KR101345219B1 - Aluminum interposer and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a technique for manufacturing a semiconductor interposer. To this end, the present invention applies an aluminum substrate as a substrate of an interposer, and via holes formed in the aluminum substrate can be formed not only by a photoresist process but also by a laser drilling process. By doing so, it is possible to realize not only an interposer having better heat dissipation characteristics than a silicon interposer, but also to reduce the cost of manufacturing the interposer.

Description

Aluminum interposer and its manufacturing method {ALUMINUM INTERPOSER AND MANUFACTURING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor interposer fabrication technique, and more particularly, to an aluminum interposer and a method of manufacturing the same, which are suitable for fabricating a through-type aluminum interposer using an aluminum substrate in a simple process.

As is well known, a semiconductor package provides a function of protecting a semiconductor chip from an external environment and a function of smoothly connecting the semiconductor chip with a printed circuit board. A conductive hole filled with a conductive material for such a semiconductor package is provided. An interposer having an electrically connects the chip pad and the solder ball of the semiconductor chip. The interposer is mainly made of a non-conductive material such as silicon, resin, and ceramic.

For example, in the conventional silicon interposer, a via hole penetrating the upper and lower portions of a silicon wafer is formed, and a via is filled with a conductive material such as copper in the via hole, and a via is formed on a chip of a semiconductor chip. A redistribution pad connected to the pad is formed, and a lower portion of the redistribution pad has a structure in which a solder pad to which solder balls are attached is formed.

Here, the via hole is generally formed by performing a photoresist process (patterning, etching, PR strip, etc.) which is well known in the art.

Republic of Korea Publication No. 2011-0105165 (published: 2011. 09. 26.)

However, the conventional silicon interposer has a problem in that the heat dissipation characteristics are poor due to the characteristics of the silicon material, and due to this problem, there are many problems in applying the silicon interposer to the package for the heat dissipation device.

In addition, since the conventional silicon interposer forms a via hole only by a photoresist process, there is a side problem that requires a large amount of investment in semiconductor equipment and masks.

According to an aspect of the present invention, there is provided a method of forming a via hole penetrating through an upper portion and a lower portion of an aluminum substrate, forming a diffusion barrier layer on a sidewall of the via hole and a front surface of the aluminum substrate, and forming an upper portion of the aluminum substrate. Forming a mask pattern defining a pad region for the upper electrode and the lower electrode at a lower portion, filling the via hole and the pad region with a conductive material, and removing the mask pattern to integrate the upper and lower pad regions. It provides a method of manufacturing an aluminum interposer comprising the step of forming a through electrode, a step of forming a lower bump metal layer in the lower pad region, and forming a solder ball on the lower bump metal layer.

According to another aspect, the present invention is formed to penetrate the aluminum substrate and the upper and lower portions of the aluminum substrate to be filled with a conductive material, and through which the pad regions for the upper and lower electrodes are integrally formed through a single process. An aluminum interposer including an electrode, upper and lower bump metal layers respectively formed on upper and lower portions of the pad region, and solder balls formed on the lower bump metal layer is provided.

According to another aspect of the present invention, a process of forming a via hole penetrating the upper and lower portions of an aluminum substrate, forming a diffusion barrier layer on the inside of the via hole and the front surface of the aluminum substrate, and the upper portion of the aluminum substrate And forming a mask pattern defining a pad region for upper and lower electrodes, respectively, forming a conductive pad layer on sidewalls of the via hole and a pad region, and removing the mask pattern. Forming a lower bump metal layer on the conductive pad layer, attaching a chip die to a predetermined position on the aluminum substrate, bonding a metal wire electrically connecting the chip die and the conductive pad layer, and It provides a method for manufacturing an aluminum interposer comprising the step of forming a solder ball on the lower bump metal layer.

According to yet another aspect, the present invention provides an aluminum substrate, upper and lower portions of both side edges of the aluminum substrate, and thin film conductive pad layers formed along side surfaces thereof, upper and lower bump metal layers formed on the conductive pad layer; And an aluminum interposer including a chip die bonded to a predetermined position on the aluminum substrate, a metal wire connecting the electrode pad of the chip die and the upper bump metal layer, and a solder ball formed on the lower bump metal layer.

