JP2000315664A - Slicing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slicing method, capable of solving clogging of a wheel and preventing reduction in the processing quality of chipping, etc. SOLUTION: In a method for slicing a processing matter 1 by an outer peripheral blade wheel 6, the processing matter 1 is mounted on a substrate 2 and the both are held in parallelism, while the both are fixed via a low fusing point material layer 3 therebetween, and the processing matter 1 is sliced so that the leading end of the outer peripheral blade wheel 6 is positioned in a middle part of the low meeting point material layer 3. The sliced substrate 2 and a processing matter 1a are heated, and the low fusing point material layer 3 therebetween is meeted to isolate the processing matter 1a from the substrate 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for slicing a work such as a single crystal material or ceramics, and a work fixing structure used for slicing.

[0002]

2. Description of the Related Art Conventionally, when a workpiece such as a ceramic wafer or a silicon wafer is divided into a large number of chips by a blade having an outer peripheral grindstone, slicing is performed. In the slicing process, the wafer to be processed is attached to the surface of the adhesive sheet, the back surface of the adhesive sheet is sucked and held on the surface of an air chuck table, etc. In general, the workpiece is cut and sliced by moving the workpiece.

[0003]

As the pressure-sensitive adhesive sheet, a carrier film such as polyethylene terephthalate is used, and a pressure-sensitive adhesive layer made of a heat-foamable pressure-sensitive adhesive or a UV-curable pressure-sensitive adhesive is formed on the surface thereof. During slicing, the blade cuts not only the workpiece, but also the adhesive layer and the carrier film, so that a part of the carrier film is welded to the grindstone, and a part of the adhesive adheres to the grindstone.
For this reason, the grindstone is clogged, the sharpness of the blade is reduced at an early stage, the workpiece is overloaded, and the processing quality such as chipping is reduced. In addition, since the rigidity of the adhesive layer is low, the adhesive layer is elastically deformed by the pressing load by the blade during the slicing process, so that there is a problem that it is difficult to obtain a right angle accuracy of the cut surface. Furthermore, since the blade cuts not only the workpiece and the adhesive layer but also the carrier film, there is an economic disadvantage that the adhesive sheet once used cannot be reused.

Accordingly, an object of the present invention is to provide a slicing method capable of solving the above problems. Another object of the present invention is to provide a workpiece fixing structure that has a higher rigidity for holding the workpiece as compared with fixing with an adhesive layer and that can perform a high-precision slicing process. Still another object is to provide a method of manufacturing a workpiece fixing structure capable of easily and accurately manufacturing the above workpiece fixing structure.

[0005]

In order to achieve the above object, an object of the present invention is to provide a method for slicing a workpiece with an outer peripheral grindstone. A step of stably holding the workpiece-fixed structure fixed via the material layer, a step of slicing the workpiece so that the tip of the outer peripheral grinding wheel is located in the low-melting point material layer, and a step of slicing. A step of heating the workpiece fixing structure later to melt the low-melting-point material layer to separate the workpiece from the base material, thereby providing a slicing method.

A workpiece fixing structure in which a workpiece is fixed on a base material via a low melting point material layer is stably held on, for example, an air chuck table or the like. Then, by rotating a blade having an outer peripheral grindstone and moving the table in the horizontal direction, the workpiece is cut and sliced. At this time, the blade cuts not only the workpiece but also the low melting point material layer, but does not cut the base material. Since the low melting point material melts at a relatively low temperature, it is easily removed from the blade by the temperature during slicing and does not cause clogging. Therefore, the sharpness of the grindstone can be maintained, and chipping does not occur. In addition, since the solidified low-melting point material has higher rigidity than the adhesive layer, it hardly undergoes elastic deformation due to the pressing load of the blade during processing, and a high right-angle accuracy of the cut surface can be obtained. Furthermore, since the outer peripheral blade of the blade does not reach the base material, no cut groove is formed in the base material. In other words, the substrate can be reused any number of times,
It is economical.

