JP2011005741A - Method of dividing brittle material substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of dividing a highly brittle material, the method that divides it quickly, accurately and by greatly suppressing generation of chipping, without using cutting water that needs complicated piping installation and wastewater treatment.SOLUTION: The method, in processing a substrate 1 composed of a brittle material as a workpiece, includes steps of: sticking a dicing tape 2 to the lower face of the substrate 1; sticking a protective tape 3 to the upper face of the substrate; forming scribed groove M on the upper layer of the substrate 1 by sliding a cutter 4 from the upper face of the protective tape; and dividing the substrate 1 into each unit element from the scribing groove M by stretching the dicing tape 2, wherein a fixed blade is used for the cutter 4.

Description

  The present invention relates to a method for dividing a highly fragile highly brittle material substrate such as a ceramic, a silicon semiconductor, or a compound semiconductor. The present invention is used, for example, when a semiconductor chip is divided from a semiconductor wafer.

  Highly brittle materials such as silicon semiconductors, compound semiconductors, and ceramics are used by being cut into various shapes depending on the application. For example, when used as a semiconductor chip, many small rectangular semiconductor chips are cut out from one semiconductor wafer.

Generally, among brittle materials, brittle materials such as glass substrates can be easily scribed by pressing a cutter wheel. The scribed glass can be divided by subsequently performing a break treatment along the scribe line.
On the other hand, highly brittle material substrates such as silicon semiconductors, compound semiconductors, and ceramics have very brittle properties, so brittleness becomes a problem, and when pressing with a cutter wheel, a lot of chipping occurs due to the pressing load at the time of pressing. End up.
Therefore, when these highly brittle material substrates are divided, dicing is performed instead of scribing with a cutter wheel. In other words, the dicing blade is moved along the planned dividing line while rotating at high speed. At that time, cutting water is sprayed onto the blade portion to perform dicing while removing heat radiation and chips (see Patent Documents 1 and 2).

  Further, a technique is disclosed in which, after dicing a brittle material substrate, a cleaning liquid is sprayed at a high pressure toward a cut workpiece, and ultrasonic cleaning is applied to the cleaning liquid to remove chips (see Patent Document 3). . In addition, a technique is disclosed in which dicing is performed after a surfactant is applied to the material surface before dicing, and then the dicing material is washed to reduce chipping, crack reduction, and chip adhesion. (See Patent Document 4).

Japanese Patent Laid-Open No. 03-227556 Japanese Patent Laid-Open No. 08-186087 JP 11-214333 A JP-A-11-191540

As described above, the highly brittle material substrate is not subjected to pressure contact with the cutter wheel, but is subjected to cutting by dicing.
However, the dicing process inevitably takes a long time to divide each one, so that it becomes a problem when it is necessary to increase the throughput in mass production.

In dicing, cutting water and cleaning water are used for heat dissipation and chip removal, but depending on the type of high brittle material and usage, it may not be necessary to use water. There was a desire for a cutting method other than.
In addition, when cutting water is used, appropriate equipment such as cutting water supply equipment and wastewater treatment is required, and the number of processes after cutting such as a cleaning process is increased. As a result, the apparatus is complicated and large. There is a problem that the cost is high.

Therefore, the present invention provides a processing method capable of dividing even a highly brittle material that is difficult to process by press contact with a cutter wheel, specifically, a ceramic, a silicon semiconductor, or a compound semiconductor by a method other than dicing. The purpose is to do.
In addition, the present invention provides a method for dividing a highly brittle material substrate quickly and accurately without significantly using chipping and cleaning water with complicated piping equipment and wastewater treatment equipment, and significantly suppressing the occurrence of chipping. For the purpose.

  In order to achieve the above object, the present invention takes the following technical means. That is, the scribing method of the present invention is a substrate whose processing target is a brittle material, a step of attaching a dicing tape to the lower surface of the substrate, a step of attaching a protective tape to the upper surface of the substrate, and an upper surface of the protective tape A scribing process for cutting out the protective tape by sliding the cutter from the top and forming a marking groove in the upper layer part of the substrate, and a process for dividing the substrate by extending the dicing tape, and using a fixed blade as the cutter. ing.

In the above invention, it is preferable that the cutting angle formed between the edge of the fixed blade and the substrate is in the range of 2 ° to 30 °.
In the above invention, it is preferable that the depth of the groove on the substrate by the cutter is within 2/10 of the substrate thickness.

