Image sensor package including pillar bump

Abstract

The present invention relates to an image sensor package including a pillar bump, the image sensor package comprising: a substrate including an image sensor, which has a light receiving unit and a connection pad unit adjacent to the light receiving unit, a plurality of windows, which are perforated at predetermined intervals, a connection pad, which electrically connects an integrated circuit integrated on one surface except on the windows to the outside, a first contact unit, which comes into contact with the connection pad unit of the image sensor on the connection pad adjacent to the windows, a second contact unit, which is adjacent to the first contact unit on the connection pad and provided outside the outer circumferential surface of the image sensor, and a solder ball, which is provided on the second contact unit; and the pillar bump provided, between the second contact unit and the solder ball, at a height equal to or higher than the height of the image sensor, and electrically connects the connection pad and the solder ball.

Description

Image sensor package including pillar bump

[0001] The present invention relates to an image sensor package including a pillar bump.

[0002] In general, an image sensor is a device that detects subject information and converts it into an electrical image signal. It is a photoelectric conversion element that is integrated into a circuit using semiconductor device manufacturing technology.

[0003] There are line image sensors (one-dimensional image sensors) used in fax machines and copiers, and array image sensors (two-dimensional image sensors) used in television cameras, laptop cameras, CCTVs, smartphones, and digital cameras.

[0004] Among them, the array image sensor is a two-dimensional arrangement of photodiodes, and can acquire an entire screen image at once, so it is used for moving images such as video. The photodiode outputs the generated charge, and there are charge-coupled devices (CCDs) and CMOS devices for transmission function, and due to this difference, they are called CCD image sensors and CMOS image sensors.

[0005] In such a two-dimensional image sensor, an IR filter made of a light-transmitting material is installed on the upper part of the image sensor module to prevent external foreign substances from adversely affecting the image sensor and to focus light onto the image sensor.

[0006] Electronic components required for electronic devices include various active and passive circuit elements, and these circuit elements can be integrated on a semiconductor substrate, also called a semiconductor chip or die.

[0007] Electronic components of an integrated circuit can be provided in the form of an electronic component package by being mounted on a package substrate that includes circuit wiring, such as a printed circuit board (PCB) or a silicon interposer.

[0008] These electronic component packages can be mounted on the main board of an electronic device and used to construct an electronic system such as a computer, mobile device, or data storage.

[0009] Recently, when mounting semiconductor chips on a package substrate and electrically connecting them with conductive wires or interconnecting semiconductor chips with each other, a stacked structure using via holes is widely applied to electronic device packages.

[0010] For example, in order to implement a stacked structure of various types of semiconductor chips in a flip chip package, and also to secure a larger number of input / output (I / O) terminals, connection bump structures through via holes that are stacked as an electrical signal connection structure are employed.

[0011] After electrically connecting the package substrate and the semiconductor chip by bonding the connecting bumps, an underfill insulating layer is formed through an underfill process to surround and insulate the bonding structure of these connecting bumps, thereby forming a typical flip chip package structure.

[0012] However, the wire bonding method is still in operation as the main product process, and CSP products that form bumps through via holes of a laminated structure are also in operation, but there were vulnerabilities such as increased production costs due to increased image sensor yield and process costs.

[0013] Accordingly, by directly bonding the image sensor and bump substrate (PCB) after sawing, cost reduction through process shortening and yield improvement can be expected.

[0014] The present invention relates to an image sensor package including a pillar bump, and aims to provide an image sensor package that simplifies the process and minimizes the physical height by directly bonding an image sensor to a substrate using a pillar bump, thereby providing flexibility in the design of a camera module.

[0015] The present invention relates to an image sensor package including a pillar bump, and the image sensor package including the pillar bump includes: an image sensor having a light receiving portion and a connection pad portion provided adjacent to the light receiving portion; several windows formed through the light receiving portion at predetermined intervals; a connection pad electrically connecting an integrated circuit integrated on one surface excluding the windows to the outside; a first contact portion provided on the connection pad adjacent to the window and in contact with the connection pad portion of the image sensor; a second contact portion provided on the connection pad adjacent to the first contact portion but outside the outer surface of the image sensor; and a solder ball provided on the second contact portion; and a pillar bump provided between the second contact portion and the solder ball at a height equal to or higher than the height of the image sensor to electrically connect the connection pad and the solder ball.

