JP4544139B2 - Semiconductor substrate cutting apparatus and semiconductor substrate cutting method - Google Patents

Description

  The present invention relates to a semiconductor substrate cutting apparatus and a semiconductor substrate cutting method for cutting a semiconductor substrate in its thickness direction.

Conventionally, in the manufacture of semiconductor devices, a semiconductor substrate in a state in which dicing is applied to a line to be divided and attached to a sheet is expanded by expanding the sheet and applying stress to the surface direction of the semiconductor substrate. 2. Description of the Related Art A semiconductor substrate cutting apparatus that cuts into semiconductor chips is used. FIG. 10 shows an example of a conventional semiconductor substrate cutting apparatus. FIG. 10A is an explanatory view showing a state in which the semiconductor substrate is bonded to the sheet and the outer peripheral portion of the sheet is held by the frame. FIG. 10B is a diagram illustrating how the semiconductor substrate is divided into semiconductor chips by a pressing device. It is explanatory drawing of the process to do.
As shown in FIG. 10A, the back surface of the semiconductor substrate W made of a semiconductor such as silicon is bonded to a stretchable resin sheet S in a state where laser dicing is performed. The outer periphery of the sheet S is held by an annular frame F.
Then, as shown in FIG. 10B, the semiconductor substrate W is pushed up from the back side of the sheet S by using a pressing device P that is arranged below the semiconductor substrate W and moves up and down by a moving means (not shown). By pressing, the sheet S is stretched in the surface direction (the directions of arrows F1 and F2 in the figure). As a result, stress is applied to the semiconductor substrate W bonded to the sheet S in the surface direction, so that the semiconductor substrate W is divided into a plurality of semiconductor chips C (Patent Document 1).
JP 2003-10992 A

  Here, in order to improve the yield of obtaining the semiconductor chip C by dividing the semiconductor substrate W, it is preferable that the sheet S is uniformly extended. However, in the conventional semiconductor substrate cutting apparatus, since the sheet S is stretched in a state where the outer periphery of the sheet S is held, the elongation of the sheet S tends to increase toward the outer peripheral portion and to decrease at the central portion. That is, the semiconductor substrate W is appropriately divided in the vicinity of the outer periphery, but is difficult to be divided in the vicinity of the center, and there is a problem that the yield of the semiconductor chip C is reduced.

  Accordingly, an object of the present invention is to realize a semiconductor substrate cutting apparatus and a semiconductor substrate cutting method capable of improving the yield of semiconductor chips obtained by dividing the semiconductor substrate.

Invention according to claim 1,
A semiconductor substrate with a sheet bonded to the back substrate surface;
Holding means for holding the outer periphery of the sheet;
Pressing means for pressing the sheet held by the holding means from the back surface,
By pressing the back surface of the sheet by the pressing unit and stretching the sheet held by the holding unit, the semiconductor chip is divided along a dividing line for dividing the semiconductor substrate in its thickness direction. In the semiconductor substrate cutting apparatus to obtain
The pressing means has a technical feature of a semiconductor substrate cutting apparatus that presses only the position corresponding to the planned dividing line on the back surface of the sheet at the same time for the planned divided lines of all the semiconductor chips .

Invention according to claim 2, in the cutting apparatus of the semiconductor substrate according to claim 1, a laser head for irradiating a laser beam, along the cutting-scheduled line, while relatively moving with respect to the semiconductor substrate, A modified region forming means is provided for irradiating a laser beam with a condensing point inside the semiconductor substrate and forming a modified region by multiphoton absorption at the condensing point, and this modified region forming step It is a technical feature that the semiconductor substrate that has undergone the process is divided starting from the modified region.

According to a third aspect of the present invention, in the semiconductor substrate cutting apparatus according to the first or second aspect of the present invention, the semiconductor substrate cutting apparatus includes a vibration unit that applies vibration to the semiconductor substrate.

According to a fourth aspect of the present invention, in the semiconductor substrate cutting apparatus according to any one of the first to third aspects, a heating means for heating the semiconductor substrate is provided.
According to a fifth aspect of the present invention, a semiconductor substrate having a sheet bonded to the back substrate surface is prepared, a holding step for holding the outer periphery of the sheet, and a back surface of the sheet is pressed and held in the holding step. When the semiconductor substrate is obtained by stretching the sheet, the semiconductor substrate is divided along a division line for dividing the semiconductor substrate in the thickness direction, and the position corresponding to the division line on the back surface of the sheet is obtained. The method of dividing a semiconductor substrate includes a dividing step of simultaneously pressing only about the scheduled dividing lines of all semiconductor chips.

