JP5329833B2 - Adhesive sheet for semiconductor wafer processing, adjustment method for semiconductor wafer processing apparatus using the same, and evaluation method for adhesive sheet - Google Patents

Description

  The present invention relates to an adhesive sheet for semiconductor wafer processing, a method for adjusting a semiconductor wafer processing apparatus using the same, and an evaluation method for an adhesive sheet. More specifically, a predetermined mark is formed on the adhesive sheet, Adhesive sheet for semiconductor wafer processing capable of grasping the adhesion state of the adhesive sheet by measuring the distance between marks after adhering to the semiconductor wafer, adjustment method of semiconductor wafer processing apparatus using the same, and evaluation of the adhesive sheet Regarding the method.

Semiconductor wafers (hereinafter simply referred to as “wafers”) are subjected to processing steps such as backside grinding and dicing after a large number of circuit patterns are formed on the surface, and finally separated into chips. The chip is bonded to a substrate such as a lead frame.
In these processing steps, an adhesive sheet is affixed to the circuit pattern forming surface side or the back surface side of the wafer, and such an adhesive sheet is disclosed in Patent Document 1, for example.
JP 2005-191322 A

In each process as described above, for example, in the case of a protective tape for back surface grinding, if the adhesive sheet is attached to the wafer in a stretched state, as shown by a two-dot chain line in FIG. If the wafer is curled due to the residual stress of the adhesive sheet after grinding, or if it is stuck in a loose state, air bubbles may be stuck between the wafer and the adhesive sheet. .
Also, in the case of a dicing tape that is attached to a ring frame and diced, if the adhesive sheet is applied in a stretched state, the dicing tape may come off the ring frame or be attached in a loose state. If so, the adhesive sheet loosens after dicing and the chips come into contact with each other and chipping occurs.
Although the adhesive sheet (dicing die-bonding film) disclosed in Patent Document 1 is provided with a mark on a sheet-like support base, the mark was pulled after the adhesive sheet was attached to the wafer. It is not for evaluating the adhesive state of the adhesive sheet, such as whether it is attached in a state or whether it is attached in a loose state.
Therefore, even if the adhesive sheet affixed to the wafer is affixed in a partially or fully pulled or loosened state, these states cannot be detected or the adhesive sheet cannot be evaluated. .

[Object of invention]
The present invention has been devised by paying attention to such inconveniences, and the object of the present invention is to measure the distance between the marks formed after the adhesive sheet is pasted on the wafer. Semiconductor wafer processing adhesive sheet capable of grasping the pasting state, semiconductor wafer processing apparatus adjustment method and adhesive sheet evaluation method for adjusting various processing apparatuses such as sheet sticking apparatus and grinding apparatus using the same It is to provide.

In order to achieve the above object, the present invention provides an adhesive sheet for processing a semiconductor wafer for bonding a semiconductor wafer to an adhesive layer provided on one surface of a base sheet and subjecting the semiconductor wafer to a predetermined treatment. A length measurement mark is formed at a predetermined distance by printing on at least one surface of the base sheet, and the mark is attached to the surface of the semiconductor wafer when the semiconductor wafer is bonded to the adhesive layer. It has a configuration of being located inside .

  In the present invention, the mark may be configured by a straight line, a point, a concentric circle, or a combination thereof.

  Further, the semiconductor wafer processing apparatus adjustment method according to the present invention employs a technique of measuring the distance between marks and adjusting the semiconductor wafer processing apparatus.

  Furthermore, the method for evaluating an adhesive sheet according to the present invention employs a method of measuring the distance between the marks and evaluating the characteristics of the adhesive sheet.

  In the present invention, as the semiconductor wafer processing apparatus, a sheet sticking apparatus for sticking a protective sheet to the wafer, a mount apparatus for integrating the wafer and the ring frame via an adhesive sheet, a grinding apparatus for grinding the back surface of the wafer, a wafer Although a dicing apparatus etc. which divide can be illustrated, it is not limited to these apparatuses in particular.