[0016] In addition, the first contact portion may include a conductor portion that is provided with one of the methods of ACA, ACF, nanoink, and stitch bump, and electrically connects the first contact portion and the connection pad portion by directly bonding the first contact portion and the connection pad portion.

[0017] The present invention relates to an image sensor package including a pillar bump, which reduces the work process by directly bonding the image sensor to a substrate, thereby improving productivity and lowering the production cost, and reduces costs by enabling the implementation of an ultra-slim package by reducing the thickness through back grinding of the image sensor, thereby ensuring flexibility in product design, thereby providing a competitive effect.

[0018] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0019] FIG. 1 is a diagram showing an image package including a pillar bump according to the present invention, according to one embodiment.

[0020] FIGS. 2 to 8 are diagrams showing a method for manufacturing an image package including a pillar bump of the present invention.

[0021] Figure 9 is a flowchart showing the sequence of a method for manufacturing an image package including a pillar bump of the present invention.

[0022] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description have been omitted for clarity of description, and the same reference numerals designate identical or similar components throughout the specification.

[0023] In addition, the size and thickness of each component shown in the drawing are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to what is shown.

[0024] In the present invention, "on" means located above or below the target member, and does not necessarily mean located above in the direction of gravity. Furthermore, throughout the specification, when a part is said to "include" a component, this does not exclude other components, but rather means that other components may be included, unless otherwise specifically stated.

[0025] Additionally, throughout the specification, when a part is said to be "connected" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with another part in between.

[0026] FIG. 1 is a diagram showing an image package including a pilar bump according to the present invention according to one embodiment, FIGS. 2 to 8 are diagrams showing a method for manufacturing an image package including a pilar bump according to the present invention, and FIG. 9 is a flowchart showing the order of a method for manufacturing an image package including a pilar bump according to the present invention.

[0027] Hereinafter, an embodiment of an image sensor package including a pillar bump of the present invention will be described with reference to the attached drawings.

[0028] Referring to FIG. 1, an image package including a pillar bump according to the present invention will be described as an embodiment. The image package including a pillar bump includes a substrate (40) including an image sensor (10) having a light-receiving portion (11) and a connection pad portion (12) provided close to the light-receiving portion (11), several windows (41) that are penetrated at a predetermined interval, a connection pad (42) that electrically connects an integrated circuit integrated on one surface except the window (41) to the outside, a first contact portion (421) that is in contact with the connection pad portion (12) of the image sensor (10) on the connection pad (42) close to the window (41), a second contact portion (422) provided on the connection pad (42) close to the first contact portion (421) but outside the outer surface of the image sensor (10), and a solder ball (44) provided on the second contact portion (422). It includes a pillar bump (45) that is provided between the second contact portion (422) and the solder ball (44) at a height equal to or higher than the height of the image sensor (10) and electrically connects the connection pad (42) and the solder ball (44).

[0029] Image sensors (10) are arranged in a grid structure on a disk-shaped wafer, and each image sensor (10) is provided with a light receiving portion (11) that focuses incident light at the center, and a plurality of connection pad portions (12) for electrical connection with a substrate (40) can be formed on the outside of the light receiving portion (11).

[0030] The IR filter (20) may be provided with a glass material having an IR filtering function on the upper or lower surface of the substrate (40) or a glass material having an IR filtering function on the glass material itself, in which an IR filter layer forms a thin film or a coating surface.

[0031] The IR filter (20) may be provided on the other side (402) of the substrate (40) opposite to the light receiving portion (11) of the substrate (40). The IR filter (20) may focus light onto the light receiving portion (11) of the image sensor (10). The IR filter (20) may be mounted on the other side (402) of the substrate (40) described later by means of an adhesive layer (21).