According to the first aspect of the invention, in the semiconductor substrate cutting apparatus, the semiconductor substrate is obtained by dividing the semiconductor substrate by pressing the back surface of the sheet to which the semiconductor substrate is bonded by the pressing means and stretching the sheet. Since it is possible to select the location where the back side of the sheet is pressed by the pressing means, it is possible to locally press the position where the stress is generated in the planned dividing line that is difficult to be divided. It can be easily divided by applying stress.
In addition, since the contact area between the sheet and the pressing member is reduced, the sheet can be stretched uniformly without restraining the elongation of the sheet by the frictional force with the pressing member, so that the semiconductor substrate can be easily divided. And the yield of the semiconductor chip can be improved.
Therefore, it is possible to realize a semiconductor substrate cutting apparatus that can improve the yield of semiconductor chips obtained by dividing the semiconductor substrate.

According to the first aspect of the present invention, since the pressing member presses a position corresponding to the planned dividing line on the back surface of the sheet, a bending stress starting from the planned dividing line can be generated in the semiconductor substrate. Therefore, the semiconductor substrate can be easily divided and the yield of the semiconductor chip can be improved.
According to the first aspect of the present invention, the pressing means presses only the position corresponding to the scheduled cutting line on the back surface of the sheet simultaneously with respect to the scheduled cutting lines of all the semiconductor chips, so that the semiconductor chip is quickly divided. it can.

In particular, according to the first aspect of the present invention, as in the second aspect of the present invention, the laser head for irradiating the laser beam is moved relative to the semiconductor substrate along the planned dividing line, and the semiconductor A modified region forming means for forming a modified region by multiphoton absorption is provided at the focused point by irradiating a laser beam with the focused point inside the substrate, and the semiconductor that has undergone this modified region forming step The substrate is suitably used for a substrate having a structure in which the substrate is divided starting from the modified region.
In other words, since the substrate surface on the back surface of the semiconductor substrate can be diced after being bonded to the sheet, the dicing process can be shortened, and dust is not generated during dicing, so there is a risk of dust adhering to the substrate surface of the semiconductor substrate. Absent.

According to the third aspect of the present invention, since the semiconductor substrate cutting apparatus includes the vibration means for applying vibration to the semiconductor substrate, the crack can be propagated to the line to be cut by the physical action of vibration. Since the force required for dividing can be reduced, the semiconductor substrate can be easily divided and the yield of the semiconductor chip can be improved.

According to the invention described in claim 4 , since the semiconductor substrate cutting apparatus includes a heating means for heating the semiconductor substrate, it is possible to apply a thermal stress to the line to be cut, and to apply a force necessary for the cutting. Since the size can be reduced, the semiconductor substrate can be easily divided, and the yield of the semiconductor chip can be improved.
In particular, as in the invention described in claim 4, when the modified region is formed along the planned dividing line, the difference in thermal expansion between the modified region and the unmodified region is large. Since stress is generated, the semiconductor substrate can be easily divided, and the yield of the semiconductor chip can be improved.

A fifth aspect of the present invention is a method of cutting a semiconductor substrate by the semiconductor substrate cutting apparatus according to the first aspect.
Therefore, the invention described in claim 5 can obtain the actions and effects according to the invention described in claim 1 .

[First Embodiment]
A semiconductor substrate cutting apparatus and a cutting method according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing a configuration example of a semiconductor substrate to be cut by the semiconductor substrate cutting apparatus of the present invention. 1A is a plane explanatory view of the surface of the wafer, and FIG. 1B is a cross-sectional view taken along the line 1B-1B in FIG. FIG. 2 is an explanatory view of a cutting apparatus for irradiating a semiconductor substrate with laser light. FIG. 3 is an explanatory diagram of the pressing device according to the first embodiment. 3A is an explanatory view of the pressing device as viewed from above, and FIG. 3B is a cross-sectional view taken along the arrow 1C-1C in FIG. 3A. FIG. 4 is an explanatory diagram of a method for dividing a semiconductor substrate using the pressing device according to the first embodiment, and FIG. 4A is an explanatory diagram of a state before the semiconductor substrate is divided, and FIG. () Is explanatory drawing of the state after the division | segmentation of a semiconductor substrate.
In each figure, a part is enlarged and exaggerated for explanation.

First, as shown in FIG. 1A, a wafer 20 is prepared. The wafer 20 is provided with a thin disk-shaped semiconductor substrate 21 made of silicon, and an orientation flat indicating a crystal orientation is formed on a part of the outer periphery thereof. A plurality of semiconductor chips 22 formed through a diffusion process or the like are arranged on the substrate surface 21a of the semiconductor substrate 21 in a grid pattern. These semiconductor chips 22 are scheduled to be divided by a dicing process. After being divided along the line DL, through a process such as a mounting process, a bonding process, and an enclosing process, a packaged IC or LSI is completed. In the present embodiment, the semiconductor substrate 21 can form a silicon layer that serves as a support substrate for the semiconductor chip 22.
The semiconductor substrate 21 has a rear substrate surface 21b bonded to a stretchable resin sheet 41, and the outer periphery of the sheet 41 is held by an annular frame 42 while the sheet 41 is stretched (holding step). .
As shown in FIG. 1B, six semiconductor chips 22a to 22f are formed on the 1B-1B line. Seven division planned lines DL1 to DL7 are set in the thickness direction of the semiconductor substrate 21, and a modified region serving as a starting point of the division is formed by a method described later.

