JPH0499321A - Automatic pasting method for wafer protective tape - Google Patents

Abstract

PURPOSE:To eliminate that air bubbles and wrinkles are produced on the pasting face between a protective tape and a wafer by a method wherein the ascent and descent stroke of a roller attached to a suction body which sucks and conveys the protective tape can be adjusted according to the thickness and the diameter of the protective tape and the difference in a height between the rear surface of the roller and the suction face of the suction body can be selected. CONSTITUTION:The face as a nonadhesive face of an adhesive protective tape 2 matched to the shape size of a wafer 1 is sucked and held, by using a vacuum suction grit 7, to a position where the start end of the protective tape 2 is situated in the center of a press rubber roller 10 attached to the grit. The force of an electrostatic field in the protective tape 2, the press rubber roller 10 and other surroundings is adjusted and stabilized. Then, the height interval (t), between a first-stage descent lower end and the suction grit 7, which corresponds to the size and the thickness of the protective tape 2 is adjusted; the protective tape 2 is sucked to the height of (t) by using the electrostatic force of the press rubber roller 10 and the protective tape 2; a hung part at an end part and a wavy face produced at the end part are made smooth. Then, the pasting start end of the protective tape 2 is aligned with the start end part of the wafer 1 ; the second-stage descent of the press roller 10 is executed; the wafer 1 is moved horizontally and pasted.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to the production of IC1LSI, and as a pre-process for polishing the back side of the wafer, a protective tape is pasted to protect the surface and prevent damage such as cracks. Automatic pasting in the process relates to a method.

<Prior Art> The conventional method is to attach a viscous protective tape to a rubber roll or a spatula, and then manually cut the periphery according to the size of the wafer.

In addition, semi-automation and automation have recently been attempted.

<Problem to be Solved by the Invention> Conventionally, uneven thickness of the protective tape also affects the finishing accuracy of the wafer, so of course there is a special requirement for uniform thickness accuracy, and this pasting has been done during the process to ensure protection. When attaching the tape to the wafer, bubbles and wrinkles on the surface are not allowed. Since the protective tape is thin and soft, it is extremely difficult to prevent these problems both manually and in the process, and the actual yield rate is low. Therefore, the present invention has developed a method for attaching the protective tape and the wafer to the surface. The purpose is to provide a method for automatic application that does not generate bubbles and wrinkles.

<Means for Solving the Problems> The means for solving the problems according to the present invention is to attach a PVC-based special single-sided adhesive protective tape 2 to the surface of the wafer 1, as shown in FIG. 1.2.3, a). In order to prevent air bubbles from entering the adhesive surface and wrinkles in the protective tape, the high electrostatic force generated from the adhesive press rubber roller 10, protective chip 12, and their surroundings is controlled, and the protective tape 2 and press rubber roller are This is a method that utilizes the electrostatic force between 10 and 10, and adjusts the vertical stroke of a press rubber roller 10 attached to a vacuum suction grid 7, which is an example of an adsorbent that attracts and conveys the protective tape 2, according to the thickness and diameter of the protective tape 2. The surface of the breath rubber roller 10 and the suction grid 7
Automatic pasting is a method that allows selection of the height difference between the suction surface and the suction surface.

<Operation> In the above means, as shown in FIG. 2(A), the non-adhesive surface of the adhesive protective tape 2, which has been precisely die-cut to match the shape and size of the wafer 1, is placed on the vacuum suction grid 7.
The starting end of the protective tape 2 is suctioned and held at the center of the press rubber roller 10 attached to this.

As shown in Figure 2 (b), the starting end 2 of the protective tape 2
Since A is cantilevered by the suction grid 7, it hangs down and has a wavy surface.

The force of the electrostatic field of the protective tape 2, the breath rubber roller 10, and other environments is adjusted and stabilized.

The height interval t between the lower end of the first stage descent and the suction grid 7 can be adjusted in accordance with the size and thickness of the protective tape 2.

The electrostatic force of the breath rubber roller 10 and the protective tape 2 attracts the protective tape 2 to the height of t, smoothing out the drooping of the end and the wavy surface occurring at the end.

To apply the protective tape 2 to the starting end of the wafer 1, the starting ends are aligned, and after the press rubber roller 10 is lowered to the second stage, the wafer 1 is moved horizontally and the application is performed.

<Example> Below, one example of the present invention will be described based on FIG. The conveying tape 3 is arranged in a column at regular intervals and releasably attached, and this conveying tape 3 connects a first pulse motor 4 (which can correct the eccentricity ΔX described later), a take-up roller 4A, a conveyance guide 4B, and a guide roller 4.
If the conveyance direction is the χ axis and the direction perpendicular to the χ axis is the Y axis, two position detection sensors 5A are placed in the Y axis direction at an interval close to the radius R of the circular protective tape 2.
, 5B, and this sensor 5A.

5B is the reference line X0-XO, the distance from the center position of the protective tape 2 detected during transportation to the center position where it is temporarily stopped is the reference length P, and the circular periphery of the protective tape 2 is defined as the reference line X0-XO. is detected by one of the position detection sensors 5A and 5B, and then by the other of the position detection sensors 5A and 5B, and the distance S between the detections of these position detection sensors 5A and 5B is determined relative to the reference length P. Eccentricity of −△X
And the amount of eccentricity ±ΔY from the reference line xo-xo is calculated by a microcomputer.