[0032] Meanwhile, the IR filter (20) can form a patterned layer. For example, the IR filter (20) has a predetermined pattern formed and aligned to the photosensitive area of ​​the image sensor.

[0033] Each pattern in the IR filter (20) may have a barrier layer of a certain width. For example, since the pattern layer of the IR filter (20) has a width greater than 50 mm, it can provide sufficient support and stability for bonding of the subsequent transparent filter and image sensor.

[0034] The pattern layer of the IR filter (20) may have a single-layer structure or a multi-layer structure, and the thickness of the pattern layer of the IR filter (20) may be determined by the distance between the IR filter (20) and the bonded image sensor (10).

[0035] For example, the formation of the pattern layer may utilize a photolithography process. The pattern layer may include a single patterned dry film, and the process of forming the patterned dry film may include a step of forming a single layer of dry film on each transparent filter, patterning the dry film using a photolithography process, thereby forming the patterned dry film.

[0036] When the pattern layer of the IR filter (20) is a patterned dry film, the patterned dry film may include a multilayer structure, and this multilayer structure may include one layer of a photosensitive layer interposed between multilayer polymer layers.

[0037] Here, the polymer layer may be a polyethylene terephthalate (PET) layer, a polyester molecule (PE) layer, or any other suitable polymer layer. The photosensitive layer may include a synthetic monomer of a photosensitive material, a photopolymerization initiator, a polymer binder, and additives (e.g., a catalyst and a dye). The synthetic monomer is one of the components of the pattern layer.

[0038] The insulating layer (30) covers the image sensor (10) and the pillar bump (45), and may expose a portion of the solder ball (44) and the IR filter (20). The insulating layer (30) may be any one of materials such as epoxy, resin, SINR (Siloxane polymer), BCB (Benzo Cyclo Butene), etc., and may also be an ultraviolet-ray and / or heat-curable material. In the present invention, it is described that it is preferably made of epoxy.

[0039] According to this, the substrate (40) is electrically connected to an image sensor (10) on one side (401), and an insulating layer (30) is formed to expose a portion of the solder ball (44) and IR filter (20) described later, so that light can be focused onto the light receiving unit (11) through the IR filter (20), and another external substrate can be electrically connected through the solder ball (44).

[0040] The substrate (40) may include several windows (41) that are formed at a predetermined interval, a connection pad (42) that electrically connects an integrated circuit integrated on one surface excluding the windows (41) to the outside, a first contact portion (421) that is in contact with the connection pad portion (12) of the image sensor (10) on the connection pad (42) that is close to the window (41), a second contact portion (422) that is provided on the connection pad (42) that is close to the first contact portion (421) but is provided outside the outer surface of the image sensor (10), and a solder ball (44) provided on the second contact portion (422).

[0041] The substrate (40) may include a pillar bump (45) that is provided between the second contact portion (422) and the solder ball (44) at a height equal to or higher than the height of the image sensor (10) to electrically connect the connection pad (42) and the solder ball (44).

[0042]

[0043] *Here, the substrate (40) may mean a semiconductor substrate forming a semiconductor chip with an integrated circuit such as DRAM or FLASH, or a package substrate such as a printed circuit board (PCB) or interposer.

[0044] The substrate (40) can be mounted in a silicon wafer state on an image sensor wafer, which is an assembly of image sensors (10), and a window (41) formed by dry or wet etching is provided in the area where the light-receiving portion (11) of the image sensor (10) is formed.

[0045] The substrate (40) is laminated with the image sensor (10) on top, with the light receiving portion (11) and the window (41) aligned, and the connection pad portion (12) of the image sensor (10) is connected to the first contact portion (421) of the substrate (40) and bonded.

[0046] Meanwhile, the connection pad (42) is equipped with a conductor portion (43) so that it can be electrically connected to the connection pad portion (12).

[0047] The connection pad (42) may be an aluminum (Al) pad provided to electrically connect an integrated circuit integrated on one side of the substrate (40), i.e., the active area, to the outside, and the connection pad (42) may be internally connected to the integrated circuit integrated on the active area by a metal wire. The connection pad (42) may be selected from Ni, Cu, Au, and a combination thereof.

