Optical fingerprint module

Abstract

The utility model discloses an optical fingerprint module, which comprises an optical fingerprint chip, a flexible circuit board and a lens assembly, and is characterized in that an adhesive piece is preset on one side surface of the optical fingerprint chip; a binding area is arranged on one side surface of the flexible circuit board, and the optical fingerprint chip is bound on the binding area through an adhesive piece; the lens assembly comprises a lens base and a lens, the lens is arranged on the lens base, an avoiding cavity is formed in the lens base, and when the lens base is arranged on the flexible circuit board, the optical fingerprint chip is located in the avoiding cavity. Thus, the optical fingerprint chip can be directly attached to the binding area of the flexible circuit board through the adhesive piece, so that double-Y-shaped carrying adhesive does not need to be arranged on the flexible circuit board, meanwhile, the adhesive dispensing procedure before the optical fingerprint chip is carried is omitted, and the phenomenon that the optical fingerprint chip is damaged due to unstable adhesive dispensing can be avoided. The overall carrying precision of the chip is affected by factors such as expansion caused by thermal curing of the glue, and then the problem of poor resolution of the optical fingerprint module can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of fingerprint modules, in particular to an optical fingerprint module. Background Art

[0002] Fingerprint recognition technology is a widely used identity recognition technology, which collects fingerprint information and compares it to determine the identity of an individual. In fingerprint recognition technology, the optical fingerprint module is an important collection device. In the field of optical fingerprint module production and manufacturing, the entire processing process is usually divided into three parts: SMT (Surface Mounted Technology) process, COB (Chip On Board) process and detection process. Among them, in the COB process, the chip is mounted on the flexible circuit board to complete the connection of the entire circuit of the module, and then the filter is attached, the oven is cured and the lens is mounted. At the same time, before the chip is mounted, it is necessary to perform glue dispensing on the flexible circuit board. When dispensing, it is necessary to draw a "double Y" type mounting glue on the flexible circuit board, but there are many defects in the dispensing operation. For example, factors such as unstable dispensing and expansion caused by thermal curing of the glue will also affect the overall mounting accuracy of the chip, which will lead to poor resolution of the optical fingerprint module. Utility Model Content

[0003] The purpose of the utility model is to overcome at least one shortcoming of the prior art and provide an optical fingerprint module capable of improving production quality.

[0004] The purpose of this utility model is achieved through the following technical solutions:

[0005] An optical fingerprint module comprises: an optical fingerprint chip, a flexible circuit board and a lens assembly, wherein an adhesive piece is preset on one side surface of the optical fingerprint chip so that the adhesive piece and the optical fingerprint chip form an integrated structure; a binding area is arranged on one side surface of the flexible circuit board, and the optical fingerprint chip is bound to the binding area through the adhesive piece; the lens assembly comprises a lens base and a lens, the lens is arranged on the lens base, and an avoidance cavity is opened on the lens base, and when the lens base is arranged on the flexible circuit board, the optical fingerprint chip is located in the avoidance cavity.

[0006] In one embodiment, a first positioning column and a second positioning column are disposed on the lens base, and the first positioning column and the second positioning column are respectively located at two corner ends of a diagonal line on the lens base.

[0007] In one embodiment, the adhesive member is a DAF tape.

[0008] In one embodiment, the thickness of the adhesive member is 0.155 mm.

[0009] In one of the embodiments, the optical fingerprint chip is also bound to an IR filter.

[0010] In one of the embodiments, an air escape hole is further provided on the lens base, and the air escape hole is communicated with the avoidance cavity.

[0011] In one of the embodiments, the lens assembly is further covered with a protective member, the protective member is used to isolate and protect the lens, and the protective member is provided with a tear handle.

[0012] In one embodiment, the protective member is provided with a tearable handle.

[0013] In one of the embodiments, a reinforcement plate is provided on a side of the flexible circuit board away from the optical fingerprint chip, and the reinforcement plate is located below and close to the lens assembly.

[0014] In one of the embodiments, the reinforcement plate is a steel sheet reinforcement plate.

