JP3459234B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device having a columnar electrode and a method of manufacturing the same.

[0002]

2. Description of the Related Art For example, a semiconductor device called CSP (Chip Size Package) is shown in FIG. In this semiconductor device, the connection pad 2 is formed on the upper surface of the semiconductor substrate 1 made of silicon or the like, the insulating film 3 is formed on a portion of the upper surface except the central portion of the connection pad 2, and the opening formed in the insulating film 3 is formed. The rewiring 5 is formed from the upper surface of the connection pad 2 exposed through the portion 4 to a predetermined position on the upper surface of the insulating film 3, and the columnar electrode 6 is formed on the upper surface of the pad portion at the tip of the rewiring 5. The sealing film 7 is formed on the entire upper surface except 6 and the surface treatment layer 8 for oxidation prevention is formed on the upper surface of the columnar electrode 6 by electrolytic plating or electroless plating, and the solder balls 9 are formed on the surface of the surface treatment layer 8. It has a formed structure.

[0003]

By the way, in the above conventional semiconductor device, since the lower surface of the semiconductor substrate 1 is exposed, the semiconductor substrate 1 itself can absorb noise due to static electricity or the like from the outside. If it is not possible, there is a problem that electrical noise may occur, and a crack may occur in the semiconductor substrate 1 during various operations such as mounting on another electronic component such as a circuit board. In particular, in order to reduce the thickness of the semiconductor device, the semiconductor substrate 1
If the lower surface of is properly polished, electrical noise is likely to occur and cracks are likely to occur in the semiconductor substrate 1. An object of the present invention is to electrically and mechanically protect the lower surface of a semiconductor substrate.

[0004]

Means for Solving the Problems A semiconductor device according to the first aspect of the present invention, the columnar electrodes and the columnar electrodes on the upper surface
A semiconductor substrate having a surface treatment layer for oxidation prevention formed on the upper surface, a sealing film formed on the upper surface of the semiconductor substrate excluding the columnar electrodes, and a conductive resin film formed only on the lower surface of the semiconductor substrate. And is provided. (Claim 2) In the invention according to claim 1, the upper surface of the semiconductor substrate.
The connection pad and the rewiring connected to the connection pad.
The columnar electrodes are formed on the upper surface of the pad portion of the rewiring.
A semiconductor device characterized by being formed . Claim 3
The semiconductor device according to the invention described in ( 1 ) is characterized in that, in the invention according to ( 1 ), solder balls are formed on the surface of the surface treatment layer. According to a fourth aspect of the present invention, in the semiconductor device according to any one of the first to third aspects, the thickness of the semiconductor substrate is smaller than the initial thickness of a wafer for obtaining the semiconductor substrate. It is characterized by that. According to a fifth aspect of the present invention, there is provided a semiconductor device manufacturing method, wherein a sealing film is formed on an entire upper surface of a wafer having columnar electrodes on the upper surface except for the columnar electrodes, and the wafer is diced to form a semiconductor substrate.
In the method for manufacturing a semiconductor device, which obtains a semiconductor device including individual chips, a conductive resin film is formed on the lower surface of the wafer, the wafer is diced, and the semiconductor substrate
Device in which the conductive resin film is formed only on the lower surface of the semiconductor device
It is characterized by obtaining . According to a sixth aspect of the present invention, in the method of manufacturing a semiconductor device according to the fifth aspect, after forming the sealing film, a surface treatment layer for preventing oxidation is formed on an upper surface of the columnar electrode. It is characterized by that. According to a seventh aspect of the present invention, there is provided a method of manufacturing a semiconductor device according to the sixth aspect,
After forming the surface treatment layer, solder balls are formed on the surface of the surface treatment layer. According to an eighth aspect of the present invention, in the method of manufacturing a semiconductor device according to the fifth aspect, the lower surface of the wafer is polished to make the wafer thinner, and It is characterized in that a conductive resin film is formed. A method of manufacturing a semiconductor device according to a ninth aspect of the present invention is the method of manufacturing the semiconductor device according to any one of the fifth to seventh aspects, wherein after the sealing film and the columnar electrodes on the wafer are polished, The lower surface is polished to thin the wafer, and the conductive resin film is formed on the lower surface of the wafer.

