprint sensor die 200'. The problem of the assembly of the fingerprint sensor module on the mobile terminal device is effectively solved, and compared with a TSV (through silicon via) process, the process is relatively cheap and high in yield.

Note that encapsulant 304/304 'described above is an integrated circuit package material known in the art to protect sensor die 200/200' from mechanical, electrical, and environmental damage.

Further, the substrate 300/300 'is a rigid-flexible structure, the rigid side of the substrate is used to carry the sensor die 200/200', and the flexible side of the substrate is led out to form the FPC flexible board 306, and one end of the FPC flexible board is attached with the connector 307, and the connector 307 is used to electrically connect with a main board (not shown) inside the mobile terminal housing 20.

Referring to fig. 6 to 7, fig. 6 is a diagram illustrating a fingerprint sensor module independently packaged by an injection molding process according to another embodiment of the present invention; fig. 7 is a back view of the fingerprint sensor module of fig. 6. In an embodiment of the present invention, the fingerprint sensor module 10 "is independently encapsulated into an injection molding part by using an injection molding (Moulding) process, and the sensor module 10" includes: the semiconductor fingerprint sensor die 200 "and the sensing pixel array 201" on the surface are electrically connected by bonding wires 302 "sensor die front side pins 202" and pins 301 "of the substrate 300", and the sensor die 200 "(sensing pixel array 201 including the surface), the bonding wires 302" and the substrate 300 "are encapsulated by injection molding a molding material 305.

A grid array of pads 205 is provided on the back side of the substrate 300 "for electrically connecting the sensor module 10" to a backing 309. The lining board 309 is a rigid-flexible structure, one rigid side of the lining board is used for bearing the sensor module 10 ", and one flexible side of the lining board is led out to form an FPC flexible board 306, one end of the FPC flexible board is attached with a connector 307, and the connector 307 is used for electrically connecting with a main board (not shown) in the mobile terminal casing 20.

It should be noted that the molding material 305 is a molding sealing material used in a conventional integrated circuit molding process, such as epoxy resin, which is well known in the art, and the dielectric constant (3.1-4.2) of the molding material is generally low, which means that the thickness of the molding material 305 covering the surface of the sensor die 200 "(including the sensing pixel array 201") cannot be greater than 100 um. Alternatively, the sensor module 10 "may be injection molded into a rectangular shape, a bar shape, a circular shape, or other applicable shapes.

More preferably, a standard Molding device is adopted for Molding (Molding) in the packaging process, an expensive non-standard Molding device is not needed, the price is very cheap compared with an expensive TSV process and a Trench + RDL process, the process difficulty is greatly reduced, the yield is very high, the packaging of the fingerprint sensor module is very cheap, and the large-scale mass production of the fingerprint sensor module is facilitated.

It should be noted that the semiconductor fingerprint sensor die 200/200'/200 ″ described above is typically a silicon-based semiconductor formed in one or more layers including integrated circuit devices such as transistors, capacitors, resistors, etc., as well as interconnect lines, vias, and the like, formed by photolithography or other semiconductor manufacturing processes. Specifically, die 200/200'/200 ″ has image storage units (not shown), image reading circuitry (not shown), and sensing pixel arrays 201/201'/201 ″ formed thereon.

The touch cover 100 may be made of Sapphire glass (Sapphire), which has a hardness of 9H, a dielectric constant: a to 13.2, C to 11.4; the Glass can also be strengthened Glass, the hardness of the Glass can reach 7H, and the dielectric constant of the Glass is 6.0-7.38, such as third generation Corning Gorilla Glass (Gorilla Glass). Because the dielectric constant of the sapphire glass is high, the thickness of the touch cover plate 100 can be high and can be 500um in standard; the dielectric constant of the tempered glass is low, and the tempered glass needs to be properly thinned to improve the detection sensitivity of the fingerprint sensor module 10/10 '/10' and is beneficial to the sensor module to acquire images.

The material of the touch cover 100 is ideal as a protective material for the surface of the sensor module 10/10'/10 ″. The mobile device with the sensor modules 10/10'/10 "mounted thereon is placed in a pocket or bag and contacted, rubbed against a key, pen or other rigid object therein, and the protective material of the sensor modules 10/10'/10" is very rigid and protected from damage. More preferably, the surface of the touch cover 100 is further coated with a layer of hydrophobic nano-material, so that fingerprint residues formed by the capacitive fingerprint sensor in the sampling process can be effectively prevented. Because the touch cover 100 has a thickness of several hundred microns, it is difficult for finger static electricity to cause electrostatic damage to the sensor modules 10/10'/10 "under the touch cover.