According to the present invention, an aluminum substrate is used as an interposer substrate, and via holes formed in the aluminum substrate can be formed not only by a photoresist process but also by a laser drilling process. Not only can you realize the poser, but you can also reduce the cost of making it.

1 is a cross-sectional view of an aluminum interposer manufactured according to an embodiment of the present invention,
2a to 2h is a process flow diagram showing the main process of manufacturing an aluminum interposer according to an embodiment of the present invention,
3 is a cross-sectional view of an aluminum interposer manufactured according to another embodiment of the present invention;
Figures 4a to 4h is a process flow diagram showing the main process of manufacturing an aluminum interposer according to another embodiment of the present invention.

SUMMARY OF THE INVENTION The technical idea of the present invention is to form a via hole penetrating the upper and lower portions of an aluminum substrate, and to form a diffusion barrier layer on the sidewall of the via hole and the front surface of the aluminum substrate, and for upper and lower electrodes on the upper and lower portions of the aluminum substrate. Forming a mask pattern defining a pad area of the pad, filling the via hole and the pad area with a conductive material, removing the mask pattern to form a through electrode integrated with the upper and lower pad areas, and lower bumps in the lower pad area. By forming a metal layer and forming a solder ball on the lower bump metal layer, the present invention can effectively solve the problems in the prior art by realizing the object through these technical means.

In addition, the present invention forms a via hole penetrating the upper and lower portions of the aluminum substrate, the diffusion barrier layer formed on the inside of the via hole and the front surface of the aluminum substrate, and pads for the upper electrode and the lower electrode on the upper and lower portions of the aluminum substrate. A mask pattern defining a region is formed, a conductive pad layer is formed on the sidewalls and the pad region of the via hole, a mask pattern is removed, a lower bump metal layer is formed on the conductive pad layer, and a chip is formed at a predetermined position on the aluminum substrate. The method may further include a technical gage for attaching a die, bonding a metal wire electrically connecting the chip die and the conductive pad layer, and forming solder balls on the lower bump metal layer.

Here, the via hole formed in the aluminum substrate may be formed through a laser drilling process or a photoresist process, and the diffusion barrier layer may be formed through an anodizing method of forming an aluminum oxide film.

In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may be changed according to intention or custom of a user, an operator, or the like. Therefore, the definition should be based on the technical idea described throughout this specification.

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

[Example 1]

1 is a cross-sectional view of an aluminum interposer manufactured according to an embodiment of the present invention, which is formed to penetrate the aluminum substrate 102 and the upper and lower portions of the aluminum substrate 102 to form a conductive material (eg, Cu). And a through electrode 112 formed integrally with pad regions for the upper and lower electrodes through a single process.

Here, the through electrode 112 formed by filling a conductive material in a via hole formed to completely penetrate the upper and lower portions of the aluminum substrate 102 includes, for example, filling the via hole and the pad region with the conductive material through a plating process. After the CMP process, the upper and lower portions of the conductive material filled in the via holes may be removed to be flat.

In addition, the aluminum interposer of the present embodiment includes upper and lower bump metal layers 114a and 114b formed on the upper and lower portions of the pad region, and solder balls 116 formed on the lower bump metal layer 114b, respectively. The lower bump metal layers 114a and 114b may be formed by, for example, an electroless plating process, and the solder balls 116 may be formed through, for example, a screen printing or plating process.

Next, a series of processes for manufacturing the aluminum interposer of the present embodiment having the structure as described above will be described in detail.

2A to 2H are flowcharts illustrating main processes of manufacturing an aluminum interposer according to an embodiment of the present invention.

Referring to FIG. 2A, a laser drilling process is performed to form a desired number of via holes at a target position of the aluminum substrate 102, that is, via holes 104 completely penetrating the upper and lower portions of the aluminum substrate 102. Here, the via hole 104 may be formed not only by laser drilling but also through photoresist processes (patterning, etching, PR strips, etc.).

Next, by performing an anodizing process, as shown in FIG. 2B, an aluminum oxide film, i.e., a diffusion barrier layer 106 serving as an insulating film for preventing leakage current, is formed in the via hole 104. As shown in FIG. It is formed on the side wall and the front surface of the aluminum substrate 102.

