WO2018107341A1

WO2018107341A1 - Fingerprint recognition module for implementing backlight by means of light guide layer

Info

Publication number: WO2018107341A1
Application number: PCT/CN2016/109535
Authority: WO
Inventors: 易治明; 向鹏; 傅强; 叶勇
Original assignee: 红蝶科技(深圳)有限公司
Priority date: 2016-12-12
Filing date: 2016-12-12
Publication date: 2018-06-21

Abstract

A fingerprint recognition module for implementing backlight by means of a light guide layer. At least one light-emitting source (301, 302, 303, 304, 601) connected to a circuit board (104) of the module is additionally arranged. A light transmission region is additionally arranged on a panel (102) of the module; meanwhile, a light guide layer having a diffusion or fluorescent function is additionally arranged on the upper surface of a packaging material (508) of a fingerprint recognition chip. The light guide layer is a main light guide medium for light emitted by the light-emitting sources (301, 302, 303, 304, 601), and the light is emitted out from the light transmission region of the panel (102) after passing through the light guide layer. The light-emitting sources (301, 302, 303, 304, 601) can be disposed outside the packaging material (508) or packaged inside the packaging material (508) together with a bare core (507). A backlight function of the fingerprint recognition module is implemented in a limited space, and a light transmission pattern (101) formed in the light transmission region of the panel (102) can emit light.

Description

Fingerprint recognition module for backlight through light guiding layer

[0001] The present invention relates to a fingerprint identification module, in particular to a capacitive sensor type fingerprint recognition module or a radio frequency sensor type fingerprint recognition module in a product such as a smart phone, and more particularly, to a light guide layer Backlit fingerprint identification module.

Background technique

[0002] The human fingerprint repetition rate is extremely small, about one-fifth of a billion, with the characteristics of "human identity card"; because of its lifetime immutability, uniqueness and convenience, it has almost become synonymous with biometric identification. The application of fingerprint recognition technology is very extensive, especially the number of fingerprint recognition modules on smartphones, which is already very large. According to statistics, the monthly shipment volume of China's smart phone market is about 80 million, and the monthly shipment of mobile phone with fingerprint identification module is about 35 to 40 million.

[0003] As shown in FIG. 9 , a fingerprint sensor or a radio frequency sensor is generally used in the fingerprint recognition module 901 on the smart phone. The panel of the fingerprint recognition module cannot be illuminated and cannot be illuminated to be presented. Specific light transmission patterns (such as corporate trademarks); if a specific light transmission pattern can be presented, the aesthetic effect and brand recognition of the fingerprint recognition module will be greatly improved.

[0004] A typical structure of the fingerprint recognition module is shown in FIG. 1. The fingerprint identification module 100 can be electrically connected to a motherboard inside the smart phone through the circuit board 104. The upper portion of Fig. 1 is a panel 102 for a user to place a finger for fingerprint recognition. Around the panel 102 is a ring of metal rings 103. The length L and the width W of the panel 102 are approximately 10 mm.

2 is a side cross-sectional view of the fingerprint recognition module, wherein the fingerprint identification chip 203 is electrically connected to the circuit board 104. The fingerprint recognition chip 203 is bonded to the panel 102 whose ink 201 is coated on the bottom surface by the adhesive layer 202. The panel 102 (or cover plate) may be made of glass, sapphire, ceramic, resin, or the like. The panel of the existing fingerprint recognition module cannot emit light due to its structural limitation. 2 is an enlarged schematic effect, the actual thickness dimension of each part is very small, wherein the thickness HI of the entire fingerprint recognition module is strictly controlled by the function of the implementation itself, and the limitation of the thinning of the mobile phone is generally only about 1 mm; The thickness H5 of the layer 202 is between 0.01 and 0.02 mm; the thickness H3 of the panel 102 is about 0.2 mm; The thickness H4 is about 0.1 mm; and the identification thickness that the fingerprint recognition chip can support, that is, the maximum vertical distance H2 from the upper surface of the die to the finger contact point, must be controlled within 0.35 mm. Therefore, adding any complicated micro optical structure will bring great troubles and cost increase to the mass production of the fingerprint identification module, and cannot meet the mass production needs.

[0006] At the same time, the existing fingerprint recognition module technology mainly uses a capacitive sensor and a radio frequency sensor. The material of the manufacturing module has strict dielectric or other performance requirements, and thus the illumination source cannot be placed at the center of the fingerprint recognition chip or Top, only on the side. In the existing structure, the only place that can be used for light transmission is to use a transparent adhesive layer 202, but its thickness is too thin, and there is a serious lack of effective path for light conduction, and the light of the light source cannot be transmitted to the panel to exhibit light transmission. pattern.

technical problem

In view of the above-mentioned deficiencies of the prior art, the present invention solves the problem that the panel of the existing fingerprint recognition module cannot emit light and cannot be illuminated to present a specific light-transmitting pattern.