As the low melting point material, for example, wax can be used. As the substrate, a carrier film such as polyethylene terephthalate may be used, or a rigid plate having a flat surface may be used. In any case, it is necessary to use a material having good adhesion to the low melting point material so that the low melting point material and the base material do not peel off during the slicing process.

For slicing, it is desirable to use a work fixing structure having a three-layer structure as described in claim 2. That is, the parallelism between the base material and the workpiece is maintained, and a good squareness and high dimensional accuracy of the cut surface can be obtained in combination with the high rigidity of the low melting point material. After the slicing process, the workpiece fixing structure can easily remove the low-melting point material by slightly heating, so that it can be taken out of the base material without applying a load to the cut chip-shaped workpiece. .

In order to manufacture the workpiece fixing structure as described in claim 2, as in claim 3, the first suction surface having an opening on the lower surface side and vacuum-sucking the workpiece on the ceiling surface is provided. It is preferable to use a first jig provided with a filling space and a second jig having an upper surface parallel to the first suction surface and having a second suction surface for sucking the substrate. That is, the substrate is sucked on the second suction surface of the second jig, and the workpiece is vacuum-sucked on the first suction surface. Then, the lower end opening surface of the first jig is brought into close contact with the base material, and the filling space of the first jig is filled with a low melting point material and solidified. Thereafter, the first jig is separated from the substrate while leaving the low melting point material layer and the workpiece on the substrate.
Separate the substrate from the jig. With this configuration, the workpiece is attracted to the first suction surface of the first jig by the surface. Therefore, even if the workpiece has warpage or twist, the workpiece is corrected by warping or twisting. The workpiece and the workpiece can be fixed with high parallelism. Therefore, the processing accuracy during slicing is also increased.

[0010]

FIG. 1 shows an example of a workpiece fixing structure A for slicing according to the present invention. The workpiece fixed structure A has a three-layer structure of a workpiece 1, a base material 2, and a low-melting material layer 3. The workpiece 1 is, for example, a wafer such as a fired ceramic wafer or silicone wafer. The substrate 2 is made of a carrier film such as polyethylene terephthalate. The base material 2 may be a sheet cut to a certain length, or may be a continuous sheet extending long. The low-melting-point material layer 3 is made of, for example, wax or the like, and is interposed between the workpiece 1 and the substrate 2 with a predetermined thickness t, and the workpiece 1 is attached in parallel to the substrate 2. Thickness t of low melting point material layer 3
For example, in order to ensure a clearance allowance of the grindstone when performing slicing with the outer peripheral grindstone described below, for example, 0.1
mm.

Next, a method of performing slicing using the workpiece fixing structure A will be described with reference to FIG. First, as shown in (a), the workpiece fixed structure A is placed on the air chuck table 4, and the substrate 2 is sucked and held on the surface of the table 4 by vacuum suction through the suction hole 5. Next, as shown in FIG.
The workpiece 1 is slicing-processed by disposing a blade 6 having an outer peripheral grindstone above the table 1 and horizontally moving the table 4 in a direction perpendicular to the paper surface while rotating the blade 6. At this time, the height of the blade 6 is adjusted so that the tip of the outer peripheral grindstone of the blade 6 is located in the low melting point material layer 3. When one slicing is completed, the blade 6 is shifted in the horizontal direction by one pitch, and the slicing is repeated. During slicing, the low-melting-point material has relatively rigidity, so that it does not bend due to the pressing load of the blade 6 and can secure the right-angle accuracy of the cut surface of the workpiece 1. Next, the workpiece fixing structure A for which slicing has been completed as shown in FIG. At this stage, the workpiece 1 a cut into chips is held on the base material 2 by the low melting point material layer 3. Finally,
The low-melting material layer 3 is removed by heating the workpiece fixing structure A to a temperature at which the low-melting material layer 3 melts. As a result, the workpiece 1a cut into chips as shown in FIG. At this time, since almost no load is applied to the workpiece 1a, even if the workpiece 1a is fragile, the risk of cracking or damage can be avoided.

