KR20230120905A - Optical filter carrier, image sensor package having optical filter, method of fabricating optical filter carrier and image sensor package - Google Patents

Abstract

An optical filter carrier, an image sensor package having an optical filter, a method for manufacturing an optical filter carrier, and a method for manufacturing an imaging sensor package are disclosed. An image sensor package according to an embodiment includes a semiconductor chip having pixels for image sensing disposed on an upper surface and solder balls for electrical connection formed on a lower surface thereof, an optical filter disposed on the semiconductor chip, and disposed between the optical filter and the semiconductor chip. A spacer is included, but the spacer is formed of black ink.

Description

Optical filter carrier, image sensor package having an optical filter, method for manufacturing an optical filter carrier, and method for manufacturing an image sensor package }

The present invention relates to a camera system for optical imaging and sensing, and more particularly to an image sensor package having an optical filter and a method of manufacturing the image sensor package.

Various optical filters and image sensors are used in camera systems for optical imaging and sensing in various fields such as automobiles, mobile phones, and CCTVs. An optical filter is an optical element that transmits light in a selected wavelength range and blocks other light in VR (Virtual Reality), AR (Augmented Reality), autonomous vehicles, drones, face recognition, iris recognition, gesture recognition, etc. The field of application continues to expand.

The image sensor is disposed downstream of the optical filter and senses light passing through the optical filter. The image sensor generally includes a CCD or CMOS image sensor, and these image sensors are manufactured using a silicon substrate. In recent years, image sensors using a 12-inch silicon substrate have been manufactured according to the large-area silicon substrate.

The image sensor includes pixels, and each pixel detects incident light and converts it into an electrical signal. The image sensor is mounted on a printed circuit board, and bonding wires are generally used to electrically connect the image sensor to the printed circuit board. The bonding wire electrically connects pads formed around the pixel area and pads on the printed circuit board. The pad for bonding the wire increases the area of the image sensor in addition to the pixel area required for light sensing. An increase in the area of the image sensor increases the size of a front camera module of a mobile phone or the like, making it difficult to display, for example, a full screen.

Furthermore, since the image sensor using the bonding wire is not freely movable, there is a limit in application to a sensor moving optical image stabilization (OIS) module that achieves optical image stabilization by moving the image sensor.

Meanwhile, a conventional camera module adjusts a focal length by moving a lens using an actuator including a voice coil motor (VCM). In such a camera module, an optical filter is usually mounted on an actuator and placed near the image sensor. Accordingly, the process of manufacturing the optical filter module and the process of manufacturing the image sensor package have been separated from each other.

An object to be solved by the present invention is to provide an image sensor package having an optical filter.

Another problem to be solved by the present invention is to provide an image sensor package capable of reducing a plane area.

Another problem to be solved by the present invention is to provide a large-area optical filter carrier that can be used for manufacturing an image sensor package using a large-area substrate.

Another problem to be solved by the present invention is to provide a method for manufacturing an optical filter carrier and an image sensor package.

An image sensor package according to an embodiment of the present invention includes a semiconductor chip having pixels for image sensing disposed on an upper surface and solder balls for electrical connection formed on a lower surface; an optical filter disposed on the semiconductor chip; and a spacer disposed between the optical filter and the semiconductor chip, wherein the spacer is formed of black ink.

By forming the spacer using black ink, the spacer can be easily formed with a small thickness. In one embodiment, the spacer may have a thickness within the range of 20um to 100um.

The spacer may have an optical density (OD) of 3 or greater for visible and infrared light and a reflectance of less than 3%. Furthermore, the spacer may have a reflectance of 1% or less for visible light and infrared light, and furthermore, a reflectance of 0.5% or less. Accordingly, flare may be prevented by blocking light incident to the spacer.

The optical filter may include a transparent substrate transparent to visible light and infrared light; a lower filter stack disposed on a lower surface of the transparent substrate; an upper filter stack disposed on the transparent substrate to face the lower filter stack; An organic material layer disposed between the transparent substrate and the upper filter stack may be included, and the lower filter stack and the upper filter stack may each include inorganic material layers having different refractive indices.

In addition, the organic material layer may be formed of a polymer containing a light absorber, and a glass transition temperature of the organic material layer may be 220° C. or higher. The light absorber may have a maximum absorption wavelength within a range of 620 nm to 780 nm.

