JP2007103870A - Wafer processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer processing method in which burr formation itself can be suppressed without a special device nor processing stage as measures against burrs of a semiconductor chip with an adhesive film. <P>SOLUTION: The wafer processing method includes the stages of sticking the adhesive film 3 to the reverse surface of a wafer W in a specified sticking direction by using a sticking device while moving the wafer W in one direction, and cutting and dividing the wafer W on which the adhesive film 3 is stuck in a grating shape into a plurality of chips C with adhesive films 3 by using a cutting device 20. In the sticking stage, the adhesive film 3 is stuck on the reverse surface of the wafer W so that the sticking direction of the adhesive film 3 is nearly parallel to a street 31 in one direction on the top surface of the wafer W. In the cutting stage, a street 32 which is nearly orthogonal to the sticking direction of the adhesive film 3 is cut after the street 31 is cut which is nearly parallel to the sticking direction of the adhesive film 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wafer processing method, and more particularly, to a wafer processing method in which an adhesive film for die bonding is attached to the back surface.

Conventionally, in a die bonding process of a semiconductor chip divided by a dicing process, the semiconductor chip is bonded to a base such as a lead frame using a resin paste or the like as a die bonding material. However, with such a method, the semiconductor chip is tilted and bonded, or the resin paste protrudes from the edge of the semiconductor chip, so that die bonding cannot be performed with high accuracy, and the thickness control of the adhesive layer is difficult. There was a problem.

  For this reason, in recent years, a technique using a semiconductor chip in which an adhesive film for die bonding, that is, a so-called DAF (die attach film) is attached in advance to the back surface is becoming widespread. Since this DAF has a substantially uniform thickness and is easy to control the thickness, the semiconductor chip can be die-bonded with high accuracy.

  However, since the original semiconductor chip with DAF was manufactured by bonding the DAF cut according to the size of the semiconductor chip to the back surface of the semiconductor chip, it could not cope with small semiconductor chips and the productivity was also very high. There was a problem of being low.

  From such a problem, Patent Document 1 proposes a method in which DAF is bonded to the back surface of a semiconductor wafer by thermocompression bonding, and DAF and the semiconductor wafer are simultaneously diced. According to this method, DAF can be easily attached to a semiconductor wafer, and any chip size can be easily accommodated.

  However, in the above-described conventional method for manufacturing a semiconductor chip with DAF, as shown in FIG. 6A, the wafer W and the DAF 3 attached to the back surface of the wafer W are simultaneously applied by the cutting means such as the cutting blade 1. When cut and divided into a plurality of semiconductor chips C with DAF3, the cut surface of DAF3 does not become a smooth surface, but as shown in FIG. There was a problem that a large number of burrs 5 were generated.

  When this burr 5 exists, as shown in FIG. 7A, when the semiconductor chip C with DAF 3 is picked up and picked up by the collet 7 which is a holding means corresponding to the shape of the semiconductor chip C to be picked up, Since it is obstructed by the burr 5 extending above the semiconductor chip C, there is a problem that the semiconductor chip C cannot be suitably held by the collet 7 and cannot be picked up. Furthermore, as shown in FIG. 7B, when the semiconductor chip C with DAF 3 is wire-bonded, the burrs 5 extending to the side come into contact with the wire-bonding pads, so that wire bonding can be suitably performed. There was also a problem of being unable to do so.

  In order to solve these problems, Patent Document 2 proposes a technique for reducing the size of the burrs by heat shrinking by heating the burrs generated in the semiconductor chip with DAF.

Japanese Patent Laid-Open No. 11-219962 JP 2004-79597 A

  However, the burr countermeasure method described in Patent Document 2 requires a separate heat treatment apparatus and requires a long time for the heat treatment process, which reduces the productivity of semiconductor chips with DAF. It was. Further, since the above-described burr countermeasure method has no effect of suppressing the burr generation itself, a method capable of fundamentally solving the burr generation has been demanded.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to prevent the occurrence of burrs without requiring a separate apparatus or processing steps as a countermeasure against burrs in a semiconductor chip with an adhesive film. It is an object of the present invention to provide a new and improved wafer processing method capable of suppressing itself.