Then, a force △Y is applied to the suction grid 7, which is an example of the suction body for the two wafers 1 located at a specific distance on the reference line xo-xo and the protective tape 2 located in the opposite direction, and a second pulse is applied to drive the suction grid 7. From motor 8, feed screw 8A, nut body 8B, moving guide mechanism 8C1 moving plate 8D, board 8E and third pulse motor 9, feed screw 9A, nut body 9B, moving guide mechanism 90, moving plate 9D and board 9E. With this device,
to correct.

That is, the suction grid 7 moves concentrically with the protective tape 2 and stops, and the suction grid 7 removes the protective tape 2.
The wafer 1 is peeled off from the transport tape 3 and is adsorbed, and the wafer 1 is placed on standby at the original position at a specific distance. correction) and return to normal.

When pasting the protective tape 2 on the surface of the wafer 1, in order to prevent air bubbles from entering the pasting surface and wrinkles in the protective tape, air bubbles generated from the pasting rubber roller 10, the protective tape 2, and the surrounding area are prevented. The electrostatic force between the protective tape 2 and the press rubber roller 10 is utilized.

An air cylinder 11 (this is a moving guide mechanism 11C1 moving plate 11
D, the stroke of the tape (combined with the substrate 11E) can be adjusted according to the thickness and diameter of the protective tape 2, and the height difference between the lower surface of the breath rubber roller 10 and the suction surface of the suction grid 7 can be selected. It is said that

As shown in Figures 2 (a) and (b), the protective tape 2 is attached because the starting end 2A is supported in a cantilevered manner, resulting in a distorted surface that hangs and waves due to the influence of the electric field strength, etc. , the breath rubber roller 10 is connected to the air cylinder 11 in the first stage.
The height difference t from the suction grid surface (for example, 0.1 m)
m or less), the starting end 2A of the protective tape 2 is attracted to the breath rubber roller 10 by electrostatic force, as shown by the dotted line in FIG.

Next, as shown in FIG. 2(C), the air cylinder 12 of FIG.
This includes the movement guide mechanism 12C5 movement plate 12D, and the board 12.
The roller support frame IOA supporting the breath rubber roller 10 (combined with E) is pressed against the starting end of the wafer 1 with its own weight adjusted appropriately. At this time, a suitable distance U between the grid 7 and the wafer 1 is 0.05 mm.

As shown in FIG. 2(d), the table 13 of the wafer 1 is horizontally moved by a device consisting of a fourth pulse motor 14, a feed screw 14A, a nut body 14B, a movement guide mechanism 14c, a movement plate 14D, and a substrate 14E. and paste it.

The protective tape 2 is precisely die-cut to match the size of the wafer 1, and in order to match their peripheral edges, it is necessary to match their center points. 1st
In the figure, a wafer 1 is waiting for a protective tape 2 to be applied on a predetermined reference line xo-xo. The center position of the wafer 1 and the center of the protective tape 2 to be adsorbed to the adsorption grid 7 (connected to a vacuum pump) coaxially and perpendicularly to the center position are located on the same axis.

On the other hand, while the protective tape 2 on the transport tape 3 is being transported, its periphery is detected by the detection sensor 5A at each position.

5B, and the eccentricity in the X direction is determined by the distance S between them.
Determine △Y on the amount of eccentricity in △X and Y directions.

The diameter 2R of the protective tape 2 and the distance a between the circumferential edges of the protective tapes 2, 2 are appropriately determined, and 2R+a=P.The detected protective tape 2 is located at the reference line xo-x.

If the center points coincide with each other on the line, that is, if △X = 0, then it is sufficient to proceed a distance of P and then stop. Also, if △Y = 0, and there is an eccentricity of ±△Y, then P If it moves ten ΔX, it will stop at a predetermined position.

The calculation standard is that if circle 0 located on the reference line X〇-XO in Fig. 3 is eccentric to circle C, then the average point d' in the △X becomes shorter from d.

That is, from FIG. 1, ΔX=dd' Equation 1) exists when the distance between the detection sensors 5A and 5B is chosen to be the radius -R of the protective tape 2.

△Y-〇〇 is guided.

FIG. 4 shows the amount of eccentricity -ΔXmm with respect to the detected value Smm, and FIG. 5 shows the amount of eccentricity ΔYmm with respect to the detected value Smm.

During the movement of the transport tape 3 on which the protective tape 2 is arranged, position 1
The distance from the detection point on the reference line xo-xo determined from the measured value S detected by the detection sensors 5A and 5B to the temporarily stopped protective tape 2 is P, and at this time, the protective tape 2 is waiting from the stopped position. The distance to the center of the wafer 1 and the accuracy of the arrangement Wi of the detection sensors 5A and 5B can easily be maintained within ±0.01 mm from the viewpoint of processing technology, and the suction grid 7 that the protective tape 2 holds by suction The accuracy of the grid holding device 7A that performs positioning is also ±0.
01mm is obtained.