Subsequently, by performing any one of a deposition process such as a sputtering process, an atomic layer deposition process, an E-beam evaporation process, and an electroless plating process, as an example, as shown in FIG. 2C, the sidewalls of the via holes 104 and aluminum A thin seed metal film 108 is formed on the entire surface of the substrate 102. Here, the seed metal film 108 may be, for example, any one of Cr / Cu, Cr / Au, Ti / Cu, Ti / Au, Ta / Cu, and Ta / Au.

Again, by performing photoresist patterning (photoresist material application, development, cleaning, etc.), as shown in FIG. 2D, for example, pad regions for the upper electrode and the lower electrode are disposed on the upper and lower portions of the aluminum substrate 102. Each mask pattern 110 is defined.

Next, for example, the via hole 104 and the pad region are filled with a conductive material by performing a plating process, and the upper and lower portions of the filled conductive material are smoothly removed, for example, as shown in FIG. 2E. As shown, the through electrode 112 is formed integral with the upper and lower pad regions. Here, as the conductive material, for example Cu may be used.

Thereafter, by performing a PR strip process or the like, as shown in FIG. 2F, the remaining mask pattern 110 is removed. At this time, the seed metal layers 108 formed on the entire surface of the aluminum substrate 102 are also removed. Can be removed at the same time.

Subsequently, by performing an electroless plating process or the like, upper and lower bump metal layers 114a and 114b are formed on the upper and lower pad regions, as shown in FIG. 2G as an example. Such upper and lower bump metal layers 114a are formed. 114b), for example, Ni / Au or the like can be used.

Finally, for example, by performing a screen printing process, plating process, etc., as shown in FIG. 2H, the solder ball 116 is formed (attached) on the lower bump metal layer 114b.

[Example 2]

3 is a cross-sectional view of an aluminum interposer manufactured according to another embodiment of the present invention, wherein the aluminum substrate 202 and upper and lower portions of both edges of the aluminum substrate 202 and thin film conductive pads formed along the side surfaces thereof are shown. Layer 212 and upper and lower bump metal layers 214a and 214b formed on the conductive pad layer 212.

Here, the conductive pad layer 212 may be, for example, Cu, and may be formed through a plating process, and the upper and lower bump metal layers 214a and 214b may be formed, for example, by performing an electroless plating process or the like. .

Here, the conductive pad layer 212 and the upper and lower bump metal layers 214a and 214b formed on the conductive pad layer 212 are formed along upper and lower portions of both edges of the aluminum substrate 202 and along side surfaces thereof. The structure is formed by performing a laser drilling process or the like to form a via hole at a target position of the aluminum substrate 202 and performing a plating process or the like to form a thin conductive pad layer 212 on the sidewalls (side wells) and the pad region of the via hole. And removing the mask pattern by performing a PR strip process and the like, followed by an electroless plating process to form upper and lower bump metal layers 214a and 214b on the upper and lower pad regions. The chip die 216, the metal wire 218, and the solder ball 220 may be formed at a target position of the aluminum substrate 202, and then diced along a via hole having an empty inside.

In addition, the aluminum interposer of this embodiment electrically connects the chip die 216 bonded to a predetermined position on the aluminum substrate 202, the electrode pad (not shown) of the chip die 216, and the upper bump metal layer 214a. The solder ball 220 is further formed on the metal wire 218 and the lower bump metal layer 214b. Here, the solder ball 220 may be formed through, for example, a screen printing process or a plating process.

Next, a series of processes for manufacturing the aluminum interposer of the present embodiment having the structure as described above will be described in detail.

4A through 4H are flowcharts illustrating main processes of manufacturing an aluminum interposer according to another exemplary embodiment of the present invention.

4A to 4D, reference numerals 202 to 210 are substantially the same as each of the corresponding reference numerals 102 to 110 shown in FIGS. 2A to 2D of Embodiment 1 described above, and proceed for the manufacture of an aluminum interposer. Processes and methods are also substantially the same as each process and method of Figures 2a to 2d described in Example 1 described above. Therefore, in order to avoid unnecessary duplication of description for the sake of brevity, descriptions of the processes of FIGS. 4A to 4D will be omitted herein.