  In the past, for brittle materials such as glass, a scribe groove was formed using a cutter wheel (rotating blade) and then broke. Further, since the material is very brittle, a highly brittle material that cannot be pressure-welded is divided by dicing. The highly brittle material is thought to be difficult to scribe because a large number of chippings occur when a scribe groove is formed with a fixed blade or a cutter wheel (rotating blade).

In general, the fixed blade can reduce the thickness of the blade as compared to the rotary blade (cutter wheel), and therefore the ridge line angle in the thickness direction of the blade edge is smaller than that of the rotary blade. When such a fixed blade is brought into contact with the substrate surface at an angle and the blade tip is moved, scribing is performed by a tearing action instead of a press-contacting action. When the substrate to be processed is a highly brittle material, it has been thought that scribing with a fixed blade cannot be performed because chipping is likely to occur when a tearing action is applied to the substrate. However, if a scribing is performed by adjusting the height of the blade edge so that a protective tape is applied in advance to the substrate surface of the highly brittle material, and a scribing groove is formed only on the upper surface of the substrate, the material is highly brittle. It has also been found that chipping can be suppressed with a protective tape, and an inscribed groove with little chipping can be formed. In addition, when the same scribing was performed with the rotary blade, a scribing groove was formed by the pressure-contacting action, but many chippings were generated in the scribing groove in that case. In other words, chipping could only be suppressed with a fixed blade.
The present invention can realize scribing that does not cause chipping by performing scribing with a fixed blade, which was thought to be impossible with a highly brittle material, by applying a protective tape and performing scribing with a shallow cutting angle. is there.

  According to the scribing method of the present invention, even if it is a highly brittle material, the scribing process can be performed without causing chipping by sliding the cutter of the fixed blade so as to contact only the upper layer of the substrate from the upper surface of the protective tape. it can. Moreover, since it is not necessary to use cutting water, even if it is a material and a use which do not want water splashing to a board | substrate, it can process without a problem.

In the above invention, it is preferable that the cutting angle formed between the edge of the fixed blade and the substrate is in the range of 2 ° to 30 °.
In the said invention, it is preferable that the depth of the marking groove | channel of the board | substrate by a cutter is less than 2/10 of board | substrate thickness.
By limiting the cutting angle and the depth of scribing to the above ranges, scribing that does not cause chipping is possible.

The perspective view which shows an example of the cutting device used when enforcing the method of this invention. The elements on larger scale of the slider in FIG. The elements on larger scale which show the attachment state of the cutter of FIG. The expanded sectional view at the time of processing a marking groove on a board | substrate with the said cutter. Explanatory drawing which shows the 1st process of the parting process concerning this invention. Explanatory drawing which shows the 2nd process of the division | segmentation process concerning this invention. Explanatory drawing which shows the 3rd process of the parting process concerning this invention.

  Hereinafter, details of the cutting method according to the present invention will be described in detail with reference to the drawings showing embodiments thereof.

  Initially, the cutting apparatus used when implementing the cutting method of this invention is demonstrated. FIG. 1 is a perspective view of the cutting device S. FIG. FIG. 2 is a partially enlarged view of the slider 23 in the cutting device S. FIG. The cutting apparatus S includes a table 18 that can move in a substantially horizontal direction (Y direction) and that can rotate in a horizontal plane. The table 18 includes a vacuum suction mechanism (not shown) for holding the substrate W.

  A bridge 19 including support columns 20 and 20 on both sides provided with the table 18 interposed therebetween and a guide bar 21 extending in the X direction is provided so as to straddle the table 18. The slider 23 is movably attached along a guide 22 formed on the guide bar 21, and moves in the X direction by the rotation of the motor 24.

As shown in FIG. 2, the cutter 4 is fixed to the slider 23. That is, the cutter 4 is attached to the attachment base 6 attached to the lower end of the cutter support 5 via the holder 7. And the board | substrate can be scribed by moving to the arrow direction of FIG.
The cutter support 5 is provided with an adjusting mechanism 5a for adjusting the magnitude of the pressing load pressing the cutter 4 against the substrate and the height of the cutter blade.