A method of manufacturing a mobile terminal of the present invention is as follows: first, the fingerprint sensor module 10/10'/10 ″ is manufactured by a method selected from one of the four embodiments, and more preferably, by Molding (Molding) using a standard Molding apparatus. Then, a touch screen 21 is prepared, the touch screen 21 includes a touch cover 100 and a touch sensing sensor film 23, the touch sensing sensor film 23 is used for sensing signals of fingers on the touch screen, a hole 24 is formed in the middle of a non-display area at the bottom of the touch sensing sensor film 23 near the Home key position, and the size of the touch sensing sensor film opening 24 is slightly larger than that of the fingerprint sensor module 10/10'/10 ", so that the sensor module 10/10'/10" can pass through the opening 24. Finally, a thin layer of anisotropic conductive adhesive 303 is applied to the surface of the fingerprint sensor module 10/10'/10 ", and the sensor module 10/10'/10" is adhered under the touch cover 100. When the finger 30 presses the virtual Home key position shown in the dotted line box in the figure, the fingerprint sensor module 10/10'/10 ″ can capture the fingerprint image of the finger 30. Of course, those skilled in the art will recognize that the mobile terminal may be an electronic device with a full touch screen, such as a cell phone, a tablet computer, a personal PDA device, and the like. Those skilled in the art will also recognize that this is only one possible manufacturing method and that there are other similar assembly methods.

The above description is only for the preferred embodiment of the present invention, and the embodiment is not intended to limit the scope of the present invention, so that all the equivalent structural changes made by using the contents of the description and the drawings of the present invention should be included in the scope of the present invention.

Claims

1. A mobile terminal comprises a shell, a liquid crystal display screen and a touch screen, wherein the touch screen comprises a touch cover plate and is characterized by further comprising a fingerprint sensor module, and the touch cover plate covers the fingerprint sensor module; fingerprint sensor module includes: the semiconductor fingerprint sensor die and the sensing pixel array located on the surface of the semiconductor fingerprint sensor die are located on the substrate, and the mobile terminal further comprises one of the following four structures:

the first structure is as follows: a through-silicon via structure for guiding pins of the front side of the sensor die to the back side; copper pillars or balls for electrically connecting the sensor die backside pins and the substrate pins; the packaging material is used for packaging the side face of the sensor tube core with the exposed surface, the copper column or copper ball on the back of the tube core and the area between the base plates, so that the sensor tube core is in direct contact with the touch cover plate;

the second structure is as follows: a through-silicon via structure for guiding pins of the front side of the sensor die to the back side; a grid array pad on the die backside; and an encapsulant covering the exposed sides of the sensor die and the area between the die and the substrate such that the sensor die and the touch cover plate are in direct contact;

a third structure: a reset pin formed in the deep pit of the die using a deep recess process and a rewiring technique; a bonding wire for electrically connecting the reset pin and the substrate; and an encapsulating material covering the side surface of the sensor die with the exposed surface, the bonding wires and the area between the substrates, so that the sensor die is in direct contact with the touch cover plate;

a fourth configuration: bonding wires for electrically connecting the sensor die pins and the substrate pins; and an injection molding material encasing the sensor die (including the surface sensing pixel array), the bonding wires, and the substrate such that the sensor die and the touch cover plate are in direct contact; the back of the substrate is provided with a grid array welding plate so that the fingerprint sensing module can be electrically connected with the lining plate.

2. The mobile terminal of claim 1, wherein the substrate is a rigid-flex structure, a rigid side of the substrate is used for carrying the sensor die, and a flexible side of the substrate has a flexible FPC board led out, and a connector is attached to one end of the flexible FPC board and is used for electrically connecting with a main board of the mobile terminal.

3. The mobile terminal according to claim 1, wherein the fingerprint sensor module is independently encapsulated as an injection molded part by using an injection molding process.

4. The mobile terminal of claim 1, wherein the substrate is used for carrying the fingerprint sensor module, the substrate is of a rigid-flexible structure, one rigid side of the substrate is used for carrying the sensor die, and one flexible side of the substrate is led out to form an FPC (flexible printed circuit) flexible board, one end of the FPC flexible board is attached with a connector, and the connector is used for electrically connecting with a main board of the mobile terminal.

5. The mobile terminal of claim 1, wherein the touch screen further comprises a touch sensitive sensor film located below the touch cover.

6. The mobile terminal according to claim 5, wherein the touch sensitive sensor film is provided with an opening, and the fingerprint sensor module is placed in the opening.

7. The mobile terminal of claim 1, wherein the touch cover is made of sapphire glass or tempered glass.

8. The mobile terminal of claim 1, wherein the thickness of the touch cover plate is thinned.

9. The mobile terminal of claim 1, wherein the fingerprint sensor module is adhered to the bottom of the touch cover by an anisotropic conductive adhesive.

10. The mobile terminal of claim 1, wherein a silk screen layer is further disposed on a lower surface of the touch cover plate.

11. The mobile terminal according to claim 1, wherein a layer of hydrophobic nano-material is further sprayed on the surface of the touch cover.