  In order to solve the above problems, according to one aspect of the present invention, an adhesive film for die bonding is attached to the back surface of a wafer having a plurality of semiconductor elements formed on the surface, and the wafer having the adhesive film attached thereto is attached. A wafer processing method is provided in which a wafer is cut into a lattice shape together with an adhesive film and divided into a plurality of chips with an adhesive film. This wafer processing method uses a sticking apparatus that gradually presses and attaches an adhesive film from the front side to the rear side in the wafer moving direction while moving the wafer in one direction. An attaching step of attaching an adhesive film to the back surface in a predetermined attaching direction; and a wafer attached with the adhesive film using a cutting device that cuts two orthogonal streets on the surface of the wafer with a cutting blade, Cutting with an adhesive film in a lattice shape and dividing into a plurality of chips with adhesive film. In the attaching step, the adhesive film is attached to the back surface of the wafer so that one of the two directions on the surface of the wafer is substantially parallel to the attaching direction of the adhesive film. . Moreover, in the said cutting process, after cutting | disconnecting the street of a direction substantially parallel with the sticking direction of an adhesive film, the street of the direction substantially orthogonal to the sticking direction of an adhesive film is cut | disconnected.

  In the wafer processing method having such a configuration, the sticking device attaches the adhesive film so that the sticking direction of the adhesive film to the wafer is substantially parallel to the direction of one street on the surface of the wafer, and then uses the cutting device to When the wafer with the adhesive film attached is cut into a lattice shape, the wafer is first cut from the streets that are substantially parallel to each other. Thereby, the damage given to the adhesive film can be minimized by cutting the adhesive film in parallel with the direction of the strongest tensile stress acting on the adhesive film. Therefore, the generation | occurrence | production of the burr | flash which generate | occur | produces when cut | disconnecting an adhesive film can be reduced. Therefore, as a countermeasure against burrs in a semiconductor chip with an adhesive film, it is possible to suppress the occurrence of burrs during cutting without using a separate device or processing step.

  As described above, according to the present invention, when the wafer to which the adhesive film is attached is cut, damage to the adhesive film can be reduced, so that occurrence of burrs can be reduced. Therefore, as a countermeasure against burrs in the semiconductor chip with an adhesive film, no separate device or processing step is required, and the occurrence of burrs can be suppressed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
The wafer processing method according to the first embodiment of the present invention will be described below. In the wafer processing method according to the present embodiment, first, a DAF (Die Attach Film), which is an adhesive film for die bonding, is pasted in a predetermined pasting direction on the back surface of the wafer with a pasting device (paste). Process). Next, the semiconductor wafer to which the DAF is attached is cut into a lattice shape by a cutting device provided with a cutting blade and divided into semiconductor chips with DAF (cutting step).

  At this time, in the attaching step, the DAF is attached to the back surface of the wafer in the attaching direction parallel to the one-way street among the two orthogonal streets of the wafer. In the cutting step, first, a street in a direction parallel to the sticking direction is cut, and then a street in a direction orthogonal to the sticking direction is cut. Therefore, in the following, the configuration of the sticking device and the cutting device and the wafer processing method for manufacturing the semiconductor chip with DAF using the sticking device and the cutting device will be described in detail.

  First, with reference to FIGS. 1-3, the structure and operation | movement of the sticking apparatus 10 concerning this embodiment are demonstrated. FIG. 1 is a front view showing the configuration of the sticking device 10 according to the present embodiment. FIG. 2 is a bottom view (a) showing the DAF 3 held on the base tape 16 and a plane showing the wafer W placed on the movable base 12 in the sticking apparatus 10 according to the present embodiment. FIG. 3 is an enlarged cross-sectional view (a) showing a state in which DAF 3 is attached to the back surface of the wafer W by the attaching device 10 according to the present embodiment, and an enlarged view showing the wafer W in which DAF 3 is attached to the back surface. It is sectional drawing (b).

  As shown in FIG. 1, the sticking device 10 is a device for sticking DAF 3, which is an adhesive film for die bonding, to the back surface of the semiconductor wafer W.

  The semiconductor wafer W is, for example, a silicon wafer having a substantially disk shape, and has an outer diameter of, for example, 6, 8, 10 inches, and a thickness of, for example, 50 μm. In the following, the surface of the semiconductor wafer W refers to the circular flat surface on the side where the semiconductor elements (circuits) are formed, and the back surface of the semiconductor wafer W refers to the circular flat surface on the side opposite to the above surface. Shall. The definition of the front surface and the back surface is the same for the semiconductor chips formed by cutting the semiconductor wafer W.

