KR20030069321A - Fabrication and assembly method of image sensor using by flip chip packaging process - Google Patents

Abstract

PURPOSE: A semiconductor image device package using flip chip bumping and a fabricating method therefor are provided to minimize the size of the package and remarkably reduce the size of an ultimate module by directly forming Au in an electrode pad and mounting the electrode pad on a circuit board. CONSTITUTION: A plurality of electrode pads are exposed by an insulation layer in a semiconductor image device(110). A multilayered lower metal layer is formed on the electrode pad. An Au bump is formed in the lower metal layer. The semiconductor image device package having the Au bump has a plurality of substrate electrode pads. An image sensor assembly is attached to a glass substrate(200) by using anisotropic conductive polymer. The Au bump of the attached package and its surroundings are protected and sealed by the anisotropic conductive polymer. An image sensor region is sealed by a transparent circuit board.

Description

Semiconductor imaging device package using flip chip bumping and manufacturing method thereof {Fabrication and assembly method of image sensor using by flip chip packaging process}

The present invention relates to an image sensor package for a semiconductor imaging device, and more particularly, to a semiconductor imaging device package using flip chip Au bumping and a method of manufacturing the same.

In general, an image sensor chip is also referred to as a solid-state image pickup device, and refers to a device for photographing a subject using an photoelectric conversion device and a charge coupling device to output an electrical signal.

In order to mount such an image sensor chip on a substrate, a packaging operation for mounting the chip in a package body is performed.

1A to 1C, an image sensor module of a conventional semiconductor imaging device 1 includes a lens holder 10, a lens unit 9 attached to a range holder, and the lens holder as shown in FIG. 1C. It is composed of an image sensor package 12 and the like configured at the lower end.

The dual image sensor package 12 is made of a plastic or ceramic package connected to the lead 7 on the ceramic substrate 6 as shown in FIG. 1B, and the semiconductor imaging device 1 is formed inside the package. It has an image sensor chip, which is electrically connected to the substrate 6 through the bonding of gold wires 4, and the upper surface of the glass plate 5 is bonded with an adhesive 8 to protect it from the external environment. do.

According to the above, the size of the semiconductor image pickup device image sensor module depends entirely on the area with the package size on which the semiconductor image pickup device 1 is mounted. It depends on whether you reduce it.

Therefore, the conventional gold wire (4) bonding and plastic molding or a package by a ceramic process that is applied to the existing product has the disadvantage that the package size is increased by the gold wire bonding (4), and the manufacturing process time is longer As a result, production costs increase, and these products have a disadvantage in that they cannot actively respond to the trend of miniaturization of these product sizes.

Accordingly, the present invention provides a new type of package and assembly process that can satisfactorily meet the miniaturization requirements of the lens unit which occupies a large area according to the recent trend of miniaturization of peripheral components for mobile communication devices or PCs. I want to achieve.

The present invention introduced two important concepts to solve the above conventional problems.

That is, in the present invention, an important issue of the size reduction of the semiconductor image sensor image sensor module is flip chip Au bumping, in which Au is directly formed on an electrode pad and mounted on a circuit board, rather than the conventional gold wire bonding method, to reduce the package size. It is to provide a package for a semiconductor imaging device.

Another technical problem to be achieved by the present invention is to provide an assembly method in which the image pickup device is mounted on a circuit board after Au bumping, and the process of protecting the surface of the device to an external environment is completed in one step.

Another feature of the present invention is to provide an image sensor module having a novel structure using a semiconductor imaging device flip chip package and an anisotropic conductive polymer manufactured by the above process.

1A to 1C schematically illustrate a semiconductor imaging device and an image sensor module having a plurality of electrode pads according to the prior art.

2A to 2F show a preferred embodiment of the present invention, and showing a process of forming Au bumps in the image pickup device according to the present invention.

3A to 3J are flowcharts illustrating a structure of a circuit board for a semiconductor imaging device flip chip package manufactured by the present invention and a process of mounting a package on the circuit board.

4 is a diagram of a semiconductor imaging device module manufactured according to the present invention.

5 is a schematic explanatory diagram showing a state in which a semiconductor imaging device package manufactured according to the present invention is mounted on a product;

FIG. 6 conceptually compares a size reduction effect of a semiconductor image pickup device package manufactured by the present invention with a conventional image sensor package for the same device size; FIG.