As described above, the blade 6 is made of the low melting point material layer 3.
However, since the thickness t of the low-melting material layer 3 is set so as not to cut the substrate 2, welding debris of the substrate 2 does not adhere to the blade 6. Although the low melting point material 3 temporarily adheres to the blade 6, it is easily melted and removed at the temperature during the slicing process, and thus does not cause clogging of the blade 6. Therefore, the sharpness of the blade 6 does not decrease, and chipping of the workpiece 1 can be prevented. Further, since the substrate 2 after slicing is not damaged, the substrate 2 can be reused any number of times.

Here, a method of manufacturing the workpiece fixing structure A will be described with reference to FIG. First, as shown in (a), in addition to the workpiece 1 and the base material 2, the first
A jig 10 and a second jig 20 are prepared. The first jig 10 includes a filling space 11 having an open lower surface, and a first surface for vacuum-sucking the workpiece 1 on a ceiling surface of the filling space 11.
A suction surface 12 is provided. The suction surface 12 is provided with a number of suction holes 13 connected to vacuum suction means.
Further, a first suction surface 12 is provided on the lower end opening surface of the first jig 10.
The height T from the reference surface 14 to the first suction surface 12 is the sum of the thicknesses of the workpiece 1 and the low-melting material layer 3. An injection port 15 for injecting the low melting point material is formed in the side wall of the first jig 10. On the other hand, the second jig 20 is formed in a thick plate shape, and a flat second suction surface 21 for sucking the substrate 2 is provided on an upper surface thereof. And, in the second jig 20,
A large number of suction holes 22 are provided on the second suction surface 21. Next, as shown in (b), the substrate 2 is suction-held on the second suction surface 21 of the second jig 20 and the reference surface 1 of the first jig 10 is held.
The workpiece 1 is suction-held on the first suction surface 12 in a state where the workpiece 4 is in close contact with the base material 2. In this state, the substrate 2 and the workpiece 1 are parallel. Next, as shown in (c), the second jig 2
The low melting point material 3 such as wax is injected from the injection port 15 while the heater 23 is heated by the heater 23. At this time, the substrate 2
Is warmed, the low melting point material 3 flows and fills the filling space 11 without gaps. After the filling is completed, the second jig 20 is cooled to solidify the low melting point material 3. After the solidification of the low melting point material 3, when the first jig 10 is pulled up while the substrate 2 is adsorbed by the second jig 20, the low melting point material layer 3 and the workpiece are formed on the substrate 2 as shown in FIG. 1 and the first jig 10 is separated from the base material 2. Thereafter, the suction of the second jig 20 is released, and the substrate 2 is separated from the second jig 20, so that the workpiece fixing structure A shown in FIG. 1 can be obtained.

In the above embodiment, the workpiece 1 is vacuum-adsorbed in order to bring the workpiece 1 into close contact with the ceiling surface 12 of the filling space 11 of the first jig 10. The workpiece 1 may be in close contact with the ceiling surface 12. However,
It is desirable that the suction is performed by the suction surface 12 having a large number of suction holes 13, since there is an effect of correcting the warp and twist of the workpiece 1.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, a rigid plate is used as the substrate 2. In this case, in order to manufacture the workpiece fixing structure B,
As shown in (a), the workpiece 1 is placed on the substrate 2 and the first jig 10 is brought into close contact with the substrate 2. Then, the workpiece 1 is adsorbed on the first adsorption surface 12 of the first jig 10 while being warmed by the heater 23 from below the base material 2, and the low melting point material 3 such as wax is injected into the filling space 11 from the injection port 15. Fill. After filling, the low melting point material 3 is solidified. After solidification of the low melting point material 3, when the first jig 10 is pulled up, (b)
The low melting point material layer 3 and the workpiece 1 are left on the base material 2 as shown in FIG. In this embodiment, since the substrate 2 also serves as the second jig, the manufacturing apparatus is simplified, and since the substrate 2 is substantially non-deformed, the substrate 2 functions as a transport pallet. Fulfill. Accordingly, the low melting point material 3 is less likely to crack during transportation, and transportation is facilitated.