  As shown in FIG. 2B, a plurality of semiconductor elements (not shown) are formed on the surface of the wafer W, and a plurality of streets (scheduled cutting lines) are formed between the plurality of semiconductor elements. ) 31, 32 are arranged in a grid pattern. The streets 31 and 32 extend in directions orthogonal to each other.

  The DAF 3 is a film adhesive (double-sided adhesive film) for die-bonding the semiconductor chip into which the wafer W is divided. The DAF 3 is mainly made of, for example, a polyimide resin, an acrylic resin, or an epoxy resin. The DAF 3 is formed so as to be a circular film having an outer diameter approximately equal to the diameter of the wafer W. Further, the thickness of the DAF 3 is, for example, about 50 μm, and can be set to the same level as the wafer W. For example, a cover film or a carrier film is not attached to the DAF 3.

  For example, as shown in FIG. 1, the sticking device 10 includes a moving base 12 on which a wafer W is placed with the back surface facing upward, and a moving mechanism (not shown) that moves the moving base 12 in a predetermined direction. And a base tape 16 suspended between the feed roller 13, the pressure roller 14, and the take-up roller 15.

  The movable base 12 is a support base whose upper surface is a flat surface, and supports the wafer W placed thereon. As shown in FIGS. 1A and 2B, an annular ring frame 4 larger than the outer diameter of the wafer W is provided around the wafer W placed on the movable base 12. And placed on a concentric circle with a gap. The ring frame 4 is a frame that supports the wafer W via a dicing tape 6. The thickness of the ring frame 4 is about the same as the sum of the thickness of the wafer W (for example, 50 μm) and the thickness of the DAF 3 (for example, 50 μm) (for example, about 100 μm).

  The moving base 12 can be moved horizontally in a predetermined direction (X-axis direction) by the moving mechanism. Thereby, the wafer W mounted on the support base 12 can be horizontally moved in the one direction.

  Further, when the wafer W is placed on the support base 12 as described above, one of the streets 31 and 32 in two directions orthogonal to each other on the surface of the wafer W, and the moving base The wafer W is arranged so that the twelve movement directions are parallel to each other. As a result, the direction of DAF 3 to be described later and the direction of the street 31 coincide.

  The feed roller 13, the pressure roller 14, and the take-up roller 15 are disposed above the moving base 12. Among these, the feed roller 13 for feeding the base tape 16 and the take-up roller 15 for winding the base tape 16 are disposed relatively above, and the pressure roller 14 presses the base tape 16 toward the wafer W. Is arranged at the bottom.

  With this configuration, the base tape 16 can be moved in substantially the same direction as the moving direction of the moving base 12. At this time, the base tape 16 delivered from the delivery roller 13 is directed downward as it approaches the pressure roller 14, protrudes downward at the lower end position of the pressure roller 14, and then upwards as it approaches the take-up roller 15. , And finally, it is wound around the winding roller 15.

  As shown in FIGS. 1A and 2A, a dicing tape 6 having a larger circle than DAF 3 and a concentric circle are pasted on the dicing tape 6 on the lower surface of the base tape 16. DAF3 is held. At this time, for example, the dicing tape 6 is held on the base tape 16 by the adhesive force of the base tape 16, and the DAF 3 is held on the dicing tape 6 by the adhesive force of the dicing tape 6 and DAF 3. The dicing tape 6 is an adhesive tape for holding the wafer W during dicing. For example, an ultraviolet curable adhesive tape can be used.

  By moving the wafer W in one direction (X-axis direction) by the moving base 12 by the sticking apparatus 10 having the above-described configuration, the DAF 3 is moved in the same direction as the wafer W by the base tape 16. The DAF 3 is gradually pressed against the rear surface of W from the front side to the rear side in the moving direction, and the same sticking direction as one of the two streets 31 and 32 of the wafer W (the moving direction and the moving direction). DAF3 can be pasted in the same direction). Hereinafter, the DAF 3 sticking operation (that is, the sticking step in the wafer processing method according to the present embodiment) by the sticking apparatus 10 will be described in detail.

