JP4714950B2 - Expanding ring and substrate dividing method using the expanding ring - Google Patents

Description

  The present invention relates to an expanding ring and a method of dividing a substrate using the expanding ring, and particularly uses the expanding ring used when cutting a workpiece such as a semiconductor or an electronic component material, and the expanding ring. The present invention relates to a substrate dividing method.

  In a semiconductor manufacturing process, a wafer having a semiconductor device or electronic component formed on the surface is subjected to an electrical test in a probing process, and then divided into individual chips (also referred to as dies or pellets) in a dicing process. Next, individual chips are die-bonded to a component base in a die bonding process. After die bonding, the chip is resin-molded to be a finished product such as a semiconductor device or an electronic component.

  After the probing process, as shown in FIG. 5, the adhesive sheet S (also called a dicing sheet or dicing tape) S having a thickness of about 100 μm with an adhesive layer formed on one side is pasted on the back side, and the adhesive sheet S Is mounted on a rigid ring-shaped frame F. In this state, the wafer W is transferred in the dicing process, between the dicing process and the die bonding process, and in the die bonding process.

  In the dicing process, a dicing apparatus that cuts the wafer by inserting grinding grooves into the wafer W with a thin grindstone called a dicing blade is used. The dicing blade is obtained by electrodepositing fine diamond abrasive grains with Ni, and an extremely thin one having a thickness of about 10 μm to 30 μm is used.

  The dicing blade is rotated at a high speed of 30,000 to 60,000 rpm to cut into the wafer W, and the wafer W is completely cut (full cut) or partially cut (half cut). In the case of full cut, since the adhesive sheet S stuck on the back surface of the wafer W is cut only about 10 μm from the front surface, the wafer W is cut into individual chips T, but the individual chips T are not cut. Since the arrangement of the chips T is not broken, the wafer state is maintained as a whole.

  Further, without using a dicing blade, a laser beam having a focused point is irradiated inside the wafer W to form a modified region due to a multiphoton absorption phenomenon inside the wafer, and the wafer W is started from this modified region. Laser dicing has been proposed to cleave. Also in this laser dicing process, since the wafer W is diced in the state as shown in FIG. 5, the arrangement of the chips T does not collapse and the wafer state is maintained as a whole.

  Here, even after dicing and dividing into individual chips T in this way, an assembly of the chips T in which the arrangement of the chips T is not broken is also referred to as a wafer W for convenience.

  Thereafter, the wafer W is sent to a die bonding process. A die bonder is used in the die bonding process. In the die bonder, the wafer W is first placed on the chuck stage, and then the adhesive sheet S is expanded to widen the interval between the chips T so that the chips T can be easily picked up.

  Next, the chip T is pushed up with a pusher from below, and the chip T is picked up with a collet from above, and the chip T is bonded to a predetermined position of the base.

Such an expanding method and an expanding apparatus for expanding the adhesive sheet S and expanding the interval between the chips T have been conventionally used. In addition, various improvements and developments have been made in this expanding apparatus (for example, Patent Document 1 and Patent Document 2).
JP 2005-109044 A JP 2005-057158 A

  However, in the conventional wafer expansion, the peripheral members of the frame F are large-sized, which is not only inconvenient to handle but also cannot be stored in the wafer cassette, so that simplification and compactness have been demanded.

  That is, in the conventional expand, the pressure-sensitive adhesive sheet S is expanded, the pressure member ring member is bonded to the pressure-sensitive adhesive sheet S in a state where the interval between the chips T is widened, and the expanded state of the pressure-sensitive adhesive sheet S is caused by this ring member. The so-called double ring system was used to maintain this, but the thickness of the ring member was large. It was difficult to store the frame F or the like.

  Moreover, in the conventional expand, the automation at the time of fitting a ring member to the flame | frame F after the expansion of the adhesive sheet S was difficult, and there also existed a problem that productivity was bad.

  Further, in the conventional expand, a mechanism for fitting the ring member to the frame F after expansion is required. However, this mechanism has a problem that dust is generated and the wafer is contaminated.

  The present invention has been made in view of such a situation, and expands the adhesive sheet adhered to the back surface of the wafer on which the linear modified region along the planned dividing line is formed, and between the chips. An expanded method (substrate dividing method) that can maintain the expanded state of the pressure-sensitive adhesive sheet in a state where the interval is widened and can be stored in a wafer cassette in this state, and which can be simplified, and this expanded. An object of the present invention is to provide an expanding ring that is preferably used in the method.

