KR20200024454A - Fingerprint sensor module and method of manufacturing same - Google Patents

Abstract

The present invention relates to a fingerprint sensor module which can stably mount a fingerprint sensor package on a main board and a method for manufacturing the same. The fingerprint sensor module comprises the fingerprint sensor package and the main board, wherein the main board can expose a part of a pad of the fingerprint sensor package. According to the present invention, damage of the fingerprint sensor module due to heat can be minimized.

Description

Fingerprint sensor module and its manufacturing method {FINGERPRINT SENSOR MODULE AND METHOD OF MANUFACTURING SAME}

The present invention relates to a fingerprint sensor module and a method for manufacturing the same, and more particularly, to a fingerprint sensor module and a method for manufacturing the fingerprint sensor package can be mounted on the main board stably.

Recently, as public attention has focused on portable electronic devices, such as smartphones and tablet PCs, research and development in the related technical fields are being actively conducted.

BACKGROUND OF THE INVENTION Portable electronic devices often include a touch screen integrated with a display, which is a display device, as an input device for receiving a specific command from a user. In addition, the portable electronic device may include various function keys or soft keys as input devices other than the touch screen.

These function keys or softkeys can act as home keys, for example, to exit a running application and return to the home screen, or to return the user interface one layer back, or frequently. Can act as a menu key to call a menu to write. Such a function key or soft key may be implemented in a manner of sensing a capacitance of a conductor, a method of sensing electromagnetic waves of an electromagnetic pen, or a complex method in which both methods are implemented, and may be implemented as a physical button.

On the other hand, as the use of portable electronic devices is rapidly expanded to services requiring security, a trend toward mounting a biometric sensor (biometric sensor) having a function of measuring biometric information due to high security is increasing.

Biometric information includes fingerprints, blood vessels on the back of the hands, voices, irises, and the like, and fingerprint sensors are widely used as biometric sensors.

The fingerprint sensor is a sensor that detects a human finger fingerprint. The fingerprint sensor protects data stored in a portable electronic device and prevents a security accident by performing a user registration or authentication procedure through the fingerprint sensor.

The fingerprint sensor may be manufactured in the form of a module including peripheral components or structures, and may be integrated with a physical function key so that the fingerprint sensor may be effectively mounted on various electronic devices.

Conventional fingerprint sensor module may be composed of a fingerprint sensor package and the main substrate. The fingerprint sensor package includes a molding unit covering the base substrate, the fingerprint sensor, and the fingerprint sensor. A coating layer may be formed on the top surface of the molding part. The coating layer covers a part inside the molding part or performs a function of expressing color or glossy / matte. The fingerprint sensor package is mounted on the main board.

As a method of mounting the fingerprint sensor package on the main substrate, a soldering method using reflow may be used. The fingerprint sensor package and the main board are formed with pads for electrical connection on opposite surfaces. After solder is placed on the pad of the fingerprint sensor package or the pad of the main board, the fingerprint sensor package is mounted on the main board so that the pads coincide with each other. The pads are then fused to be electrically connected through a reflow process. This reflow process takes place at a high temperature of approximately 250 degrees. However, when the fingerprint sensor module is exposed to high temperature for a long time, a problem occurs such that the color of the coating layer of the fingerprint sensor module is changed or the surface shape is changed.

On the other hand, after the above-described reflow process, the sidefill and underfill are performed to prevent oxidation of the solder and to fill the empty space around the solder. Sidefill and underfill inject a filler such as epoxy between the fingerprint sensor package and the main substrate, which fills the solder periphery. However, since the gap between the fingerprint sensor package and the main substrate is very small, it is difficult to check whether the filler is properly filled. If the solder is not completely covered by the filler, the solder may be oxidized, and the electrical connection between the fingerprint sensor package and the main board may be unstable, resulting in a problem of a failure of the fingerprint sensor module.

In order to solve the above problems, the present invention is to provide a fingerprint sensor module and a method for manufacturing the fingerprint sensor package that can minimize the damage caused by heat while mounting the fingerprint sensor package on the main board.

In order to solve the above problems, the fingerprint sensor module according to an embodiment of the present invention, the fingerprint sensor package and the main substrate, the main substrate may partially expose the pad of the fingerprint sensor package.

Fingerprint sensor module according to embodiments of the present invention has the effect that the damage caused by heat is minimized.

In addition, the fingerprint sensor module according to the embodiments of the present invention has the effect that it is possible to mount the fingerprint sensor package on the main substrate stably.

In addition, the fingerprint sensor module according to the embodiments of the present invention has the effect of preventing the oxidation of the solder portion.

