KR20190143584A - Optical sensor package - Google Patents

Abstract

The present invention relates to an optical sensor package for reducing the thickness thereof. The optical sensor package comprises: a base substrate; and an optical sensor positioned on the base substrate and having a wire for electrical connection with the base substrate. The base substrate has a recessed unit. The optical sensor is located in the recessed unit.

Description

Optical sensor package {OPTICAL SENSOR PACKAGE}

The present invention relates to an optical sensor package.

Recently, electronic devices are developing in a slim form. The slim form of the electronic device has an advantage that not only the appearance is beautiful but also the grip feeling of the user is improved and the likeness of the product is improved. At the same time, recent electronic devices have implemented complex functions. To this end, the number of components accommodated inside the electronic device is increasing.

Optical sensors, which are used as fingerprint sensors for fingerprint recognition by detecting light emitted from a sensing target or reflected from the sensing target, are widely used in recent electronic devices. In accordance with the slimming trend of the electronic device described above, the optical sensor package is also required to be slimmed.

Conventional optical sensors include a light receiving element for detecting light emitted from the outside and converting the light into an electrical signal, and a light blocking member formed to surround the light receiving element. Here, the light blocking member exposes only the light-receiving surface portion of the optical sensor to the outside and covers the other portion so as to block the light, thereby blocking the light flowing from the side surface. Mainly, the light blocking member is a black plastic injection molding or metal workpiece with light shielding properties.

Korean Patent Publication No. 10-1457069 (registered October 27, 2014) discloses an optical sensor package including such a light blocking member.

However, as the structure of the optical sensor package including the conventional light blocking member becomes smaller, more precise processing and assembling of the light blocking member is required, thereby increasing the processing cost and increasing the defective rate. In addition, the structure of the optical sensor package has a problem that there is a limit in miniaturization and slimming.

In addition, the optical sensor package is often mounted and used under the display device panel such as a liquid crystal display panel. In this case, when the thickness of the optical sensor package becomes thick, during the packaging process of a product having the optical sensor package and the display device package. Many difficulties arise.

Republic of Korea Patent No. 10-1457069 (Registration Date: October 27, 2014, the name of the invention: optical roughness sensor)

The problem to be solved by the present invention is to reduce the thickness of the optical sensor package.

An optical sensor package according to an aspect of the present invention for solving the above problems includes a base substrate and an optical sensor positioned on the base substrate, the optical sensor having a wire for electrical connection with the base substrate, Has a depression, and the optical sensor is located within the depression.

The optical sensor package may further include a wire protection film disposed on the optical sensor and filling the wire.

The wire protection film may be formed of a film over wire (FOW).

The base substrate may be formed of a cavity flexible printed circuit board.

A separation space is formed between the optical sensor and the side of the depression,

The wire protection film may be additionally located in the separation space.

The depression may include an upper depression formed on an upper surface of the base substrate and a lower depression formed on a lower surface of the base substrate, and the optical sensor may be mounted in the upper depression. The optical sensor package may further include an electronic component mounted in the lower recess.

The optical sensor may include an active region positioned on an upper surface of the optical sensor to face the optical filter, the wire protection film may be positioned above the active area and a peripheral area of the active area, and the wire protection film may be It may have a light transmittance of 75% or more in the visible light band.

The optical sensor may include an active region positioned on an upper surface of the optical sensor to face the optical filter, and the wire protection film may be positioned on an upper surface of the optical sensor except for the active region.

The optical filter may be positioned to be spaced apart from the active region by the thickness of the wire protective film.

The optical sensor package according to the above feature may further include a double-sided tape positioned on the optical filter.

The optical sensor package according to the above feature may further include a spacer positioned between an edge portion of the base substrate and the optical filter corresponding to the edge portion.

According to a feature of the optical center package according to an embodiment of the present invention, since the wire protruding above the upper surface of the optical sensor is embedded into the wire protection film, the adhesion state of the wire is safely maintained.

In addition, since the empty space for preserving the bonded state of the wire is unnecessary, the thickness of the optical sensor package is greatly reduced.

In addition, when the wire protection film is placed in an area other than the active area of the optical sensor, light incident to the optical sensor through the optical filter is prevented from being lost by the wire protection film, which adversely affects the operation efficiency of the optical sensor package. Effectively reducing the thickness of the optical sensor package.