  As shown in FIG. 2, the cutting apparatus 1 for the semiconductor substrate 21 is provided with a laser head 31 that emits a laser beam L. The laser head 31 includes a condensing lens 32 that condenses the laser light L, and can condense the laser light L at a predetermined focal length. Here, the condensing point P of the laser beam L is set so as to be formed at a depth d from the substrate surface 21 a of the semiconductor substrate 21.

In order to form the modified region K inside the semiconductor substrate 21, first, one of the planned dividing lines DL shown in FIG. 1A is scanned with a laser beam for wafer detection, and FIG. The outer peripheral end 21c shown is detected, and the scanning range of the laser light L is set.
Subsequently, as shown in FIG. 2, the laser head 31 is scanned along the planned division line DL (in the direction of arrow F4 in the figure), and the laser beam L is irradiated from the substrate surface 21a, thereby condensing the laser beam L. The modified region K by multiphoton absorption is appropriately formed in the path of depth d scanned by the point P. By adjusting the depth d of the condensing point P of the laser beam L, the modified region K having an arbitrary number of layers can be formed at an arbitrary depth within the thickness range of the semiconductor substrate 21. For example, when the thickness is relatively thick, the condensing point P is moved in the thickness direction to form the modified region K continuously in the thickness direction or at a plurality of locations, thereby dividing the semiconductor substrate 21. Can be made easier.
Here, multiphoton absorption means that a substance absorbs a plurality of the same or different photons. Due to the multiphoton absorption, a phenomenon called optical damage occurs at the condensing point P of the semiconductor substrate W and in the vicinity thereof, thereby inducing thermal strain, generating cracks in the portion, and a layer in which the cracks are gathered. That is, the modified region K is formed.

  Subsequently, by applying a stress in the in-plane direction of the semiconductor substrate 21, a crack is propagated in the substrate thickness direction starting from the modified region K, and the semiconductor substrate 21 is divided along the planned division line DL. To do. Here, as shown in FIG. 1B, a dividing process for dividing the six semiconductor chips 22a to 22f arranged on the 1B-1B line will be described.

As shown in FIG. 4A, the cutting device 1 for the semiconductor substrate 21 is provided with a pressing device 43 for pressing the back surface of the sheet 41 to cut the semiconductor substrate 21.
As shown in FIG. 3A, on the upper surface of the pressing device 43, a pressing protrusion 44 having a triangular cross section is formed on the surface in contact with the back surface of the sheet 41 at a position corresponding to the division line DL of the semiconductor substrate 21. Is provided. For example, as shown in FIG. 3B, on the 1C-1C line corresponding to the 1B-1B line in FIG. 1A, the pressing protrusions 44a-44g are provided at seven locations corresponding to the division lines DL1-DL7. Is provided.

First, as shown in FIG. 4A, the semiconductor substrate 21 into which the modified region K (FIG. 2) is introduced is conveyed above the pressing device 43 in a state of being bonded to the sheet 41, and the frame 42 is not shown. Fix with fixing means.
Next, as shown in FIG. 4B, when the pressing device 43 is lifted by lifting means (not shown), the pressing protrusions 44a to 44g come into contact with the back side of the semiconductor substrate 21 through the sheet. At this time, the pressing protrusion 44a contacts the lower part of the dividing line DL1, and similarly, the pressing protrusions 44b to 44g contact the lower part of the dividing lines DL2 to DL7.

Subsequently, when the pressing device 43 is further raised, the sheet 41 is stretched upward and expanded in the surface direction of the semiconductor substrate 21, so that a tensile stress is applied to the semiconductor substrate 21 in the surface direction.
At this time, the pressing protrusions 44a to 44f of the pressing device 43 locally press only the planned dividing lines DL1 to DL7. Therefore, the contact area between the sheet 41 and the pressing protrusions 44a to 44f is greatly reduced as compared with the case where the sheet 41 and the pressing protrusions 44a to 44f are pressed, so that the elongation of the sheet 41 is restrained by the frictional force between the pressing protrusions 44a to 44f. The sheet 41 can be stretched uniformly. Therefore, sufficient stress can be applied to the semiconductor chip near the center of the semiconductor substrate 21, for example, the semiconductor chips 22 c and 22 d, so that the semiconductor substrate 21 can be easily divided into the semiconductor chips 22.
Furthermore, when the pressing protrusions 44a to 44f locally press only on the planned split lines DL1 to DL7, bending stress is superimposed on the planned split lines DL1 to DL7 around the contact portions of the pressing protrusions 44a to 44f. Therefore, since it is possible to apply a larger stress to the planned dividing lines DL1 to DL7, it becomes easy to cause cracks to propagate in the planned dividing lines DL1 to DL7, so that the semiconductor substrate 21 can be easily divided into the semiconductor chips 22. it can.