In addition, the fingerprint sensor module according to the embodiments of the present invention has the effect of improving the waterproof performance.

1 is a plan view of a fingerprint sensor module according to an embodiment of the present invention.
2 is a cross-sectional view of the fingerprint sensor package shown in FIG.
3 is a partially enlarged cross-sectional view of the fingerprint sensor module shown in FIG. 1.
4 is a plan view of a fingerprint sensor module according to another embodiment of the present invention.
5 shows a modification of the second pad according to embodiments of the present invention.

Hereinafter, with reference to the accompanying drawings will be described the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, "on" means to be located above or below the target member, and does not necessarily mean to be located above the gravity direction. In addition, when a part is "connected" with another part, this includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with the other member in between. In other words, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless specifically stated otherwise.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a fingerprint sensor module 100 according to an embodiment of the present invention.

As shown in FIG. 1, the fingerprint sensor module 100 includes a fingerprint sensor package 10 and a main substrate 20. The fingerprint sensor package 10 and the main substrate 20 are electrically connected to each other through the pads 18 and 22.

The fingerprint sensor package 10 will be described in detail with reference to FIG. 2. 2 is a cross-sectional view of the fingerprint sensor package 10 shown in FIG.

As shown in FIG. 2, the fingerprint sensor package 10 includes a base substrate 12, a fingerprint sensor 14, and a cover 16. The base substrate 12 may mount the fingerprint sensor 14. The base substrate 12 may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB) capable of transmitting electrical signal information.

The fingerprint sensor 14 is a sensor capable of sensing an image of a fingerprint, and various sensing methods may be used. For example, the fingerprint sensor 14 may detect an image of a fingerprint using a capacitive method, an optical method, an ultrasonic method, a heat sensing method, a non-contact method, or the like. Hereinafter, for convenience of description, the case in which the fingerprint sensor 14 uses a capacitive method will be described as an example.

In detail, the fingerprint sensor 14 may detect a difference in capacitance according to the height difference between the peaks and valleys of the fingerprint, and transmit the detected signal to a controller (not shown). The controller may acquire an image of a fingerprint based on the received signal.

In addition, the fingerprint sensor 14 may include various types of sensing structures to detect a fingerprint. For example, the fingerprint sensor 14 may include a plurality of sensing pixels arranged in two dimensions. Alternatively, the fingerprint sensor 14 may include a plurality of line type driving electrodes and receiving electrodes. Alternatively, the fingerprint sensor 14 may include a plurality of image receiving units of AREA type.

The fingerprint sensor 14 may be electrically connected to the main substrate 20 through the terminal 18.

Meanwhile, the cover part 16 may be provided on the fingerprint sensor 14. The cover part 16 is configured to protect the fingerprint sensor 914 from external shock or foreign matter.

The cover part 16 may be configured in various ways, such as a coating product or a glass material or a ceramic material. For example, when the cover part 16 is made of a glass material, various glass substrates such as a soda lime organic substrate, an alkali free glass substrate, or a tempered glass substrate may be applied. In addition, the cover portion 16 may be made of a material selected from sapphire, zirconium, and a transparent resin, and the transparent resin may be acrylic or the like.

This cover portion 16 may have a color according to the appearance requirements. For example, the cover 16 may have a color layer therein. Alternatively, the cover part 16 may have a separate color layer on the back of the cover part 16. Alternatively, the cover unit 16 may include a material that can implement color.

The fingerprint sensor package 10 may further include a support (not shown). The support part may be provided on the main substrate 20, and may cover side surfaces of the fingerprint sensor 14 and the cover part 16. This support may be a bezel.

The main board 20 may mount the fingerprint sensor package 10. The main board 20 may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB) capable of transmitting electrical signal information.

The base substrate 12 and the main substrate 20 each include a first pad 18 and a second pad 22. The first pad 18 of the base substrate 12 is provided on one surface of the base substrate 12 facing the main substrate 20. The second pad 22 of the main substrate 20 is provided on one surface of the main substrate 20 facing the base substrate 12. The first pad 18 and the second pad 22 are disposed to face each other.

A portion of the first pad 18 may be exposed through the edge of the main substrate 20. As shown in FIG. 1, the main substrate 20 is disposed on the fingerprint sensor package 10 to cover the first pads 18. The main substrate 20 does not completely cover the first pads 18, but only a portion of the first pads 18. FIG. 1 illustrates a state in which the main substrate 20 exposes the upper side of the first pads 18 and covers the lower side. To this end, the main substrate 20 may have an area smaller than that of the fingerprint sensor package 10. Here, the area means an area of a plane where the base substrate 10 and the main substrate 20 face each other.