According to the present invention, since the marks are formed at a predetermined distance on the base sheet, the distance between the marks before the adhesive sheet is attached to the wafer is compared with the distance between the marks after the adhesive sheet is attached to the wafer. Thus, it is possible to grasp the extension and slack of the adhesive sheet.
In other words, if the distance between marks after sticking to the wafer is longer than the distance between marks before sticking, the adhesive sheet is stuck in a pulled state, and conversely when it is short, it is stuck in a loose state. Will be.
Therefore, by adjusting each part in the semiconductor wafer processing apparatus based on the length measurement result, there is a problem that the adhesive sheet is stuck on the wafer in a partially or fully pulled state. It can be avoided.
Furthermore, by measuring the distance between the marks and analyzing the data, it is possible to determine in advance by an image processing device how the adhesive sheet will be deformed by residual stress or slackness after back grinding or wafer singulation. Can foresee. Thereby, the factor which destroys a wafer is removed by reattaching an adhesive sheet before back surface grinding or before dicing, and the yield fall of a semiconductor chip can be prevented effectively.
In addition, when partial extension or slack is detected by measuring the distance between marks, it can be used as an evaluation standard for the presence or absence of some defect in the quality or properties of the adhesive sheet, It is also possible to evaluate the characteristics of each adhesive sheet.
Furthermore, when the mark is a straight line, the experimental results have revealed that another effect is that there is less temperature change, extension and slackness due to tension, etc., compared to an adhesive sheet without a straight mark.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic perspective view of an original fabric R provided with a semiconductor wafer processing adhesive sheet S (hereinafter simply referred to as “adhesive sheet S”) according to the present embodiment, and FIG. A cross-sectional view of FIG. In these drawings, the raw fabric R is composed of a strip-shaped release sheet RL and a plurality of adhesive sheets S temporarily attached to the release sheet RL at a predetermined distance. The adhesive sheet S includes a base sheet BS having a substantially circular planar shape, an adhesive layer A provided on one surface (the lower surface in FIG. 2) of the base sheet BS, and the other of the base sheet BS. And a mark M formed on the surface. The base sheet BS is not particularly limited, but in the present embodiment, the base sheet BS is configured by a transparent resin sheet.

  The adhesive layer A is located on the outer peripheral side of the base sheet BS, and is provided with a pressure-sensitive adhesive outer adhesive layer A1 provided along a substantially ring-shaped locus, and on the inner side of the outer adhesive layer A1. It consists of the provided heat-sensitive adhesive inner adhesive layer A2.

  The mark M is formed by printing on the base sheet BS. The mark M includes a straight line in the extending direction of the release sheet RL and a straight line in the width direction perpendicular to the extending direction, and the marks M, that is, straight lines are printed at a predetermined distance from each other. In the illustrated example, in order to avoid complication of the drawings, the distance between the straight lines becomes clear, but actually, the distance between the straight lines is finer. Incidentally, in the present embodiment, the distance between adjacent straight lines is 1 mm, but the distance is not limited.

  As shown in FIGS. 3 and 4, the adhesive sheet S of the present embodiment integrates the wafer W and the ring frame RF and separates the wafer W into chips, and then the inner adhesive layer A <b> 2. It can be used as a dicing die bonding sheet for performing bonding via the substrate. As shown in FIG. 7, the mounting apparatus 10 as a semiconductor wafer processing apparatus that integrates the wafer W and the ring frame RF is bonded to a table T that supports the ring frame RF and the wafer W and the release sheet RL. A sheet feeding device 11 that peels the sheet S and feeds the adhesive sheet S, and a pressing means 12 that applies a pressing force to the fed adhesive sheet S are included. The pressing means 12 includes a press roller PR, and a left linear motor ML and a right linear motor MR that are positioned on both the left and right sides of the press roller PR and adjust the pressing force by moving the press roller PR up and down. . With such a configuration, the integration is performed by moving the table T supporting the ring frame RF and the wafer W in synchronism with the adhesive sheet S to be fed, and the wafer W represents the circuit pattern forming surface. In the extended state, it is mounted on the ring frame RF. In order to stick the inner adhesive layer A2 to the wafer W, the table T or the press roller PR is provided with a heating means.

For example, the adhesive sheet S is imaged by an imaging device (not shown) before and after the pasting, and the distance between each straight line is measured, and the adhesive sheet S is compared by comparing the measured distance data. It is possible to grasp in what state the tape is attached. As a result of this comparison, for example, when the distance between each straight line becomes longer or shorter before and after the pasting is performed in the entire region, the speed difference between the feeding speed of the adhesive sheet S and the table moving speed, or the press roller PR Adjust the pressing force. Specifically, when the adhesive sheet S tends to be pulled and pasted, the feeding speed of the adhesive sheet S is set to be relatively faster than the table moving speed, or the left and right linear motors ML, What is necessary is just to adjust so that the pressing force of the press roller PR becomes small by raising MR, and conversely, when the adhesive sheet S tends to be loosened and stuck, the feeding speed of the adhesive sheet S is set to the table moving speed. May be adjusted so as to be relatively slow, or the left and right linear motors ML and MR are lowered so that the pressing force of the press roller PR is increased.
When the above-mentioned tendency appears in a specific part, the left / right linear motors ML, MR are moved up and down to adjust the balance between the left and right pressing forces of the press roller PR, or the press roller PR itself Just align or exchange.