  In the present embodiment, the dicing method of the semiconductor substrate 21 is exemplified by the laser dicing method in which the laser beam L is irradiated from the substrate surface 21a and the modified region K is formed in the semiconductor substrate 21, but the present invention is not limited thereto. It is not a thing. For example, the cutting apparatus 1 according to this embodiment can be applied to a cutting apparatus that cuts the semiconductor substrate 21 by applying stress after forming a notch in the semiconductor substrate 21 with a diamond blade. In addition, the cutting apparatus 1 according to this embodiment can be applied to a cutting apparatus that performs laser dicing after a notch is formed in the semiconductor substrate 21 with a diamond blade, and loads the stress to cut the semiconductor substrate 21.

[Effect of the first embodiment]
(1) Since the pressing device 43 provided in the semiconductor substrate cutting device 1 locally presses the back surface of the sheet 41 bonded to the back surface of the semiconductor substrate 21, it is the back surface of the sheet 41 and is difficult to cut. By locally pressing the position where the stress for dividing the semiconductor chip 22 is generated by the pressing projection 44, the semiconductor chip 22 that is difficult to be divided can be divided by applying sufficient stress.
Further, since the contact area between the sheet 41 and the pressing protrusion 44 is reduced, the elongation of the sheet 41 is not restricted by the frictional force with the pressing device 43, and the sheet 41 can be uniformly stretched. 21 can be easily divided, and the yield of the semiconductor chip 22 can be improved.
Therefore, it is possible to realize the cutting apparatus 1 and the cutting method for the semiconductor substrate 21 that can improve the yield of the division of the semiconductor chip 22 obtained by dividing the semiconductor substrate 21.

(2) Since the pressing device 43 presses the position corresponding to the planned dividing line DL on the back surface of the sheet 41, the semiconductor substrate 21 can generate a bending stress starting from the planned dividing line DL. 21 can be easily divided, and the yield of the semiconductor chip 22 can be improved.

(3) By applying the laser dicing method, the semiconductor substrate 21 can be diced after being bonded to the sheet 41, so that the dicing process can be shortened and dust is not generated during dicing. There is no risk of dust adhering to the surface 21a.

[Second Embodiment]
A second embodiment of a semiconductor substrate cutting apparatus according to the present invention will be described with reference to the drawings. FIG. 5 is an explanatory diagram of a pressing device according to the second embodiment. 5A is an explanatory view of the pressing device as viewed from above, and FIG. 5B is a cross-sectional view taken along the 1D-1D arrow in FIG. 3A. FIG. 6 is an explanatory diagram of a semiconductor substrate dividing method using the pressing device according to the second embodiment, and FIG. 6A is an explanatory diagram of a state before the semiconductor substrate 21 is divided, and FIG. ) Is an explanatory diagram of a state after the semiconductor substrate 21 is divided.
In addition, about the structure similar to 1st Embodiment, while using the same code | symbol, description is abbreviate | omitted.

  As shown in FIG. 5A, on the upper portion of the pressing device 43, pin-like pressing members 45 are erected upward at positions corresponding to the central portion of the semiconductor chip 22, respectively. For example, as shown in FIG. 5 (B), the pressing members 45a to 45f are provided at six locations on the 1D-1D line corresponding to the 1B-1B line in FIG. ing.

First, as shown in FIG. 6A, the semiconductor substrate 21 on which the modified region K (FIG. 2) is formed is arranged above the pressing device 43 by the same method as in the first embodiment, and the frame 42 is fixed.
Next, as shown in FIG. 6B, when the pressing device 43 is lifted by a lifting / lowering means (not shown), the pressing members 45 a to 45 f come into contact with the back side of the semiconductor substrate 21 through the sheet 41. At this time, the pressing member 45a abuts below the central portion of the bottom surface of the semiconductor chip 22a, and similarly, the pressing members 45b to 45f abut below the central portion of the semiconductor chips 22b to 22f, respectively.

Subsequently, when the pressing device 43 is further raised, the sheet 41 is stretched upward and expanded in the surface direction of the semiconductor substrate 21, so that a tensile stress is applied to the semiconductor substrate 21 in the surface direction. At this time, the pressing members 45a to 45f of the pressing device 43 locally press only below the central portions of the semiconductor chips 22a to 22f.
Therefore, each semiconductor chip 22a to 22f can be appropriately loaded with a stress necessary for dividing, and a bending stress can be generated on the semiconductor substrate 21 from the central portion of the semiconductor chips 22a to 22f. Therefore, the semiconductor chips 22a to 22f can be easily divided. The semiconductor substrate 21 can be easily divided into semiconductor chips 22.