Problem solution

Technical solution

The technical solution adopted by the present invention to solve the technical problem is: providing a fingerprint recognition module for implementing a backlight through a light guiding layer, comprising a circuit board, a fingerprint identification chip disposed on the circuit board, and The fingerprint recognition chip includes a package material and a bare core, and further includes at least one light source connected to the circuit board; the panel is provided with at least one light transmissive area; a light guiding layer is disposed on the upper surface of the encapsulating material; the light emitted by the illuminating source is the light guiding layer with the light guiding layer as the main light guiding medium, and the light transmitting area from the panel after passing through the light guiding layer The light guiding layer is at least one of: a diffusing surface provided on an upper surface of the encapsulating material and having a micro-optical structure; a guide plated on an upper surface of the encapsulating material and having a diffusing function or a fluorescent function a light film or a light guiding film; a light guiding film or a light guiding plate attached to the upper surface of the packaging material and having a diffusing function or a fluorescent function.

In the present invention, the encapsulating material may be made of a light transmissive material or a non-transparent material, and the light emitting source may be disposed outside the packaging material. When the encapsulating material is made of a light transmissive material, the light emitting source may also be packaged inside the encapsulating material together with the bare core.

[0010] In the present invention, the panel is attached to the upper surface of the fingerprint identification chip through a light-transmissive adhesive layer, and the light emitted by the illumination source passes through the light guiding layer and then through the bonding. Light transmission from the panel after the layer The area is shot.

[0011] In the present invention, a dimming material for adjusting a light-emitting effect may be provided in at least one of the following: in the encapsulating material, in the adhesive layer, on the top of the bare core, in the The bottom of the light transmissive area of the panel. The dimming agent is a phosphor; or a microparticle and/or microporous that changes the direction and/or composition of light propagation.

[0012] In the present invention, the non-conductive reflective material may also be disposed in at least one of the following: a top of the bare core, and a non-transparent area at the bottom of the panel.

[0013] In the present invention, in a direction away from the light-transmitting region of the light-emitting source, a high-reflection film and a reflective portion partially surrounding the light-emitting source to concentrate the light mainly toward the light-transmitting region may be further disposed. Any of a cover, or a mirror.

[0014] In the present invention, the light source may be any one of the following: a light emitting diode, a light emitting diode die, a laser, a laser die, a laser array die, an organic light emitting device, and an organic light emitting array device.

[0015] In the present invention, the light transmissive area may form a corporate trademark, a universal logo, or a specific light transmissive pattern.

Advantageous effects of the invention

Beneficial effect

[0016] Through the above technical solution, the present invention can realize the backlight function of the fingerprint recognition module by using at least one illumination source as a backlight source in a limited space while satisfying the fingerprint recognition requirement, and can make the panel transparent. The light-transmitting pattern formed by the light area emits light, thereby greatly improving the aesthetic degree and brand recognition of the fingerprint recognition module.

Brief description of the drawing

DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

1 is a schematic structural diagram of a conventional fingerprint recognition module;

2 is a side elevational cross-sectional view of the fingerprint recognition module of FIG. 1;

3 is an exploded perspective view of a fingerprint identification module in a preferred embodiment of the present invention;

[0021] FIG. 4 is a schematic top plan view of a light source in the fingerprint recognition module of FIG. 3;

5 is a side elevational cross-sectional view of the fingerprint recognition module of FIG. 3;

6 is an exploded perspective view of a fingerprint identification module in another preferred embodiment of the present invention; 7 is a top plan view of a light source in the fingerprint recognition module shown in FIG. 6;

8 is an enlarged side elevational cross-sectional view of the fingerprint recognition module of FIG. 6; [0025] FIG.

9 is a schematic diagram of a fingerprint recognition module in a conventional smart phone.

BEST MODE FOR CARRYING OUT THE INVENTION

[0027] FIG. 3 shows a preferred embodiment of the fingerprint identification module of the present invention. In this embodiment, a light transmissive area is formed on the panel 102, and the light transmissive area can form a light transmissive pattern 101. The conventional fingerprint recognition module shown in Fig. 1 generally does not have this light transmission pattern 101 because it does not have a light transmitting function. The light transmissive pattern 101 may be of a different shape, specifically a corporate logo, a universal logo, or other light transmissive pattern.

In this embodiment, illumination sources 301, 302, 303, and 304 are disposed around the outside of the fingerprint recognition chip 203.

. These light sources are physically connected to the circuit board 104 by soldering together with the fingerprint identification chip, and the top view effect is as shown in FIG. For specific implementation, the number and position of the light source can be adjusted accordingly. The panel 102 is attached to the fingerprint recognition chip 203 through an adhesive layer. The metal ring 103 surrounds the panel 102 and the fingerprint identification chip 203, and is also physically connected and electrically connected to the circuit board 104.