First, as shown in FIG. 1 (a), the wafer W and the ring frame 4 are placed on the support base 12, and the DAF 3 is placed on the lower surface of the base tape 16 positioned above it via the dicing tape 6. paste. At this time, as shown in FIG. 2B, the wafer W is placed on the moving base 12 so that one street 31 of the wafer W and the moving direction (X-axis direction) of the moving base 12 are parallel to each other. Is placed.
Next, as shown in FIG. 1A, the moving base 12 is moved in a predetermined direction (X-axis direction) by the moving mechanism to move the wafer W horizontally, and the feed roller 13 and the take-up roller 15 are rotated. Accordingly, the base tape 16 is moved in the same direction as the moving base 12 and the dicing tape 6 and the DAF 3 are conveyed. The moving speed of the moving base 12 and the moving speed of the base tape 16 are adjusted to such a speed that the wafer W and the DAF 3 are in contact with each other under the pressure roller 14.

  As a result, the wafer W on the movable base 12 is positioned at the lower part of the pressure roller 14, and the DAF 3 on the base tape 16 is positioned at the lower end of the pressure roller 14. As a result, as shown in FIG. 3A, the pressure roller 14 causes the DAF 3 on the base tape 16 to move in the moving direction of the moving base 12 with respect to the back surface of the wafer W on the support base 12. The DAF 3 is gradually affixed from the front end side to the rear end side in the X-axis direction on the back surface of the wafer W. As shown in FIG. 1 (a), when the movable base 12 has sufficiently moved past the lower part of the pressure roller 14, the DAF 3 and the dicing tape 6 are completely separated from the base tape 16, As shown in FIG. 3B, the DAF 3 is attached to the back surface of the wafer W, and the outer peripheral portion of the dicing tape 6 is attached to the ring frame 4.

  As described above, in the pasting process using the pasting apparatus 10, the DAF 3 is pasted on the back surface of the wafer W so that the direction of any one street 31 of the wafer W and the pasting direction of the DAF 3 are parallel to each other. Attached.

  Next, with reference to FIG. 4, the structure and operation | movement of the cutting device 20 concerning this embodiment are demonstrated. FIG. 4 is a front view showing the configuration and operation of the cutting device 20 according to the present embodiment.

  As shown in FIG. 4, the cutting apparatus 20 includes, for example, a chuck table 21 that holds the wafer W, a cutting unit 23 that cuts the wafer W, and a cutting unit movement that moves the cutting unit 23 in the Y and Z-axis directions. A mechanism (not shown) and a chuck table moving mechanism (not shown) for cutting and feeding the chuck table 21 in the cutting direction (X-axis direction) are mainly provided.

  The wafer W is placed on the chuck table 21 with the front side facing upward while being supported by the frame 4 via the DAF 3 and the dicing tape 6 attached to the back side as described above.

  The chuck table 21 is, for example, a disk-shaped table whose upper surface is substantially flat, and has a vacuum chuck (not shown) on its upper surface. The chuck table 21 stably holds the wafer W placed on the vacuum chuck by vacuum suction.

  The cutting unit 23 includes a cutting blade 22 attached to the tip of the spindle 24. The cutting blade 22 is an extremely thin ring-shaped cutting grindstone formed by bonding abrasive grains such as diamond with a bonding material. As shown in FIG. 4B, the cutting unit 23 cuts the streets 31 and 32 of the wafer W by cutting a cutting blade 22 rotated at a high speed by a spindle 24 into the wafer W, thereby making it extremely thin. A kerf is formed.

  The cutting unit moving mechanism moves the cutting unit 23 in the Y-axis direction. The Y-axis direction is a horizontal direction orthogonal to the cutting direction (X-axis direction), and coincides with the axial direction of the spindle 24 extended in the cutting unit 23. The cutting edge of the cutting blade 22 can be aligned with the streets 31 and 32 of the wafer W by moving the cutting unit 23 in the Y-axis direction. Further, this cutting unit moving mechanism moves the cutting unit 23 also in the Z-axis direction (vertical direction). Thereby, the cutting depth of the cutting blade 22 with respect to the wafer W can be adjusted.

  The chuck table moving mechanism reciprocates the chuck table 21 holding the wafer W in the cutting direction (X-axis direction) during the cutting process, and causes the cutting edge of the cutting blade 22 to act on the wafer W along a linear locus. Further, the chuck table moving mechanism can rotate the chuck table 21 in a horizontal plane around a rotation axis extending in the vertical direction through the center of the chuck table 21 by a motor (not shown). As a result, the wafer W held on the chuck table 21 also rotates about the rotation axis.