[0048] The connection pad (42) may be provided with a first contact portion (421) on the connection pad (42) around the window (41), and a second contact portion (422) may be provided on the connection pad (42) at a predetermined distance from the first contact portion (421).

[0049] The first contact portion (421) is provided on the connection pad (42) close to the window (41), so that the connection pad portion (12) of the image sensor (10) can be brought into close contact with each other.

[0050] The first contact portion (421) may include a conductor portion (43) to enable electrical connection between the connection pad portion (12) and the connection pad (42).

[0051] The conductive portion (43) is provided on the first contact portion (421) and can electrically connect the first contact portion (421) to the connection pad portion (12) between the first contact portion (421) and the connection pad portion (12). At this time, the conductive portion (43) directly bonds the connection pad portion (12) to the first contact portion (421) and connects the image sensor (10), thereby reliably connecting the substrate (40) and the image sensor (10), thereby improving electrical conductivity and connection strength.

[0052] The conductive portion (43) can be provided on the first contact portion (421) using any one of the following methods: ACA (Anisotropic Conductive Adhesives), ACF (Anisotropic Conductive Film), nano ink, or stitch bonding.

[0053] Additionally, the second contact portion (422) may be provided on the connection pad (42) close to the first contact portion (421), but outside the outer surface of the image sensor (10).

[0054] The second contact portion (422) may be provided in several numbers to protrude from the connection pad (42) of the circuit pattern formed on the surface of the substrate (40), and may further include an external connection means such as a solder ball (44).

[0055] The solder ball (44) may protrude higher than the image sensor (10) for connection with another substrate. The solder ball (44) may protrude partly to the same height as or slightly higher than the insulating layer or the height of the image sensor (10) so that electrical connection can be made with the camera module described later.

[0056] Additionally, a pillar bump (45) may be included between the second contact portion (422) and the solder ball (44) to enable mutual electrical connection by receiving electricity from the connection pad (42).

[0057] A pillar bump (45) is provided between the connection pad (42) and the solder ball (44), enabling electrical connection between the solder ball (44) and the connection pad (42).

[0058] The pillar bump (45) is provided between the substrate (40) and the second contact portion (422) and the solder ball (44) at a height equal to or higher than the height of the image sensor (10) so as to electrically connect the connection pad (42) and the solder ball (44).

[0059] A pillar bump (45) protrudes from the substrate (40) between the substrate (40) and the solder ball (44), supports the solder ball (44), and electrically connects the solder ball (44) to another connection pad. The pillar bump (45) protrudes from the other connection pad in the direction in which the image sensor (10) is mounted.

[0060] The pillar bump (45) may be formed into a columnar shape and may be provided with a metal filler. Here, the filler may be a material with good conductivity, for example, may be composed of any one of gold (Au), silver (Ag), platinum (Pt), aluminum (Al), iron (Fe), copper (Cu), platinum (Pt), chromium (Cr), and tin (Sn), and may preferably be provided with copper (Cu) to achieve cost reduction.

[0061] The pillar bump (45) is connected to the second contact portion (422) on one side and to the solder ball (44) on the other side, thereby connecting the second contact portion (422), i.e., the connection pad (42), and the solder ball (44) so ​​that an electrical connection is established.

[0062] For example, the pillar bump (45) may have a predetermined height, and preferably may be provided to be equal to or higher than the height of the image sensor (10) connected to the substrate (40), and insulation isolation may be achieved between the pillar bumps (45) by an insulating layer (30), such as an underfill, formed to isolate between the substrate (40) and another substrate.

[0063] Referring to FIGS. 2 to 9, an embodiment of a method for manufacturing an image sensor package including a pillar bump will be described. In FIGS. 2 and 9, a method for manufacturing an image sensor package including a pillar bump includes: in step S10 of FIGS. 2 and 9, a substrate (40) provided with a perforated window (41) is prepared; in step S20, a first contact portion (421) and a second contact portion (422) are formed on a connection pad (42) electrically connected to the outside on one surface (401) excluding the perforated window (41); and a conductive portion (43) can be formed on the first contact portion (421) using any one of ACA, ACF, nanoink, and stitch bump methods.