[0015] Compared with the prior art, the utility model has at least the following advantages:

[0016] The optical fingerprint module of the utility model is provided with an optical fingerprint chip, a flexible circuit board and a lens assembly, and an adhesive part is preset on one side surface of the optical fingerprint chip, so that the optical fingerprint chip and the adhesive part form an integrated structure, and the optical fingerprint chip can be directly attached to the binding area of ​​the flexible circuit board through the adhesive part. In this way, there is no need to set a "double Y" type mounting glue on the flexible circuit board, and the gluing process before the optical fingerprint chip is mounted is omitted, thereby avoiding the factors such as unstable gluing and expansion caused by thermal curing of the glue that affect the overall mounting accuracy of the chip, thereby reducing the problem of poor resolution of the optical fingerprint module. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for use in the embodiments are briefly introduced below.

[0018] Figure 1 This is a schematic diagram of the exploded structure of an optical fingerprint module in one embodiment of the utility model;

[0019] Figure 2 This is a schematic diagram of the structure of an optical fingerprint module in an embodiment of the utility model without a protective component;

[0020] Figure 3 The figure is a schematic cross-sectional structural diagram of an optical fingerprint module in one embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings.

[0022] Please combine Figure 1 , Figure 2 and Figure 3 As shown, an optical fingerprint module 10 includes: an optical fingerprint chip 100, a flexible circuit board 200 and a lens assembly 300. An adhesive member (not shown) is preset on one side of the optical fingerprint chip 100 so that the adhesive member and the optical fingerprint chip are in an integrated structure; a binding area is provided on one side of the flexible circuit board 200, and the optical fingerprint chip 100 is bound to the binding area through the adhesive member; the lens assembly 300 includes a lens base 310 and a lens 320, the lens 320 is provided on the lens base 310, and an avoidance cavity is opened on the lens base 310. When the lens base 310 is provided on the flexible circuit board 200, the optical fingerprint chip 100 is located in the avoidance cavity.

[0023] It should be noted that, by presetting an adhesive member on one side of the optical fingerprint chip 100, that is, pre-attaching a layer of adhesive member on the optical fingerprint chip 100, before the optical fingerprint chip 100 is mounted, the optical fingerprint chip 100 and the adhesive member form an integrated structure, and the integrated adhesive member does not need to be heat-cured later. In this way, the optical fingerprint chip 100 can be directly attached to the binding area of ​​the flexible circuit board 200 through the adhesive member on the optical fingerprint chip 100. In this way, there is no need to add a dispensing process, and there is no need to draw a "double Y"-shaped mounting glue on the flexible circuit board 200, thereby avoiding the factors such as unstable dispensing and expansion caused by thermal curing of the glue that affect the overall mounting accuracy of the chip, thereby reducing the problem of poor resolution of the optical fingerprint module. In addition, the cumbersome dispensing process is omitted, the production process can be shortened, and the efficiency of mounting the optical fingerprint chip can be improved. In this embodiment, the adhesive member is a DAF (Die Attach Film) tape, which has excellent electrical conductivity and thermal conductivity, and high adhesive force, and can ensure the firmness of the optical fingerprint chip. Preferably, the thickness of the adhesive member is 0.155 mm. Further, a avoidance cavity is provided on the lens base 310, and the optical fingerprint chip 100 is located inside the avoidance cavity, so that the overall structure of the optical fingerprint module 10 is more compact. In addition, in the traditional optical fingerprint module, since the adhesive in the dispensing process is liquid, a corresponding limiting structure is required to ensure that the adhesive does not spread seriously, and the adhesive member in the utility model is a solid DAF tape, so there is no need to set a limiting structure, and the DAF tape pre-set on the optical fingerprint chip is the entire surface covering one side of the optical fingerprint chip, so the contact surface of the DAF tape on the optical fingerprint chip is larger, and the "double Y" type mounting glue with a smaller contact surface with the optical fingerprint chip can further ensure the conductive effect and bonding firmness.

[0024] In one implementation, a first positioning column 311 and a second positioning column 312 are disposed on the lens base 310 . The first positioning column 311 and the second positioning column 312 are respectively located at two corner ends of a diagonal line on the lens base 310 .