  The cutting apparatus 20 configured as described above is arranged in a lattice pattern on the surface of the wafer W by moving the cutting unit 23 and the chuck table 21 relative to each other while cutting the cutting blade 22 rotating at high speed into the wafer W. Along the plurality of streets 31, 32, the wafer W and the DAF 3 attached to the back surface of the wafer W are simultaneously cut. Thus, the wafer W and DAF 3 can be diced and divided into a plurality of semiconductor chips C with DAF 3.

  Hereinafter, the cutting operation of the wafer W with DAF 3 by the cutting apparatus 20 (that is, the cutting step in the wafer processing method according to the present embodiment) will be described in detail.

  In this cutting process, the cutting device 20 first cuts a plurality of streets 31 extending in a direction parallel to the DAF 3 application direction in the application process as shown in FIGS. 4 (a) and 4 (b). To do. Next, the chuck table 21 is rotated 90 degrees so that the direction of the street 32 is matched with the cutting feed direction (X-axis direction), and then, as shown in FIG. A plurality of streets 32 extending in the direction are cut.

  In this way, by first cutting the street 31 parallel to the direction in which the DAF 3 is applied, it is possible to significantly suppress the generation of the beard-like burrs 5 that accompany the cutting of the DAF 3 (see FIG. 6). The reason why this burr can be suppressed is considered as follows.

  That is, the tensile stress of the DAF 3 and the tensile stress of the dicing tape 6 are determined in the DAF 3 application direction as shown in FIGS. 4 (a) and 4 (b) in consideration of the DAF 3 application method by the application device 10. It is considered to work most. Therefore, by cutting the DAF 3 in a direction parallel to the DAF 3 sticking direction (direction of the street 31), it is possible to minimize the force that pushes the DAF 3 in a direction orthogonal to the cutting direction. Therefore, by cutting the street 31 parallel to the DAF 3 application direction in the first cutting, the generation of burrs can be suppressed during the cutting.

  Further, when the DAF 3 is cut in a direction perpendicular to the DAF 3 sticking direction (direction of the street 32), the DAF 3 is already divided into strips by the cutting of the street 31, so that the DAF 3 or the like The tensile stress does not act so much, and as a result, the force that pushes the DAF 3 in the direction orthogonal to the cutting direction does not act so much. Therefore, even if it is cut along the street 32 perpendicular to the DAF 3 attaching direction in the second cutting, the generation of burrs can be suppressed.

  As described above, the wafer W with the DAF 3 can be divided into a plurality of semiconductor chips C with the DAF 3 by cutting the wafer W with the DAF 3 into a lattice shape. In the divided semiconductor chip C with DAF 3, the generation of burrs on the cut surface of the DAF 3 is suppressed as described above.

  Therefore, the pickup can be suitably picked up by the collet without being disturbed by burrs (see FIG. 7A) in the pickup process which is a subsequent process. Further, after the picked-up semiconductor chip C with DAF3 is die-bonded to the base, the wire and the pad are preferably connected with the wire without being disturbed by the burr in the wire bonding process (see FIG. 7B). Can connect. For this reason, since the said wire bonding process can be performed smoothly and rapidly, wire bonding precision and productivity improve.

  Next, in order to verify the burr suppression effect by the wafer processing method according to the above embodiment, the DAF 3 attaching direction to the wafer W and the cutting order of the streets 31 and 32 in the two directions are changed, and the wafer W with DAF 3 is cut. In each case, the results of experiments for measuring the number of burrs generated in the cut DAF 3 will be described. In addition, this invention is not limited to the following Example.

(Comparative Example 1)
In the wafer processing method according to Comparative Example 1, as shown in FIG. 5A, in the attaching process, the DAF 3 is applied in a direction parallel to the street 31 in one direction, and in the cutting process, first, A plurality of streets 32 in a direction orthogonal to the sticking direction was cut (first cut), and then a plurality of streets 31 in a direction parallel to the sticking direction was cut (second cut). Compared with the wafer processing method according to the first embodiment, the comparative example 1 is different in the cutting order of the streets 31 and 32.