The image sensor package may further include a base coat disposed between the organic material layer and the transparent substrate. The base coat improves adhesion of the organic material layer.

The image sensor package may further include a mask disposed on the optical filter to face the spacer. The mask may have a width equal to or greater than that of the spacer and may overlap the spacer.

Furthermore, an outer surface of the spacer and an outer surface of the mask may be parallel to a side surface of the semiconductor chip and a side surface of the optical filter.

Meanwhile, the image sensor package may further include a light blocking layer covering a side surface of the optical filter.

An optical filter carrier according to an embodiment of the present invention includes an optical filter wafer; and

and spacers arranged in a mesh shape on the optical filter wafer, and the spacers are formed of black ink.

The optical filter wafer may have a diameter of at least 12 inches.

The spacer may have a thickness in the range of 10 um to 50 um, and has an optical density (OD) of 3 or more and a reflectance of less than 3%, further, a reflectance of 1% or less, and furthermore, a reflectance of 0.5% or less for visible light and infrared light. can have

The optical filter wafer may include a transparent substrate transparent to visible light and infrared light; a lower filter stack disposed on a lower surface of the transparent substrate; an upper filter stack disposed on the transparent substrate to face the lower filter stack; and an organic material layer disposed between the transparent substrate and the upper filter stack, wherein the lower filter stack and the upper filter stack may each include inorganic material layers having different refractive indices, and the organic material layer contains a light absorber. The organic material layer may have a glass transition temperature of 220° C. or more, and the light absorber may have a maximum absorption wavelength within a range of 620 nm to 780 nm.

An optical filter carrier manufacturing method according to an embodiment of the present invention includes preparing an optical filter wafer, forming a mask of a light blocking material on one surface of the optical filter wafer, and using black ink on the other surface of the optical filter wafer. It may include forming a mesh-shaped spacer.

The spacer may have an optical density of 3 or more and a reflectance of less than 3% for visible light and infrared light, furthermore, a reflectance of 1% or less, and even more, a reflectance of 0.5% or less.

Meanwhile, in preparing the optical filter wafer, a transparent substrate transparent to visible light and infrared rays is prepared, inorganic material layers having different refractive indices are laminated on the lower surface of the transparent substrate to form a lower filter laminate, and a lower filter stack is formed on the upper surface of the transparent substrate. forming an upper filter stack by stacking inorganic material layers having different refractive indices, and forming an organic material layer on the upper surface of the transparent substrate before or after forming the upper filter stack, wherein the organic material layer has a glass transition temperature of 220° C. or higher It can be formed using a polymer having.

The transparent substrate may have a diameter of at least 12 inches.

A method of manufacturing an image sensor package according to an embodiment of the present invention includes manufacturing an optical filter carrier by the method described above, manufacturing a semiconductor wafer on which a plurality of image sensing pixels are formed, and placing the optical filter carrier on the semiconductor wafer. and cutting together the optical filter carrier and the semiconductor wafer to fabricate individualized imaging sensor packages.

While cutting the optical filter carrier and the semiconductor wafer together, the mask and the spacer may also be cut together.

According to embodiments of the present invention, a spacer between an image sensing semiconductor chip and an optical filter may be reduced by forming a spacer using black ink, thereby reducing an overall thickness of an image sensor package including an optical filter.

In addition, by providing a large-area optical filter carrier, it is possible to mass-manufacture an image sensor package having an optical filter at a wafer level together with a large-area semiconductor wafer on which a plurality of image sensing pixels are formed. In particular, it is possible to provide a large-area optical filter carrier of 12 inches or more by coating an organic material layer having infrared absorption characteristics on a transparent substrate, and accordingly, an image sensor package can be manufactured at a wafer level together with a semiconductor wafer of 12 inches or more. .

In addition, by adopting an image sensor package employing a ball grid array, the plane area of the camera module can be reduced. Accordingly, the image sensor package may be directly mounted on the main board without the need to mount the image sensor package on a separate printed circuit board and electrically connect it to the main board.

