JP2004296586A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device by which the corrosion or peeling of the external wiring would hardly occur when the external wiring is formed in cut parts of the surface. <P>SOLUTION: The method of manufacturing a semiconductor device comprises a laminate formation process S12 of forming a laminate by fastening a support substrate for covering a region wherein a plurality of integrated circuits are formed on a semiconductor substrate formed with the plurality of integrated circuits via an insulating resin, a notch cutting process S14-2 of cutting the semiconductor substrate together with the insulating resin with at least part of the support substrate being left over, and a dicing process S22 of dividing the laminate into individual pieces by cutting the support substrate. In the notch cutting process S14-2, a dress board 50 is cut by a dicing saw whose teeth have been set before cutting the semiconductor substrate including the laminate by a dicing saw. After checking the cut shape of the dress board 50, the teeth of the dicing saw are set again and then the semiconductor substrate including the laminate is cut by the dicing saw. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of manufacturing a semiconductor device including a stacked body formed by stacking a plurality of layers, and more particularly to a method of manufacturing a semiconductor device including a step of cutting the stacked body with a dicing saw.
[0002]
[Prior art]
In recent years, a chip size package (CSP) has been widely used to reduce the chip size of a semiconductor device.
[0003]
In recent years, such a chip size package has been adopted in the field of CCD image sensors, and has been adopted for packaging sensor chips used in small cameras.
[0004]
FIG. 6 is an example of a semiconductor device employing a chip size package, and FIGS. 6A and 6B are perspective views of the semiconductor device as viewed from the front side and the back side, respectively.
[0005]
A semiconductor chip 4 is sealed between the first and second support bases 2 and 3 via an insulating resin 5. A plurality of ball-shaped terminals 8 are arranged on the main surface of the lower support base 3, that is, on the back side of the device, and these ball-shaped terminals 8 are connected to the semiconductor chip 4 via external wirings 7. Wirings are drawn out of the semiconductor chip 4 and connected to the plurality of external wirings 7, and each ball-shaped terminal 8 is in contact with the semiconductor chip 4.
[0006]
FIG. 7 shows a flow of the manufacturing method of FIG. The internal wiring 24 is formed via an oxide film so as to straddle the boundary of each semiconductor element adjacent to the surface of the semiconductor substrate 10 on which the plurality of semiconductor elements are formed. The internal wiring 24 is electrically connected to the semiconductor element via a contact hole formed in the oxide film (S10). The semiconductor body 10 is sandwiched between the upper support base 2 and the lower support base 3 with the resin layer 5 interposed therebetween to form the laminate 100 (S12). At this time, after the semiconductor substrate 10 is etched along the scribe line from the lower support base 3 side to expose the internal wiring 24 once, the lower support base 3 is bonded to the semiconductor substrate 10. The buffer member 30 is further formed on the lower support base 3. The cushioning member 30 plays a role of a cushion that relieves stress applied to the ball-shaped terminal 8.
[0007]
Next, as shown in FIG. 8, an inverted V-shaped notch (notch groove) 22 is formed on the laminate 100 along the scribe line from the lower support base 3 side using a dicing saw 34, and the internal wiring of the element is formed. The end 26 of the notch 24 is exposed on the side surface of the notch 22 (S14).
[0008]
Thereafter, a metal film 28 is formed on the surface of the lower support base 3 and the inner surface of the notch 22 (S16), and the metal film 28 is brought into contact with the internal wiring 24. The external wiring 7 is formed by patterning the metal film 28 from the internal wiring 24 to the buffer member 30 along a predetermined wiring pattern (S18). Further, the protection film 30 and the ball-shaped terminals 20 are formed (S20), and the semiconductor devices of the chip size package are completed by dividing the semiconductor device along the scribe lines (S22).
[0009]
For example, since a CCD image sensor of a chip size package has a light receiving surface, an optically transparent glass plate is used for at least the upper support base 2, and the resin layer 12 also has transparency for bonding to the semiconductor substrate 10. Epoxy resin is used.