(Comparative Example 2)
In the wafer processing method according to Comparative Example 2, as shown in FIG. 5 (b), in the attaching process, the attaching direction of the DAF 3 is set to a direction intersecting with the streets 31 and 32 in both directions obliquely by 45 degrees, and the cutting process First, a plurality of streets 32 in a direction intersecting with the pasting direction at 45 degrees are cut (first cut), and then a plurality of streets 31 in a direction intersecting with the pasting direction at 45 degrees are cut. (Second cut). The comparative example 2 differs from the wafer processing method according to the first embodiment in the DAF 3 sticking direction and the cutting order of the streets 31 and 32.

(Example)
In the wafer processing method according to the embodiment of the present invention, as shown in FIG. 5C, in the attaching step, the attaching direction of the DAF 3 is a direction parallel to the street 31 in one direction, and in the cutting step, First, a plurality of streets 31 in a direction parallel to the sticking direction was cut (first cut), and then a plurality of streets 32 in a direction orthogonal to the sticking direction was cut (second cut). This example corresponds to the wafer processing method according to the first embodiment.

  Table 1 shows the experimental conditions and experimental results of the wafer processing methods according to the comparative examples 1 and 2 and the example.

  First, the experimental conditions are explained. As shown in Table 1, in Experiment 1, the experiments were performed for Comparative Examples 1 and 2 and Examples, respectively. In Experiments 2 to 4, the experiment was performed only for Comparative Example 1 and Examples. In Experiments 1 and 2, DAF3 with the product name “LE5000 P8A (manufactured by Lintec)” was used, and in Experiments 3 and 4, DAF3 with the product name “LE5000 P8AS (manufactured by Lintec)” was used.

  The rotation speed of the spindle 24 in the cutting process was 40,000 [rpm] in Experiments 1 and 2, and 30,000 [rpm] in Experiments 3 and 4. In the cutting process, water is supplied as a cutting fluid for cooling the processing points of the wafer W and the cutting blade 22, and the amount of the cutting fluid supplied is 2.0 [L / min] in Experiment 1. In 3-4, it was set to 1.4 [L / min]. Also, the DAF 3 application speed in the application process was 60 [mm / s] in Experiment 1, 10 [mm / s] in Experiments 2 and 3, and 80 [mm / s] in Experiment 4.

  Although not shown in Table 1, in any of Experiments 1 to 4, an 8-inch silicon wafer whose back surface is dry-polished (dry polished) is used as the wafer W, and each street 31 of the wafer W is used. 32 is 38 lines, the grain size of the abrasive grains constituting the cutting blade 22 is 126 J (# 4800), and the cutting feed rate in the cutting process is 50 [mm / s].

  Next, the burr measurement method and measurement results will be described. The number of streets 31 and 32 on the surface of the wafer W was 38 lines. The number of burrs generated on the entire length (2830 mm) of the 2nd, 6th, 10th, 15th, 20th, 25th, 30th, 34th and 38th streets 31 (total 9 lines) out of the total 38 lines 31 was measured. . At this time, burrs with a length of 3 microns or more were counted. Similarly, the number of burrs generated on the street 32 was also measured. Table 1 shows the total number of burrs measured along the street 31 and the number of burrs measured along the street 32.

  As a result of the measurement, in Comparative Example 1, generation of 55, 27, 590, and 393 burrs was confirmed in Experiments 1 to 4, respectively. In Comparative Example 2, the occurrence of 122 burrs was confirmed in Experiment 1. In the example, the occurrence of burrs of 4, 3, 451, and 302 was confirmed in Experiments 1 to 4, respectively.

  As can be seen from the measurement results, in the example of the present invention, the number of measured burrs is significantly reduced as compared with Comparative Examples 1 and 2, and the generation of burrs is suppressed in the cutting process. It can be said. That is, in the embodiment of the present invention, the number of burrs generated was reduced by 92.7% in Experiment 1, 88.9% in Experiment 2, and 33.4% in Experiment 3, compared with Comparative Example 1. 4 is reduced by 23.1%. Further, in the example of the present invention, the number of burrs generated in Experiment 1 is reduced by 96.7% in comparison with Comparative Example 2. In particular, in Experiment 1 and Experiment 2 in which the rotational speed of the spindle 24 is set to a high condition of 40,000 [rpm], the burr reduction ratio is about 90% as compared with Comparative Examples 1 and 2. It can be seen that the inhibitory effect is extremely significant. Further, it has been found that when the rotational speed of the spindle 24 is set to a low value of 30,000 [rpm], it is originally known that burrs are likely to occur. However, it can be seen that the embodiment of the present invention has a burr suppressing effect.