1 is a schematic plan view illustrating an image sensor package according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view taken along the line A-A' in FIG. 1 .
FIG. 3 is a schematic cross-sectional view taken along the line BB' in FIG. 1 .
4 is a schematic cross-sectional view for explaining an optical filter according to an embodiment of the present invention.
5 is a schematic plan view for explaining a semiconductor wafer on which a plurality of pixels for image sensing are formed.
6A is a schematic plan view for explaining an optical filter carrier according to an embodiment of the present invention.
6B is a partially enlarged plan view of FIG. 6A.
FIG. 6C is a schematic cross-sectional view taken along the line C-C′ in FIG. 6B.
7A, 7B, 7C, and 7D are schematic plan views illustrating a method of manufacturing an image sensor package according to an exemplary embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention may be embodied in other forms without being limited to the embodiments described below. And in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numbers indicate like elements throughout the specification.

1 is a schematic plan view for explaining an image sensor package according to an exemplary embodiment of the present invention, and FIGS. 2 and 3 are schematic cross-sectional views taken along lines AA′ and BB′ of FIG. 1 , respectively.

1, 2, and 3 , the image sensor package according to the present embodiment may include an image sensor semiconductor chip 10a, an optical filter 20a, a spacer 30, and a mask 40. can

The semiconductor chip 10a for an image sensor may include a semiconductor substrate 11 and a pixel region 13 . For example, the pixel region 13 may be formed in a semiconductor substrate 11 such as silicon. The pixel region 13 may be formed of CCD or CMOS, and thus a CCD image sensor or CMOS image sensor may be provided. Since the semiconductor chip 10a for a CCD or CMOS image sensor is a well-known semiconductor chip in the art, further detailed description thereof will be omitted.

On the semiconductor chip 10a for an image sensor, micro lenses 15 for forming an image may be aligned. The micro lenses 15 may be disposed to form an image on the pixel region 13 of light passing through the optical filter 20 . Micro-scale lenses may be aligned on the pixel area 13 . Although FIG. 2 shows that the micro lenses 15 protrude above the upper surface of the semiconductor substrate 11 , the micro lenses 15 may be disposed below the upper surface of the semiconductor substrate 11 .

Meanwhile, solder balls 17 may be disposed on the lower surface of the image sensor semiconductor chip 10a. The solder balls 17 may be electrically connected to the pixel area through via holes. The solder balls 17 are used to supply electricity for operation of the pixel region 13 to the pixel region 13 or to transmit electrical signals generated in the pixel region 13 to the printed circuit board. In particular, the solder balls 17 are bonded on the printed circuit board, and thus bonding wires according to the prior art are omitted. Furthermore, since the solder balls 17 are disposed on the lower surface of the semiconductor chip 10a, the area for forming pads in the prior art can be omitted or greatly reduced. Accordingly, the planar area of the semiconductor chip 10a can be reduced. The image sensor package according to the present exemplary embodiment may be particularly suitably used for a camera module for a full screen display (FSD) due to a reduction in the plane area of the semiconductor chip 10a. Moreover, since the image sensor package can be manufactured in a small size, the image sensor package can be directly mounted on the main board.

Furthermore, the thickness of the semiconductor chip 10a may be reduced before forming the solder balls 17 . The thickness of the semiconductor chip 10a can be reduced by polishing a substrate such as silicon using a technique such as grinding. By reducing the thickness of the semiconductor chip 10a, an increase in the height of the package due to the formation of the solder balls 17 can be alleviated.

By reducing the thickness of the image sensor package, it is possible to prevent the overall height of the camera module from being increased. can

The optical filter 20a transmits light in a wavelength band required by various camera systems for imaging or sensing and blocks light in an unnecessary area. The optical filter 20a may vary depending on the purpose, and may be, for example, an infrared cutoff filter that blocks infrared rays in an imaging system, and an infrared transmission filter that blocks visible light and transmits infrared rays in a 3D image sensing system. can The optical filter 20a may have the same area as the semiconductor chip 10a. For example, side surfaces of the optical filter 20a may be parallel to side surfaces of the semiconductor chip 10 a. An infrared cutoff filter 20a according to an embodiment is shown in FIG. 4 and will be described in detail later.

The spacer 30 is disposed between the semiconductor chip 10a and the optical filter 20a. The spacer 30 may be arranged in a ring shape along the edge of the optical filter 20a. As shown in FIG. 1 , the spacer 30 may have a rectangular ring shape, but is not limited thereto.