1 is a cross-sectional view of an optical sensor package according to an embodiment of the present invention.
2 is a cross-sectional view of an optical sensor package according to another embodiment of the present invention.
3 is a cross-sectional view of an optical sensor package according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention; In describing the present invention, if it is determined that adding specific descriptions of techniques or configurations already known in the art may make the gist of the present invention unclear, some of them will be omitted from the detailed description. In addition, terms used in the present specification are terms used to properly express the embodiments of the present invention, which may vary according to related persons or customs in the art. Therefore, the definitions of the terms should be made based on the contents throughout the specification.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. As used herein, the meaning of “comprising” specifies a particular characteristic, region, integer, step, operation, element, and / or component, and other specific characteristics, region, integer, step, operation, element, component, and / or group. It does not exclude the presence or addition of.

Hereinafter, an optical sensor package according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

First, the optical sensor package according to an embodiment of the present invention will be described with reference to FIG. 1.

As shown in FIG. 1, the optical sensor package 100 of the present example includes a base substrate 10 positioned at the bottom and an optical sensor 20 positioned on a first surface (eg, an upper surface) of the base substrate 10. , A wire protective film 30 positioned on the optical sensor 20, an optical filter 40 positioned on the wire protective film 30, and a housing structure 50 positioned on the base substrate 10.

The base substrate 10 may be a portion forming the bottom surface of the optical sensor package 100 of the present example, and thus, the optical sensor 20, the wire protection film 30, and the optical filter (on the base substrate 10) may be formed. 40 may be sequentially located.

The base substrate 10 may include a hard printed circuit board (HPCB), a flexible printed circuit board (FPCB), a rigid flexible printed circuit board (RFPCB), or the like. Can be.

The upper and lower surfaces of the base substrate 10 may be mounted with various types of electronic components 60, such as an optical sensor 20, a passive element or an active element, and may be mounted on the mounted electronic component 60 and the electronic component. A pad 110 or a pattern made of a conductive material is printed for electrical and physical connection between the optical sensors 20.

Therefore, the electrical signal and the power supply are made through the pad 110 and the patterns, thereby operating the optical sensor 20.

Also, as shown in FIG. 1, the base substrate 10 includes a printed circuit board having a cavity, which is a space for mounting the electronic components 60 and 20, on a corresponding surface of the base substrate 10. Cavity RFPCB) can be used.

In this case, since the electronic components 20 and 60 mounted on the base substrate 10 are mounted in a recessed shape, the mounted electronic components 20 and 60 do not protrude outward from the corresponding surface or protrude height. Is greatly reduced.

As a result, the total thickness of the optical sensor package 100 is greatly reduced.

The optical sensor 20 is located in a corresponding area (ie, mounting area) of the upper surface of the base substrate 10, where the mounting area is recessed by a predetermined depth from the upper surface to the lower surface as shown in FIG. 1. It may be a depression.

The depression may have a larger size in the horizontal direction than the optical sensor 20, so that a space may be formed between the optical sensor 20 and the side surface of the depression.

The optical sensor 20 may be mounted on a corresponding mounting area of the base substrate 10 using surface mount technology (SMT).

In this example, the upper surface of the optical sensor 20 facing the optical filter 40 is a light receiving surface on which light passing through the optical filter 40 is incident, and part of the light receiving surface is directed to the optical sensor 20. It operates as an active region 210 of the optical sensor 20 in which a plurality of light receiving elements are integrated, which detects the irradiated light and generates and outputs an electric signal in a corresponding state according to the detected light.

Although the plurality of light receiving elements positioned in the active region 210 are determined to operate most suitably in a predetermined wavelength band, on the other hand, light other than the predetermined wavelength band may be detected, and in some cases, the predetermined wavelength band may be used. Light other than this can be recognized by the optical sensor 20 as noise.

Therefore, as in the present example, the active region 210 may be covered by the optical filter 40 that passes only light of a predetermined wavelength band or blocks light of a predetermined wavelength band.

The optical sensor 20 may be electrically connected to the base substrate 10 in various ways. For example, the optical sensor 20 may be a wire, a ball grid array (BGA), a land grid array (LGA), a PID, or a dual in-line package (DIP) using the base substrate 10 and a wire bonding process. Can be electrically connected.

Referring to FIG. 1, the optical sensor 20 is electrically connected to the base substrate 10 using a wire bonding method using a wire 220.

Specifically, the upper surface of the optical sensor 20 is formed with a pad 230 to which one end of the wire 220 is coupled, and the other end of the wire 220 is also coupled to the upper surface of the base substrate 10. The pad 110 is located.

Therefore, both ends of the wire 230 are connected to the pads 110 and 230 respectively positioned on the base substrate 10 and the optical sensor 20, respectively, to electrically connect the base substrate 10 and the optical sensor 20.