As can be seen from FIG. 3, a light guiding film 305 having a diffusing function is provided, which is disposed on the upper surface of the encapsulating material of the fingerprint identifying chip, between the panel 102 and the fingerprint identifying chip 203. The light guiding film is only one of the implementation manners. In particular, a diffusing surface having a micro-optical structure may be disposed on the surface of the packaging material, or a light guiding film having a diffusing function or a fluorescent function may be disposed on the surface of the packaging material. Or a light guiding film, or a light guide plate having a diffusing function or a fluorescent function on the surface of the packaging material.

[0030] As shown in FIG. 5, the bottom of the panel 102 is coated with black ink regions 501 and 502 by printing. A gap is left between the black ink areas, or a clear ink is used to form a light transmissive area, typically a specific light transmissive pattern 101. The panel 102 with the ink areas 501, 502 and the light transmissive pattern 101 is attached to the fingerprint recognition chip by an adhesive layer 202. The fingerprint identification chip is composed of a bare core 507 and an encapsulating material 508. In this embodiment, a light guiding film 305 having a diffusing function is added; and the encapsulating material 508 and the adhesive layer 202 are both light transmissive materials, specifically It is a colorless transparent material or a colored transparent material. The light emitted by the light source is guided by the light guiding film 305 as a main light guiding medium, and can be emitted from the light transmitting pattern 101 on the panel 102 after the sealing material 508, the light guiding film 305, and the adhesive layer 202.

[0031] The encapsulating material therein may be made of a light transmissive material or a non-transparent material. In this embodiment, colorless is used. A transparent encapsulating material and mixing the dimming material into the encapsulating material. In other embodiments, the dimming material may also be disposed at the top 504 of the encapsulation material, or at the top 505 of the die 507, or at the bottom of the light transmissive region of the panel 202; when disposed at the bottom of the panel 202吋, mainly to cover the area where the light-transmitting pattern 101 is located.

[0032] Only the illumination sources 301, 303 are shown in FIG. In particular, the light sources 301, 303 and other illumination sources not shown are physically and electrically connected to the circuit board 104. The top of the light source 301, 303 is its illuminating center. From the viewpoint of light efficiency, the height of the illuminating center must be higher than the bare core 507 and lower than the bottom 503 of the panel. The main direction of its illumination should be substantially toward the light transmissive pattern 101.

[0033] In a preferred embodiment, the light source may be a blue light emitting diode, such as a Group III nitride light emitting diode. The phosphor can be selected from suitable phosphors. For example, there are two main types of red nitride phosphors, which are all miscellaneous nitrides. The structure can be written as M ₂ xSi ₅ N ₈ : xEu 2+

(M = Ca, Sr, Ba, where 0 ≤ x ≤ 0.4) and CaAlSiN ₃ : Eu ²⁺ . Green and yellow phosphor nitrogen oxides present, there Eu ^{^2+,} Ce ^3+, Y ²⁺ ions and other rare earth activated sialon (of Sialon) MSiO _₂ N ₂ and class two categories.

[0034] In the present invention, the light source and the light control may have various combinations, and those skilled in the art may change the type of the light source, the color and wavelength of the light, or change the type and ratio of the light control, as needed. Thereby changing the illuminating effect of the light transmitting pattern. The dimming agent may be a phosphor or a microparticle and/or microporous which changes the direction and/or composition of light propagation. For micro-optical structures such as microparticles and micropores, there are many optical phenomena such as reflection, refraction, diffraction, scattering, and polarization of light; the weight of these phenomena varies with the size of the micropore; But in the final analysis, it changes the direction and composition of light. Changing the direction of propagation means that the object is illuminated without directly seeing the light source. Changing the composition means changing the wavelength and polarization of the constituent light. For example, you can see the blue and red sky, relying on the particles in the air. Scattering of sunlight.

In addition, at the bottom of the non-transmissive region of the panel 102, that is, at the bottom of the ink regions 501, 502, a non-conductive reflective material may be disposed by coating, printing, plating, or the like to improve the light efficiency. Alternatively, a non-conductive reflective material can be placed at the top 505 of the bare core.

As shown in FIG. 5, in the direction of the light source 301, 303 facing away from the light transmitting pattern 101, reflective masks 50 6 and 509 are further provided to further improve the light effect.