  In order to achieve the above object, the present invention provides an expanding ring that stretches by applying tension to a sheet material whose peripheral edge is fixed to an annular member, and the expanding ring has an outer diameter smaller than the inner diameter of the annular member. The sheet material comprises: a certain ring main body; and a projecting piece that extends outward and downward from an upper edge of the outer periphery of the ring main body and has an outer diameter of a tip portion larger than an inner diameter of the annular member. When the expanding ring is pushed in from below and stretched by applying tension to the sheet material, the protruding piece bends downward, and the tip of the protruding piece gets over the inner diameter portion of the annular member, and then the protruding When the bending of the piece is recovered and the tip of the protruding piece is engaged with the upper surface of the annular member via the sheet material, the stretched state of the sheet material is obtained. Providing an expandable ring, characterized in that is adapted to be lifting.

  Further, in the present invention, a substrate on which a linear modified region along a predetermined dividing line is formed on the surface or inside is bonded to the upper surface of the sheet material, and the sheet is formed using the expanding ring. There is provided a method for dividing a substrate, wherein the substrate is divided along the planned dividing line by applying tension to the material and stretching the material.

  According to the present invention, when the expanding ring is pushed from below the sheet material stretched on the annular member and the sheet material is stretched by applying tension, the projecting piece bends downward, and the tip of the projecting piece Gets over the inner diameter part of the annular member, then the flexure of the overhanging piece recovers, and the tip of the overhanging piece engages the upper surface of the annular member through the sheet material, so that the stretched state of the sheet material is maintained. It has come to be.

  Therefore, the pressure-sensitive adhesive sheet can be expanded uniformly using a simple instrument (expanding ring), and the expanded state of the pressure-sensitive adhesive sheet can be easily maintained with the space between the chips widened. Thereby, it is possible to expand the wafer with improved yield.

  Further, according to the present invention, automation is easy and productivity can be improved. Furthermore, according to the present invention, the mechanism is simple and no dust is generated by the mechanism.

  Note that the surface or internal linear modified region is a linear region along the planned dividing line into individual chips of the wafer, and when formed on the surface of the wafer, the wafer is formed by a dicing blade. Full cut (full cut) or partial cut (half cut) is typical, and when it is formed inside the wafer, internal cracks (micro cracks) due to laser light irradiation with the focused point inside the wafer Is representative.

  In the present invention, it is preferable that the thickness of the protruding piece decreases from the base end portion toward the tip end portion. If the projecting piece has such a configuration, the tip end portion gets over the inner diameter portion of the annular member, and then the deflection of the projecting piece is recovered, and the tip end portion of the projecting piece is engaged with the upper surface of the annular member via the sheet material. Can be easily done.

  In the present invention, it is preferable that the protruding piece is an annular member. If it is such a shape, an adhesive sheet can be expanded uniformly.

  In the present invention, it is preferable that the projecting piece is a member provided with a plurality of notches in the circumferential direction of the annular member. If it is such a shape, while being able to expand an adhesive sheet uniformly, a notch absorbs the slack which generate | occur | produces when an overhanging piece bends below, and can make the bending of an overhanging piece uniform.

  As described above, according to the present invention, it is possible to expand a wafer with improved yield.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments (first embodiment) of an expanding ring according to the present invention and a substrate dividing method using the expanding ring will be described in detail with reference to the accompanying drawings. In addition, the same number is attached | subjected to the same member in each figure.

  First, the configuration of the expanding ring will be described. FIG. 1 is a sectional view showing a configuration of an expanding ring according to the present invention, and FIG. 2 is a plan view.

  As shown in FIGS. 1 and 2, the expand ring 10 includes a ring body 12 and a projecting piece 14 that extends outward and downward from the upper peripheral edge of the ring body 12. The outer diameter D1 of the ring main body 12 is smaller than the inner diameter of the frame F (see FIG. 5) that is an annular member. The outer diameter D2 of the tip end portion of the overhanging piece 14 is larger than the inner diameter of the frame F that is an annular member.

  By adopting such a configuration for the frame F, when the expand ring 10 is pushed in from below the adhesive sheet (sheet material) S (see FIG. 5) and stretched by applying tension to the adhesive sheet S, the protruding piece 14 is bent downward, the leading end of the overhanging piece 14 gets over the inner diameter portion of the frame F, and then the bending of the overhanging piece 14 is recovered. The leading end of the overhanging piece 14 is attached to the frame F via the adhesive sheet S. Engage with the upper surface, and thereby the stretched state of the adhesive sheet S is maintained. Details of this will be described later with reference to FIG.

  There are no particular restrictions on the material, height, ring thickness, etc. of the ring body 12, depending on the size, thickness, material of the adhesive sheet S, the size (particularly the inner diameter) of the frame F, etc. The size can be selected.

  There are no particular restrictions on the material of the overhanging piece 14, the angle of inclination with respect to the axis of the ring body 12, the thickness distribution in the radial direction, etc. The size, thickness and material of the adhesive sheet S and the size of the frame F (particularly the inner diameter) ) Etc., an appropriate material and size can be selected.