A solder portion 30 (see FIG. 3) is disposed between the first pad 18 and the second pad 22. The solder part 30 will be described in more detail with reference to FIG. 3.

3 is a cross-sectional view of the fingerprint sensor module 100 illustrated in FIG. 1 taken along a line A-A. Although FIG. 1 illustrates that the main substrate 20 is disposed on the fingerprint sensor package 10, for convenience of description, FIG. 3 illustrates that the main substrate 20 is disposed below the fingerprint sensor package 10. That is, the cross-sectional view of FIG. 3 may represent a state in which the fingerprint sensor module 100 of FIG. 1 is cut after being cut along the A-A line.

As shown in FIG. 3, the fingerprint sensor package 10 includes a first pad 18. The first pad 18 is formed on the base substrate 12. The main substrate 20 includes a second pad 22. The first pad 18 and the second pad 22 may be disposed at positions facing each other. The solder portion 30 is disposed between the first pad 18 and the second pad 22. The solder part 30 bonds the first pad 18 and the second pad 22 to each other to be electrically connected to each other. The solder part 30 may be formed in a liquid state and may be provided in a cream form to cover the first pad 18 or the second pad 22. In FIG. 3, the solder part 30 covers the first pad 18. In this case, the solder part 30 is provided between the pair of first pads 18 and the second pads 22, respectively. In other words, it is disposed between the first pad 18 and the second pad 22 separately, and is not connected to the neighboring first pad 18 and the second pad 22. The solder portion 30 is cured by heat and bonds the first pad 18 and the second pad 22 to each other.

The filling part 32 is provided to cover the solder part 30. The filling part 32 may be made of a resin material, and may be made of a non-conductive epoxy material. The filling part 32 is injected between the base substrate 12 and the main substrate 20 to cover the exposed portion of the solder part 30. The filling part 32 may be injected in a sufficient amount so that the solder part 32 may be completely covered to the inside which is not exposed to the outside. In FIG. 3, the filling part 32 is partially implanted at the portion where the solder part 32 is disposed, but the filling part 32 may be entirely injected between the base substrate 12 and the main substrate 20. . The filling part 32 may be injected and then cured to stably bond the base substrate 1 and the main substrate 20.

On the other hand, since the solder portion 30 is formed in a state where a part of the solder portion 30 is exposed between the base substrate 12 and the main substrate 20, it is difficult to confirm whether the filling portion 32 completely covers the solder portion 30. It is easy. The filling part 32 can be adjusted to completely cover the solder part 30 when the filling part 32 is injected, and even after the first injection of the filling part 32 is completed, the partially exposed part can be easily checked, and thus the filling part 32 is filled. The additional injection of) may minimize the exposure of the solder portion 30. Accordingly, penetration of moisture or foreign matter into the periphery of the solder part 30 can be suppressed, and as a result, there is an effect of preventing oxidation of the solder part 30.

4 illustrates a fingerprint sensor module 200 according to another embodiment of the present invention. In the fingerprint sensor module 200 of FIG. 4, the same components as in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 4, the fingerprint sensor module 200 includes a fingerprint sensor package 10 and a main substrate 24. The main substrate 24 includes an opening 26. The opening 26 may be formed in the center of the main substrate 24, and may have various shapes such as a circle and a rectangle. The main substrate 24 exposes the fingerprint sensor package 10 through the opening 26. More specifically, the main substrate 24 exposes the base substrate 12 and the first pads 18 through the opening 26. The first pads 18 may be disposed to be partially exposed by the opening 26. Second pads 22 are formed on one surface of the main substrate 24 facing the first pads 18. The first pad 18 and the second pad 22 are disposed to face each other and are electrically connected by the solder portion 30. 4, illustration of the solder part 30 is omitted for convenience of description.

The main substrate 24 may have a smaller area than the fingerprint sensor package 10. Here, the area means an area of a plane where the base substrate 10 and the main substrate 24 face each other. In FIG. 4, the main substrate 24 exposes the fingerprint sensor package 10 through the opening 26 and the edge, but the main substrate 24 exposes the fingerprint sensor package 10 only through the opening 26. You can also In other words, the main substrate 24 and the fingerprint sensor package 10 may be formed in the same size such that the edges thereof coincide with each other. Even in this case, since the area of the main substrate 24 is reduced by the opening 26, the main substrate 24 may have an area smaller than that of the fingerprint sensor package 10.

5 shows a modification of the second pad 22 in accordance with embodiments of the present invention.