Meanwhile, an outer surface of the spacer 30 may be parallel to a side surface of the optical filter 20a and a side surface of the semiconductor chip 10a. The thickness of the spacer 30 may be smaller than the thickness of the optical filter 20a and may be smaller than the thickness of the semiconductor substrate 11 . The thickness of the spacer 30 is greater than the height of the lenses 15, thus spacing the optical filter 20 away from the lenses 15.

The spacer 30 is formed of a material that can withstand the mounting temperature when the image sensor package is mounted on the printed circuit board using the surface mounting technology using the solder balls 17 . In particular, the image sensor package may be surface mounted using a reflow process, and in this case, the mounting temperature may exceed 220°C. The spacer 30 is formed of a material that can withstand high temperatures in a reflow process. Furthermore, the spacer 30 may be formed of a material that absorbs light and may be formed of a material that has low reflectivity for visible light and infrared light. In one embodiment, the spacer 30 may be formed of black ink, for example, photosensitive black ink. Black ink absorbs and blocks light and has low light reflectance. Moreover, black ink can be easily formed with a small thickness. In one embodiment, the spacer 30 may have a thickness within a range of 20 um to 100 um, for example. The spacer 30 may have a thickness of about 50 μm or less, and has an optical density (OD) of 3 or more and a reflectance of 3% or less for light transmitted through the optical filter 20a, for example, visible light and infrared light. , and may further have a reflectance of 0.5% or less. By using black ink, it is possible to provide a spacer having a small thickness, thereby reducing the overall height of the image sensor package. In addition, by forming the spacer 30 using black ink, it is possible to prevent light from being reflected from the spacer 30 and incident into the pixel region 13 . Plasma treatment may be performed on the surface of the spacer 30 to lower reflectance of the spacer 30 using black ink.

Light passing through the optical filter 20a or light reflected by the micro lens 15 or the semiconductor chip 10a may be reflected by the spacer 30 and be incident to the pixel region 13 . Light reflected from the spacer 30 may cause problems such as flare, resulting in image defects. However, by forming the spacer 30 using black ink, reflection of light that may be generated in the spacer 30 is blocked, thereby preventing flare.

According to the present embodiment, by adopting the spacer 30 formed of a material that can withstand high temperatures, an image sensor package capable of surface mounting can be provided by coupling the optical filter 20a to the image sensor semiconductor chip 10a. .

A mask 40 is disposed on the optical filter 20a. The mask 40 limits a region through which light is incident to the semiconductor chip 10a. The mask 40 may be disposed in a ring shape along the edge of the optical filter 20a. An outer surface of the mask 40 may be parallel to a side surface of the optical filter 20a, and may be parallel to an outer surface of the spacer 30 and an outer surface of the semiconductor chip 10a. In the drawings, the mask 40 is shown as a square ring having the same width as the spacer 30, but the present embodiment is not limited thereto. For example, the mask 40 may be formed as a square ring having a wider width than the spacer 30 . The mask 40 may include a light absorbing material such as Cr. Furthermore, an alignment key may be formed within the mask 40 .

Meanwhile, a light blocking layer 50 covering a side surface of the optical filter 20a may be added to block external light from being incident into the image sensor package through the side surface of the optical filter 20a. The light blocking layer 50 may cover side surfaces of the optical filter 20a and further cover side surfaces of the spacer 30 and/or the mask. In addition, the light blocking layer 50 may cover the side surface of the semiconductor substrate 11 .

4 is a schematic cross-sectional view for explaining an optical filter 20a according to an exemplary embodiment.

Referring to FIG. 4 , the optical filter 20a may include a substrate 21 , a base coat 27 , an organic material layer 29 , an upper filter stack 25 , and a lower filter stack 23 .

The substrate 21 is a transparent substrate that transmits light of a required wavelength, and may be, for example, an inorganic substrate such as a glass substrate, a quartz substrate, or a silicon substrate.

The lower filter stack 23 may be disposed on the lower surface of the substrate 21 . The lower filter stack 23 may be deposited on the substrate 21, but the present invention is not necessarily limited thereto. For example, the lower filter stack 23 may be deposited on another substrate such as a temporary substrate and then attached to the substrate 21 .