Explanation of symbols on the main parts of the drawings

1 semiconductor imaging device 2 electrode pad

3: image sensing area 4: gold wire

5: glass 6: ceramic substrate

7: lead 8: adhesive

9: lens unit 10: lens holder

11: module substrate 12: conventional image sensor package

100: lower metal layer 110: semiconductor imaging device

120: insulating layer 130: metal adhesive layer

140: plating electrode layer 150: electrode pad

160: photosensitive material for the plating process 170: Au bumps

200: transparent circuit board 210: substrate electrode pad

220: electrode pad for external connection 230: anisotropic conductive polymer

240: conductive metal ball 245: substrate metal circuit

250: flip chip bonding head 260: flexible substrate

270: Cutting wheel 280: Image sensor assembly unit

290: image sensing area 300: lens unit

310: lens 320: lens holder

A preferred embodiment of the semiconductor image sensor image sensor module for achieving the object of the present invention as described above,

A semiconductor imaging device having a plurality of electrode pads separated by an insulating layer;

Sequentially forming a metal adhesive layer and an Au plating electrode layer on the exposed electrode pad and the insulating layer;

Coating a photosensitive material for a plating process on the electrode layer for Au plating, and then exposing and developing the photosensitive material to remove the photosensitive material of only the electrode pad region and patterning the exposed electrode pad;

Forming Au bumps by plating Au on the exposed Au plating electrode layers;

And applying the plated Au bumps as a mask to etch the electrode layer for Au plating and the metal adhesive layer.

In addition, the semiconductor imaging device image sensor module of the present invention, the lower metal layer formed on the upper portion of the electrode pad and the peripheral insulating layer;

The lower metal layers are composed of a metal adhesive layer and a plating electrode layer from an electrode pad;

Applying or adhering an anisotropic conductive polymer containing conductive metal balls having a size within a predetermined range to a transparent circuit board on which electrode pads are formed;

Bonding the semiconductor image pickup device on which the Au bumps are formed to a transparent circuit board on which an anisotropic conductive polymer is coated or bonded;

The conductive metal ball is mechanically contacted between the Au bumps and the substrate electrode pad of the transparent circuit board by applying pressure to the anisotropic conductive polymer, and at the same time, the polymer resin is cured by applying heat to seal the image sensing area of the semiconductor imaging device. It is characterized by.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings in order to understand the objects and features according to the preferred embodiments of the present invention in more detail.

2 illustrates a step-by-step process of applying Au bumping to the semiconductor imaging device 110 according to the present invention.

First, referring to FIG. 2A, an insulating layer 120 is formed on a surface of the semiconductor imaging device 110, and then selectively etched to expose a plurality of electrode pads 150 spaced apart from each other. The metal adhesive layer 130 and the Au plating electrode layer 140 are sequentially formed on the substrate.

In this case, the metal adhesive layer 130 may be any one of Ti, Al, or Cr selected from the insulating layer 120 and the electrode pad 150 of the semiconductor imaging device 110, or alloys containing them. The Au plating electrode layer 140 may be Au or Cu or an alloy thereof and Ni or an alloy thereof in terms of cost as a metal having excellent electrical conductivity.

The metal adhesive layer 130 is preferably formed of any one selected from Al material, Al-based alloy material, Ti material, Ti-based alloy material, Cr material or Cr alloy material having a thickness of 100 to 5,000Å, Ti or The alloy material is appropriate.

The Au plating electrode layer 140 is preferably formed of any one selected from Au, Cu, Cu, NiV, and Ni-based alloys having a thickness of 100 to 5,000 100, but Au is most stable in terms of electrical conductivity and oxidation resistance. Can be represented.

As a process for forming the Au bumps 170 only in the electrode pad 150 or a specific region, as shown in FIG. 2B, the photosensitive material 160 for the plating process is formed on the entire upper surface of the Au plating electrode layer 140. After coating, the photosensitive material is exposed and developed to pattern the photosensitive material such that only the area of the electrode pad 150 to which Au is to be plated is exposed.

2C and 2D, Au is plated on the exposed Au plating electrode layer 140 to form Au bumps 170.

As shown in FIG. 2D, the patterned plating photosensitive material 160 is removed, and finally, as shown in FIG. 2E, the Au bumps 170 are applied as a mask to form the electrode layer for Au plating. By chemically etching the 140 and the metal adhesive layer 130, a semiconductor imaging device in which the Au bumps 170 are formed according to a preferred embodiment of the present invention is manufactured.

2F schematically illustrates a semiconductor imaging device 110 on which Au bumps 170 are formed.

The semiconductor imaging device wafer of the present invention manufactured by the above processes is selected from only the devices of good products from the electrical test results and placed in a tray of a certain standard.

The next step is to assemble the package manufactured by the above process, that is, the semiconductor imaging device 110 package in which the Au bumps 170 are formed and to manufacture the transparent circuit board 200 therefor, which is shown in FIG. Indicated.