In this embodiment, although the pressing member 45 was fixed to the upper part of the pressing device 43 and the structure which presses the semiconductor substrate 21 when the pressing device 43 raises was illustrated, it is not limited to this. For example, each of the pressing members 45 may include a linear motion mechanism such as a motor and can be moved up and down individually.
In addition, the pressing members 45 may each be provided with a moving mechanism in the horizontal direction, and the arrangement may be variable. When this configuration is used, the arrangement of the pressing members 45 can be changed in accordance with the arrangement of the semiconductor chips 22, so that the single pressing device 43 can cope with the division of various semiconductor chips.

[Effects of Second Embodiment]
The pressing device 43 provided in the semiconductor substrate cutting device 1 presses a position corresponding to the center portion of the semiconductor chip 22 on the back surface of the sheet 41 bonded to the back surface of the semiconductor substrate 21, and is necessary for cutting. The stress can be appropriately applied to each semiconductor chip 22, and the bending stress starting from the central portion of the semiconductor chip 22 can be generated in the semiconductor substrate 21, so that the semiconductor substrate 21 can be easily divided. In addition, the yield of the semiconductor chip 22 can be improved.

[Third Embodiment]
A third embodiment of a semiconductor substrate cutting apparatus according to the present invention will be described with reference to the drawings. FIG. 7 is an explanatory diagram of a semiconductor substrate dividing method using the pressing device according to the third embodiment, and FIG. 7A is an explanatory diagram of a state before the semiconductor substrate 21 is divided, and FIG. B) is an explanatory diagram of a process of dividing the semiconductor chips 22c and 22d, FIG. 7C is an explanatory diagram of a process of dividing the semiconductor chips 22b and 22e, and FIG. 7D is a schematic diagram of the semiconductor chips 22a and 22f. It is explanatory drawing of the process to part.
In addition, about the structure similar to 1st Embodiment, while using the same code | symbol, description is abbreviate | omitted.

  As shown in FIG. 7A, at the upper part of the pressing device 43, the pin-like pressing members 46a to 46f are closer to the central part of the semiconductor substrate 21 at positions corresponding to the central part of the semiconductor chips 22a to 22f. Each is provided so as to have a high height. That is, the pressing members 46c and 46d closest to the central portion of the semiconductor substrate 21 are formed highest, the pressing members 46b and 46e are next highest, and the pressing members 46a and 46f are lowest.

  Next, as shown in FIG. 7B, when the pressing device 43 is raised by a moving means (not shown), only the pressing members 46 c and 46 d closest to the central portion of the semiconductor substrate 21 are exposed from the back side of the semiconductor substrate 21. The semiconductor chips 22c and 22d are respectively in contact with the lower part of the central part and pressed locally. As a result, stress is concentrated on the planned dividing lines DL3 to DL5, so that the semiconductor chips 22c and 22d in the vicinity of the central portion that are difficult to be divided can be preferentially divided.

  Subsequently, when the pressing device 43 is further raised, as shown in FIG. 7C, the pressing members 46b and 46e come into contact with the lower part of the semiconductor chips 22b and 22e from the back side of the semiconductor substrate 21, respectively. , Press locally. As a result, stress is concentrated on the dividing lines DL2 and DL6, so that only the semiconductor chips 22b and 22e are divided.

When the pressing device 43 is further raised, as shown in FIG. 7D, the pressing members 46a and 46f come into contact with the lower side of the semiconductor chip 22a and 22f from the back side of the semiconductor substrate 21, respectively. Press on. As a result, stress is concentrated on the planned dividing lines DL1 and DL7, so that the semiconductor chips 22a and 22f are divided.
That is, the pressing members 46a to 46f provided in the pressing device 43 press in order from the central direction of the semiconductor substrate 21 toward the outer peripheral direction, and divide the semiconductor chips 22a to 22f in order from the central direction toward the outer peripheral direction. To do.

  In this embodiment, although the pressing member 46 illustrated the structure fixed to the upper part of the press apparatus 43, it is not limited to this. For example, the pressing member 46 may be provided with elevating means that moves up and down individually, and a configuration that is set to a predetermined height may be used.

[Effect of the third embodiment]
The pressing device 43 provided in the semiconductor substrate cutting device 1 presses a predetermined position on the back surface of the sheet 41 bonded to the back surface of the semiconductor substrate 21 in order from the center direction of the semiconductor substrate 21 toward the outer peripheral direction. Therefore, since the semiconductor chips 22c and 22d in the vicinity of the central portion of the semiconductor substrate 21 that is difficult to be divided can be preferentially divided, the semiconductor substrate 21 can be easily divided and the yield of the semiconductor chips 22 can be improved. Can do.
It should be noted that the same effect can be obtained when using a configuration in which the pressing protrusion 44 of the first embodiment is provided so that the height becomes higher as it is closer to the central portion of the semiconductor substrate 21.