The lower filter stack 23 includes a plurality of inorganic material layers having different refractive indices. In one embodiment, the lower filter stack 23 may be an antireflection film. In another embodiment, the lower filter stack 23 may have a stack structure in which layers having different refractive indices are alternately stacked, and may be, for example, a short-wavelength, long-wavelength, or band pass filter stack.

The lower filter stack 23 may function as an antireflection film to prevent light of a specific wavelength band transmitted through the upper surface of the substrate 21 from being reflected on the lower surface. Furthermore, the lower filter stack 23 may block at least a portion of light transmitted through the upper surface of the substrate 21 .

In one embodiment, the lower filter stack 23 may include a plurality of low refractive index layers (L) and high refractive index layers (H), and the low refractive index layer (L) and the high refractive index layer (H) are It may have an alternating layered structure. The low refractive index layer (L) may include, for example, SiOx (eg, SiO ₂ ), MgFx (eg, MgF ₂ ), and the like, and the high refractive index layer (H) may include SiNx (eg, Si ₃ N ₄ ), TiOx (eg, , TiO ₂ ), NbOx (eg, Nb ₂ O ₅ ), TaOx (eg, Ta ₂ O ₅ ), or AlOx (eg, Al ₂ O ₃ ).

An upper filter stack 25 is disposed on the upper surface of the substrate 21 . The upper filter stack 25 is disposed facing the lower filter stack 23 with the substrate 21 therebetween.

The upper filter stack 25 may include a plurality of low refractive index layers (L) and a plurality of high refractive index layers (H). The upper filter stack 25 may have a structure in which a plurality of low refractive index layers L and a plurality of high refractive index layers H are alternately stacked. The low refractive index layer (L) may include, for example, SiOx (eg, SiO ₂ ), MgFx (eg, MgF ₂ ), and the like, and the high refractive index layer (H) may include SiNx (eg, Si ₃ N ₄ ), TiOx (eg, , TiO ₂ ), NbOx (eg, Nb ₂ O ₅ ), TaOx (eg, Ta ₂ O ₅ ), or AlOx (eg, Al ₂ O ₃ ).

The upper filter stack 25 may be a short wavelength, long wavelength, or band pass filter stack. The upper filter stack 25 and the lower filter stack 23 may be combined to exhibit band transmission characteristics. For example, upper filter stack 23 and/or lower filter stack 25 may be designed to transmit visible light in the range of 420 nm to 695 nm and block light in the range of 720 nm to 1100 nm.

The deposition method of each layer in the upper and lower filter stacks 23 and 25 may vary. For example, thin film deposition may be performed by processes such as chemical vapor deposition (CVD), e-beam evaporation, sputtering, and the like.

A base coat 27 may be disposed on the substrate 21 . A base coat 27 is disposed between the substrate 21 and the top filter stack 25 . The base coat 27 may be used to improve adhesion of the organic material layer 29 to the substrate 21 and may be omitted. The base coat 27 may be formed of a material that is transparent to visible light, and may be formed of, for example, silicone resin, polyurethane, polyacrylic, acrylate, or the like.

In one embodiment, the organic material layer 29 may be disposed between the substrate 21 and the upper filter stack 25 . The organic material layer 29 may be disposed on the base coat 27, and may directly contact the substrate 21 when the base coat 27 is omitted. However, the present invention is not limited thereto, and the organic material layer 29 may be disposed on the upper filter stack 25 .

The organic layer 29 may be formed of a polymer having a glass transition temperature of, for example, 220° C. or higher. For example, the organic material layer 29 may be formed of transparent polyimide (CPI) containing one or more types of light absorbers that absorb light in the near-infrared wavelength region. Light absorbers can be dyes or pigments. For example, the maximum absorption wavelength of the light absorber may be within a range of 670 to 780 nm.

Hereinafter, a method of manufacturing an image sensor package will be described in detail. The image sensor package is manufactured by manufacturing a semiconductor wafer having pixels for an image sensor and an optical filter carrier, respectively, then bonding the optical filter carrier to the semiconductor wafer and unifying the image sensor packages. Hereinafter, each manufacturing process will be described with reference to the drawings.

(Semiconductor wafer manufacturing)

5 is a schematic plan view for explaining a semiconductor wafer 10w on which a plurality of pixels for image sensing are formed.