[0025] It should be noted that the lens base 310 is fixed to the flexible circuit board 200 by adhesive, and a first positioning column 311 and a second positioning column 312 are arranged on the upper surface of the lens base 310. The lens base 310 is a rectangular structure, and the first positioning column 311 and the second positioning column 312 are respectively located at the two corners on the diagonal of the lens base 310, that is, the first positioning column 311 and the second positioning column 312 are respectively arranged at the two corners on the diagonal of the lens base 310. In this way, the first positioning column 311 and the second positioning column 312 can be used to realize the positioning installation of the optical fingerprint module 10, so as to avoid the problem of position deflection when the optical fingerprint module is installed on other components, thereby improving the installation accuracy, and further ensuring the recognition accuracy of the optical fingerprint module. In this embodiment, an anti-rotation plane 311a is arranged on the side wall of the first positioning column 311. Since the first positioning column 311 is a cylindrical structure, the anti-rotation plane 311a can be arranged to further improve the accuracy of installation positioning.

[0026] Furthermore, an IR filter 110 is also bound to the optical fingerprint chip 100 , and the IR filter 110 is bonded to the optical fingerprint chip 100 by conductive adhesive.

[0027] In one embodiment, the lens base 310 is further provided with an air escape hole 313, which is connected to the escape cavity. The air escape hole 313 can be provided to exhaust air, thereby preventing the escape cavity of the lens base 310 from forming a closed space. In this way, when the lens base is attached, there will be no problem of bubbles or unstable bonding in the glue.

[0028] In one embodiment, the lens assembly 300 is also covered with a protective member 400, and the protective member 400 is used to isolate and protect the lens 320. In this embodiment, the protective member 400 is a protective film, and the protective film plays a role of isolating and protecting the lens. Furthermore, the protective member 400 is provided with an easy-tear handle 410, which is used to easily tear off the protective member 400.

[0029] In one embodiment, a reinforcing plate 210 is provided on one side of the flexible circuit board 200 away from the optical fingerprint chip 100, and the reinforcing plate 210 is located below the lens assembly 300. Since the material of the flexible circuit board 200 is relatively soft, it is easy to break after other components are installed, so it is necessary to increase the strength of the flexible circuit board 200 by adding a reinforcing plate 210. Preferably, the reinforcing plate 210 is a steel sheet reinforcing plate, and the steel sheet reinforcing plate can be adhered and fixed to the flexible circuit board 200 by a steel sheet adhesive.

[0030] Furthermore, a connector is installed on the flexible circuit board 200 , and a steel sheet reinforcement plate is also provided on the back side of the flexible circuit board 200 near the connector, so that the strength of the flexible circuit board 200 is enhanced by the steel sheet reinforcement plate.

[0031] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. An optical fingerprint module, characterized in that: include: An optical fingerprint chip, wherein an adhesive member is preset on one side of the optical fingerprint chip so that the adhesive member and the optical fingerprint chip form an integrated structure; A flexible circuit board, wherein a binding area is provided on one side surface of the flexible circuit board, and the optical fingerprint chip is bound to the binding area through the adhesive member; and A lens assembly, wherein the lens assembly comprises a lens base and a lens, wherein the lens is arranged on the lens base, and an avoidance cavity is provided on the lens base, and when the lens base is arranged on the flexible circuit board, the optical fingerprint chip is located in the avoidance cavity; An air escape hole is also provided on the lens base, and the air escape hole is communicated with the avoidance cavity.

2. The optical fingerprint module according to claim 1, characterized in that: A first positioning column and a second positioning column are arranged on the lens base, and the first positioning column and the second positioning column are respectively located at two corner ends of a diagonal line on the lens base.

3. The optical fingerprint module according to claim 1, characterized in that: The adhesive piece is a DAF tape.

4. The optical fingerprint module according to claim 3, characterized in that: The thickness of the adhesive piece is 0.155 mm.

5. The optical fingerprint module according to claim 1, characterized in that: The optical fingerprint chip is also bound with an IR filter.

6. The optical fingerprint module according to any one of claims 1 to 5, characterized in that: The lens assembly is also covered with a protective piece, and the protective piece is used to isolate and protect the lens.

7. The optical fingerprint module according to claim 6, characterized in that: The protective piece is provided with an easy-to-tear handle.

8. The optical fingerprint module according to any one of claims 1 to 5, characterized in that: A reinforcing plate is arranged on a side surface of the flexible circuit board away from the optical fingerprint chip, and the reinforcing plate is located below and close to the lens assembly.

9. The optical fingerprint module according to claim 8, characterized in that: The reinforcement plate is a steel sheet reinforcement plate.

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