  In general, a metal member that generates elastic deformation (for example, stainless steel) and a resin member that generates elastic deformation (for example, various types of polyacetal, polyamide, and engineering plastics) can be preferably used.

  Further, the ring body 12 and the projecting piece 14 can be made of the same material, or can be formed of different materials.

  There is no limitation on the method of forming the expanded ring 10, for example, a metal member may be machined by cutting, or each machined ring body 12 and overhanging piece 14 may be shrink-fitted to form a resin. The material may be integrally formed by injection molding.

  As shown in FIG. 1, the overhanging piece 14 preferably has a thickness that decreases from the base end toward the tip. With the projecting piece 14 having such a configuration, the tip end portion gets over the inner diameter portion of the frame F, and then the flexure of the projecting piece 14 is recovered, and the tip end portion of the projecting piece 14 passes through the adhesive sheet S to the frame F. It can be easily engaged with the upper surface.

  Further, the projecting piece 14 has an annular shape as shown in FIG. If it is such a shape, the adhesive sheet S can be expanded uniformly.

  Next, another embodiment (second embodiment) of the expanding ring according to the present invention will be described. The description of the same or similar members as those in the first embodiment described above will be omitted.

  FIG. 3 is a plan view showing the configuration of the expanding ring 10 'according to the present invention. In the present embodiment, the sectional view of the expanding ring 10 ′ is omitted because it is the same as FIG. 1 (first embodiment) described above.

  In the present embodiment, the projecting piece 14 is a member provided with a plurality of notches 14A, 14A... In the circumferential direction of the annular member. If it is the shape provided with such notches 14A, 14A ..., the adhesive sheet S can be expanded uniformly, and notches 14A, 14A ... are generated when the overhanging piece 14 is bent downward. Can be absorbed, and the bending of the overhanging piece 14 can be made uniform.

  The number and shape (opening angle, etc.) of the notches 14A, 14A... Are not limited to the configuration shown in FIG. 3, but the material of the projecting piece 14, the cross-sectional shape, the size, thickness, and material of the adhesive sheet S. Depending on the size of the frame F (in particular, the inner diameter), an appropriate material and size can be selected.

  Next, the usage method of the expand ring 10 comprised in this way is demonstrated. Here, a case where it is applied to the subsequent stage of the dicing apparatus will be described.

  In a dicing apparatus (not shown), the wafer W is attached to an adhesive sheet S having an adhesive material on one surface (upper surface) as shown in FIG. 5 described above, and is integrated with the frame F via the adhesive sheet S. Then, it is carried in and is conveyed through the dicing apparatus.

  The laser dicing unit, which is a main part of the dicing apparatus, dices the wafer W into individual chips by making laser light incident from the surface of the wafer W and forming a modified region inside the wafer W. . In this laser dicing unit, laser light is incident from the surface of the wafer W to form a modified region inside the wafer W.

  The wafer W in which the modified region is formed is transferred to an expanding unit, which is a subsequent stage of the laser dicing unit, in a state of being integrated with the frame F.

  Hereinafter, the flow in the expanded portion will be described with reference to the cross-sectional views of FIGS.

  FIG. 4A shows an expanded preparation state. In FIG. 4A, the adhesive sheet S adhered to the back surface of the wafer W is placed on the wafer table 20. At this time, the frame F is placed on the frame support base 22 and is pressed from above by the frame presser 24 to restrain the movement. In this state, the adhesive sheet S maintains a horizontal state.

  The expand ring 10 is fixed on the elevating stage 26, and is in the lower limit position in the state of FIG.

  The wafer table 20 is provided with heating means, and the wafer W and the adhesive sheet S are heated to a predetermined temperature.

  4A, the protective tape H is peeled (peeled) from the surface of the wafer W in the direction of the arrow in the figure. This protective tape H is stuck to protect the surface of the wafer W during the backgrinding or the like, which is a previous process. During laser dicing, laser light is incident on the inside of the wafer W with the protective tape H attached.

  FIG. 4B shows a state where the wafer W is expanded. In FIG. 4B, the elevating stage 26 is lifted from the lower limit position in FIG. 4A, and the expanding ring 10 is in contact with the wafer W, pushing the wafer W upward and expanding. At the same time, cooling air is ejected from the air ejection holes (not shown) provided in the expand ring 10 in the direction of the arrow in the figure, and the adhesive sheet S is cooled. Thereby, expansion (expanding) of the adhesive sheet S is promoted.

  When the elevating stage 26 is further raised from the state of FIG. 4B, the projecting piece 14 of the expanding ring 10 bends downward, the tip of the projecting piece 14 gets over the inner diameter portion of the frame F, and then The deflection of the overhanging piece 14 is restored, and the tip end portion of the overhanging piece 14 is engaged with the upper surface of the frame F via the adhesive sheet S, whereby the stretched state of the adhesive sheet S is maintained. . FIG. 4C shows this state.