Referring to FIG. 5 , a semiconductor wafer 10w has a plurality of image sensing pixels 13 formed on a semiconductor substrate 11 . Pixels 13 for image sensing are aligned in the semiconductor substrate 11 . Micro lenses 15 as described with reference to FIGS. 2 and 3 may be formed on each image sensing pixel 13 .

The semiconductor substrate 11 may be, for example, a silicon substrate. The pixel 13 for image sensing may be formed on the silicon substrate 11 using a conventional technique. Here, the size of the silicon substrate 11 is not particularly limited, but may have a diameter of, for example, at least 8 inches, and further, at least 12 inches. By using the large-area substrate 11, a plurality of image sensor packages can be manufactured through a single manufacturing process. The present invention does not particularly limit the size of the substrate 11, but is more useful when the substrate 11 is relatively large.

(manufacturing optical filter carriers)

6A, 6B, and 6C are schematic plan views and cross-sectional views for explaining a manufacturing method of the optical filter carrier 20w. Here, FIG. 6B is a partially enlarged plan view of FIG. 6A, and FIG. 6C is a schematic cross-sectional view taken along the line C-C′ of FIG. 6B. The pixels 13 for image sensing are shown together in FIGS. 6A and 6B.

Referring to FIGS. 6A, 6B, and 6C, spacers 30 and masks 40 are formed on both sides of the optical filter wafer 20, respectively. The spacer 30 may be formed first, or the mask 40 may be formed first.

The size of the optical filter wafer 20 may be substantially the same as that of the semiconductor wafer 10w. For example, when the diameter of the semiconductor wafer 10w is 8 inches, the diameter of the optical filter wafer 20 may also be 8 inches, and when the diameter of the semiconductor wafer 10w is 12 inches, the optical filter wafer 20 ) may also be 12 inches in diameter. When the diameter of the semiconductor wafer 10w exceeds 12 inches, the diameter of the optical filter wafer 20 may exceed 12 inches.

As described with reference to FIG. 4, the optical filter wafer 20 may include a substrate 21, a lower filter stack 23, an upper filter stack 25, a base coat 27, and an organic material layer 29. can The order of forming the lower filter stack 23, the upper filter stack 25, the base coat 27, and the organic material layer 29 on the substrate 21 is not particularly limited. In one embodiment, the base coat 27 and the organic material layer 29 are first formed on the substrate 21, and the lower filter stack 23 and the upper filter stack 25 are formed on both sides of the substrate 21, respectively. can do. In another embodiment, after forming the lower filter laminate 23 on the lower surface of the substrate 21, the base coat 27, the organic material layer 29, and the upper filter laminate 25 may be sequentially formed.

The base coat 27 and the organic material layer 29 may be formed using, for example, spin coating or spray coating technology, and the lower and upper filter stacks 23 and 25 may be formed using chemical vapor deposition technology or physical vapor deposition technology. , or may be formed using an electron beam evaporation method or the like.

In the case of an infrared cutoff filter, so-called blue glass containing an absorbing material that absorbs infrared rays is used. By forming the filter stack on the blue glass, cutoff characteristics can be improved and a wavelength shift according to an incident angle can be reduced. However, it is difficult to form blue glass to have a large area of 8 inches or 12 inches. In contrast, in the present invention, a substrate 21 that is transparent to visible light and infrared rays can be used, and infrared rays can be absorbed by using the organic material layer 29 . Therefore, according to the embodiments of the present invention, it is possible to provide a large-area optical filter wafer 20 having a size of 8 inches or more, or even 12 inches or more, having good infrared cutoff characteristics. The thickness of the substrate 21 is not particularly limited, but may be 0.3 mm or less, and further, 0.1 mm or less.

Again referring to FIGS. 6A , 6B , and 6C , the spacer 30 is formed on the lower surface of the optical filter wafer 20 . The spacer 30 may be formed using black ink. For example, the spacer 30 may be formed by patterning black ink using screen printing or inkjet printing technology. In order to adjust the thickness of the spacer 30, black ink may be printed twice or more. In another embodiment, the spacer 30 may be formed by developing and exposing photosensitive black ink. The photosensitive black ink may be applied on the optical filter wafer by, for example, spin coating. The spacer 30 may be formed to a thickness of, for example, 20 um or more and 100 um or less, and further, 50 um or less.