FIG. 3 is a partially enlarged view showing a state in which the cutter 4 is attached to the attachment base 6. The cutter 4 to be used is a fixed blade, and is formed of a thin plate material having a thickness of about 0.5 mm so that the blade tip has a sharp protrusion.
An attachment portion 4 a for attaching to the holder 7 is provided at the rear end portion of the cutter 4. The tip of the cutter 4 is preferably formed with a sharp pointed shape like a knife, and the tip angle β is preferably about 25 to 30 degrees. Moreover, the cutter 4 can adjust the cutting angle α between the cutting edge ridge line 4b and the substrate 1 in the traveling direction within a range of 2 to 30 degrees. That is, a plurality of attachment holes 8 for attaching the holder 7 to the attachment base 6 are provided, and by selecting one of these attachment holes 8 and attaching the holder 7 holding the cutter 4 with the attachment screw 9. The cutting angle α can be adjusted step by step. As a result, the cutting angle α can always be changed to an appropriate angle according to the hardness and brittleness of the brittle material to be processed. For example, when it is desired to reduce the load as much as possible, the cutting angle α may be adjusted to a small angle. The smaller the load is, the smaller the scribe groove depth is processed, but the generation of chipping can be made more difficult to occur.

Next, the procedure of the cutting method of the present invention using the cutter 4 will be described.
In FIG. 4, a substrate 1 to be divided is made of a highly brittle material such as silicon, ceramic, compound semiconductor, etc., a dicing tape 2 is attached to the lower surface of the substrate 1, and a protective tape 3 is attached to the upper surface of the substrate 1. Affixed.
As the dicing tape 2 and the protective tape 3, resin tapes such as vinyl chloride can be used, and an adhesive layer for adhering to the substrate 1 is provided on one surface thereof. The dicing tape 2 is given elasticity so that it can be stretched when the substrate 1 is diced in a later step. Further, the protective tape 3 is preferably made of a material that can be easily peeled off from the substrate 1 by irradiating ultraviolet rays in a subsequent process or by applying heat to reduce the adhesive force.

For such a substrate 1, a marking groove M is processed along the cutting line on the substrate 1 with a cutter 4 from the upper surface of the protective tape 3.
FIG. 5 shows a state where the substrate M shown in FIG. 4 is processed with the cutter 4 from the upper surface of the protective tape 3 to the substrate 1 with a marking groove M. FIG. When processing the marking groove M, the height of the cutter 4 with respect to the substrate 1 is adjusted so that the depth L of the marking groove M is within 1/10 to 2/10 of the substrate thickness t. At the same time, the pressing load is adjusted. According to experiments, when processing a substrate having a thickness of 0.5 mm, it is preferable that the depth L of the marking groove M is 50 μm. As a result of obtaining the optimum value of the depth L for various highly brittle materials, chipping is prevented by scoring the groove groove M, which is about one tenth of the thickness of the substrate 1, with the cutter 4 in the upper layer portion of the substrate 1. It has been found that generation can be remarkably suppressed and the marking groove M can be processed quickly and accurately.

FIG. 6 is a view of the substrate shown in FIG. 5 as viewed from a direction rotated 90 degrees in a horizontal plane after scribing. The scribe groove can be formed with almost no chipping around the scribe groove. Then, after processing a plurality of marking grooves M on the substrate 1, as shown in FIG. 7, the dicing tape 2 is extended to divide the substrate 1 from the marking grooves M into individual unit elements 1a. In this case, even if the marking groove M processed in the substrate 1 is shallow, the substrate 1 is made of a highly brittle material, and therefore can be easily separated from the marking groove M by the extension of the dicing tape 2.
Then, by separating the protective tape 3, a divided unit element is obtained.

  While typical examples of the present invention have been described above, the present invention is not necessarily limited to the above embodiments. For example, the shape of the cutter 4 is not limited to the female shape as shown in the embodiment, and can be formed in the form of a replaceable blade such as a commercially available OLFA (manufactured by Olfa Corporation; registered trademark). Others The present invention can be appropriately modified and changed within the scope of achieving the object and without departing from the scope of the claims.

  The cutting method of the present invention can be used to cut highly brittle materials such as silicon wafers, ceramic substrates, and compound semiconductors.

1 substrate 2 dicing tape 3 protective tape 4 cutter (fixed blade)
4b Cutting edge ridge line α Angle M between cutting edge ridge line and substrate in cutter traveling direction

Claims (3)

A method for scribing a substrate made of a brittle material,
Attaching a dicing tape to the lower surface of the substrate;
Attaching a protective tape to the upper surface of the substrate;
A scribing step of cutting out the protective tape by sliding the cutter from the upper surface of the protective tape and forming a marking groove in the upper layer portion of the substrate;
Cutting the substrate by stretching the dicing tape,
A brittle material scribing method, wherein a fixed blade is used as the cutter.   The brittle material scribing method according to claim 1, wherein a cutting angle formed by the edge of the fixed blade and the substrate is in a range of 2 ° to 30 °. 2. The brittle material scribing method according to claim 1, wherein the depth of the substrate groove groove by the cutter is within two-tenths of the substrate thickness.

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