FIG. 5A shows the first pad 18 and the second pad 22 shown in FIGS. 1 to 4. The second pad 22 may have the same width (horizontal length) as the first pad 18. As shown in FIG. 5B, the second pad 22b has a recess 221. The recessed portion 221 is a portion dug inward of the second pad 22b at the edge of the second pad 22b. The first pad 18 of FIG. 5B exposes more area than the first pad 18 of FIG. 5A. As a result, the exposed area of the solder part 30 applied to the first pad 18 of FIG. 5B also becomes wider, so that the solder part 30 is easily supplied with heat during the bonding process, and as a result, the solder part 30 is applied. Has the effect of improving the adhesion performance.

As shown in FIG. 5C, the second pad 22c includes an opening hole 222. A portion of the first pad 18 is exposed through the opening hole 222. That is, a portion of the first pad 18 is exposed through the upper edge of the second pad 22c, and a portion of the first pad 18 is exposed through the opening hole 222 below. The first pad 18 of FIG. 5C also exposes more area than the first pad of FIG. 5A. The first pad 18 is exposed through the upper side of the second pad 22c and is exposed through the opening hole 222 formed in the opposite direction. Since the heat transfer is easy in the portion exposed to the upper and lower sides, the adhesive force of the solder portion 30 is increased, and thus the first pad 18 and the second pad 22c may be more stably coupled.

As shown in FIG. 5D, the second pad 22d includes a recess 221 and an opening hole 222. Accordingly, the first pad 18 and the second pad 22d may be more firmly coupled.

Meanwhile, in the above description, the second pads 22b, 22c, and 22d have the recesses 221 and the openings 222, but the main substrates 20 and 24 also include the second pads 22b. It has the same shape as (22c) (22d). That is, although not shown, the main substrates 20 and 24 also include recesses and openings.

The manufacturing method of the fingerprint sensor module 100 as described above will be described. After arranging the main substrates 20 and 24 on the jig, the solder portions 30 are formed on the second pads 22, 22b, 22c and 22d. The solder portion 30 may be a cream type formulation and may be supplied to the second pads 22, 22b, 22c, and 22d by a metal mask. Then, the fingerprint sensor package 20 is mounted on the main boards 20 and 24 using the pickup device. In this case, the first pads 18 and the second pads 22, 22b, 22c, and 22d are disposed to face each other. Then, heat is supplied from the lower side of the jig to fuse the solder portion 30. Accordingly, the first pads 18 and the second pads 22, 22b, 22c, and 22d facing each other are electrically connected to each other. The jig is formed to locally heat the solder portion 30, the first pads 18, and the second pads 22, 22b, 22c, and 22d. For example, the jig may have a structure in which portions corresponding to the solder part 30, the first pads 18, and the second pads 22, 22b, 22c, and 22d are open. Heat may be supplied through a laser, a tip, or a hot air fan through the open portion of the jig. In other words, instead of supplying heat to the entire fingerprint sensor package 10 and the main substrates 20 and 24, the heat is locally supplied through the open portion of the jig, so that the fingerprint sensor package 10 or the main substrate is not supplied. Phenomenon such as change in coating color or surface due to the high temperature of (20) and (24) can be suppressed.

As such, after the fingerprint sensor package 10 and the main board 20 and 24 are bonded to each other through the solder unit 30, the filling unit 32 is interposed between the fingerprint sensor package 10 and the main board 20 and 24. ). Since the first pads 18 and the solder portion 30, the first pads 18, and the second pads 22, 22b, 22c, and 22d are exposed, visual inspection can be performed. Easy to check for defects In addition, since the solder part 30 is located at the edge of the main substrate 20, the filling part 32 may be easily injected to completely fill the space between the fingerprint sensor package 10 and the main substrate 20. Accordingly, there is an effect of improving the waterproof performance of the fingerprint sensor module 100. Meanwhile, according to embodiments of the present invention, in the fingerprint sensor module to which the dome switch (not shown) is applied, the first pads 18, the solder part 30, the first pads 18, and the second pads may be used. Since the fields 22, 22b, 22c and 22d can be disposed at the edge of the fingerprint sensor module, there is an easy effect in the press test of the dome switch.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is represented by the following claims, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and equivalent concepts thereof are included in the scope of the present invention.

100: fingerprint sensor module 10: fingerprint sensor package
20: main substrate 18: first pad
22: second pad

Claims (1)

Fingerprint sensor package; And
Main board
It includes, wherein the main substrate is a fingerprint sensor module to partially expose the pad of the fingerprint sensor package.

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