[0037] FIG. 6 shows another preferred embodiment of the fingerprint recognition module of the present invention. In the fingerprint recognition module, The light source 601 is integrated into the inside of the fingerprint recognition chip 203. The fingerprint identification chip 203 is physically connected and electrically connected to the circuit board 104 by soldering. The relative position of the top 吋 is shown in Fig. 7. There is also added a light guiding film 305 having a diffusing function, and the panel 102 is attached to the fingerprint identifying chip 203 through an adhesive layer. The metal ring 103 surrounds the panel 102 and the fingerprint identification chip 203, and is also physically connected and electrically connected to the circuit board 104. Also, a light transmissive pattern 101 is provided on the panel 102.

As shown in FIG. 7, the fingerprint identification chip 203 is packaged with a bare core 507 and a light source 601. As long as the normal operation of the bare core 507 is not affected, the number and position of the light source can be adjusted according to the needs, and is not limited to the number and position shown in Fig. 6 and Fig. 7.

As shown in FIG. 8, the bottom of the panel 102 is coated with black ink regions 501 and 502 by printing. A gap is left between the black ink areas, or a clear ink is used to form the light transmitting pattern 101. The panel 102 with the ink regions 501, 502 and the light transmissive pattern 101 is attached to the fingerprint recognition chip by an adhesive layer 202. The fingerprint identification chip is composed of a bare core 507 and a packaging material 508, and a light guiding film 305 having a diffusing function is added; the light source 601 and other possible sources not shown are also packaged inside the packaging material 508. The encapsulating material 508 is a light transmissive material, and specifically may be a colorless transparent material or a colored transparent material.

As shown in FIG. 8, in the direction of the light source 601 facing away from the light transmitting pattern 101, a reflector 901 is further provided to further improve the light effect.

Claims

Claim

A fingerprint recognition module for implementing a backlight through a light guiding layer, comprising a circuit board, a fingerprint identification chip disposed on the circuit board, and a panel mounted on an upper surface of the fingerprint identification chip, wherein the fingerprint identification chip comprises a package Materials and bare cores, characterized in that

Also including at least one illumination source coupled to the circuit board;

The panel is provided with at least one light transmissive area;

The upper surface of the encapsulation material is provided with a light guiding layer;

The light emitted by the light source is mainly used as the light guiding medium, and is emitted from the light transmitting area on the panel after passing through the light guiding layer;

The light guiding layer is at least one of the following:

a diffusing surface disposed on the upper surface of the encapsulating material and having a micro-optical structure;

a light guiding film or a light guiding film system plated on the upper surface of the packaging material and having a diffusing function or a fluorescent function;

A light guiding film or a light guide plate attached to the upper surface of the encapsulating material and having a diffusing function or a fluorescent function.

The fingerprint recognition module for implementing a backlight through a light guiding layer according to claim 1, wherein the packaging material is made of a light transmissive material or a non-transparent material, and the illumination source is disposed outside the packaging material. .

The fingerprint recognition module for implementing a backlight through a light guiding layer according to claim 1, wherein the packaging material is made of a light transmissive material, and the light emitting source is packaged in the package together with the bare core. Inside the material.

The fingerprint recognition module for realizing a backlight through a light guiding layer according to claim 1, wherein the panel is attached to the upper surface of the fingerprint identification chip through a light-transmissive adhesive layer, and the illumination source emits The light is sequentially emitted from the light-transmitting layer on the panel through the light guiding layer and then through the adhesive layer.

The fingerprint recognition module for realizing a backlight through a light guiding layer according to any one of claims 2 to 4, wherein a dimming object for adjusting a lighting effect is further provided at at least one of the following: Within the material, within the bonding layer, at the top of the die, at The bottom of the light transmissive area of the panel.

[Claim 6] The fingerprint recognition module for implementing a backlight through a light guiding layer according to claim 5, wherein

The light control is a phosphor;

Alternatively, the dimming agent is a microparticle and/or microporous that changes the direction and/or composition of light propagation.

[Claim 7] The fingerprint recognition module for implementing a backlight through a light guiding layer according to claim 3, wherein at least one of the following places is further provided with a non-conductive reflective material: a top of the bare core, the The non-transparent area at the bottom of the panel.

The fingerprint recognition module for implementing a backlight through a light guiding layer according to any one of claims 1 to 4, wherein in a direction of the light source facing away from the light transmitting region, There is also provided any one of a high-reflection film, a reflector, or a mirror partially surrounding the light-emitting source to concentrate the light toward the light-transmitting region.

The fingerprint recognition module for implementing a backlight through a light guiding layer according to any one of claims 1 to 4, wherein the light emitting source mainly emits light toward the light transmitting area; The light source is any of the following: light emitting diodes, light emitting diode dies, lasers, laser dies, laser array dies, organic light emitting devices, organic light emitting array devices.

The fingerprint recognition module for implementing a backlight through a light guiding layer according to any one of claims 1 to 4, wherein the light transmissive area forms a corporate trademark, a universal logo, or a specific light transmission.