First, an example of the structural diagram of a transparent circuit board 200 in which a circuit suitable for the present invention is formed as shown in FIG. 3A is shown.

The transparent circuit board 200 is a material having excellent transmittance to allow light to pass therethrough, and may be of a glass type, and on one side thereof, a substrate electrode pad 210 to which an Au bumped element is bonded is present. Finally, a separate external connection electrode pad 220 to which the flexible substrate 260 for electrically connecting the completed assembly and the system is connected is formed.

The external connection electrode pad 220 is formed by a metal deposition method and patterned through an etching process, and the material thereof may be applied alone or in a combination of the lower metal adhesive layers 130 used in the Au bump forming process. For example, it may be used by In-Sn-O deposition.

The transparent circuit board 200 on which the metal film is deposited is completed by a general process of coating, exposing and patterning a photosensitive polymer to form a circuit through an etching process and finally removing the photosensitive polymer.

In addition, the transparent circuit board 200 may be manufactured in a single package size, but for productivity, the transparent circuit board 200 may be manufactured by arranging an array so that a plurality of packages may be mounted. It is cut and finally finished.

In order to electrically interconnect and fix the transparent circuit board 200 on which the package and the circuit formed with the process are formed, a medium capable of conducting electricity is used.

The conductive medium may be provided in various forms and materials, but suitably for the present invention, the conductive medium is provided in a polymer state containing the conductive metal balls 240, and the polymer is an anisotropic conductive adhesive (ACA) and a quasi Anisotropic Conductive Film (ACF) may be cured to have a predetermined shape.

The anisotropic conductive polymer 230 is mainly composed of a thermosetting resin or a thermoplastic resin, or a combination thereof, and contains a predetermined amount or more of conductive metal balls 240 such as Au, Ni, Ag, and Cu in a spherical or rectangular shape. The metal ball 240 is required to be uniformly distributed. The size of the conductive metal ball 240 may vary depending on the interval between bumps, but has a particle size range of 0.5 to 10 um.

After the anisotropic conductive polymer 230 is interposed between the transparent circuit board 200 and the semiconductor imaging device 110 in which the Au bumps 170 are formed, the resin is heated by heating to a temperature of about several tens to 2,000 degrees Celsius. Hold for several seconds to cure.

As a result, the electrical contacts are obtained by contacting the plurality of electrodes with the conductive metal balls 240, and mechanical fixation is obtained by curing of the resin at a portion where the Au bumps 170 and the substrate electrode pads 210 are not present. Lose.

In another embodiment, the bonded adhesive may be reheated to further cure the polymer resin.

The package mounting process is performed in an inert gas atmosphere for the reliability of the semiconductor imaging device 110 to seal the transparent circuit board 200 and the inside of the image sensing region 3 of the package in an inert atmosphere.

These processes are performed on a transparent circuit board 200 that is arranged in a plane so that a plurality of packages can be mounted and cut into individual package modules after mounting.

When mounting of the package in which the Au bumps 170 are formed by the above processes is completed, electrical connection between the substrate electrode pad 210 of the transparent circuit board 200 and the external system is performed using the flexible substrate 260.

To this end, the flexible substrate 260 prepared after placing the anisotropic conductive polymer 230 described above on the external connection electrode pad 220 formed outside the semiconductor image pickup device as shown in FIGS. After contact, heat press to complete the final assembly. The anisotropic conductive polymer 230 in this process may be interposed before or after package mounting.

As shown in FIG. 3J, the plurality of surface array assemblies completed by the above process are separated into the image sensor assembly unit 280 using the equipment equipped with the cutting wheel 270 to complete the process.

Therefore, the image sensor assembly unit 280 of the present invention manufactured through the above process can ultimately minimize the size of the package compared to the image sensor package manufactured by the conventional gold wire bonding method as shown in FIG. 4. There is an advantage of greatly reducing the size of the final module, and by fixing the image sensor assembly unit 280 to the lower end of the lens unit 300 as shown in Figure 5, the overall size of the semiconductor image pickup device image sensor module breakthrough Can be reduced to.

As described above, the semiconductor image pickup device package using flip chip bumping and the assembly method thereof according to the present invention have been described with reference to the illustrated drawings, but the present invention is not limited thereto by the embodiments and drawings disclosed herein, and the present invention. Of course, various modifications can be made by those skilled in the art within the scope of the technical idea.

As described above, the semiconductor image pickup device package using flip chip bumping according to the present invention and the image sensor assembly 280 manufactured by the method of manufacturing the same are manufactured using a conventional gold wire bonding method as shown in FIG. 6. Compared to the image sensor package 12, there is an effect of minimizing the size of the package and ultimately greatly reducing the size of the final module.