[Fourth Embodiment]
A fourth embodiment of a semiconductor substrate cutting apparatus according to the present invention will be described with reference to the drawings. FIG. 8 is an explanatory diagram of a method for dividing a semiconductor substrate using the pressing device according to the fourth embodiment, and FIG. 8A is an explanatory diagram of a state before the semiconductor substrate 21 is divided, and FIG. B) is an explanatory diagram of a process of dividing the semiconductor chips 22c and 22d, FIG. 8C is an explanatory diagram of a process of dividing the semiconductor chips 22b and 22e, and FIG. 8D is a schematic diagram of the semiconductor chips 22a and 22f. It is explanatory drawing of the process to part.
In addition, about the structure similar to 1st Embodiment, while using the same code | symbol, description is abbreviate | omitted.

  As shown in FIG. 8 (A), pin-like pressing members 47a to 47f are individually provided at the top of the pressing device 43 at positions corresponding to the central portions of the semiconductor chips 22a to 22f. It has been.

  First, as shown in FIG. 8B, when the pressing device 43 is raised by a moving means (not shown), only the pressing members 47 c and 47 d closest to the central portion of the semiconductor substrate 21 are raised, and the back surface of the semiconductor substrate 21 is From the side, the semiconductor chips 22c and 22d are respectively in contact with the lower part of the central part and pressed locally. As a result, stress is concentrated on the planned dividing lines DL3 to DL5, so that the semiconductor chips 22c and 22d in the vicinity of the central portion that are difficult to be divided can be preferentially divided.

  Subsequently, as shown in FIG. 8C, the pressing members 47b and 47e are moved upward, abut on the lower side of the semiconductor chip 22b and 22e from the back side of the semiconductor substrate 21, respectively, and press locally. As a result, stress is concentrated on the dividing lines DL2 and DL6, so that only the semiconductor chips 22b and 22e are divided.

Further, as shown in FIG. 8D, the pressing members 47a and 47f are lifted and come into contact with the lower side of the central portion of the semiconductor chips 22a and 22f from the back side of the semiconductor substrate 21 to press locally. As a result, stress is concentrated on the planned dividing lines DL1 and DL7, so that the semiconductor chips 22a and 22f are divided.
That is, the pressing members 47a to 47f provided in the pressing device 43 rise in order from the center direction of the semiconductor substrate 21 toward the outer peripheral direction, and press the positions corresponding to the central portions of the semiconductor chips 22a to 22f. Then, the semiconductor chips 22a to 22f are divided in order from the central direction toward the outer peripheral direction.
Here, since the semiconductor chip in the center direction previously divided is held by the pressing member from the back surface, the sheet 41 is stably held horizontally, so that when the semiconductor chip in the outer peripheral direction is divided, cracks occur. Can be improved, and the yield of the semiconductor chip 22 can be improved.

[Effect of Fourth Embodiment]
The pressing device 43 provided in the semiconductor substrate cutting device 1 presses a predetermined position on the back surface of the sheet 41 bonded to the back surface of the semiconductor substrate 21 in order from the center direction of the semiconductor substrate 21 toward the outer peripheral direction. Therefore, since the semiconductor chips 22c and 22d in the vicinity of the central portion of the semiconductor substrate 21 that is difficult to be divided can be preferentially divided, the semiconductor substrate 21 can be easily divided and the yield of the semiconductor chips 22 can be improved. Can do.
The same effect can also be obtained when the pressing protrusions 44 of the first embodiment are configured to be individually moved up and down and pressed in order from the center direction of the semiconductor substrate 21 toward the outer peripheral direction.

[Fifth Embodiment]
A fifth embodiment of a semiconductor substrate cutting apparatus according to the present invention will be described with reference to the drawings. FIG. 9 is an explanatory diagram of a method for dividing a semiconductor substrate using the pressing device according to the fifth embodiment. FIG. 9A is an explanatory diagram of a state before the semiconductor substrate 21 is divided, and FIG. B) is an explanatory diagram of a process of dividing the semiconductor chips 22a and 22f, FIG. 9C is an explanatory diagram of a process of dividing the semiconductor chips 22b and 22e, and FIG. 9D is a schematic diagram of the semiconductor chips 22c and 22d. It is explanatory drawing of the process to part.
In addition, about the structure similar to 1st Embodiment, while using the same code | symbol, description is abbreviate | omitted.