The spacer 30 formed using black ink may have an OD of 3 or more, a reflectance of less than 3%, a reflectance of 1% or less, and a reflectance of 0.5% or less. Accordingly, the light incident on the spacer 30 is blocked by the spacer 30, thereby improving the flare phenomenon. A surface of the spacer 30 may be plasma treated to lower reflectance of the spacer 30 .

Meanwhile, the mask 40 may be formed of a light blocking material. The mask 40 may be formed of Cr using, for example, a lift-off technique using a photoresist pattern. The mask 40 defines a region through which light is transmitted on the optical filter wafer 20 . The mask 40 may be formed in a mesh shape at substantially the same position as the spacer 30 . The mask 40 may be formed to have the same width as the spacer 30, but is not limited thereto. For example, the mask 40 may be formed to overlap the spacer 30 with a wider width than the spacer 30 .

Meanwhile, although not shown, an alignment key may be formed in the mask 40 . The alignment key is used to align the semiconductor wafer 10w and the optical filter carrier 20w in the image sensor package manufacturing process. Alignment keys do not have to be formed corresponding to all pixels, and may be formed in several parts on the optical filter wafer 20 .

(Image sensor package manufacturing method)

Referring to FIGS. 7A and 7B , an optical filter carrier 20w is disposed on a semiconductor wafer 10w with a spacer 30 interposed therebetween. The optical filter carrier 20w can be aligned to the semiconductor wafer 10w using an alignment key.

The optical filter carrier 20w may be attached on the semiconductor wafer 10w. For example, the optical filter carrier 20w may be attached to the semiconductor wafer 10w using the spacer 30 formed on the optical filter wafer 30 . In another embodiment, a bonding layer such as adhesive may be disposed between the spacer 30 and the semiconductor wafer 10w to bond the optical filter carrier 20w and the semiconductor wafer 10w.

The semiconductor wafer 10w and the optical filter carrier 20w may have a similar size, for example, a diameter of 12 inches, and pixels for image sensing on the semiconductor wafer 10w are arranged in regions defined by the spacers 30. An optical filter carrier 20w is aligned on the semiconductor wafer 10w.

Meanwhile, as described with reference to FIGS. 1 to 3 , micro lenses 15 may be formed on the image sensing pixel area, and thus, the micro lenses 15 face the optical filter wafer 20 . The semiconductor wafer 10w and the optical filter wafer 20w are bonded.

Referring to FIGS. 7C and 7D , the image sensor package described with reference to FIGS. 1 to 3 is completed by cutting the optical filter wafer 20 and the semiconductor wafer 10w together. The optical filter wafer 20 and the semiconductor wafer 10w may be cut together through a sawing process. Sawing can be performed using a laser, for example.

The semiconductor wafer 10w becomes an image sensor chip 10a within an individual image sensor package, and the optical filter wafer 20 becomes an optical filter 20a within an individual image sensor package. The mask 40 and the spacer 30 may also be cut together in the sawing process, so that the side of the optical filter 20a, the side of the image sensor chip 10a, and the mask 40 are formed within the individualized image sensor package. Both the outer surface of the outer surface and the outer surface of the spacer 30 may be formed side by side. Meanwhile, after the sawing process, a light blocking layer 50 may be formed on a side surface of each image sensor package. The light blocking layer 50 may be formed by applying a light blocking material to the side surface of the image sensor package using a process such as screen printing or inkjet printing.

Meanwhile, before cutting the semiconductor wafer 10w, the thickness of the semiconductor wafer 10w may be reduced by grinding the lower surface of the semiconductor wafer 10w. For example, the thickness of the semiconductor wafer 10w may be polished to be smaller than the thickness of the optical filter wafer 20w. In addition, solder balls 17 as described with reference to FIGS. 1 to 3 may be formed on the lower surface of the semiconductor wafer 10w to correspond to each image sensing pixel. In FIGS. 7A to 7D , the micro lenses 15 and the solder balls 17 are omitted to simplify the drawings.

According to the present embodiment, by providing an optical filter carrier having a relatively large size, image sensor packages may be mass-manufactured at a wafer level by combining the large-area semiconductor wafer 10w and the optical filter carrier 20w.

Although various embodiments have been described above, the present invention is not limited to these embodiments, and various modifications may be made without departing from the scope of the invention.