[0010]
[Non-patent document 1]
"PRODUCTS", [online], SHELLCASE, [searched October 1, 2002], Internet <URL http: // www. shellcase. com / pages / products-shellOP-process. asp>
[0011]
[Problems to be solved by the invention]
In the case of the semiconductor device having the above-described configuration, the metal film is deposited on a surface having a predetermined inclination with respect to the surface of the semiconductor substrate 10, so that the metal film is deposited on the surface of the lower support base 3. It is difficult to deposit a metal film at a high density. Further, since the notch 22 is formed by cutting the laminate 100 using a dicing saw, the resin of the resin layer 12 is melted by frictional heat, and the melted resin adheres to the inner surface of the notch 22 or the dicing saw. For this reason, large irregularities are generated on the inner surface of the notch 22, and the metal film 28 cannot be vapor-deposited on the inner surface, and there is a problem that the density of the formed metal film 28 is further reduced. Further, in the notch step, there is a problem that a desired cutting shape cannot be obtained unless the surface of the dicing saw is in a clean state.
[0012]
As described above, when the density of the metal film 28 decreases, a chemical solution for removing the resist used when patterning the metal film 28 soaks into the metal film 28, and the chemical solution remains in the metal film 28 as it is. This causes a serious problem that the external wiring 18 is corroded or peeled off.
[0013]
The present invention has been made in view of the above-mentioned problems of the prior art, and has made it possible to provide a manufacturing method suitable for a semiconductor device having a laminated structure in which a supporting base is fixed to a semiconductor substrate via an insulating resin.
[0014]
[Means for Solving the Problems]
In order to solve the above problems, a method of manufacturing a semiconductor device according to the present invention includes, on a semiconductor substrate on which a plurality of integrated circuits are formed, a supporting base covering an area where the plurality of integrated circuits are formed via an insulating resin. A first step of fixing and forming a laminate, a second step of cutting the semiconductor substrate including the laminate together with the insulating resin while leaving at least a part of the support base, and cutting the support base And a third step of dividing the laminated body, and wherein the second step comprises, when cutting the semiconductor substrate including the laminated body with a dicing saw, after sharpening the dicing saw, Cutting the semiconductor substrate including the body.
[0015]
In the second step, the sample substrate is cut by the sharpened dicing saw, and after confirming the cut shape, the dicing saw is sharpened again to cut the semiconductor substrate including the stacked body. And
[0016]
Here, in the method of manufacturing a semiconductor device, it is preferable that the second step uses a dicing saw polished with a grindstone.
[0017]
Further, in the second step, cooling is preferably performed by spraying a cooling medium onto the dicing saw.
[0018]
Further, the method for manufacturing a semiconductor device further includes a step of forming a metal wiring on a cut surface of the laminate formed in the second step.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The method for manufacturing a semiconductor device according to the embodiment of the present invention includes an internal wiring forming step (S10), a stacked body forming step (S12), a notch cutting step (S14-2), and a metal film as shown in the flowchart of FIG. It basically comprises a film forming step (S16), a patterning step (S18), a terminal forming step (S20), and a dicing step (S22).
[0020]
In the method of manufacturing a semiconductor device according to the present embodiment, each step other than the notch cutting step S14-2 is the same as the conventional semiconductor device manufacturing step, and thus the description is omitted.
[0021]
Here, the configuration of the laminate 100 will be described. In the following description, the semiconductor substrate 10 may be a general semiconductor material such as a silicon substrate or gallium arsenide. On the semiconductor substrate 10, a semiconductor device including a semiconductor element such as a transistor element, a photoelectric conversion element, a charge-coupled element (CCD), a resistor, and a capacitor can be formed.
[0022]
The resin layer 5 bonds the semiconductor substrate 10 to the upper support base 2 and the lower support base 3, and may be a cured resin material such as epoxy. When forming a solid-state imaging device, it is preferable to use a transparent resin layer 5.
[0023]
The upper support base 2 and the lower support base 3 serve to increase the structural strength of the element, and may be made of glass, metal, plastic, or the like. When forming a solid-state imaging device, it is preferable to use transparent glass or plastic for at least the upper support base 2.
[0024]
Hereinafter, the improved notch cutting process, which is a feature of the present embodiment, will be described in detail.
[0025]
In the notch cutting step of step S14-2, the stacked body 100 is cut from the lower support base 3 side using a tapered dicing saw to form an inverted V-shaped notch 22. The lower support base 3, the resin layer 5, the semiconductor substrate 10, and a part of the upper support base 2 are cut by the dicing saw, and the end 26 of the internal wiring 24 is exposed on the inner surface of the notch 22.
[0026]
The notch cutting step is performed using a dicing saw 34 in which fine diamond particles are adhered on the circumference of a disc-shaped dicing saw.
[0027]
Hereinafter, the notch cutting step will be described with reference to the flowchart showing the notch cutting step in FIG.