In addition, in the embodiment of the present invention, the position detection sensors 5A, 5
For B, a reflection type photoelectric switch was used, and when precision was required, a laser type photoelectric switch was used.

The minimum spot diameter of the light beam is 0.03 mm for the former, and (
'), 01mm, repeatability 0.003~0°005
mm, which is easily available on the market, was used, but higher accuracy can be obtained by using a more accurate one.

To describe one process of this device, detection sensors 5A and 5B
The winding amount of the transport tape 3 is advanced by a distance of P + △X from the distance S, and then the tape is temporarily stopped.
travels a distance L in the negative direction, and moves ten △Y
If the correction is made and the tape is stopped, the tape will be located in the same position as the protective tape 2 on the transport tape 3.

Here, if the conveying tape 3 and suction grid 7 are moved in the positive direction at the same speed while applying suction force, the protective tape 2 will be peeled off from the conveying tape 3 and the suction grid 7 will perform the negative ΔY correction. When it stops at a distance of L, it returns to its original position and starts attaching the wafer 1 and the protective tape 2 to each other.

As shown in FIG. 2(a), the non-adhesive surface of the adhesive protective tape 2, which has been precisely cut to match the shape and size of the wafer 1, is held by a vacuum suction grid 7, and a breath rubber roller 10 attached to this is used. The starting end 2A of the protective tape 2 is suctioned and held at the center of the protective tape 2. As shown in FIG. 2 (b), the application starting end 2A of the protective tape 2
Since it is cantilevered at 7, it hangs down and has a wavy surface. Protective tape 2, breath rubber roller 10
, the force of the electrostatic field in other environments can be adjusted and stabilized.

The height interval t between the lower end of the first stage descent and the suction grid 7 can be adjusted in accordance with the size and thickness of the protective tape 2. The electrostatic force of the press rubber roller 10 and the protective tape 2 attracts the protective tape 2 to the height of t to smooth out the drooping of the ends and the wavy surface occurring at the ends.

To apply the protective tape 2 to the starting end of the wafer 1, the starting ends are aligned, and after the breath rubber roller 10 is lowered to the second stage, the wafer 1 is moved horizontally and applied.

In addition, in order to prevent the strength of the electrostatic field from changing even during continuous operation, the electrostatic field is stabilized using a self-discharge type or voltage application type static eliminator, and the protective tape 2 is electrostatically adsorbed on the breath rubber roller 10. After smoothing the adhesive surface, do the pasting work. Highly accurate and homogeneous pasting provides a uniform surface and improves production efficiency through automation.

The protective tape 2 is attached to the wafer 1 during the manufacturing process of ICs and LSIs. The size of the wafer l is 3, 4, 5.6, or 8 inches, and the protective tape 2 is also made according to this size. The diameter and thickness of this tape are selected within the range of 0.03 mm to 0.07 mm.

Note that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that many modifications and changes can be made to the above-mentioned examples within the scope of the present invention.

<Effects of the Invention> As is clear from the above explanation, according to the present invention, at the beginning of applying the protective tape, the first stage of lowering of the application roller and the second stage of adjustable self-weight press are performed. In the first stage, the height of the lower surface of the center point of the roller and the suction surface of the adsorbent can be adjusted, making it possible to handle a wide range of types of protective tape. Further, by utilizing electrostatic force, it is possible to prevent sagging occurring at the starting end of the protective tape, obtain a flat surface by adsorption to the roller, prevent air from entering, and eliminate the cause of wrinkles. Furthermore, the starting edges of the wafer and the protective tape can be accurately aligned, which has the excellent effect of reducing protrusion of the tape around the periphery and insufficient bonding surface.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an apparatus implementing the method of the present invention, FIG. 2 is a diagram illustrating the operation of the suction grid section, and FIG. 3 is a diagram illustrating the centering correction calculation method. Toeba, 2. Protective tape, 2A: Starting end for applying the protective tape, 7: Adsorption grid as an example of an adsorbent, 10: Press rubber roller for application. Applicant Soatetsu Co., Ltd.

Claims (1)

[Claims] 1. When attaching a special single-sided adhesive protective tape to the surface of a wafer, in order to prevent air bubbles from entering the adhesive surface and wrinkles in the protective tape, an application roller and a protective tape are used. A method of controlling the high electrostatic force generated from the tape and its surroundings and utilizing the electrostatic force between the protective tape and the roller, in which the vertical stroke of a roller attached to an adsorbent that attracts and conveys the protective tape is controlled by the protective tape. The automatic pasting method is characterized in that the height difference between the lower surface of the roller and the suction surface of the adsorbent can be selected according to the thickness and diameter of the adsorbent. 2 In claim 1, since the starting end of the protective tape is cantilever-supported, it hangs down and has a distorted surface with waves due to the influence of the strength of the electric field, etc. An automatic pasting method characterized in that when the protective tape is lowered to a height difference t between the protective tape and the protective tape, the starting end of the protective tape is attracted to the roller by electrostatic force, thereby smoothing out the wavy deformation of the starting end.