As such, since the wire 220 positioned on the upper surface of the optical sensor 20 and connected to the adjacent portion of the base substrate 10 is a thin strip made of a conductive material such as gold, an upward direction is due to the characteristics of the connection method. It jumps out and is led out of the upper surface which is the connection surface of the optical sensor 20.

However, in this example, the wire 220 drawn outward is protected by being embedded in the wire protection film 30.

As a result, the impact applied to the wire 220 is reduced, so that the incidence of contact failure, such as disconnection or disconnection of the wire 220, is greatly reduced.

As shown in FIG. 1, the wire protection film 30 is positioned directly on the optical sensor 20 to be in contact with the upper surface of the optical sensor 20. The wire protection film 30 is positioned above the active area 210 and the peripheral area of the optical sensor 20. In this case, light irradiated and sensed by the active region 210 must pass through the wire protection film 30. The wire protection film 30 may be formed to be transparent to the wavelength band detected by the active region 210.

For example, the active region 210 may detect the visible light band, and in this case, the wire protection film 30 preferably has a light transmittance of 75% or more in the visible light band. More preferably, the wire protection film 30 may have a light transmittance of 85% or more in the visible light band.

The wire protective film 30 is formed of a film over wire (FOW), and when heated above a predetermined temperature (about 135 degrees), a gel state changes.

Therefore, as the protective film 30 in the gel state is attached to the upper surface of the optical sensor 20, the wire 220 protruding from the upper surface of the optical sensor 20 is embedded in the wire protective film 30. do.

When the temperature of the wire protection film 30 is lowered to the set temperature, the wire protection film 30 is solidified in a gel state to fix the position of the wire 220 embedded therein.

When the wire protection film 30 is in a gel state, a lower portion of the wire protection film 30 may be pushed up to a spaced space between the optical sensor 20 and the side surface of the depression. When a portion of the wire protection film 30 is solidified in a state located in the separation space, a part of the wire protection film 30 is located in the separation space.

Because of this, as already described, the connection state of the wire 220 is safely maintained.

In addition, despite the presence of the wire 220 drawn out of the optical sensor 20, the total thickness of the optical sensor package 100 is large as the wire protection film 30 is attached directly on the optical sensor 20. Decreases.

In general, in order to protect the wire protruding toward the optical filter 40 from the upper surface of the optical sensor 20, the area above the optical sensor 20, where the wire 220 is located, was kept empty. As a result, the optical filter 40 is positioned above the optical sensor 20 at intervals of the empty space.

Therefore, the empty space for the wire 220 becomes a wasteful space in which no component of the optical sensor package is located other than the wire 220, and the thickness of the optical sensor package increases in proportion to the depth of the empty space. .

However, in the present example, since the wire 220 protruding to the outside using the wire protection film 30 is embedded in the wire protection film 30 to prevent the occurrence of empty space for the wire 220 only.

At this time, since the thickness of the wire protection film 30 is much smaller than the depth of the empty space for the wire 220, in the case of protecting the wire 220 by adding a wire protective film 30 instead of the empty space, the optical sensor package The total thickness of 100 is greatly reduced.

Accordingly, the total thickness of the optical sensor package 100 according to the comparative example having an empty space for the wire 220 is about 0.755 mm, while the total thickness of the optical sensor package 100 according to the present example is about 0.46 mm to 0.57 mm. As a result, the thickness of the optical sensor package was reduced.

The optical filter 40 is positioned on the wire protective film 30 in contact with the upper surface of the protective film 30 using an adhesive or an adhesive film. As a result, the optical filter 40 is positioned above the active region 210 of the optical sensor 20.

The optical film 40 is a filter that is incident from the upper portion of the light passes through the light of a predetermined wavelength band or blocks the light of the predetermined wavelength band, the optical filter 40 selectively blocks the light of the infrared band. It may be an infrared cut filter.

The housing structure 50 surrounds the optical sensor 20, the wire protection film 30, and the optical filter 40 from the outside so that these components 20-40, which are located therein, are free from external impact and impurities. Protect.

Since the housing structure 50 is located at the edge of the base substrate 10 and the housing structure 50 is not present at the portion where the optical sensor 20 is located, the housing structure 50 is surrounded by the housing structure 50. External light is incident to the optical sensor 20 through the light.

The housing structure 50 may be made of a conductive material such as metal or an insulating material such as plastic.

In the optical sensor package 100 according to the present exemplary embodiment having the above structure, a display device panel such as a liquid crystal display panel may be positioned under the optical sensor package 100. To this end, the optical sensor package 100 may be disposed on an upper surface of the optical filter 40 and an upper surface of the housing structure 50. Double sided tape 70 may be additionally attached with adhesive applied to both sides.