[0028]
First, prior to cutting the laminate 100, the dicing saw is dressed (step S14-21: dressing step 1). Here, dressing refers to grinding the surface of a dicing saw with a grindstone to treat it to a desired shape.
[0029]
Subsequently, as shown in FIG. 3, a dress board 50 as a sample substrate is precut. In the present embodiment, a laminated substrate of glass and a semiconductor substrate made of silicon is used as a sample substrate, and the laminated substrate is cut to a desired depth at a desired rotation speed (step S14-22).
[0030]
Next, the angle and depth of the notch formed on the dress board 50 are observed using a microscope or the like (step S14-23).
[0031]
Further, when the shape (angle, depth, etc.) of the formed notch is desired, the dicing saw is dressed again. That is, since the surface of the dicing saw may be clogged by the cutting process in step S14-23, the dicing saw may be ground again with a grindstone to obtain a desired shape (to eliminate the clogged eyes). (Step S14-24: dressing step 2).
[0032]
Then, the laminate 100 is actually cut to form a desired notch shape (step S14-25).
[0033]
When notching is performed on another position on the semiconductor substrate, the dicing saw is similarly dressed before the notching step, and then the laminate 100 is subjected to notching. That is, the dress board 50 is pre-cut (step S14-26), and the angle and depth of the notch formed on the dress board 50 are observed using a microscope or the like (step S14-27). If the shape (angle, depth, etc.) of the formed notch is desired, the dicing saw is dressed again (step S14-28: dressing step 3), and the laminate 100 is actually removed. The desired notch shape is formed by cutting (step S14-29). Hereinafter, the notch processing is similarly repeated.
[0034]
In the notch cutting step using the dicing saw 34, by cooling the dicing saw 34, the temperature of the cutting surface of the laminate 100 is lower than the softening temperature of the layer having the lowest softening temperature among the layers included in the laminate 100. It is preferable to perform cutting under the following conditions.
[0035]
Specifically, as shown in FIG. 4, cutting is performed while injecting the cooling medium 36 to the dicing saw 34 and cooling using the cooling apparatus provided with the first and second cooling medium injection apparatuses 38 and 39. Do.
[0036]
In front of the dicing saw 34, a first cooling medium injection device 38 is located, and as shown in FIG. 4A, the cooling medium 36 is supplied from the first cooling medium injection device 38 to the dicing saw 34 and the cutting portion 40. To perform cooling. As described above, by directly spraying the cooling medium 36 to cool, the dicing saw 34 and the cutting portion 40 can be locally cooled, the cooling efficiency can be improved, and the temperature rise can be suitably suppressed. As the cooling medium 36, pure water, acetone, ethyl alcohol, isopropyl alcohol, or the like can be appropriately selected and used.
[0037]
Further, it is preferable that the cooling medium 36 be sprayed in a direction along the rotation direction of the dicing saw 34. As a result, the cooling medium 36 that has hit the cutting portion 40 flows from the cutting portion 40 toward the notch 22 along the rotation of the dicing saw 34, thereby cooling the cutting portion 40 more efficiently and attaching to the cutting portion 40. Garbage can be removed.
[0038]
At this time, it is preferable to spray the cooling medium 36 toward the cutting point 40 at an elevation angle of 5 ° to 45 ° with respect to the cutting direction. Further, it is more preferable to spray the cooling medium 36 at an elevation angle of 30 ° or more and 40 ° or less with respect to the cutting direction.
[0039]
It is preferable that the width of the cooling medium 36 is wider than the width of the dicing saw so as to completely cover the dicing saw of the dicing saw 34. As a result, as shown in FIG. The cooling medium 36 is evenly supplied to both surfaces of the dicing saw 34, so that the dicing saw 34 can be cooled efficiently during cutting.
[0040]
On the other hand, if the above conditions are not satisfied, as shown in FIG. 5B, the flow of the cooling medium 36 along the dicing saw becomes uneven, or the supply of the cooling medium 36 to the inner surface of the notch 22 becomes insufficient. Cooling efficiency decreases.
[0041]
On both sides of the dicing saw 34, a second cooling medium ejecting device 39 is positioned so as to sandwich the dicing saw 34, and as shown in FIG. And, by directly spraying the cooling medium 36 on the cutting portion 40, the cooling efficiency can be further improved. It is preferable that the spray of the cooling medium 36 from the second cooling medium injection device 39 is also performed at an elevation angle of 5 ° to 45 ° with respect to the stacked body 100.