[0064] Referring to FIGS. 3, 4, and 9, step S30 can create a protruding pillar bump (45) on the second contact portion (422) and create a solder ball (44) at the end of the pillar bump (45). Accordingly, the pillar bump (45) and the solder ball (44) can be electrically connected through the second contact portion (422) extended from the connection pad (42).

[0065] Referring to FIG. 5 and FIG. 9, step S40 places the light-receiving portion (11) of the image sensor (10) on the window (41), and directly bonds the connection pad portion (12) of the image sensor (10) to the conductor portion (43) so that it can be electrically connected to the connection pad (42) through the first contact portion (421).

[0066] Referring to FIGS. 6 and 9, step S50 can bond an IR filter (20) to the other side (402) opposite to one side (401) of the substrate (40) in accordance with the window (41). At this time, foreign substances that may be present on the substrate (40) and the image sensor (10) can be removed before bonding the IR filter (20), thereby reducing the defect rate.

[0067] In addition, the IR filter (20) is bonded to the window (41) by an adhesive layer (21). Accordingly, since the IR filter (20) is directly bonded on the upper surface, convenience is improved and the yield can be increased by reducing the defect rate.

[0068] Referring to FIGS. 7 and 9, step S51 creates a first insulating layer (30) so that the image sensor (10) and the pillar bump (45) are locked, but a part of the solder ball (44) protrudes (a), so that it can be electrically connected to another external substrate through the solder ball (44).

[0069] Step S52 can form a first insulating layer by hardening the insulating layer for a predetermined period of time after step S51.

[0070] Referring to FIGS. 8 and 9, step S53 can be cured again to create a second insulating layer (30) so that a part of the IR filter (20) is exposed (b) after step S52.

[0071] Finally, step S60 cuts (C) the package completed in wafer form in step S51 and separates it individually to complete the image sensor package. The direction of cutting (C) can be determined according to user settings.

[0072] According to the image sensor package including such a pillar bump, the work process is reduced by directly bonding the image sensor to the substrate, thereby improving productivity and lowering the production cost, and costs are reduced by reducing the thickness through back grinding of the image sensor, thereby enabling the implementation of an ultra-slim package, which allows for flexible product design, resulting in a competitive advantage.

[0073] The above description of the present invention is for illustrative purposes only, and a person having ordinary skill in the art to which the present invention pertains will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential characteristics of the present invention.

[0074] Therefore, it should be understood that the embodiments described above are exemplary in all respects and not limiting.

[0075] For example, each component described as a single entity may be implemented in a distributed manner, and likewise, components described as distributed may be implemented in a combined manner.

[0076] The scope of the present invention is indicated by the claims described below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

[0077] Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the patent claims, the detailed description of the invention, and the attached drawings, and it is obvious that this also falls within the scope of the present invention.

Claims

1. An image sensor having a light receiving portion and a connection pad portion provided close to the light receiving portion; A substrate including a plurality of windows penetrated at a predetermined interval, a connection pad electrically connecting an integrated circuit integrated on one surface excluding the windows to the outside, a first contact portion that is in contact with a connection pad portion of the image sensor on the connection pad adjacent to the windows, a second contact portion provided on the connection pad adjacent to the first contact portion but further outside the outer surface of the image sensor, and a solder ball provided on the second contact portion; and An image sensor package including a pillar bump, characterized in that it includes a pillar bump that is provided between the second contact portion and the solder ball at a height equal to or higher than the height of the image sensor and electrically connects the connection pad and the solder ball.

2. In paragraph 1, An image sensor package including a pillar bump, wherein the first contact portion is provided with one of the methods of ACA, ACF, nano-ink, and stitch bump, and the conductive portion directly bonds the first contact portion and the connection pad portion to electrically connect the first contact portion and the connection pad portion.

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