In order to manufacture the optical sensor package 100, the optical filter of the disc and the wire protective film of the disc is attached to each other using an adhesive or an adhesive film, and then the size suitable for one optical sensor package 100 using a cutting machine Cut the optical filter and the wire protection film which are attached to each other in the form of and. For this reason, the optical filter 40 and the wire protection film 30 adhering to each other are formed.

In addition, the optical sensor 20 is mounted at a corresponding position of the base substrate 10 using a wire bonding method or the like. In this case, a wire 220 for electrical connection with the base substrate 10 protrudes from the upper surface of the optical sensor 20.

As such, when the base substrate 10 on which the optical sensor 20 is mounted, the wire protection film 30 and the optical filter 40 adhered to each other are completed, hot air having a predetermined temperature on the exposed surface of the wire protection film 30 is completed. The surface of the wire protection film 30 is heat-treated in the same manner as to apply a to change the state of the wire protection film 30 to a gel state.

Next, the surface of the wire protection film 30 that maintains the gel state is positioned on the base substrate 10 to which the optical sensor 20 is attached, and then pressure is applied to the wire protection film 30 to the base substrate 10. Attach on top.

As a result, the wire protection film 30 is positioned in contact with the upper surface portion of the exposed base substrate 10 and the upper surface of the exposed optical sensor 20, and the wire protective film 30 in a gel state is applied by an applied pressure. The wire 220 guided to the upper part of the optical sensor 20 is embedded in the inside.

In this process, a portion of the wire protection film 30 may be filled in the spaced space between the optical sensor 20 and the side surface of the depression.

In this state, when the wire protection film 30 is cooled below the set temperature, the wire protection film 40 is solidified in a solid state to maintain the adhered state.

As a result, the wire 220 electrically connecting the optical sensor 20 and the base substrate 10 is safely embedded in the wire protection film 30 to maintain a secure connection state regardless of external impact.

In addition, as the wire 220 is embedded in the wire protection film 30, a separate protective space for protecting the wire 220 is unnecessary. Accordingly, the thickness from the optical sensor 20 to the optical filter 40 is reduced, so that the total thickness of the optical sensor package 100 is also greatly reduced.

As such, when the wire protection film 30 having the optical filter 40 attached thereto is mounted on the optical sensor 20, the optical sensor package 100 may be installed by installing the housing structure 50 at a corresponding position of the base substrate 10. Complete

Next, the double-sided tape 70 is attached onto the optical filter 40 and the housing structure 50.

Next, an optical sensor package 100a according to another embodiment of the present invention will be described with reference to FIG. 2.

In the optical sensor package 100a of the present example, components having the same structure and performing the same function are denoted with the same reference numerals as those of FIG. 1 and detailed description thereof will be omitted.

As shown in FIG. 2, the optical sensor package 100a of this example has the same structure as the optical sensor package 100 shown in FIG. 1 except for the installation position and the cutting shape of the wire protection film 30a.

Accordingly, the optical sensor package 100a of the present example is mounted on the base substrate 10 on which the electronic component 60 is mounted, on the upper surface of the base substrate 10, and includes the active region 210 and the base on the upper surface. On the optical sensor 20 from which the wire 220 for electrical connection with the substrate 10 is derived, the wire protection film 30a positioned on the upper surface of the optical sensor 20, and the wire protection film 30a. A positioned optical filter 40 and a housing structure 50 located along the edge of the base substrate 10 and surrounding components 20, 30a, 40 located therein.

In the optical sensor package 100a, the wire protection film 30a includes all parts facing its lower surface, and the upper surface of the optical sensor 20 including the active area 210 and the optical sensor 20 are mounted. Instead of being positioned on the exposed portion of the exposed base substrate 10, all exposed portions of the optical sensor 20 except the active region 210, that is, of the optical sensor 20 except the active region 210, may be formed. The upper surface portion and the optical sensor 20 are positioned on the upper surface portion of the base substrate 10 on which it is not mounted.

Therefore, the wire protection film 30a completely fills the wire 220 for electrical connection between the base substrate 10 and the optical sensor 20, thereby protecting the wire 220 exposed to the outside safely.

In addition, due to the installation position of the wire protection film 30a, the wire protection film 30a is not positioned on the active region 210 of the optical sensor 20, and is optically spaced apart by the thickness of the wire protection film 30a. The filter 40 is located.

Therefore, the light passing through the optical filter 40 is directly incident to the active region 210 of the optical sensor 20, and thus is caused by the wire protection film 30a positioned above the active region 210 of the optical sensor 20. The light loss is prevented and the operating efficiency of the optical sensor 20 is improved.