[0042]
The cleaning medium ejecting device 41 is located behind the dicing saw 34, and the cleaning medium 42 is sprayed from the cleaning medium ejecting device 41 onto the laminated body 100 after cutting, so that the notch 22 and the surface of the laminated body 100 are attached. Remove garbage. As the cleaning medium 42, the cooling medium 36 can be used.
[0043]
In such a configuration, for example, as a result of cooling the structure in which the stacked body 100 sandwiches the silicon semiconductor layer between the glass substrates via the epoxy resin layer, the dicing saw 34 having a diameter of 20 cm and a dicing saw width of 0.62 mm is obtained. Is used at 40,000 revolutions / minute, by spraying 20 l / min of pure water toward the cutting portion 40 at an elevation angle of 30 ° or more and 40 ° or less, thereby lowering the temperature of the cutting portion 40 to the epoxy resin layer having the lowest softening temperature. The cutting was able to be performed while keeping the softening temperature of 150 ° C. or lower.
[0044]
As described above, by using the method of manufacturing a semiconductor device according to the present embodiment, it is possible to suppress an increase in the temperature of the inner surface of the notch 22 during cutting, and to prevent unnecessary substances from adhering to the inner surface of the notch 22. be able to. As a result, the density of the metal film formed thereon increases, and corrosion and peeling of the external wiring can be prevented.
[0045]
Furthermore, since the dicing saw is dressed before performing the notch processing, the notch 22 can be formed stably, and similarly, corrosion and peeling of the external wiring can be prevented.
[0046]
【The invention's effect】
According to the present invention, in a semiconductor device having a laminated structure in which a supporting base is fixed to a semiconductor substrate via an insulating resin, corrosion and peeling of wiring due to a cutting step can be prevented. Therefore, the reliability of the semiconductor device can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a method for manufacturing a semiconductor device according to an embodiment of the present invention.
FIG. 2 shows a flow of a cutting process using a dicing saw in the present embodiment.
FIG. 3 is a diagram showing a precut process using a dress board in the present embodiment.
FIG. 4 is a diagram showing a cutting process using a dicing saw in the present embodiment.
FIG. 5 is a diagram illustrating an operation of a cutting process according to the embodiment of the present invention.
FIG. 6 is a diagram showing an appearance of a semiconductor device of a chip size package.
FIG. 7 is a diagram showing a flow of a method of manufacturing a semiconductor device of a chip size package.
FIG. 8 is a diagram showing a cutting process using a dicing saw in a conventional method for manufacturing a semiconductor device.
[Explanation of symbols]
2 upper support base, 3 lower support base, 4 semiconductor chip, 5 resin layer, 7 external wiring, 8 ball-shaped terminal (solder bump), 10 semiconductor substrate, 22 notch (notch groove), 24 internal wiring, 26 internal wiring End, 28 metal film, 30 contact portion, 32 insulating film, 34 dicing saw, 36 cooling medium, 38 first cooling medium injection device, 39 second cooling medium injection device, 40 cutting portion, 41 cleaning medium injection device , 42 cleaning media, 50 dress boards, 100 laminates.

Claims (5)

A first step of fixing a support base covering an area where the plurality of integrated circuits are formed on the semiconductor substrate on which the plurality of integrated circuits are formed via an insulating resin to form a laminate;
A second step of cutting the semiconductor substrate including the laminate together with the insulating resin while leaving at least a part of the support base;
A third step of cutting the support base and dividing the laminate.
The semiconductor device according to claim 2, wherein the second step is to cut the semiconductor substrate including the stacked body after sharpening the dicing saw when the semiconductor substrate including the stacked body is cut by the dicing saw. Manufacturing method. The method for manufacturing a semiconductor device according to claim 1,
The second step is characterized in that the sample substrate is cut by the sharpened dicing saw, and after confirming the cut shape, the dicing saw is sharpened again to cut the semiconductor substrate including the stacked body. A method for manufacturing a semiconductor device. The method for manufacturing a semiconductor device according to claim 1 or 2,
The method of manufacturing a semiconductor device, wherein the second step uses the dicing saw polished with a grindstone. 4. The method of manufacturing a semiconductor device according to claim 1, wherein
The method of manufacturing a semiconductor device according to claim 2, wherein in the second step, cooling is performed by spraying a cooling medium onto the dicing saw. The method for manufacturing a semiconductor device according to claim 1, wherein
A method for manufacturing a semiconductor device, further comprising a step of forming a metal wiring on a cut surface of the stacked body formed in the second step.

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