  As shown in FIG. 9A, as in the fourth embodiment, pin-like pressing members 47a to 47f are individually provided on the upper portion of the pressing device 43 at positions corresponding to the central portions of the semiconductor chips 22a to 22f. Are provided so that they can be moved up and down.

First, as shown in FIG. 9B, when the pressing device 43 is raised by a moving means (not shown), only the outermost pressing members 47 a and 47 f of the semiconductor substrate 21 are raised, and the back surface side of the semiconductor substrate 21. To the lower part of the central part of the semiconductor chips 22a and 22f, respectively, and press locally. Thereby, stress is concentrated on the planned dividing lines DL1, DL2, DL6, and DL7, so that the semiconductor chips 22c and 22d in the vicinity of the outer peripheral portion can be preferentially divided.
At this time, since the semiconductor chips 22a and 22f in the outer peripheral direction of the semiconductor substrate 21 are surely divided, the sheet 41 is not excessively stretched and no force is applied to the central portion.

  Subsequently, as shown in FIG. 9C, the pressing members 47a and 47f are lowered, and the pressing members 47b and 47e are raised so that the lower side of the semiconductor substrate 21 is below the central portion of the semiconductor chips 22b and 22e. Each abuts and presses locally. As a result, stress is concentrated on the division lines DL3 and DL5, so that only the semiconductor chips 22b and 22e are divided.

Subsequently, as shown in FIG. 9D, the pressing members 47b and 47e are lowered, and the pressing members 47c and 47d are raised to the lower side of the semiconductor substrate 22c and 22d from the back side of the semiconductor substrate 21. Each abuts and presses locally. As a result, stress is applied to the division line DL4, so that the semiconductor chips 22c and 22d are divided.
That is, the pressing members 47a to 47f provided in the pressing device 43 rise in order from the outer peripheral direction of the semiconductor substrate 21 toward the central direction, and press the positions corresponding to the central portions of the semiconductor chips 22a to 22f. Then, the semiconductor chips 22a to 22f are divided in order from the outer peripheral direction toward the central direction.

[Effect of Fifth Embodiment]
The pressing device 43 provided in the semiconductor substrate cutting apparatus 1 presses a predetermined position on the back surface of the sheet 41 bonded to the back surface of the semiconductor substrate 21 in order from the outer peripheral direction of the semiconductor substrate 21 toward the central direction. Therefore, since the semiconductor chip 22 is surely divided from the semiconductor chip 22 in the outer peripheral direction of the semiconductor substrate 21, even when the semiconductor chip 22 that is difficult to be divided exists in the vicinity of the outer periphery of the semiconductor substrate 21, the sheet 41 is excessively stretched. No force is applied to the center of 21. Therefore, the semiconductor substrate 21 can be easily divided, and the yield of the semiconductor chips 22 can be improved.

[Other Embodiments]
(1) When the back surface of the sheet 41 is pressed by the pressing device 43, vibration may be applied to the semiconductor substrate 21 using a vibrating means such as an ultrasonic vibrator. When this configuration is used, cracks can be propagated from the modified region K by the physical action of vibration, and the force required for division can be reduced, so that the semiconductor substrate 21 can be easily divided. The yield of the semiconductor chip 22 can be improved.

(2) When the back surface of the sheet 41 is pressed by the pressing device 43, the semiconductor substrate 21 may be heated using a heating means such as a heater. When this configuration is used, a thermal stress can be applied to the modified region K, and the force necessary for the division can be reduced. Therefore, the semiconductor substrate 21 can be easily divided, and the semiconductor chip 22 can be divided. Yield can be improved.

(3) Although the semiconductor substrate made of only silicon is used as the semiconductor substrate 21, the application of the present invention is not limited to this. For example, an oxide film made of silicon oxide is used as the substrate surface of the semiconductor substrate 21. The present invention can also be applied to those formed in 21a and SOI (Silicon On Insulator) wafers.

[Correspondence between each claim and embodiment]
The frame 42 corresponds to the holding means according to claim 1, and the pressing device 43 , the pressing protrusions 44 (44 a to 44 f), the pressing members 45 a to 45 f, 46 a to 46 f, and 47 a to 47 f correspond to the pressing means, respectively.