In addition, according to the present invention, since the semiconductor image sensor package 110 is manufactured in a batch process, the production cost can be greatly reduced.

In addition, since the image sensor package is mounted on the glass substrate on which the circuit is formed and simultaneously sealed, the existing mounting process can be shortened.

Claims (8)

In the semiconductor imaging device 110 in which a plurality of electrode pads 150 spaced apart from the insulating layer 120 are exposed, A lower metal layer 100 formed in multiple layers on the electrode pad 150; Au bumps 170 formed on the lower metal layer 100; The semiconductor image pickup device 110 on which the Au bumps 170 are formed has a plurality of substrate electrode pads 210, and an image is bonded to the glass substrate 200 on which the circuit is formed using the anisotropic conductive polymer 230. A sensor assembly 270; The bonded bump Au bumps 170 and the periphery are protected and sealed with an anisotropic conductive polymer 230, and the image sensor region 3 includes flip chip bumping including a structure sealed with a transparent circuit board 200. Semiconductor imaging device package. In the semiconductor imaging device 110 having a plurality of electrode pads 150, Exposing the electrode pad 150 by being spaced apart from the insulating layer 120; Forming a metal adhesive layer 130 and a plating electrode layer 140 on the exposed electrode pad 150 and the insulating layer 120 sequentially; Coating the photosensitive material 160 for the plating process on the plating electrode layer 140, and then exposing and developing the patterning layer to selectively expose the plating electrode layer 140 on the electrode pad; Plating Au on the exposed plating electrode layer 140; Removing the patterned plating photosensitive material (160), and then etching the remaining lower metal layer (100) by applying the plated Au bumps (170) as a mask; Depositing a metal thin film on a transparent substrate to form a substrate electrode pad 210 on which the image forming device on which the Au bumps 170 are formed is to be seated; Coating, exposing and developing a photosensitive polymer on the deposited metal to remove a polymer other than a region where a metal circuit is to be formed; Etching the remaining polymer using an etching mask to form a substrate metal circuit (245) and a substrate electrode pad (210); Applying or adhering an anisotropic conductive polymer (230) containing conductive metal balls (240) only to the formed substrate electrode pad (210); A method for manufacturing a semiconductor image pickup device package using flip chip bumping, comprising a step of mounting and sealing a completed package on a transparent circuit board 200 having a circuit, and simultaneously sealing the package. The method of claim 2, The metal adhesive layer 130 is a semiconductor using flip chip bumping, characterized in that formed of any one selected from Al, Al-based alloy material, Ti material, Ti-based alloy material, Cr material or Cr alloy material having a thickness of 100 ~ 5,000Å. Image pickup device package manufacturing method. The method of claim 2, The plating electrode layer 140 is a semiconductor imaging device package manufacturing using flip chip bumping, characterized in that formed of any one selected from 100 to 5,000Å thick Au material, Cu material and Cu-based alloy material or Ni and Ni-based alloy material. Way. The method of claim 2, The circuit board 200 on which the semiconductor image pickup device 110 on which the Au bumps 170 are formed is mounted is made of a transparent material including glass, and a circuit is provided in an area other than the image sensing area 3 of the semiconductor image pickup device 110. And a plurality of substrate electrode pads (210) on which the Au bumps (170) of the semiconductor image pickup device (110) are to be placed. The method of claim 5, The substrate metal circuit 245 formed on the transparent circuit board 200, the electrode pad 220 for external connection, and the substrate electrode pad 210 are provided. Provided in the form of a single or multi-layer metal film sequentially by the deposition method, the material of the lower layer is Ti or Ti-based alloy material, the material of the upper layer is Au or Cu and Cu-based alloy material, in the case of forming a single layer Formed from an In-Sn-O alloy material, the thickness of the semiconductor imaging device package manufacturing method using flip chip bumping, characterized in that the 100 ~ 5,000 Å. The method of claim 2, The anisotropic conductive polymer 230 coated on the transparent circuit board 200 is based on a thermosetting or thermoplastic resin and a combination thereof, and the conductive metal balls 240 are contained in a square or spherical shape in the resin, A method of manufacturing a semiconductor imaging device package using flip chip bumping, wherein the size has a particle size range of 0.5 to 10 um. The method of claim 1, Mounting the semiconductor image pickup device 110 on which the Au bumps 170 are formed on the transparent circuit board 200 on which the circuit is formed to simultaneously bond the semiconductor image pickup device and seal the image sensing area 3 to be protected from the outside. A semiconductor imaging device package manufacturing method using flip chip bumping, characterized in that.