Since the wire protection film 30a in this structure is positioned so as not to cover the active region 210, it is not necessary to be transparent to the wavelength band of light detected by the active region 210.

For this reason, the optical sensor package 100a of the present example additionally generates not only the wire protection effect and the thickness reduction effect by the wire protection film 30a but also the effect of improving the operation efficiency of the optical sensor 20.

The method of manufacturing the optical sensor package 100a is as follows.

The optical sensor 20 is mounted at the corresponding position of the base substrate 10. At this time, the wire 220 for electrical connection with the base substrate 10 is projected on the upper surface of the optical sensor 20.

Next, the wire protection film of the original plate is cut into the desired shape to produce a wire protection film 30a, and then heat is applied to the corresponding surface (eg, the bottom surface) of the cut wire protection film 30a to form a wire protection film. (30a) is made into a gel state.

Then, the wire protective film 30a is placed on the upper surface of the optical sensor 20 except the active region 210 and the exposed portion of the exposed base substrate 10 without the optical sensor 20 mounted. Is applied to bury the wire 220 into the wire protection film 30a, and in this state the wire protection film 30a is placed on the corresponding portions of the base substrate 10 and the optical sensor 20.

Next, after the optical filter 40 is positioned on the wire protection film 30a using an adhesive or the like, the housing structure 50 is attached to the edge of the base substrate 10 to complete the optical sensor package 100a.

If necessary, a double-sided tape 70 is attached over the optical filter 40 and the housing structure 50.

In the embodiment shown in FIGS. 1 and 2, the optical sensor package 100, 100a has a wire protection film 30, 30a in which the wire 220 is embedded, but in another embodiment shown in FIG. 3. The wire protective films 30 and 30a may be omitted.

In this case, in order to space the base substrate 10 and the optical filter 40 by a predetermined distance, the spacer 90 located at the edge portion of the base substrate 10 is positioned. At this time, the spacer 90 may be made of an elastic material having a restoring force.

As a result, an air gap exists between the base substrate 10 and the optical filter 40 and between the optical sensor 20 and the optical filter 40.

As such, when an air gap exists between the optical sensor 20 and the optical filter 40 using the spacer 90, the light transmittance to the optical sensor 20 increases.

In addition, when the optical sensor package 100b of the present example is applied to the touch sensor module, the reaction speed and the user's touch feeling according to the user's touch operation are improved, and after the touch operation is released, the restoring force of the spacer 90 The recovery time for recovering the touch area to the initial state is also shortened.

In the above, embodiments of the optical sensor package of the present invention have been described. The present invention is not limited to the above-described embodiment and the accompanying drawings, and various modifications and variations will be possible in view of those skilled in the art to which the present invention pertains. Therefore, the scope of the present invention should be defined not only by the claims of the present specification but also by the equivalents of the claims.

100, 100a, 100b: optical sensor package 10: base substrate
20: optical sensor 210: active area
220: wire 30: wire protective film
40: optical filter 50: housing structure
60: electronic component 70: double-sided tape
90: spacer

Claims (11)

A base substrate; And
An optical sensor positioned on the base substrate and having a wire for electrical connection with the base substrate;
Including,
The base substrate has a depression,
The optical sensor is located in the depression
Optical sensor package. According to claim 1,
Wire protection film located on the optical sensor and embedding the wire
Optical sensor package further comprising. The method of claim 2,
The wire protection film is an optical sensor package consisting of a film over wire (FOW). According to claim 1,
The base substrate is an optical sensor package consisting of a cavity flexible printed circuit board. According to claim 1,
A separation space is formed between the optical sensor and the side of the depression,
The wire protective film is additionally located in the separation space optical sensor package. According to claim 1,
The depression includes an upper depression formed on an upper surface of the base substrate and a lower depression formed on a lower surface of the base substrate.
The optical sensor is mounted in the upper depression,
The optical sensor package further comprises an electronic component mounted in the lower recess. The method of claim 2,
The optical sensor includes an active area on the upper surface facing the optical filter,
The wire protection film is positioned over the active area and a peripheral area of the active area,
The wire protective film has a light transmittance of 75% or more in the visible light band.
Optical sensor package. The method of claim 2,
The optical sensor includes an active area on the upper surface facing the optical filter,
The wire protection film is positioned on an upper surface of the optical sensor except for the active area.
Optical sensor package. The method of claim 8,
And the optical filter is spaced apart from the active area by the thickness of the wire protection film. According to claim 1,
The optical sensor package further comprises a double-sided tape positioned on the optical filter. According to claim 1,
And a spacer disposed between an edge portion of the base substrate and the optical filter corresponding to the edge portion.

Images