FIG. 1A is an explanatory plan view of the surface of a wafer, and FIG. 1B is an enlarged cross-sectional view taken along the line 1B-1B in FIG. It is explanatory drawing of the cutting device which irradiates a semiconductor substrate with a laser beam. It is explanatory drawing of a press apparatus. 3A is an explanatory view of the pressing device as viewed from above, and FIG. 3B is a cross-sectional view taken along the arrow 1C-1C in FIG. 3A. FIG. 4A is an explanatory diagram of a method for dividing a semiconductor substrate using the pressing device according to the first embodiment, FIG. 4A is an explanatory diagram of a state before the semiconductor substrate is divided, and FIG. It is explanatory drawing of the state after the division | segmentation of a board | substrate. It is explanatory drawing of the press apparatus which concerns on 2nd Embodiment. 5A is an explanatory view of the pressing device as viewed from above, and FIG. 5B is a cross-sectional view taken along the 1D-1D arrow in FIG. 5A. FIG. 6A is an explanatory diagram of a semiconductor substrate dividing method using the pressing device according to the second embodiment, FIG. 6A is an explanatory diagram of a state before the semiconductor substrate 21 is divided, and FIG. It is explanatory drawing of the state after parting of the semiconductor substrate. FIG. 7A is an explanatory diagram of a method for dividing a semiconductor substrate using the pressing device according to the third embodiment, FIG. 7A is an explanatory diagram of a state before the semiconductor substrate 21 is divided, and FIG. 7C is an explanatory diagram of a process of dividing the semiconductor chips 22c and 22d, FIG. 7C is an explanatory diagram of a process of dividing the semiconductor chips 22b and 22e, and FIG. 7D is a process of dividing the semiconductor chips 22a and 22f. It is explanatory drawing. FIG. 8A is an explanatory diagram of a semiconductor substrate dividing method using the pressing device according to the fourth embodiment, FIG. 8A is an explanatory diagram of a state before the semiconductor substrate 21 is divided, and FIG. 8C is an explanatory diagram of a process of dividing the semiconductor chips 22c and 22d, FIG. 8C is an explanatory diagram of a process of dividing the semiconductor chips 22b and 22e, and FIG. 8D is a process of dividing the semiconductor chips 22a and 22f. It is explanatory drawing. FIG. 9A is an explanatory diagram of a method for dividing a semiconductor substrate using the pressing device according to the fifth embodiment, FIG. 9A is an explanatory diagram of a state before the semiconductor substrate 21 is divided, and FIG. 9C is an explanatory diagram of a process of dividing the semiconductor chips 22a and 22f, FIG. 9C is an explanatory diagram of a process of dividing the semiconductor chips 22b and 22e, and FIG. 9D is a process of dividing the semiconductor chips 22c and 22d. It is explanatory drawing. FIG. 10A is an explanatory view of a conventional semiconductor substrate cutting apparatus, and FIG. 10A is an explanatory view showing a state in which the semiconductor substrate is bonded to a sheet and the outer peripheral portion of the sheet is held by a frame. ) Is an explanatory diagram of a process of dividing a semiconductor substrate into semiconductor chips by a pressing device.

Explanation of symbols

1 Cutting device 21 Semiconductor substrate 22 Semiconductor chip 31 Laser head 41 Sheet 42 Frame (holding means)
43 Pressing device (pressing means)
44 (44a-44f) Pressing protrusion (Pressing means)
45a-45f, 46a-46f, 47a-47f Pressing member (pressing means)
DL Divided line K Modified region L Laser beam P Condensing point

Claims (5)

A semiconductor substrate with a sheet bonded to the back substrate surface;
Holding means for holding the outer periphery of the sheet;
Pressing means for pressing the sheet held by the holding means from the back surface,
By pressing the back surface of the sheet by the pressing unit and stretching the sheet held by the holding unit, the semiconductor chip is divided along a dividing line for dividing the semiconductor substrate in its thickness direction. In the semiconductor substrate cutting apparatus to obtain
The semiconductor substrate cutting apparatus according to claim 1, wherein the pressing means presses only the position corresponding to the scheduled cutting line on the back surface of the sheet locally and simultaneously on the planned cutting lines of all the semiconductor chips. In the semiconductor substrate cutting device according to claim 1 ,
A laser head that irradiates a laser beam is moved relative to the semiconductor substrate along the planned dividing line, and the laser beam is irradiated with a laser beam that is focused on the inside of the semiconductor substrate. And a modified region forming means for forming a modified region by multiphoton absorption is provided, and the semiconductor substrate that has undergone the modified region forming step is divided starting from the modified region. Semiconductor substrate cutting device. In the semiconductor substrate cutting device according to claim 1 or 2 ,
A semiconductor substrate cutting apparatus comprising a vibrating means for applying vibration to the semiconductor substrate. In the semiconductor substrate cutting device according to any one of claims 1 to 3 ,
A semiconductor substrate cutting apparatus comprising heating means for heating the semiconductor substrate. Prepare a semiconductor substrate with a sheet bonded to the back substrate surface,
A holding step for holding the outer periphery of the sheet;
When a semiconductor chip is obtained by pressing the back surface of the sheet and stretching the sheet held in the holding step to divide the semiconductor substrate along a dividing line for dividing the semiconductor substrate in its thickness direction. A cutting method for a semiconductor substrate, comprising: a step of locally pressing only a position corresponding to the planned cutting line on the back surface of the sheet, simultaneously with respect to the planned cutting lines of all semiconductor chips.

Images