Claims (21)

a semiconductor chip having pixels for image sensing disposed on an upper surface and solder balls for electrical connection formed on a lower surface thereof;
an optical filter disposed on the semiconductor chip; and
A spacer disposed between the optical filter and the semiconductor chip,
The spacer is an image sensor package formed of black ink. The method of claim 1,
The spacer is an image sensor package having a thickness in the range of 20um to 100um. The method of claim 1,
The spacer has an optical density (OD) of 3 or more for visible light and infrared light and a reflectance of 1% or less. The method of claim 3,
Wherein the spacer has a reflectance of 0.5% or less for visible light and infrared light. The method of claim 1,
The optical filter,
a transparent substrate transparent to visible and infrared light;
a lower filter stack disposed on a lower surface of the transparent substrate;
an upper filter stack disposed on the transparent substrate to face the lower filter stack;
An organic material layer disposed between the transparent substrate and the upper filter stack,
The lower filter stack and the upper filter stack include inorganic material layers having different refractive indices, respectively. The method of claim 5,
The organic material layer is formed of a polymer containing a light absorber,
The glass transition temperature of the organic layer is 220 ° C or higher,
The light absorber has a maximum absorption wavelength in the range of 620nm to 780nm image sensor package. The method of claim 5,
The image sensor package further comprises a base coat disposed between the organic material layer and the transparent substrate. The method of claim 1,
Further comprising a mask disposed on the optical filter facing the spacer,
The image sensor package of claim 1 , wherein the mask has a width equal to or greater than that of the spacer and overlaps the spacer. The method of claim 8,
An outer surface of the spacer and an outer surface of the mask are parallel to the side surface of the semiconductor chip and the side surface of the optical filter. The method of claim 1,
Image sensor package further comprising a light blocking layer covering a side surface of the optical filter. optical filter wafers; and
A spacer arranged in a mesh shape on the optical filter wafer;
The spacer is an optical filter carrier formed of black ink. The method of claim 11,
The optical filter carrier of claim 1 , wherein the optical filter wafer has a diameter of at least 12 inches. The method of claim 11,
The spacer has a thickness in the range of 20um to 100um,
An optical filter carrier having an optical density (OD) of 3 or greater and a reflectance of 1% or less for visible and infrared light. The method of claim 13,
The spacer has a reflectance of 0.5% or less for visible light and infrared light. The method of claim 11,
The optical filter wafer
a transparent substrate transparent to visible and infrared light;
a lower filter stack disposed on a lower surface of the transparent substrate;
an upper filter stack disposed on the transparent substrate to face the lower filter stack; and
An organic material layer disposed between the transparent substrate and the upper filter stack,
The lower filter stack and the upper filter stack each include inorganic material layers having different refractive indices,
The organic material layer is formed of a polymer containing a light absorber,
The organic layer has a glass transition temperature of 220° C. or higher, and the light absorber has a maximum absorption wavelength within a range of 620 nm to 780 nm. preparing an optical filter wafer;
Forming a mask of a light blocking material on one surface of the optical filter wafer;
and forming a mesh-shaped spacer on the other surface of the optical filter wafer using black ink. The method of claim 16
The spacer has an optical density of 3 or more and a reflectance of 1% or less for visible light and infrared light. The method of claim 16
Preparing the optical filter wafer,
Preparing a transparent substrate transparent to visible light and infrared light,
Forming a lower filter laminate by stacking inorganic material layers having different refractive indices on the lower surface of the transparent substrate;
An upper filter laminate is formed by stacking inorganic material layers having different refractive indices on the upper surface of the transparent substrate,
Forming an organic material layer on the upper surface of the transparent substrate before or after forming the upper filter laminate,
The organic layer is formed using a polymer having a glass transition temperature of 220 ° C. or higher. The method of claim 16
The method of claim 1 , wherein the transparent substrate has a diameter of at least 12 inches. An optical filter carrier is manufactured by the manufacturing method of any one of claims 16 to 19,
Manufacturing a semiconductor wafer on which a plurality of image sensing pixels are formed;
attaching the optical filter carrier on the semiconductor wafer;
and cutting together the optical filter carrier and the semiconductor wafer to fabricate individualized imaging sensor packages. The method of claim 20
While cutting the optical filter carrier and the semiconductor wafer together, the mask and the spacer are also cut together.