First, referring to FIG. 4E, for example, an inner side of a via hole 204 formed in an aluminum substrate 202 having a mask pattern 210 defining a pad region for an upper electrode and a lower electrode, for example, by performing a plating process or the like. A thin film conductive pad layer 212 is formed in the side well of the via hole and the pad region. As the conductive pad layer 212, for example, Cu or the like can be used. That is, the aluminum interposer of the present exemplary embodiment has a structure in which the conductive pad layer 212 of the thin film is formed in such a manner that the inside of the via hole 204 is not filled (filled). Here, the via hole 204 may function as a dicing (scribing) line in a subsequent process to separate the aluminum interposers separately.

Again, by performing a PR strip process or the like, as shown in FIG. 4F, the remaining mask pattern 210 is removed. At this time, the seed metal layers 208 formed on the entire surface of the aluminum substrate 202 are also removed. Can be removed at the same time.

Subsequently, by performing an electroless plating process or the like, upper and lower bump metal layers 214a and 214b are formed on the upper and lower pad regions as shown in FIG. 4G as an example. Such upper and lower bump metal layers 214a are formed. 214b), for example, Ni / Au or the like can be used.

Next, the chip die 216 is attached to a predetermined position on the aluminum substrate 202 using an adhesive member or the like, and a wire bonding process or the like is performed to form an electrode pad (not shown) and an upper bump metal layer of the chip die 216. 214a is connected to each other by a metal wire 218, and finally, for example, by performing a screen printing process, plating process, or the like, as shown in FIG. 4H as an example, the solder balls 220 on the lower bump metal layer 214b. ) Is formed (attached). In FIG. 4H, the dotted line means a dicing (scribing) line for separately separating the aluminum interposers.

In the above description has been described by presenting a preferred embodiment of the present invention, but the present invention is not necessarily limited thereto, and those skilled in the art to which the present invention pertains have various scope within the technical spirit of the present invention. It will be readily appreciated that branch substitutions, modifications and variations are possible.

102, 202: aluminum substrate 104, 204: via hole
106,206: diffusion barrier layer 108,208: seed metal film
110 and 210: mask pattern 112: through electrode
114a, 214a: upper bump metal layer 114b, 214b: lower bump metal layer
116 and 220 solder ball 212 conductive pad layer
216: chip die 218: metal wire

Claims (24)

Forming a via hole penetrating the upper and lower portions of the aluminum substrate;
Forming a diffusion barrier layer on the sidewalls of the via holes and the front surface of the aluminum substrate;
Forming a seed metal film in the via hole and on the entire surface of the aluminum substrate;
Forming a mask pattern on upper and lower portions of the aluminum substrate to define pad regions for upper and lower electrodes, respectively;
Filling the via hole and the pad region with a conductive material;
Simultaneously removing the seed metal layer and the mask pattern to form a through electrode integrated with upper and lower pad regions;
Forming a lower bump metal layer in the lower pad region;
Process of forming a solder ball on the lower bump metal layer
Aluminum interposer manufacturing method comprising a.
The method of claim 1,
The via hole is
Formed through laser drilling process
Method of manufacturing aluminum interposers.
The method of claim 1,
The via hole is
Formed through a photoresist process
Method of manufacturing aluminum interposers.
The method of claim 1,
The diffusion barrier layer,
Aluminum oxide film formed through anodizing process
Method of manufacturing aluminum interposers.
delete The method of claim 1,
The seed metal film,
Formed by any one of sputtering process, atomic layer deposition process, E-beam evaporation process and electroless plating process
Method of manufacturing aluminum interposers.
The method of claim 1,
The seed metal film,
Any one of Cr / Cu, Cr / Au, Ti / Cu, Ti / Au, Ta / Cu, Ta / Au
Method of manufacturing aluminum interposers.
delete The method of claim 1,
The process of forming the through electrode,
Performing a plating process to fill the via hole and the pad region with a conductive material;
Process of removing the top and bottom of the filled conductive material by performing CMP process
Aluminum interposer manufacturing method comprising a.
The method of claim 9,
The conductive material may include,
Cu
Method of manufacturing aluminum interposers.
The method of claim 1,
The solder ball,
Formed by screen printing process or plating process
Method of manufacturing aluminum interposers.
delete delete delete delete delete delete delete delete delete delete delete delete delete

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