  According to the above experimental results, it can be said that the use of the wafer processing method according to the above-described embodiment proves that there is a significant burr suppression effect.

  The wafer processing method according to the present embodiment has been described in detail above. According to the wafer processing method of the present embodiment, the DAF 3 is pasted by the pasting apparatus 10 so that the pasting direction of the DAF 3 with respect to the wafer W and the direction of the one street 31 on the surface of the wafer W are substantially parallel. Later, when the cutting apparatus 20 cuts the wafer W with the DAF 3 into a lattice shape, the wafer W is first cut from the streets 32 aligned substantially in parallel. As a result, the damage to the DAF 3 can be minimized by cutting the DAF 3 parallel to the direction of the strongest tensile stress acting on the DAF 3. Therefore, the generation of burrs that occur when DAF 3 is cut can be greatly suppressed. Therefore, as a countermeasure against burrs of the semiconductor chip C with DAF3, there is an advantage that no separate device or processing step is required, and the generation of burrs during cutting can be suppressed, and the burrs problem can be fundamentally solved. .

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, this invention is not limited to this example. It will be obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, the adhesive film according to the above embodiment is a single-layer DAF 3 having only an adhesive layer such as a polyimide resin, but the present invention is not limited to such an example. The adhesive film may be, for example, a DAF with a carrier film obtained by applying a pressure sensitive adhesive such as a polyimide resin on the carrier film and drying it, or on a porous substrate as a substitute for a dancing tape. An adhesive may be applied to the surface.

  The present invention can be applied to a method of manufacturing a chip with an adhesive film by cutting a wafer having a die bonding adhesive film affixed to the back surface into a lattice shape.

It is a front view which shows the structure of the sticking apparatus concerning the 1st Embodiment of this invention. In the sticking device concerning the embodiment, it is a bottom view (a) which shows DAF held on a base tape, and a top view (b) showing a wafer laid on a movement base. It is the expanded sectional view (a) which shows the state which has affixed DAF on the back surface of the wafer with the sticking apparatus concerning the embodiment, and the expanded sectional view (b) which shows the wafer by which DAF was affixed on the back surface. It is a front view which shows the structure and operation | movement of the cutting device concerning the embodiment. It is explanatory drawing which shows the sticking direction of DAF concerning the Example of this invention and Comparative Examples 1 and 2, and the cutting order of a street. It is sectional drawing (a) which shows the aspect which cut | disconnects the wafer with DAF with a cutting blade, and the top view (b) which shows the burr | flash produced in the divided | segmented DAF. It is explanatory drawing which shows the aspect (a) which the burr | flash of the conventional DAF obstructs pickup, and the aspect (b) which obstructs wire bonding.

Explanation of symbols

3 DAF (adhesive film for die bonding)
4 ring frame 5 burr 6 dicing tape 10 sticking device 12 moving base 13 sending roller 14 pressure roller 15 winding roller 16 base tape 20 cutting device 21 chuck table 22 cutting blade 23 cutting unit 24 spindle 31 street (DAF sticking direction and parallel)
32 Street (perpendicular to DAF sticking direction)
W Wafer C Semiconductor chip

Claims (1)

A plurality of adhesive films are obtained by attaching an adhesive film for die bonding to a back surface of a wafer having a plurality of semiconductor elements formed on the front surface, and cutting the wafer having the adhesive film attached together with the adhesive film in a lattice shape. A wafer processing method that divides into attached chips:
The back surface of the wafer is moved by using a sticking apparatus that gradually presses and adheres the adhesive film from the front side to the rear side in the moving direction of the wafer while moving the wafer in one direction. A sticking step of sticking the adhesive film in a predetermined sticking direction;
Using a cutting device that cuts two orthogonal streets on the surface of the wafer with a cutting blade, the wafer to which the adhesive film has been attached is cut into a lattice shape together with the adhesive film, and a plurality of A cutting step of dividing into chips with adhesive film;
Including
In the attaching step, the adhesive film is formed on the back surface of the wafer such that any one of the two-direction streets on the surface of the wafer is substantially parallel to the attaching direction of the adhesive film. Paste,
In the cutting step, after cutting the street in a direction substantially parallel to the adhesive film application direction, the street in a direction substantially perpendicular to the adhesive film application direction is cut. 、 Wafer processing method.

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