12. A method of preparing the mobile terminal of claim 1, comprising: the fingerprint sensor module is prepared by adopting one of the following four processes:

the first process of preparing the fingerprint sensor module comprises the following steps:

step S11: providing a substrate with a structure of rigid-flexible bonding, and using the rigid side of the substrate for the fingerprint sensor tube core, wherein the surface of the semiconductor fingerprint sensor tube core is provided with a sensing pixel array, a silicon through hole structure for guiding the pins on the front surface of the sensor tube core to the back surface, copper columns or copper balls for electrically connecting the pins on the back surface of the sensor tube core and the pins of the substrate, and an encapsulating material for wrapping the side surface of the sensor tube core exposed on the surface, the copper columns or the copper balls on the back surface of the tube core and the substrate, and the exposed part on the surface of the sensor tube core is directly contacted with the touch cover plate;

step S12: leading out an FPC (flexible printed circuit) flexible board from one flexible side of the substrate, and attaching a connector to one end of the FPC flexible board, wherein the connector is used for electrically connecting with a main board of the mobile terminal;

the second preparation of the fingerprint sensor module process comprises the following steps:

step S21: providing a substrate with a structure of rigid-flexible bonding, wherein the rigid side of the substrate is used for bearing the fingerprint sensor tube core, the surface of the semiconductor fingerprint sensor tube core is provided with a sensing pixel array, a through silicon via structure for guiding pins on the front surface of the sensor tube core to the back surface, a grid array bonding pad for bearing the back surface of the sensor tube core, and an encapsulating material for wrapping the side surface of the sensor tube core with an exposed surface, copper columns or copper balls on the back surface of the tube core and the area between the substrate, and the exposed part on the surface of the sensor tube core is in direct contact with the touch cover plate;

step S22: leading out an FPC (flexible printed circuit) flexible board from one flexible side of the substrate, and attaching a connector to one end of the FPC flexible board, wherein the connector is used for electrically connecting with a main board of the mobile terminal;

the third preparation fingerprint sensor module process includes the following step:

step S31: providing a substrate with a structure of rigid-flexible combination, wherein the rigid side of the substrate is used for bearing the fingerprint sensor tube core, the surface of the semiconductor fingerprint sensor tube core is provided with a sensing pixel array, a reset pin formed in a pit of the tube core by adopting a deep-recess process and a rewiring technology, a substrate for bearing the sensor tube core, a bonding wire for electrically connecting the reset pin and the substrate, and an encapsulating material for encapsulating the side surface of the sensor tube core with an exposed surface, the bonding wire and the substrate, and the exposed part of the surface of the sensor tube core is in direct contact with the touch cover plate;

step S32: leading out an FPC (flexible printed circuit) flexible board from one flexible side of the substrate, and attaching a connector to one end of the FPC flexible board, wherein the connector is used for electrically connecting with a main board of the mobile terminal;

the fourth process for preparing the fingerprint sensor module comprises the following steps:

step S41: providing a substrate with a structure of being combined by steel and flexible, and using the rigid side of the substrate to bear the fingerprint sensor tube core, wherein the fingerprint sensor module is independently packaged into an injection molding part by adopting an injection molding process; the sensor module includes: the fingerprint sensor comprises a semiconductor fingerprint sensor tube core, a sensing pixel array on the surface, a substrate for bearing the sensor tube core, a bonding wire for electrically connecting a pin of the sensor tube core and a pin of the substrate, and an injection molding material for wrapping the sensor tube core (including the sensing pixel array on the surface), the bonding wire and the substrate, wherein the exposed part of the surface of the sensor tube core is directly contacted with a touch cover plate, and a grid array bonding pad is arranged on the back surface of the substrate so that a fingerprint sensing module can be electrically connected with a lining plate;

step S42: and leading out an FPC (flexible printed circuit) flexible board from one flexible side of the substrate, and attaching a connector to one end of the FPC flexible board, wherein the connector is used for electrically connecting with a main board of the mobile terminal.

13. The method for manufacturing a mobile terminal according to claim 12, further comprising a step of manufacturing a touch screen, wherein the touch screen comprises a touch cover plate and a touch sensitive sensor film, the touch sensitive sensor film is used for sensing a signal of a finger on the touch screen, and the step of manufacturing the touch screen comprises:

firstly, opening a hole in the middle of a non-display area at the bottom of a touch sensing sensor film, which is close to a Home key position, wherein the size of the opening of the touch sensing sensor film is slightly larger than that of the fingerprint sensor module, so that the sensor module can penetrate through the opening;

then, a thin layer of anisotropic conductive adhesive is coated on the surface of the fingerprint sensor module, and then the sensor module is adhered under the touch cover plate.

14. The method for manufacturing a mobile terminal according to claim 12, wherein the fingerprint sensor module is adhered to the bottom of the touch cover to hide the fingerprint sensor module.