  Therefore, according to such an embodiment, the distance between the straight lines constituting the mark M can be measured to grasp the adhesion state of the adhesive sheet S, thereby making it possible to make adjustments in advance and subsequent wafer processing apparatuses. The effect is that the response can be taken flexibly.

As described above, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this.
In other words, the present invention has been illustrated and described mainly with respect to specific embodiments, but without departing from the scope of the technical idea and object of the present invention, the shape, position, or With respect to the arrangement and the like, those skilled in the art can make various changes as necessary.

  For example, the adhesive sheet S in the above embodiment has been illustrated and described as a dicing die bonding sheet for mounting the wafer W on the ring frame RF, but the present invention is not limited to this. Specifically, as shown in FIG. 5, the adhesive sheet S can be used as a protective sheet for protecting the circuit pattern in preparation for the back grinding of the wafer W. In this case, the adhesive sheet S is configured by providing only the pressure-sensitive adhesive layer A1 on one surface of the base sheet BS, and a straight line similar to that of the above embodiment is formed as the mark M on the opposite surface. ing. Such an adhesive sheet S is pasted by a sheet pasting apparatus, and the wafer W to which the adhesive sheet S is adhered is back-ground to a predetermined thickness by a grinder G as shown in FIG. The Here, if the distance between the straight lines is measured before grinding, warpage of the wafer after grinding can be predicted in advance before grinding, and cracking of the wafer can be prevented in advance. it can. Furthermore, by comparing the length measurement data before grinding and the length measurement data after grinding, what kind of external force is applied in the grinding process, what kind of stress is applied to the wafer W, etc. It can be used as an evaluation sheet for a semiconductor wafer processing apparatus, or as a dicing apparatus adjustment or evaluation sheet by comparing length measurement data before and after the wafer W is singulated.

  Also, in order to develop a new adhesive sheet, measure the distance between marks before and after various tests such as heat resistance, weather resistance, chemical resistance, tension, load resistance, etc., compare the data, base sheet BS, It can also be used as a sheet for property evaluation of the adhesive sheet itself for evaluating the properties of the adhesive.

  Further, the mark M is not limited to the orthogonal straight line, and as shown in FIGS. 6 (A) to (C), a short straight line intersects, a dot-like one, or an equal pitch. A concentric circle may be sufficient and what combined them may be adopted. In short, the mark M according to the present invention only needs to be able to grasp the extension or shrinkage of the adhesive sheet S by length measurement.

  Moreover, although the mark M in the above embodiment is provided on the surface opposite to the position of the adhesive layer A, it may be formed on the adhesive layer A side of the base sheet BS or may be formed on both surfaces. . In this case, the base sheet BS is preferably transparent or translucent.

  Furthermore, the adhesive sheet S is not limited to the one that is cut in advance and temporarily attached onto the release sheet RL, and may be a belt-like adhesive sheet S. In this case, the adhesive sheet S may be cut into a predetermined shape before or after the adhesive sheet S is attached to an adherend such as the wafer W or the ring frame RF.

The perspective view of the original fabric containing the adhesive sheet for semiconductor wafer processing concerning this embodiment. FIG. The perspective view which shows the state which mounted the wafer on the ring frame using the said adhesive sheet. B arrow sectional drawing of FIG. (A) is a perspective view which shows the state which adhere | attached the wafer on the adhesive sheet as a protective sheet, (B)-(D) is explanatory drawing of the back surface grinding of a wafer. (A)-(C) are top views which show the modification of a mark. Schematic explanatory drawing of a mounting apparatus.

Explanation of symbols

A Adhesive Layer BS Base Material Sheet M Mark S Semiconductor Wafer Adhesive Sheet W Semiconductor Wafer 10 Mounting Device (Semiconductor Wafer Processing Device)

Claims (4)

In an adhesive sheet for processing a semiconductor wafer for bonding a semiconductor wafer to an adhesive layer provided on one surface of a base sheet and performing a predetermined process on the semiconductor wafer,
A mark for length measurement is formed at a predetermined distance by printing on at least one surface of the base sheet,
An adhesive sheet for processing a semiconductor wafer , wherein the mark is located within a surface of the semiconductor wafer when the semiconductor wafer is bonded to the adhesive layer .   2. The adhesive sheet for semiconductor wafer processing according to claim 1, wherein the mark comprises a straight line, a point, a concentric circle, or a combination thereof.   3. A method for adjusting a semiconductor wafer processing apparatus, comprising: measuring a distance between marks according to claim 1; and adjusting the semiconductor wafer processing apparatus.   3. A method for evaluating an adhesive sheet, comprising measuring the distance between the marks according to claim 1 or 2 and evaluating the characteristics of the adhesive sheet.

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