[0005]

1 is a sectional view of a semiconductor device according to an embodiment of the present invention. In this semiconductor device, the connection pad 22 is formed on the upper surface of the semiconductor substrate 21 made of silicon or the like, and the connection pad 2 on the upper surface is formed.
The insulating film 23 is formed on a portion of the insulating film 23 other than the central portion, and the rewiring 25 extends from the upper surface of the connection pad 22 exposed through the opening 24 formed in the insulating film 23 to a predetermined position on the upper surface of the insulating film 23. The columnar electrode 26 is formed on the upper surface of the pad portion at the tip of the rewiring 25, and the sealing film 27 having the same height as the upper surface of the columnar electrode is formed on the entire upper surface excluding the columnar electrode 26. A surface treatment layer 28 for oxidation prevention is formed on the upper surface of the columnar electrode 26 by electrolytic plating or electroless plating, and the solder balls 2 are formed on the surface of the surface treatment layer 28.
9 is formed, and the conductive resin film 3 is formed on the lower surface of the semiconductor substrate 21.
It has a structure in which 0 is formed.

Next, an example of a method of manufacturing this semiconductor device will be described with reference to FIGS. First, as shown in FIG. 2, the connection pad 22 is formed on the upper surface of the wafer 31 for obtaining the plurality of semiconductor substrates 21 shown in FIG. 1, and the insulating film 23 is formed on the upper surface of the connection pad 22 except the central portion. And the opening 2 formed in the insulating film 23.
The rewiring 25 is formed from the upper surface of the connection pad 22 exposed via 4 to a predetermined position on the upper surface of the insulating film 23, and the height of 100 to 2 is provided on the upper surface of the pad portion at the tip of the rewiring 25.
The thing in which the columnar electrode 26 of 00 μm was formed is prepared.
The area indicated by reference numeral 32 in FIG. 2 is an area corresponding to the dicing street.

Next, as shown in FIG. 3, a sealing film 27 made of epoxy resin is formed on the entire upper surface of the insulating film 23 including the columnar electrodes 26 and the rewirings 25 by a dispenser method, a screen printing method, a transfer molding method or the like. Thus, the thickness is formed to be slightly thicker than the height of the columnar electrode 26. Therefore, in this state, the upper surface of the columnar electrode 26 is covered with the sealing film 27. Next, the conductive resin film 30 made of carbon ink, silver paste or the like is formed on the entire lower surface of the wafer 31 by a spin coating method, a dispenser method, a screen printing method, a transfer molding method or the like.

Next, the upper surface of the sealing film 27 and the upper surface of the columnar electrode 26 are appropriately polished to expose the upper surface of the columnar electrode 26, as shown in FIG. Next, FIG.
As shown in, the surface treatment layer 28 for oxidation prevention is formed on the upper surface of the columnar electrode 26 by electroless plating, sputtering, or the like. In the case of sputtering, a mask is used to form only on the columnar electrodes 26, or a mask is formed after film formation on the entire surface to remove the surface treatment layer on the sealing film 27. next,
As shown in FIG. 6, solder balls 29 are formed on the surface of the surface treatment layer 28. Returning to FIG. 5, the surface treatment layer 28 may be formed to have a uniform thickness. In that case, stress concentrates on the interface with the solder ball 29 at the same height as the sealing film 27. After removing the upper surface of the columnar electrode 26 by etching, the surface treatment layer 28 may be formed. Next, when the wafer 31 is cut along the dicing streets 32,
As shown in FIGS. 7 and 1, a semiconductor device including individual chips can be obtained.

In the semiconductor device thus obtained,
Since the conductive resin film 30 is formed on the lower surface of the semiconductor substrate 21, the lower surface of the semiconductor substrate 21 can be protected electrically and mechanically. Therefore, even if the semiconductor substrate 1 itself cannot absorb noise due to static electricity from the outside, the generation of electrical noise can be reduced. Further, it is possible to prevent the semiconductor substrate 21 from cracking during various operations such as mounting the semiconductor device on another electronic component such as a circuit board.

In the above embodiment, the solder balls 29 are formed as shown in FIG. 6, and then the wafer 31 is cut along the dicing streets 32 to obtain the semiconductor device shown in FIG. However, it is not limited to this. For example, as shown in FIG. 5, a surface treatment layer 28 may be formed, and then the wafer 31 may be cut along the dicing streets 32 to obtain the semiconductor device shown in FIG. Alternatively, as shown in FIG. 4, the upper surface of the columnar electrode 26 may be exposed, and then the wafer 31 may be cut along the dicing streets 32 to obtain the semiconductor device shown in FIG.