  In FIG.4 (C), the raising / lowering stage 26 descend | falls and exists in a descent | fall limit position. The frame F, the adhesive sheet S, and the expanding ring 10 are in an integrated state. If the pressing by the frame pressing member 24 is released in this state, the frame F, the adhesive sheet S, and the expanding ring 10 can be conveyed to the next process in a state where they are integrated.

  In the state shown in FIG. 4C, the wafer W can be image-recognized from above by an image recognition device (not shown) to identify the divided state of the wafer W.

  According to the present embodiment described above, the pressure-sensitive adhesive sheet S can be expanded uniformly using a simple instrument (expanding ring 10), and the expanded state of the pressure-sensitive adhesive sheet S can be easily expanded with the space between the chips widened. Can be maintained. As a result, it is possible to expand the wafer W with improved yield.

  Further, according to the present invention, automation is easy and productivity can be improved. Further, according to the present invention, the mechanism is simple, and no dust is generated by the mechanism.

  Furthermore, according to the present invention, the following specific effects can be obtained.

  Since the expanded state of the adhesive sheet S can be maintained in a state where the wafer W is set on the frame F, it can be stored in a cassette and transferred to the next process, which is preferable in process management.

  Since the pressure-sensitive adhesive sheet S has a function of winding around the tip of the expand ring 10, even if the amount of expansion (extension amount) of the pressure-sensitive adhesive sheet S increases, it is not necessary to change the height of the jig (elevating stage 26, etc.). Therefore, the process can be simplified.

  By performing expansion (extension) of the adhesive sheet S with a motor or the like, the expansion amount (extension amount) and the expansion speed can be set in stages, and the process can be made flexible.

  After the back grind tape (the protective tape H in FIG. 4A) is peeled off, the wafer W can be expanded without delivery, and the process can be simplified.

  As mentioned above, although embodiment of the expanding ring which concerns on this invention, and the division | segmentation method of the board | substrate using this expanding ring was described, this invention is not limited to the said embodiment, Various aspects can be taken.

  For example, in the present embodiment (flow in the expanding section), the expansion ring 10 shown in FIG. 2 is used. However, the expansion ring 10 ′ shown in FIG. 3 may be used, as in the present embodiment. The effect is obtained.

  In this embodiment, the modified region is formed inside the wafer W by the laser beam. However, the wafer W may be cut by inserting a grinding groove in the wafer W by a dicing blade.

  Further, in the present embodiment, the expand ring 10 is used for dividing the wafer W. However, the use of the expand ring 10 is not limited to this, and the expand of the sheet material in which the periphery is fixed to the annular member. (Extension) can be suitably applied to various uses.

Sectional drawing which shows the structure of the expand ring which concerns on this invention Plan view of the expansion ring in FIG. Top view of the expansion ring in other configurations Sectional drawing explaining the flow in an expanding process Perspective view showing wafer mounted on frame

Explanation of symbols

  10, 10 '... Expanding ring, 12 ... Ring body, 14 ... Overhang, 14A ... Notch, F ... Frame, S ... Adhesive sheet, T ... Chip, W ... Wafer

Claims (6)

An expanding ring that applies tension to and extends the sheet material having a peripheral edge fixed to the annular member,
The expand ring includes a ring main body having an outer diameter smaller than the inner diameter of the annular member, and extends outward and downward from the outer peripheral upper edge of the ring main body, and the outer diameter of the tip portion is larger than the inner diameter of the annular member. It is composed of a projecting piece that is a diameter,
When the expand ring is pushed in from below the sheet material and stretched by applying tension to the sheet material, the projecting piece bends downward, and the tip of the projecting piece climbs over the inner diameter portion of the annular member, Next, the bending of the protruding piece is recovered, and the leading end of the protruding piece is engaged with the upper surface of the annular member via the sheet material, so that the stretched state of the sheet material is maintained. Expanding ring, characterized by   The expanding ring according to claim 1, wherein the thickness of the projecting piece decreases from the base end portion toward the tip end portion.   The expanding ring according to claim 1, wherein the projecting piece is an annular member.   The expanding ring according to claim 1 or 2, wherein the projecting piece is a member provided with a plurality of notches in a circumferential direction of the annular member. A substrate on which a linear modified region is formed on the surface or along the planned dividing line is bonded to the upper surface of the sheet material,
Dividing the substrate along the planned dividing line by applying tension to the sheet material and stretching it using the expanding ring according to any one of claims 1 to 3. Method.   The substrate dividing method according to claim 5, wherein the substrate is a wafer, and the wafer is divided into individual chips.

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