[0016]

As is apparent from the above description, claim 1
According to the invention described in (1), when slicing a workpiece with a blade having an outer peripheral grindstone, the workpiece is floated and supported by a low melting point material so that the blade does not cut into the base material. The material can be prevented from welding and adhering to the blade. The low melting material temporarily adheres to the blade, but does not clog because the low melting material is easily removed from the blade by the temperature during slicing. Therefore, the sharpness of the grindstone can be maintained and chipping can be prevented. In addition, since the solidified low-melting point material has higher rigidity than the adhesive layer, it hardly undergoes elastic deformation due to the pressing load of the blade during processing, and a high right-angle accuracy of the cut surface can be obtained. Further, since the outer peripheral edge of the blade does not reach the base material, no cut groove is formed in the base material, and the base material can be reused any number of times, which is economical.

According to the second aspect of the present invention, the parallelism between the substrate and the workpiece is ensured by the low melting point material layer provided between the workpiece and the substrate. If the substrate is held horizontally, the level of the workpiece is also automatically secured, and high-precision slicing becomes possible. Moreover, after slicing, the low melting point material melts at a relatively low temperature,
The workpiece can be easily removed from the substrate without applying a mechanical load or a thermal load to the workpiece.

According to the third aspect of the present invention, a first jig having a filling space having a first suction surface and a second jig having a second suction surface are used to cover the first suction surface. The workpiece is adsorbed and the filling space is filled with the low melting point material while the base material is adsorbed on the second suction surface, and solidified, so that the parallelism between the base material and the workpiece can be easily obtained. Even if the workpiece is warped or twisted, it can be corrected to produce a high-quality workpiece fixing structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of a workpiece fixing structure according to the present invention.

FIG. 2 is a process diagram of slicing processing using the workpiece fixing structure of FIG. 1;

FIG. 3 is a manufacturing process diagram of the workpiece fixing structure of FIG. 1;

FIG. 4 is a manufacturing process diagram of another example of the workpiece fixing structure according to the present invention.

[Explanation of symbols]

 A, B Workpiece fixing structure 1 Workpiece 2 Base material 3 Low melting point material layer 10 First jig 20 Second jig

Claims (3)

[Claims] 1. A method for slicing a workpiece with an outer peripheral grindstone, comprising: a step of stably holding a workpiece fixing structure in which the workpiece is fixed on a base material via a low melting point material layer. A step of slicing the workpiece so that the tip of the outer peripheral grindstone is located in the low melting point material layer, and heating the workpiece fixed structure after slicing to melt the low melting point material layer. Separating the workpiece from the base material. 2. A workpiece fixing structure to which a workpiece to be sliced by an outer peripheral grindstone is fixed, wherein the workpiece, a substrate supporting the workpiece, and And a low-melting-point material layer interposed therebetween and fixing the base material and the workpiece while maintaining the parallelism therebetween. 3. A first filling space having an opening on a lower surface side and a first suction surface on a ceiling surface for vacuum-sucking a workpiece.
And a second jig having an upper surface parallel to the first suction surface and having a second suction surface for vacuum-sucking the substrate, using the second suction surface of the second jig. A step of adsorbing the base material;
Vacuum-adhering the workpiece to the suction surface of the first jig, bringing the lower end opening surface of the first jig into close contact with the base material, filling the filling space of the first jig with a low-melting-point material, and solidifying The step of causing
Workpiece fixing having a step of separating the first jig from the base material while leaving the low melting point material layer and the work piece on the base material, and a step of separating the base material from the second jig The method of manufacturing the structure.