Further, in the above-described embodiment, as shown in FIG. 3, the case where the conductive resin film 30 is formed after the sealing film 27 is formed has been described, but the present invention is not limited to this. It may be after any step before dicing. Further, when the thickness of the semiconductor device, which is an individual chip, is reduced, the conductive resin film 3 is formed on the lower surface of the wafer 31.
It is efficient to polish the lower surface of the wafer 31 before forming 0s. In that case, the conductive resin film 30 may be formed on the lower surface of the wafer 31 in any step after polishing the lower surface of the wafer 31 and before dicing the wafer 31. After the wafer 31 is deformed by heating or the like and the upper surface side of the sealing film 27 and the upper surface side of the columnar electrodes 26 shown in FIG. 4 are polished, the lower surface of the wafer 31 is polished to efficiently flatten the wafer 31. Therefore, it is preferable that the upper surface side of the sealing film 27 and the columnar electrodes 26 are polished and then the solder balls 29 are formed.

[0012]

As described above, according to the present invention, since the conductive resin film is formed only on the lower surface of the semiconductor substrate, the lower surface of the semiconductor substrate can be protected electrically and mechanically. . In particular, the manufacture of the semiconductor device of the present invention
According to the method, a conductive resin film is formed on the lower surface of the wafer.
After that, it is separated into individual chips, so each semiconductor device is electrically conductive.
Productivity can be improved compared to the method of forming a water-soluble resin.
it can.

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an initially prepared item in manufacturing the semiconductor device shown in FIG.

FIG. 3 is a cross-sectional view of the manufacturing process following FIG.

FIG. 4 is a cross-sectional view of the manufacturing process following FIG.

FIG. 5 is a cross-sectional view of the manufacturing process following FIG.

FIG. 6 is a cross-sectional view of the manufacturing process following FIG.

FIG. 7 is a cross-sectional view of the manufacturing process following FIG.

FIG. 8 is a sectional view of a semiconductor device according to another embodiment of the present invention.

FIG. 9 is a sectional view of a semiconductor device according to still another embodiment of the present invention.

FIG. 10 is a sectional view of an example of a conventional semiconductor device.

[Explanation of symbols]

21 Semiconductor substrate 22 Connection pad 23 Insulating film 25 Rewiring 26 Columnar electrodes 27 Sealing film 28 Surface treatment layer 29 Solder balls 30 Conductive resin film 31 wafers 32 Dicing Street

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Claims (9)

(57) [Claims] 1. A columnar electrode on an upper surface and an upper surface of the columnar electrode
A semiconductor substrate on which a surface treatment layer for oxidation prevention is formed,
A semiconductor device comprising: a sealing film formed on the upper surface of the semiconductor substrate excluding the columnar electrodes, and a conductive resin film formed only on the lower surface of the semiconductor substrate. 2. The invention according to claim 1, wherein the half
Connect the connection pad to the upper surface of the conductor board and the connection pad.
Rewiring is formed, the columnar electrode is
A semiconductor device, which is formed on the upper surface of a pad portion . 3. The semiconductor device according to claim 1 , wherein solder balls are formed on the surface of the surface treatment layer. 4. The semiconductor according to claim 1, wherein the semiconductor substrate has a thickness smaller than an initial thickness of a wafer for obtaining the semiconductor substrate. apparatus. 5. A semiconductor device comprising: a wafer having columnar electrodes on the upper surface thereof; a sealing film formed on the entire upper surface excluding the columnar electrodes; and dicing the wafer to obtain a semiconductor device including individual chips having a semiconductor substrate . In the manufacturing method, after the conductive resin film is formed on the lower surface of the wafer, the wafer is diced so that the conductive film is formed only on the lower surface of the semiconductor substrate.
A method of manufacturing a semiconductor device, comprising obtaining a semiconductor device having a resin film formed thereon . 6. The method of manufacturing a semiconductor device according to claim 5, wherein after forming the sealing film, a surface treatment layer for preventing oxidation is formed on the upper surface of the columnar electrode. 7. The method of manufacturing a semiconductor device according to claim 6, wherein after forming the surface treatment layer, a solder ball is formed on the surface of the surface treatment layer. 8. The invention according to claim 5, wherein the conductive resin film is formed on the lower surface of the wafer after polishing the lower surface of the wafer to thin the wafer. Of manufacturing a semiconductor device. 9. The invention according to claim 5, wherein after polishing the sealing film and the columnar electrodes on the wafer, the lower surface of the wafer is polished to thin the wafer, A method of manufacturing a semiconductor device, comprising forming the conductive resin film on a lower surface of a wafer.